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Mice were gavaged with either 14C-labeled 2,2′5,5′ tetrachlorobiphenyl; 3,3′,4,4′ tetrachlorobiphenyl; or perfluorooctanoic acid. Absorption of these compounds was determined by assay of feces collected for 48 h after the gavage. Part of the animals received test diets containing olestra during this 48-hour period to determine its effect on absorption of the compounds. Mice that received the diet without olestra during this period were divided into groups that either continued the diet without olestra or changed to a diet containing olestra. These diets were continued for 7 days, and a second 48-hour fecal collection was made to measure the effect of olestra on enterohepatic circulation of the compounds and their metabolites. The animals were sacrificed, and blood, fat, and liver concentrations of 14C were measured. Olestra decreased the absorption of 2,2′,5,5′ tetrachlorobiphenyl. It also reduced tissue and blood concentrations of this compound. Olestra also decreased the absorption of 3,3′,4,4′ tetrachlorobiphenyl, but it did not alter enterohepatic circulation or tissue concentrations. Olestra significantly increased the excretion of perfluorooctanoic acid in the second 48-hour collection, suggesting an effect on enterohepatic circulation. It did not, however, alter tissue concentrations of perfluorooctanoic acid. These data are consistent with previously observed effects of olestra on the absorption and storage of lipophilic compounds. Keywords: Olestra, Polychlorinated biphenyl, PCB, Perfluorooctanoic acid, Rat, Absorption

The aim of these studies was to evaluate the potential of some nutritional approaches to prevent or reduce the body load of organochlorines (OC) in humans. Study 1 compared plasma OC concentrations between vegans and omnivores while study 2 verified if the dietary fat substitute olestra could prevent the increase in OC concentrations that is generally observed in response to a weight-reducing programme. In study 1, nine vegans and fifteen omnivores were recruited and the concentrations of twenty-six OC (β-hexachlorocyclohexane (β-HCH),p,p′-dichlorodiphenyldichloroethane (p,p′-DDE),p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT), hexachlorobenzene, mirex, aldrin, α-chlordane, γ-chlordane, oxychlordane,cis-nonachlor,trans-nonachlor, polychlorinated biphenyl (PCB) nos. 28, 52, 99, 101, 105, 118, 128, 138, 153, 156, 170, 180, 183 and 187, and aroclor 1260) were determined. In study 2, the concentrations of these twenty-six OC were measured before and after weight loss over 3 months in thirty-seven obese men assigned to one of the following treatments: standard group (33 % fat diet;n13), fat-reduced group (25 % fat diet;n14) or fat-substituted group (1/3 of dietary lipids substituted by olestra;n10). In study 1, plasma concentrations of five OC compounds (aroclor 1260 and PCB 99, PCB 138, PCB 153 and PCB 180) were significantly lower in vegans compared with omnivores. In study 2, β-HCH was the only OC which decreased in the fat-substituted group while increasing in the other two groups (P = 0·045). In conclusion, there was a trend toward lesser contamination in vegans than in omnivores, and olestra had a favourable influence on β-HCH but did not prevent plasma hyperconcentration of the other OC during ongoing weight loss.

Background The 1996 Food and Drug Administration approval of the fat substitute olestra (sucrose polyester) called for active postmarketing surveillance because preapproval studies showed that olestra may lower circulating concentrations of fat-soluble nutrients such as vitamins and carotenoids. Objective The objective of the Olestra Post-Marketing Surveillance Study was to examine whether customary consumption of olestra-containing savory snacks was associated with changes in serum fat-soluble vitamin and carotenoid concentrations among free-living persons in geographically and ethnically distinct US cities. Design Adults (n = 2535) and their children aged 12-17 y (n = 272) in Baltimore, Minneapolis, and San Diego attended clinic visits during which data were collected on diet, savory snack consumption, lifestyle, and anthropometric indexes. Blood samples were drawn to assay carotenoids and vitamins A, D, E, and K. Data and blood samples were collected both before and after the nationwide introduction of olestra. General estimating equations were used in multivariate-adjusted models that examined olestra's association with the specified serum nutrients. Results Compared with no intake, the top 2 tertiles of olestra use in adults were associated with circulating carotenoid concentrations that were modestly but significantly lower (4.3% to 22.4%). There were no significant associations of olestra with any serum nutrients among adolescents. Conclusions This active postmarketing surveillance study of a food additive suggests that small decreases in serum fat-soluble nutrients are attributable to olestra use. Although health outcomes were not measured here, it is unlikely that these small changes in nutrient measures would adversely affect health.

Dietary studies are often conducted as longitudinal intervention or crossover trials using multiple days of measurement on each subject during each of several measurement periods, and determining the required numbers of days and subjects is important in designing these studies. Linear mixed statistical models were used to derive equations for precision, statistical power and sample size (number of days and number of subjects) and to obtain estimates of between-subject, period-to-period, and day-to-day variation needed to apply the equations. Two cohorts of an on-going exercise intervention study, and a crossover study of Olestra, each with 14 d of measurement/subject per period, were used to obtain estimates of variability for energy and macronutrient intake. Numerical examples illustrate how the equations for calculating the number of days or number of subjects are applied in typical situations, and sample SAS code is given. It was found that between-subject, period-to-period, and day-to-day variation all contributed significantly to the variation in energy and macronutrient intake. The ratio of period-to-period and day-to-day standard deviations controls the trade-off between the number of days and the number of subjects, and this remained relatively stable across studies and energy and macronutrient intake variables. The greatest gains in precision were seen over the first few measurement days. Greater precision and fewer required days were noted in the study (Olestra) that exerted greater control over the subjects and diets during the feeding protocol.

Objective: There are many health risks involved with the use of weight loss products by normal weight women. The mass media may compound this problem through the promotion of weight loss products and a thin body size. This study tested women’s perceptions of different weight loss product ads to determine if body dysphoria (i.e., an over concern with body size and shape in normal weight people) was associated with risk beliefs, past behaviors, and intention toward using weight loss products. Method: Normal weight women (age range = 18–41 yr), who were classified as either high (n=45) or low (n=43) on a measure of body dysphoria, rated different weight loss products according to their perception of health risks, past behavior, and their intention to consume the products. These products were a dietary fat substitute (olestra), a prescription obesity medication (sibutramine), and an over-the-counter appetite suppressant (phenylpropanolamine). Results: High body dysphoric women reported higher intentions to use the products as well as increased prior use of two of the three weight loss products. High body dysphoric women did not believe that these weight loss products were harmless. They recognized potential health risks associated with using such products, but nonetheless, expressed intention to use these weight loss products at a higher frequency. Also, several variables related to body image were found to effectively discriminate normal weight women at risk for abusing weight loss products. Discussion: This study found that women who do not need to lose weight but have significant body image concerns were willing to use potentially harmful weight loss products despite the knowledge that such products might pose significant health risks. Techniques utilized by advertising regulatory agencies such as warning labels did not have a strong deterrent effect for stated intentions to use the products. Implications of these findings for public health policy issues were discussed.

International audience; There has been renewed interest in vitamin D since numerous recent studies have suggested that besides its well-established roles in bone metabolism and immunity, vitamin D status is inversely associated with the incidence of several diseases, e.g., cancers, cardio-vascular diseases, and neurodegenerative diseases. Surprisingly, there is very little data on factors that affect absorption of this fat-soluble vitamin, although it is acknowledged that dietary vitamin D could help to fight against the sub-deficient vitamin D status that is common in several populations. This review describes the state of the art concerning the fate of vitamin D in the human upper gastrointestinal tract and on the factors assumed to affect its absorption efficiency. The main conclusions are: (i) ergocalciferol (vitamin D-2), the form mostly used in supplements and fortified foods, is apparently absorbed with similar efficiency to cholecalciferol (vitamin D-3, the main dietary form), (ii) 25-hydroxyvitamin D (25OHD), the metabolite produced in the liver, and which can be found in foods, is better absorbed than the nonhydroxy vitamin D forms cholecalciferol and ergocalciferol, (iii) the amount of fat with which vitamin D is ingested does not seem to significantly modify the bioavailability of vitamin D-3, (iv) the food matrix has apparently little effect on vitamin D bioavailability, (v) sucrose polyesters (Olestra) and tetrahydrolipstatin (orlistat) probably diminish vitamin D absorption, and (vi) there is apparently no effect of aging on vitamin D absorption efficiency. We also find that there is insufficient, or even no data on the following factors suspected of affecting vitamin D bioavailability: (i) effect of type and amount of dietary fiber, (ii) effect of vitamin D status, and (iii) effect of genetic variation in proteins involved in its intestinal absorption. In conclusion, further studies are needed to improve our knowledge of factors affecting vitamin D absorption efficiency. Clinical studies with labeled vitamin D, e.g., deuterated or C-13, are needed to accurately and definitively assess the effect of various factors on its bioavailability.

Olestra, çoklu yağ asidi esterleri ve sükrozun birleşmesiyle meydana gelen ve kalori içermeyen sükroz polyesteridir. Düşük yağ içerikli atıştırmalık gıdaların üretiminde kullanılabilecek, Amerikan Gıda ve İlaç Dairesi (FDA) tarafından onaylanmış bir gıda katkı maddesidir. Olestra üzerinde yapılan çalışmalar hakkında pozitif görüşler olsa da negatif görüşler de bulunmaktadır. Olestra ile ilgili hayvanlar ve insanlar üzerinde yapılan sayısız çalışmaların sonucunda, insan vücudunda bulunan mikro ve makro bileşenlerin emilimini engellediği takdirde büyüme, çoğalma ve toksisite ile ilgili olarak olumsuz etkileri olabileceği kanısına varılmıştır. Olestranın çevreden yok edilebilmesi, aktif atık ve topraklardan izole edilmiş aerobik bakteriler ve mantarlar sayesinde olabilmektedir. Olestra is, a sucrose polyester, a non caloric fat substitute, made from sucrose and several fatty acid esters. It has been approved by the FDA as a food additive used in preparing low-fat deep-frying foods such as savory snacks. Available literature on olestra was evaluated that had both positive an negative connotations. Clinical trials in numerous species of animals including humans were conducted to determine if olestra would affect the utilization and absorption of macro- and micronutrients; the effects of olestra on growth, reproduction, or its toxicity were also examined. The roles of olestra as a fat substitute, how it could effect on humans and environmental, and the potential impacts from its use in large amounts were assessed. Olestra can be removed from the environment by aerobic bacteria and fungi which may be isolated from activated sludge and soils. 86

BACKGROUND Dietary fat has been implicated as a risk factor for cardiovascular disease and obesity. OBJECTIVE We evaluated the effect on body weight, body fat, lipids, glucose, and insulin of replacing dietary fat with olestra in moderately obese men. DESIGN Forty-five healthy overweight men were randomly assigned to 1 of 3 diets: control diet (33% fat), fat-reduced diet (25% fat), or fat-substituted diet (one-third of dietary fat replaced by olestra to achieve a diet containing 25% metabolizable fat). Body fat was measured by dual-energy X-ray absorptiometry and visceral and subcutaneous abdominal fat by computed tomography. RESULTS Thirty-six men completed the 9-mo study. Body weight and body fat in the fat-substituted group declined by a mean (+/- SEM) of 6.27 +/- 1.66 and 5.85 +/- 1.34 kg, respectively, over 9 mo compared with 3.8 +/- 1.34 and 3.45 +/- 1.0 kg in the control group and 1.79 +/- 0.81 and 1.68 +/- 0.75 kg in the fat-reduced diet group. At 9 mo, the mean difference in body fat between the fat-reduced and fat-substituted groups was -4.19 +/- 1.19 kg (95% CI: -6.57, -1.81), that between the control and fat-substituted groups was -2.55 +/- 1.21 kg (-0.13, -4.97), and that between the control and fat-reduced groups was 1.63 +/- 1.18 kg (3.96, -0.70). The men eating the fat-reduced diet asked for almost no extra foods, in contrast with the significantly higher requests (P < 0.05) from both of the other 2 groups. CONCLUSION Replacement of dietary fat with olestra reduces body weight and total body fat when compared with a 25%-fat diet or a control diet containing 33% fat.

Background: Increased consumption of non-digested, non-absorbed substrates, such as dietary fibre, can lead to an increase in colonic transit rate and stool output. The effects of dietary fibre and olestra on the consistency and water content of digesta residue within the large bowel were not known. Aim: The aim of this study was to determine the effects of dietary fibre and olestra on regional dehydration and apparent viscosity of digesta residue throughout the large bowel. Methods: Seventy-eight pigs were fed diet alone (control) or supplemented with 40 g/day or 80 g/day dietary fibre or olestra and sacrificed 24, 48, 96 or 192 h after initiation of dosing. The large bowel was removed, divided into 13 segments, and the digesta residue/stool was analysed for apparent viscosity (peak force for extrusion) and percentage water content. Results: In control animals, digesta residue occurred as a continuum, from liquid in the cecum (87.9% water) to solid in the rectum (71.5% water). The relatively small decrease in percentage water content (16.4%) resulted in a marked increase in mean apparent viscosity (liquid = 87 g peak force; solid=3919 g peak force). Dietary fibre increased the percentage water content of digesta residue throughout the large bowel. In contrast, olestra decreased the percentage water content of digesta residue in the mid and distal large bowel. At 40 g/day, dietary fibre showed a significant (P

Residue from the processing of savory snacks in olestra was incorporated into dried bakery product. These blends were then included in broiler diets at levels of 5, 10, and 15%, based upon determined TMEn values for the various blends. Cohort groups of birds fed conventional corn-soybean meal diets with no bakery products served as the positive control. Male birds of a commercial strain were grown to 49 days and samples of the birds were processed to determine dressing percentage and carcass yield. No adverse effects on live performance or carcass characteristics resulted from feeding the various blends as compared to the positive control group. These results indicate that residue from processing savory snacks in olestra may be incorporated into broiler diets at levels up to 3% with no adverse effects on performance, provided that proper adjustments are made in the metabolizable energy content of the product.

Biochemical measures of nutrients or other dietary constituents can be an important component of nutritional assessment and monitoring. However, accurate interpretation of the nutrient concentration is dependent on knowledge of the determinants of the body pool measured. The purpose of this study was to identify the determinants of serum carotenoid and fat-soluble vitamin concentrations in a large, community-based sample (n = 1042). Multiple linear regression analysis was used to examine effects of demographic characteristics (age, sex, race/ethnicity, education), health-related behavior (exercise, sun exposure, smoking, alcohol consumption), and intake (diet, supplements) on serum retinol, 25-hydroxyvitamin D, alpha-tocopherol, phylloquinone, and carotenoid concentrations. Age, sex, race/ethnicity, vitamin A intake, and alcohol consumption were found to be determinants of serum retinol concentration. Race/ethnicity, vitamin D intake, body mass index, smoking status, and sun exposure were determinants of serum 25-hydroxyvitamin D concentration. Determinants of serum alpha-tocopherol were age, sex, race/ethnicity, alpha-tocopherol intake, serum cholesterol, percentage of energy from fat (inversely related), supplement use, and body mass index. Age, sex, phylloquinone intake, serum triglycerides, and supplement use were determinants of serum phylloquinone concentration. Primary determinants of serum carotenoids were age, sex, race/ethnicity, carotenoid intake, serum cholesterol, alcohol consumption, body mass index, and smoking status. Overall, the demographic, dietary, and other lifestyle factors explained little of the variability in serum concentrations of retinol (R2 = 0.20), 25-hydroxyvitamin D (R2 = 0.24), and the carotenoids (R2 = 0.15-0.26); only modest amounts of the variability in serum phylloquinone concentration (R2 = 0.40); and more substantial amounts of the variability in serum alpha-tocopherol concentration (R2 = 0.62).

Olestra is a fat substitute made from sucrose and vegetable oil. Olestra is neither digested nor absorbed, and therefore adds no calories or fat to the diet. Because the gut is the only organ that is exposed to olestra, the potential for olestra to affect gastrointestinal structure and function, and the absorption of nutrients from the gut, has been investigated. Histological evaluations performed after long-term feeding studies have shown no indications that olestra causes injury to the gastrointestinal mucosa. Olestra is not metabolized by the colonic microflora, and has no meaningful effects on the metabolic function of these organisms. Studies of gastrointestinal transit have shown that the consumption of olestra with food does not affect gastric emptying, or small or large bowel transit times. Olestra does not affect the absorption of macronutrients, water-soluble vitamins or minerals. It causes a dose-responsive decrease in the availability of the fat-soluble vitamins A, D, E and K; however, this potentially adverse effect is offset by the addition of vitamins to olestra-containing foods. Olestra has no consistent effect on the amount of total bile acids excreted in the faeces, and therefore probably has no significant effect on bile acid absorption. The occurrence of gastrointestinal symptoms, including diarrhoea, loose stools, gas and abdominal cramping, after consumption of olestra under ordinary snacking conditions is comparable to that following consumption of triglyceride-containing snacks.

Objective To describe the design of the Olestra Postmarketing Surveillance Study (OPMSS) and to present baseline results from the sentinel site. The purpose of the OPMSS is to monitor consumption patterns of olestra-containing snacks and to determine whether consumption affects nutritional status. Design The OPMSS combines repeated cross-section, random-digit dial telephone surveys before and after the market release of olestra-containing foods as well as intensive dietary and clinical assessments on a subsample of survey participants. Subjects Data are from baseline telephone (n=1,962) and clinical (n=1,069) assessment of participants (aged 18 to 74 years) in the Marion County, Indiana, sentinel site. Mean age of participants in the telephone survey was 43.2 years; 19% of respondents were black and 29% had completed college. Statistical analysis Analyses examined associations among savory snack use, fruit and vegetable consumption, and demographic and health-related characteristics. Data from the telephone survey were adjusted to be representative of the Marion County population. Results Almost 96% of the population surveyed had eaten savory snacks in the month before the survey: 74% had eaten regular-fat, 26% fat-reduced, and 78% nonfat types. Total snack consumption did not differ by gender, education, or race. Residents younger than 35 years ate snacks 16 times a month compared with 12 times a month among older residents. Types of snacks consumed differed markedly by demographic characteristics. Male, younger, and less educated residents ate more regular-fat snacks; female, white, and college-educated residents ate more nonfat snacks. In general, residents practicing healthful behaviors, including not smoking, eating fruits and vegetables, and exercising, also ate fewer regular-fat and more nonfat snacks. Fat intake was also related linearly to use of snack foods, ranging from 33.2% of energy among those consuming 1 serving per month or less to 36.8% among those consuming 20 or more servings per month. Applications/conclusions Procedures for recruitment and nutrition assessment appear adequate for evaluating the impact of olestra consumption on nutritional status. Nutritionists should be aware that there is potential for relatively high olestra consumption, given that almost 35% of Marion County residents eat snack foods at least 20 times a month. Consumers eating at least 20 servings of snacks per month derived more than 12% of their total energy and fat from snack foods, which suggests that substituting olestra snacks could substantially reduce intakes of fat and energy. J Am Diet Assoc. 1998;98:1290–1296 .

A quantitative method to determine fat in olestra-containing savory snack products was validated within the AOAC Peer-Verified Methods Program. The method may be used to demonstrate compliance with the guidelines of the U.S. Nutrition Labeling and Education Act for labeling products as "fat free" or "low fat." The method can measure total and saturated fat in savory snacks when present at levels of 0.2-10 g total fat and 0.1-3 g saturated fat per 30 g serving. The method is standardized to measure C6- C24 fatty acids. Extraction of olestra-containing savory snack samples with chloroform-methanol (modified AOAC Official Method 983.23) yields a lipid extract containing the total fat and olestra. The extracted lipid is hydrolyzed by lipase, yielding fatty acids and unreacted olestra. The fatty acids are precipitated as calcium soaps. Olestra is extracted from insoluble soaps with hexane and then discarded. The isolated soaps are converted back into fatty acids with hydrochloric acid and extracted with hexane. The isolated fatty acids are converted to methyl esters with boron trifluoride-methanol and quantitated by capillary gas chromatography using internal standard. Test samples were prepared by blending olestra-containing and full-fat (triglyceride) snacks to obtain 6 levels of spiking (0-10 g total fat added/30 g serving) in potato chips, potato crisps, cheese puffs, and nacho cheese-flavored corn chips. Results were linear (r2 > 0.997) between 0 and 10 g fat/30 g serving for each product matrix. Mean recovery was 101 6% standard deviation (SD) for total fat and 104 ± 6% SD for saturated fat. Mean recovery by peer laboratory was 88 ± 5% SD for total fat and 95 ± 4% SD for saturated fat in potato chips (0-3 g total fat added/30 g serving). Two sets of 10 replicates of potato chips (0.5 g total fat/30 g serving and 0.16 g saturated fat/30 g serving) and potato crisps (0.5 g total fat/30 g serving and 0.16 g saturated fat/30 g serving) were analyzed by submitting and peer laboratories. Repeatability relative standard deviations ranged from 3.90 to 7.33% for total fat and from 4.01 to 11.53% for saturated fat. Reproducibility relative standard deviations were 7.33% (total fat, potato chips), 7.15% (total fat, potato crisps), 11.36% (saturated fat, potato chips), and 13.50% (saturated fat, potato crisps)

The digestibility and absorption of dietary triacylglycerols are dependent on a number of factors including their fatty acid profile. Data demonstrating poor bioavailability of dietary stearic acid would suggest that hydrogenated oil sources would have lower digestibility coefficients compared with their native oils. To test this hypothesis, postweanling rats were fed one of four diets, formulated to contain 40% of energy as fat (assuming complete bioavailability), for 14 d. The diets only differed by fat type, containing soybean oil (SBO), fully hydrogenated soybean oil (HSB), medium-chain triglyceride oil (MCT), or hydrogenated coconut oil (HCO). Rats fed HSB consumed more food during the last 6 d (155.2 +/- 2.7 g) than those in each of the other groups (MCT: 118.9 +/- 2. 2 g; HCO: 124.7 +/- 3.2 g; SBO: 123.8 +/- 2.3 g), yet, they did not gain more weight. Two-day fecal excretion was almost three times greater in HSB-fed rats than in rats fed any other diet (P < 0.0001) because HSB was very poorly available. The digestibility coefficients (a measure of bioavailability) of the four fats were: HSB (30.9 +/- 1.3%) < HCO (94.5 +/- 0.4%) < SBO (97.0 +/- 0.4%) < MCT (98.7 +/- 0.2%) (P < 0.0007). All rats compensated for the incomplete availability of the fats, as apparent absorbable energy consumed did not differ among diet groups. The present data suggest that HSB only contributes 11.6 kJ/g (most fats contribute approximately 37.7 kJ/g) and that not only manufactured fat substitutes, such as olestra, but also more conventional fats are incompletely available to the body. Foods that currently contain HSB may contribute much less utilizable fat and energy than presently realized.

Olestra is a mixture of hexa-, hepta- and octa-esters formed from the reaction of sucrase and long chain fatty acids isolated from edible oils. Olestra has properties similar to those of traditional triglycerides but is not hydrolyzed by pancreatic lipases and, therefore, serves as a noncaloric replacement for fats in the diet. The safety of olestra has been established in over 100 studies in seven different species of animals, with confirmatory safety data coming from approximately 75 human studies; consumption of olestra at levels typical for savoury snacks does not result in reports of gastrointestinal problems in humans. This is consistent with the results of studies of the physiological and morphological effects of olestra in animals and in humans. It is anticipated that olestra will be available in Canada in the near future. Patients will soon be asking their physicians about its use. This article provides an overview of olestra.

Serum polychlorinated biphenyls (PCBs) in Anniston, AL, residents have been associated with hypertension and diabetes. There have been no systematic interventions to reduce PCB body burdens in Anniston or other populations. Our objective was to determine the efficacy of 15 g/day of dietary olestra to reduce PCBs in Anniston residents. Blood PCBs and 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene were measured at baseline and 4-month intervals in a double-blind, placebo-controlled, 1-year trial. Participants with elevated serum PCBs were randomized into two groups of 14 and received potato crisps made with olestra or vegetable oil (VO). Elimination rates during the study period were compared with 5-year prestudy rates. Eleven participants in the olestra group and 12 in the VO group completed the study. Except for one participant in the VO group, reasons for dropout were unrelated to treatments. The elimination rate of 37 non-coplanar PCB congeners during the 1-year trial was faster during olestra consumption compared to the pretrial period (-0.0829 ± 0.0357 and -0.00864 ± 0.0116 year(-1), respectively; P=.04), but not during VO consumption (-0.0413 ± 0.0408 and -0.0283 ± 0.0096 year(-1), respectively; P=.27). The concentration of PCBs in two olestra group participants decreased by 27% and 25% during the trial. There was no significant time by group interaction in change from baseline. However, group main effects for total PCBs and PCB 153 were of borderline significance. This pilot study has demonstrated that olestra can safely reduce body burdens of PCBs and supports a larger intervention trial that may also determine whether reduction in PCBs will reduce the risk of hypertension and diabetes.

PURPOSE: To determine the effects of olestra, a zero-calorie fat substitute that is neither digested nor absorbed, on the well-being and disease state of persons with chronic inflammatory bowel disease (IBD) in remission. PATIENTS AND METHODS: Eighty-nine patients with mild to moderate ulcerative colitis (n = 43) or Crohn's disease (n = 46) in remission, with a history of disease of 2 years or longer, were enrolled in this prospective study from nine private practices, three university-based medical centers, and one Veterans Administration medical center in the United States. Forty-four patients were randomly assigned to receive olestra and 45 to receive triglycerides in chips or cookies daily for 4 weeks. At Week 4, patients were classified as in remission, worsened, or relapsed according to an investigator's global assessment based on sigmoidoscopy (for ulcerative colitis) or the Crohn's disease activity index, laboratory findings, and clinical course. RESULTS: At Week 4, the olestra and triglyceride groups did not differ significantly with respect to the percentages of patients who relapsed ( P = 0.494; difference=2.4%; upper 95% CL=8.8%) or with respect to the percentages of patients who experienced any worsening of their symptoms ( P = 0.630; difference=0.2%; upper 95% CL=13.3%). Of evaluable patients, 90% (37 of 41) given olestra remained in remission with no worsening, compared with 90% (38 of 42) given triglycerides. Gastrointestinal symptoms were comparable between the treatment groups, and there were no treatment-related laboratory abnormalities. Six patients were excluded from analysis for reasons unrelated to treatment. CONCLUSION: Olestra did not affect the activity of quiescent mild to moderate IBD.

Comparison of Olestra Absorption in Guinea Pigs with Normal and Compromised Gastrointestinal Tracts. Daher, G. C, Lawson, K. D., Long, P. H., Tallmadge, D. H., Boothe, A. D., Vanderploeg, P., and Miller, K. W. (1997). Fundam. Appl. Toxicol. 39, 138-147. Female guinea pigs (12/group) were given a single dose of (I4C)- olestra by gavage after consuming either 3% poligeenan in tap water (Compromised group) or just tap water (Normal group) for 5 weeks. A Sentinel group (N = 2) was given 3% poligeenan for 5 weeks. Ten sentinel animals were killed 1 day before and 10 1 day after the other animals were dosed with (uC)olestra and their gastrointestinal tracts were examined by histology. The Compro- mised and Normal animals were endoscoped just before dosing with (MC)olestra. Urine and feces were collected continuously and CO2 was collected for 7 days after dosing. The samples were ana- lyzed for 14C and urine was also analyzed for (MC)sucrose. Animals (3/group) were killed 1, 3, 7, and 21 days after dosing, and tissues were collected and assayed for MC. Tissue lipids were extracted, fractionated by high-pressure liquid chromatography, and ana- lyzed for (uC)olestra by liquid scintillation. Animals fed poligee- nan showed mucosal edema, congestion, ulceration, and fibrin de- position within the distal colon and rectum. Histology revealed inflammation, epithelial degeneration, and multifocal ulceration of the cecum, distal colon, and rectum. The gastrointestinal muco- sae of nonpoligeenan fed animals were normal. No ( MC)olestra was detected in liver lipids and no (uC)sucrose was found in the urine for any animal in the Normal or Compromised groups, indi- cating that intact olestra was not absorbed. The amount, distribu- tion, and elimination of absorbed I4C did not differ between guinea pigs with normal and compromised gastrointestinal tracts. The poligeenan-treated animals displayed mucosal damage similar to that seen in human inflammatory bowel diseases; therefore, these results suggest that patients with inflammatory bowel conditions will not absorb olestra to any greater extent than normal healthy

It has been hypothesized that phytochemicals found in fruits and vegetables are responsible for the inverse association observed between diets high in fruits and vegetables and risk of certain chronic diseases and cancer. This paper assesses the potential for olestra to affect the absorption of dietary phytochemicals and estimates the effect of olestra on the availability of carotenoids when olestra-containing snacks and foods containing carotenoids are eaten in free-living diets. Experimental data compiled on the effects of olestra on the availability of 29 compounds, mainly nutrients and oral medications, showed that olestra affects the availability of only molecules having octanol-water partition coefficients greater than approximately 7.5. Partition coefficients compiled for 382 dietary phytochemicals showed that only two classes of phytochemicals, phytosterols and carotenoids, contain molecules with octanol-water partition coefficients in the range in which olestra could potentially affect bioavailability. The potential effect on the bioavailability of phytosterols would be

Olestra is a mixture of polyesters formed from sucrose and fatty acids derived from edible fats and oils. It is not absorbed or digested and can serve as a zero-calorie replacement for dietary fat. Because olestra is lipophilic and not absorbed, it has the potential to interfere with the absorption of other dietary components, especially lipophilic ones, when it is in the digestive tract with those components. A series of studies were conducted in the domestic pig and in healthy adult humans to define the nature and extent of olestra's effect on fat-soluble vitamins, selected water-soluble micronutrients, and macronutrients, and to demonstrate that the effects of olestra on the absorption of fat-soluble vitamins can be offset by adding extra amounts of the affected vitamins to olestra foods. Before conducting the human and pig studies, the intake of olestra from the consumption of snack foods made with olestra was estimated for various subgroups. The potential for olestra to affect the absorption of nonessential but potentially beneficial dietary phytochemicals was also assessed. In addition, an assessment of how consumption patterns influence the effect of olestra on the absorption of the highly lipophilic carotenoids was made. Finally, the results from the pig and human studies were used to assess the potential for olestra to affect the nutritional status of subgroups of the population who have particularly high nutrient needs or unique dietary patterns that may lead to large olestra-to-nutrient intake ratios.

Normal, healthy, free-living adults ingested either 18 g/d olestra, with or without 1.1 mg tocopheryl acetate/g olestra, or 18 g/d triglyceride placebo, for 16 wk in a double-blind, placebo-controlled study. Serum concentrations of alpha-tocopherol, alpha-carotene, beta-carotene, lycopene, lutein/zeaxanthin, retinol and cholesterol were measured biweekly. Serum 25-hydroxyvitamin D concentration, prothrombin time, partial thromboplastin time and plasma concentration of functional prothrombin (Simplastin-Ecarin assay) were measured at wk 0, 8 and 16. Relative to the placebo group, serum alpha-tocopherol concentration was reduced 6% for the group given 18 g/d olestra. Addition of tocopheryl acetate to olestra partially offset the effect of olestra. For the group given 18 g/d olestra plus 1.1 mg tocopheryl acetate/g olestra, serum alpha-tocopherol concentration was 4% less than the placebo value. Olestra reduced serum concentration of beta-carotene by 27%; the other carotenoids were similarly affected. Serum cholesterol concentration was reduced approximately 4.5% in the olestra groups, relative to placebo, but the differences were not significant. Serum triglycerides, serum 25-hydroxyvitamin D, prothrombin time, partial thromboplastin time or the plasma concentration of under-gamma-carboxylated prothrombin were unaffected by olestra. Clinical observations and laboratory measures indicated no health-related effects of olestra; mild-to-moderate transient gastrointestinal symptoms such as bloating, cramping, loose stools and diarrhea were reported by all groups.

A study was conducted in the domestic pig to determine 1 ) whether feeding olestra mixed in the diet exaggerated olestra effects on fat-soluble vitamin status compared with the effects of feeding it in a typical snack food, and 2) whether separating olestra consumption temporally from vitamin consumption affected the influence of olestra on vitamin status. Groups of 10 pigs each, five castrated males and five females, were fed 2.2% (wt/wt) olestra for 4 wk in purified diet that provided 1 time the National Research Council's requirements for swine of all micronutrients. The olestra was either mixed in the purified diet or fed in potato chips. The potato chips were given to the pigs at all three feedings, at the noon feeding only, or between the noon and the evening feedings. A control group was fed the purified diet with no olestra. The effects of olestra on indices of vitamin A, D and E status were from 1.7 to 4.5 times greater when olestra was fed three times daily mixed in the diet than when it was fed three times daily in potato chips. Because the effect of olestra on the status of the fat-soluble vitamins was diminished substantially by feeding the olestra in potato chips, it was not possible to conclude definitively how the temporal separation of olestra and vitamin consumption affected the olestra effect on vitamin status.

Groups of weanling pigs were fed a purified diet containing graded concentrations of olestra ranging from 1.1 to 7.7% (wt/wt) and the NRC's requirements for micronutrients for 12 wk. Each group consisted of 12 pigs, with the exception of the control group, which had 20, with equal numbers of females and castrated males. The purpose of the study was to determine the dose-response effects of olestra on fat-soluble vitamins and selected water-soluble micronutrients. At wk 0, 4, 8 and 12, hematology, clinical chemistry and blood concentrations of vitamins A, E, K and B12, and 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, folate, calcium, iron, zinc and adipose concentration of vitamin E were measured. Cumulative weight gain and feed efficiency were determined weekly. Prothrombin time was measured weekly for the control group and the groups fed 5.5 or 7.7% olestra, and monthly for other groups. Liver concentrations of vitamins A, E, and B12 and iron and bone concentrations of calcium, phosphorus, zinc and ash were measured for 12 pigs killed at wk 0 and for all animals at wk 12. By wk 12, the pigs were eating from 20 to 155 g/d of olestra. Olestra did not affect the pigs' growth or feed efficiency, indicating that the digestion and absorption of macronutrients were unaffected. Olestra reduced tissue concentrations of vitamin A, vitamin E and 25-hydroxyergocalciferol in a dose-responsive manner but did not affect prothrombin time. Olestra had no effect on the status of folate, vitamin B12, zinc or iron. Statistically reduced liver concentrations of vitamin B12 and iron in groups fed 5.5 or 7.7% olestra and a significant trend in bone ash content with olestra intake were possibly due to the poor vitamin A and/or vitamin E status of the pigs.

Olestra is a zero-calorie fat replacement intended to replace 100% of the fat used in the preparation of savory snacks. Olestra can affect the absorption of other dietary components, especially highly lipophilic ones, when ingested at the same time. The potential effects of olestra on the absorption of essential fat-soluble and water-soluble dietary components have been investigated in pigs and in humans. In these studies, subjects were fed daily amounts of olestra up to 10 times the estimated mean intake from savory snacks and the olestra was eaten each day of the studies. In real life, snacks are eaten on average five times in a 14-d period. Olestra did not affect the availability of water-soluble micronutrients or the absorption and utilization of macronutrients. Olestra reduced the absorption of fat-soluble vitamins A, D, E and K; however, the effects can be offset by adding specified amounts of the vitamins to olestra foods. Olestra also reduced the absorption of carotenoids; analysis of dietary patterns showed that in real life the reduction will likely be

In a 26-wk study, five groups (n = 10) of domestic pigs were fed 0.25, 0.5, 1.1, 3.3 or 5.5% olestra; three groups were fed 0.25% with graded levels of vitamins A and E; and one group was fed 5.5% with added vitamins A and E and exposed to UV light. In a 39-wk study, two groups (n = 10) were fed 0.25% olestra with or without added vitamins A and E. In each study, a control group was fed basal diet with no olestra, and a group was killed at d 0 for base-line nutrient measurements. The diets provided the NRC's requirements of micronutrients for 5- to 10-kg pigs, with the following two exceptions: vitamin D was provided at twice the requirement in the 26-wk study and vitamin K was provided at 20% of the requirement in the 39-wk study. One purpose of the studies was to determine the amounts of vitamins A and E required to restore tissue concentrations of those vitamins to control concentrations. A second purpose was to determine the effects of olestra on the status of vitamins A, D, E, K and B12, and folate, iron, calcium and zinc when pigs eat olestra at intakes similar to estimated human intake for a period covering major growth and developmental phases, including sexual maturation. Olestra reduced tissue concentrations of vitamins A, D and E but did not affect prothrombin time or the status of the water-soluble nutrients. The amount of vitamin A required to restore liver concentration to control concentration was 93 microg retinyl palmitate/g olestra. Restoration levels for serum and liver concentrations of vitamin E were 2.2 and 2.1 mg d-alpha-tocopheryl acetate/g olestra. Olestra did not affect growth or digestible feed efficiency in either study, indicating that the absorption and utilization of macronutrients were unaffected. There were no antemortem observations or changes in clinical chemistry or hematology that would indicate an adverse effect of olestra.

The effect of olestra, a zero-calorie fat replacement, on the absorption of dietary fat was determined with a dual-isotope technique in 67 healthy male subjects. After a 30-d adaptation period in which they consumed potato chips which delivered either 10 g/d olestra or 10 g/d triglyceride under free-living conditions, the subjects were housed in a metabolic ward and given 0, 8, 20 or 32 g olestra in potato chips. The chips were eaten as part of a breakfast containing about 38 g of fat, about 0.16 mg of 14 C-triolein, and a nonabsorbable marker, 51 CrCl 3 . Feces were collected for 7 d, and aliquots of the two daily collections containing the highest levels of 51 Cr were oxidized. The CO 2 was collected, and 14 C content was determined by liquid scintillation spectrometry. The fractional absorption of 14 C-triolein was calculated from the average ratios of 14 C/ 51 Cr dosed and measured in the feces. Olestra had a slight but significant dose-response effect on triglyceride absorption: the highest olestra dose (32 g) reduced absorption by 1.2%. This effect is not nutritionally significant with respect to either availability of essential fatty acids or energy intake.

Potential chronic (14-d average) and acute (single-day) estimated daily intakes (EDI) were computed for olestra, a fat replacement intended for use in preparing savory snacks. The EDI were computed from eating occasions reported during a 14-d Menu Census survey among 4741 consumers; values were increased by 10% for conservatism. The eating occasions included all meals and in-between meal occasions eaten at home or away. Data from only those individuals who ate savory snacks at least once during the 14 d were used; this included 3820 individuals (81% of the sample) and represented a total of 16,067 eating days (24% frequency). The estimated mean chronic intake ranged from 1.8 to 4.7 g/d, depending on age and gender; at the 90th percentile, the range was 4.1-11.0 g/d. For all ages and both genders, the estimated mean intake was 3.1 g/d. Estimated acute intakes at the mean and 90th percentile ranged from 5.5 to 16.5 g/d and from 10.2 to 24.0 g/d, respectively, depending on age and gender. For all ages and both genders, the estimated mean intake was 10.2 g/d. The lack of parity in the chronic and acute intake estimates indicates that savory snacks are not eaten on a daily basis by the majority of snack eaters. The survey data were analyzed to understand the potential temporal eating patterns of olestra from savory snacks. When snacks were consumed, on average, 69% of the eating occasions were with main meals and 31% were between meals. Savory snacks did not contribute a major fraction of total food to the diet; only 7 and 18% of main meals contained a savory snack food at the 50th and 90th percentile, respectively. For the 50th-percentile consumer (all ages, both genders), savory snacks were eaten four times during the 14-d survey period, and the eating occasions occurred on 3 d. Comparable results for 90th-percentile consumers were 10 eating occasions and 8 eating days.

Olestra is a class of sucrose-fatty acid polyesters intended for use as a non-caloric replacement of edible oil. Genotoxicity and subchronic toxicity studies were conducted to determine whether olestra could form genotoxic or toxic breakdown products during simulated commercial use. Heated olestra was prepared for these studies by batch-frying potato slices in olestra at 177-185 degrees C for 25-32 hr over 5-7 days. Genotoxicity of this previously heated olestra was assessed in four standard in vitro assays: (1) Salmonella mutagenesis (Ames test); (2) forward mutagenesis of mouse lymphoma cells at the thymidine kinase locus; (3) unscheduled DNA synthesis in rat hepatocytes; and (4) clastogenicity in cultured Chinese hamster ovary cells. These tests were conducted with previously heated olestra at concentrations up to at least 5 mg/ml both in the absence of exogenous bioactivation and, for assays (1), (2) and (4) with added liver microsomal (S-9) activation. The Ames and mouse lymphoma assays were performed with olestra (10 mg/ml and 23 mg/litre, respectively) either alone or emulsified with the non-toxic, non-ionic surfactant Pluronics F68, both in the presence and absence of metabolic activation. To test for clastogenicity in vivo, rats were administered previously heated olestra by gavage at 5 g/kg per day for up to 5 days and bone marrow cells were examined for chromosomal aberrations. Heated olestra lacked genotoxic activity detectable by the aforementioned assays. Heated olestra was fed to Fischer 344 rats at up to 10% of the diet (w/w) for 91 days. Evaluation of survival, food consumption, feed efficiency, physical condition, body weight, organ weight, haematological and clinical chemistry parameters, and histomorphology revealed no adverse effects attributable to ingestion of heated olestra at exposure levels in excess of those anticipated for human consumption. It is concluded that olestra used as a deep-frying medium conveys no genotoxic or toxic hazard at anticipated levels of human consumption.

In previous experiments using the fat substitute sucrose polyester (SPE, or olestra), no compensatory response was observed on day 2 after experimental manipulations, which reduced the percentage of energy from fat to approximately equal to 30% from 40% on day 1. In the present study a more severe manipulation was made; the amount of energy from fat was reduced from 32% to 20% to determine whether such a reduction would provoke any physiologic or behavioral response. Subjects came to the unit for two, 2-d test sessions. Intake on day 1 was fixed: subjects were given meals containing either control fat (11319 kJ, 32% of energy as fat) or SPE (9561 kJ, 20% of energy as fat). On day 2, intake was ad libitum. On day 1 subjects rated themselves as more hungry while consuming the fat-substituted meals than when consuming the control meals and they disclosed greater hunger in the end-of-day questionnaires. The effect of the manipulation was carried over into day 2. By the end of day 2, subjects had compensated for 74% of the energy (fat) deficit caused by the previous day's manipulation. These results differ from those obtained when fat was reduced from 40% to 30% of energy; this more severe reduction reveals that a reduction in fat of this size can lead to a biobehavioral response. Together, these data suggest that people could change their diet to meet dietary guidelines; however, if a more severe reduction is attempted, adherence may be made more difficult by the strength of the compensatory response.

This study assessed the treatability of olestra, an edible oil and shortening replacement, during conventional wastewater treatment using laboratory and bench-scale testing. Results showed removal efficiencies for primary treatment to be similar to suspended solids removal (typically ranging from 45 to 65%) and removal during secondary activated sludge treatment to be -84%. Overall removal for primary and secondary treatment was estimated to range from 91% to 94%. The removal during treatment occurred primarily by sorption onto wastewater solids and settling during clarification, although some olestra was removed by biodegradation. Olestra exhibited no adverse effects on total suspended solids (TSS) and chemical oxygen demand (COD) removal during primary or secondary treatment. In addition, olestra caused no adverse effects on sludge dewatering as determined by filtration or gas production during the anaerobic digestion process. Under expected worst-case conditions (that is, assuming that all conventional fat in savory snacks will be replaced with olestra) predicted U.S. average wastewater influent, effluent and 90th percentile receiving water concentrations under mean flow conditions were 4.9, 0.7, and 0.2 mg/L, respectively. The concentration of olestra in anaerobically digested sludge under this worst-case scenario was predicted to be 1 281 mg/L (32.0 g/kg), with a corresponding sludge-amended soil concentration of olestra immediately after sludge application (37 mt/ha) estimated to be 656 mg/kg.

To determine the effect of olestra on microbial ecology of the gut five microflora associated characteristics (MACs) were assessed in 93 subjects in a 36 d parallel, placebo-controlled, double-blind study. Degradation of tryptic activity, β-aspartylglycine and mucin, and conversion of cholesterol to coprostanol and bilirubin to urobilinogen were determined in faecal samples collected at the end of an 8 d low fibre baseline period and 28 d treatment period. The test meal consisted of either a moderate (7 g) or high (24 g) level of fibre and olestra (24 g) or an equivalent amount of conventional fat. Olestra had no effect on degradation of tryptic activity or β-aspartylglycine, and no consistent effect on mucin degradation. Olestra reduced significantly the conversion of cholesterol to coprostanol and urobilin to urobilinogen although the individual values were all within the range of healthy population after treatment. The lipophilic nature of cholesterol and urobilin is the most likely reason for the find...

В статье выполнен анализ современного состояния проблемы структурирования триацилглицеринов. Рассмотрена структура и свойства разнообразных заменителей жира, а также их влияние на организм человека. Также рассмотрены новые продукты-жирозаменители Salatrim и Olestra, как и возможности их использования в производстве продуктов питания. Проанализирована целесообразность использования ферментов при структурировании триацилглицеринов. This article gives an analysis of the current state of the problem structuring triglycerides. The structure and properties of various fat substitutes, as well as their impact on the human body. Explore new products, and fat substitutes Salatrim Olestra, as well as the possibility of their use in food production. Analyzed the feasibility of using enzymes in the structuring of triglycerides.

Three experiments were conducted in which hydrolyzed olestra (HO) and hydrolyzed olestra manufacturing by-product (HBP) were compared with corn oil (CO) and a feed-grade hydrolyzed animal-vegetable fat blend (AVF) as fat supplements in diets for broilers. Various blends of HO and HBP with AVF and other fat sources were also evaluated. Results of these experiments indicate that HO or HBP may be used as energy sources in broiler diets. Use of these materials as the sole source of supplemental fat often reduced body weight gain and impaired feed utilization as compared with CO or AVF; however, when used as a component of a blended fat product typical of industry supplements, there was little if any adverse effect on live performance. Carcass fatty acid content was a reflection of dietary fat content. If the blend of fats containing HO or HBP contains a suitable ratio of unsaturated and saturated fatty acids, the product should be an acceptable source of supplemental energy in broiler diets.

Olestra is a non-caloric fat substitute under review by the Food and Drug Administration. It consists of a mixture of octa-, hepta- and hexaesters of sucrose formed with long chain fatty acids. Previous studies showed olestra is not hydrolyzed by mammalian lipases and is not absorbed. The objective of this study was to evaluate the potential for colonic microflora to metabolize olestra after continued exposure. Neat and emulsified14C-[fatty acid] olestra was incubated for 72 h in both minimal and organically-enriched anaerobic media inoculated with feces from seven subjects who had consumed olestra (9 g per day) over a 3–4 week period.14C-sucrose and14C-glucose served as positive controls. Production of14CO2,14CH4,14C-volatile fatty acids (VFAs) and14C-long chain fatty acids (LCFAs) was determined. In addition, the ester distribution and fatty acid composition of olestra were examined before and after incubation. Significant quantities of14CO2 and14C-VFAs were generated from the14C-sugars, indicating that the microflora were active under the incubation conditions. Furthermore, free oleic acid was extensively hydroxylated and hydrogenated. In contrast, no degradation products (gas, VFAs, LCFAs) or changes in the olestra resulting from bacterial activity were detected. These results indicate that under anaerobic conditions the colonic microflora of the humans, consuming olestra, did not metabolize olestra.

Apolipoprotein A-IV (apoA-IV) is synthesized by intestinal enterocytes during lipid absorption and secreted into lymph on the surface of nascent chylomicrons. A compelling body of evidence supports a central role of apoA-IV in facilitating intestinal lipid absorption and in regulating satiety, yet a longstanding conundrum is that no abnormalities in fat absorption, feeding behavior, or weight gain were observed in chow-fed apoA-IV knockout (A4KO) mice. Herein we reevaluated the impact of apoA-IV expression in C57BL6 and A4KO mice fed a high-fat diet. Fat balance and lymph cannulation studies found no effect of intestinal apoA-IV gene expression on the efficiency of fatty acid absorption, but gut sac transport studies revealed that apoA-IV differentially modulates lipid transport and the number and size of secreted triglyceride-rich lipoproteins in different anatomic regions of the small bowel. ApoA-IV gene deletion increased expression of other genes involved in chylomicron assembly, impaired the ability of A4KO mice to gain weight and increase adipose tissue mass, and increased the distal gut hormone response to a high-fat diet. Together these findings suggest that apoA-IV may play a unique role in integrating feeding behavior, intestinal lipid absorption, and energy storage.

The use of food products designed to mimic the sensory properties of sweet and fat while providing fewer calories has been promoted as a method for reducing food intake and body weight. However, such products may interfere with one mechanism that animals use to regulate energy balance, a learned relationship between the sensory properites of food and the caloric consequences of consuming those foods. Consistent with this hypothesis, previous data have shown that providing rats with sweet tastes that are not associated with the delivery of calories using high-intensity sweeteners results in increased food intake, body weight and adiposity, but only if the diet on which they are maintained also tastes sweet. In the present experiment, we examined whether use of the fat substitute, olestra, would have similar consequences by comparing the effects of consuming high-fat, high-calorie potato chips to the effects of consuming potato chips that sometimes signalled high calories (using high-fat potato chips) and that sometimes signalled lower calories (using non-fat potato chips manufactured with the fat substitute olestra). The results demonstrated that food intake, body weight gain and adiposity were greater for rats that consumed both the high-calorie chips and the low-calorie chips with olestra compared to rats that consumed consuming only the high-calorie chips, but only if animals were also consuming a chow diet that was high in fat and calories. When animals were maintained on a low-fat chow diet, intake, weight gain, and adiposity did not differ significantly based on chip type. However, rats previously exposed to both the low-calorie chips with olestra and the high-calorie chips exhibited increased body weight gain, food intake and adiposity when they were provided with a high fat, high calorie chow diet, even though the potato chips were no longer available. This suggests that the experience with the chips containing olestra affected the ability to predict high calories based on the sensory properties associated with fat. These results extend the generality of previous findings that interfering with a predictive relationship between sensory properties of foods and calories may contribute to dysregulation of energy balance, overweight and obesity.

Infusion of a μ-opioid receptor (MOR) agonist into the nucleus accumbens (NAcc) drives voracious food intake, an effect hypothesized to occur through increased tastant palatability. While intake of many palatable foods is elevated by MOR stimulation, this manipulation has a preferential effect on fatty food ingestion. Consumption of high-fat foods is increased by NAcc MOR stimulation even in rats that prefer a carbohydrate-rich alternative under baseline conditions. This suggests that NAcc MOR stimulation may not simply potentiate palatability signals and raises the possibility that mechanisms mediating fat intake may be distinct from those underlying intake of other tastants. The present study was conducted to investigate the physiological mechanisms underlying the effects of NAcc MOR stimulation on fatty food intake. In experiment 1, we analyzed lick microstructure in rats ingesting Intralipid to identify the changes underlying feeding induced by infusion of a MOR-specific agonist into the NAcc. MOR stimulation in the NAcc core, but not shell, increased burst duration and first-minute licks, while simultaneously increasing the rate and duration of Intralipid ingestion. These results suggest that MOR activation in the core increases Intralipid palatability and attenuates inhibitory postingestive feedback. In experiment 2, we measured the effects of MOR stimulation in the NAcc core on consumption of nonnutritive olestra. A MOR-specific agonist dose dependently increased olestra intake, demonstrating that caloric signaling is not required for hyperphagia induced by NAcc MOR stimulation. Feeding induced by drug infusion in both experiments 1 and 2 was blocked by a MOR antagonist. In experiment 3, we determined whether MOR activation in the NAcc core could attenuate satiety-related signaling caused by infusion of the melanocortin agonist MTII into the third ventricle. Suppression of intake caused by MTII was reversed by MOR stimulation. Together, our results suggest that MOR stimulation in the NAcc core elevates fatty food intake through palatability mechanisms dependent on orosensory cues and suppression of satiety signals inhibiting food intake.

A liquid chromatographic (LC) method has been developed to determine the percent of olestra in lipid samples. To achieve the highest degree of accuracy, this method requires the use of an olestra standard with the same molecular composition as the olestra in the lipid sample to be analyzed. Samples were analyzed by reversed-phase LC using an evaporative light-scattering detector. Chromatography was performed with a 5 μm octadecylsilane- Zorbax column that separates olestra from other lipophilic components. Three types of olestra standards (soybean-oil olestra, unheated cottonseed- oil olestra, and heated cottonseed-oil olestra), each analyzed in soybean oil, showed linearity when the amount of olestra injected ranged from 20 to 160 fig (r= 0.9996). The area under the olestra peak (retention time 3.5 to 4.9 min) was used to quantify the amount of olestra in olestra-lipid samples, by comparing the olestra area for the sample with that of the standard using a curve derived by linear regression. The method was evaluated using 3 types of olestra blended with soybean oil and varying the percent of olestra in the olestra-lipid blend from 5 to 90%. Recovery of olestra from these olestra-lipid blends varied from 99.2 to 106.0%, demonstrating excellent accuracy, with method precision expressed as the coefficient of variation, 0.9%. Each error estimate was derived from 5 parallel determinations. With proper validation (e.g., running an olestra-free blank for each lipid matrix), this method provides a rapid, accurate, and precise technique for measuring the percent of olestra in lipids extracted from olestra-formulated foods and in olestra-lipid blends.

Field desorption (FD), fast atom bombardment (FAB) and plasma desorption (PD) mass spectrometry have been used for the characterization of olestra, a mixture of octa-, hepta- and hexaesters of sucrose formed by reaction of sucrose with long-chain fatty acids (C12–C18). Most previous applications of desorption ionization mass spectrometry have involved polar compounds; however, the relatively low-polarity olestra is also amenable to these techniques with proper sample preparation. Field desorption provides molecular weight information, but the transience of the signals limits the usefulness for observing fragmentation and measuring ester distributions. In addition, FD may not be sensitive enough to allow characterization of fractions isolated from analytical high-performance liquid chromatography (HPLC) columns. Fast atom bombardment produces longer-lasting signals, which permit characterization of components over a wide mass range. However, signal-to-noise fluctuates substantially, depending on analyte solubility in the matrix, making the characterization of partial esters collected from HPLC uncertain and difficult. Plasma desorption mass spectrometry is the easiest and most sensitive technique for olestra characterization but provides the lowest mass resolution. Because it requires no more than a few µg of material, it is effective for the characterization of HPLC fractions. Furthermore, it is the only method, of the three investigated, that allows detection of intact dimeric species having molecular masses in the 3,000 to 5,000 dalton range.