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Data voluntarily supplied by industry were examined to evaluate the success of commercial weight loss programs and products. Information about the safe loss of weight, the maintenance of this lowered weight, and resultant health benefits were reviewed. Information was received from companies that produce over-the-counter preparations designed for persons with a small weight loss goal and from physician-supervised programs for morbidity obese persons placed on very-low-calorie diets. Regardless of the products used, successful weight loss and control was limited and required individualized programs consisting of restricted caloric intake, behavior modification, and exercise. Although some manufacturers of physician-supervised weight loss products for obese persons hav defined the effectiveness of their programs with controlled clinical studies, other industry programs have only begun to accurately assess their effectiveness or safety. Given the importance to public health of reducing obesity, rigorous studies on current weight control practices should be pursued aggressively. [ABSTRACT FROM AUTHOR]

The use of high fructose corn syrup (HFCS) has increased over the past several decades in the United States while overweight and obesity rates have risen dramatically. Some scientists hypothesize that HFCS consumption has uniquely contributed to the increasing mean body mass index (BMI) of the U.S. population. The Center for Food, Nutrition, and Agriculture Policy convened an expert panel to discuss the published scientific literature examining the relationship between consumption of HFCS or "soft drinks" (proxy for HFCS) and weight gain. The authors conducted original analysis to address certain gaps in the literature. Evidence from ecological studies linking HFCS consumption with rising BMI rates is unreliable. Evidence from epidemiologic studies and randomized controlled trials is inconclusive. Studies analyzing the differences between HFCS and sucrose consumption and their contributions to weight gain do not exist. HFCS and sucrose have similar monosaccharide compositions and sweetness values. The fructose:glucose (F:G) ratio in the U.S. food supply has not appreciably changed since the introduction of HFCS in the 1960s. It is unclear why HFCS would affect satiety or absorption and metabolism of fructose any differently than would sucrose. Based on the currently available evidence, the expert panel concluded that HFCS does not appear to contribute to overweight and obesity any differently than do other energy sources. Research recommendations were made to improve our understanding of the association of HFCS and weight gain.

With the approval for use in foods in Japan and the United States, the use of diacylglycerol (DAG) oil in fat-based products may become extensive due to equivalent physicochemical properties to conventional triacylglycerol (TAG) oil. The objective of the present study was to compare the effects of high-dose consumption of DAG oil in humans with that of TAG oil. In a double-blind controlled parallel trial, moderately lean men (n=42) and women (n=39) consumed either DAG or TAG at a dose of approximately 0.5 g/kg body weight/day as part of their diet for 12 weeks. All subjects completing the study tolerated the test oils well and showed no overt effects. Total caloric and fat intake remained constant and showed no significant differences between the groups. There was no significant difference in the occurrence of clinical signs and physical complaints related to test oil consumption. Although some statistically significant effects were reported in hematological and serum chemistry parameters in both DAG and TAG groups, none of these reported changes were considered biologically significant. Overall, this 12-week clinical study revealed no significant or treatment-related adverse effects of DAG oil consumed at a dose of 0.5 g/kg of body weight/day as part of the diet.

The science and policy underlying food labeling and food fortification have evolved over the past 30 years to a point where dietary guidance and nutrition labeling now provide consumers with highly sophisticated, very specific information about links between diet and health. The focus was once on prevention of nutrient deficiency diseases, but today it is on reducing the risk of chronic diseases and health-related conditions. The Nutrition Labeling and Education Act of 1990, with its provisions for authorization of health claims on food labels, has provided a gateway through which a broader realm of nutrition and health information can be made available to consumers. However, the interpretation and implementation of the health claim provisions must evolve, based on a strong foundation of supporting science, so that industry may more readily make health information available to consumers in a form that is easily understood and effectively used in making their dietary choices. We must develop a database to support claims of beneficial effects of food components. We must be assured that the beneficial effects are not outweighed by safety concerns. And we must develop an environment that is conducive to conducting the research to develop these data. This can only be accomplished through the collaborative efforts of industry, academia, consumers and public health agencies.

Fat substitutes, in theory, may provide special health benefits to certain population segments. The most probable benefits are a reduction in total fat intake and a subsequent reduction in intake of calories from fat. Whether individuals who consume high intakes of fat substitutes that are partially or totally nondigestible also benefit from lower calorie intake on a long-term basis is unknown. It is likely that many individuals will compensate by increasing total food intake to maintain calorie intake. Consumption of fat substitutes presents nutrition problems. Those fat substitutes that are partially or totally nondigested may reduce the bioavailability of other nutrients. Similarly, fat substitutes may have adverse effects on normal gastrointestinal tract function or intestinal tract flora. Unlike other functional food additives, fat substitutes can make up a significant portion of the total diet. For this reason, traditional safety factors cannot be applied. Consequently, more reliance on data from clinical studies involving human subjects and requirements for postmarket surveillance will be necessary as part of the approval process.

Glycogen metabolism was studied in the isolated perfused liver of the monkey conceptus at 90% of gestation using an in situ recirculating perfusion system. Net uptake of glucose and galactose and the activities of the enzymes, glycogen synthetase and phosphorylase, were studied in response to varied perfusate composition. Synthetase activity was expressed as %I. the percentage of total synthetase activity in the active form. Perfusate glucose concentrations as high as 700 mg/100 ml did not lead to net glucose uptake of to an increase in the baseline %I synthetase (4 +/- 1, mean +/- SEM). In the presence of 300 mg/100 ml glucose, insulin at 10(-7) M in creased %I to 8 +/- 2, and galactose greater than 75 mg/100 ml increased %I to 8 +/- 1. The combination of galactose, glucose, and insulin increased %I to 40 +/- 5. With this latter combination, synthetase activity was proportional to perfusate glucose concentration above 100 mg/100 ml. Phosphorylase activity was diminished by either galactose or insulin, and phosphorylase activity was lowest in the group receiving galactose, glucose, and insulin. Galactose was taken up by all livers, but net glucose uptake was not observed under any condition; net hexose uptake was observed in perfusions with galactose. Glycogen levels did not vary significantly with varied perfusate composition during the 30-min perfusion periods.

With heat treatment (20 degrees C for 30 min), the glucocorticoid-receptor complex becomes 'activated' and undergoes an increase in affinity for DNA. A two-stage procedure was used to separate sequentially the rat liver glucocorticoid-receptor complex from proteins with high and low affinity for DNA. DNA-cellulose column chromatography of unheated cytosol resulted in the retention of DNA-binding proteins, but not the unactivated receptor complex. Heat treatment of the column eluate resulted in increased affinity of the receptor complex to DNA, and chromatography on DNA-cellulose then yielded receptor complex free from proteins with low affinity for DNA. Removal of DNA-binding proteins during the first chromatographic step was critically dependent on ionic conditions and the ratio of cytosol chromatographed to DNA-cellulose. A purification of 11000-fold (85% yield) was achieved by this procedure. The partially purified receptor complex was taken up by rat liver nuclei.

Near term fetal monkey livers were perfused with a closed recirculating system and a defined perfusion medium. Livers from normal fetal animals were able to release glucose rapidly into the perfusate when they were exposed to glucagon, cyclic AMP, or an aglycemic perfusate, but they did not remove glucose rapidly from the perfusate, synthesize glycogen, or activate liver glycogen synthetase in response to hyperglycemia (Figs. 1,2, and 3; Table 1). Insulin decreased glucose mobilization in response to aglycemia, but did not stimulate glucose uptake during hyperglycemia; insulin activated glycogen synthetase (Table 1; Figs. 1 and 3). Livers from fetuses of streptozotocin-treated mothers and livers from 2-week-old neonates released more glucose into the perfusate in response to aglycemia then did livers from normal fetal monkeys (Fig. 4). These observations support the possibility that neonatal monkey liver is capable of rapidly mobilizing glucose during periods of hypoglycemia but is unable to take up glucose and store glycogen rapidly during periods of hyperglycemia.

Partially purified rabbit skeletal muscle phosphorylase phosphatase (EC 3.1.3.17; phosphoprotein phosphohydrolase) was inactivated when it was incubated with exogenous cyclic AMP-dependent protein kinase (EC 2.7.1.37; ATP:protein phosphotransferase), cyclic AMP, and ATP-Mg. Subsequent separation of the phosphatase by acrylamide gel electrophoresis or sucrose density centrifugation resulted in reactivation of the enzyme. The phosphatase decreased in molecular weight from approximately 70,000 to 52,000, and a phosphorylated inhibitor with molecular weight of 26,000 was found. Reactivation of phosphatase also occurred when it was incubated with MnCl2 or trypsin. The inhibitor was effective at less than 10(-8) M and was relatively heat stable. Its activity was destroyed by tryptic digestion and by dephosphorylation by a Mn-stimulated phosphatase. These observations support the possibility that phosphorylase phosphatase activity is controlled by cyclic AMP-dependent protein kinase and a Mn-stimulated phosphatase by a reaction involving phosphorylation and dephosphorylation of a protein phosphatase inhibitor.

Daily urinary chromium (Cr) excretion of 15 healthy free-living female subjects was 0.20 +/- 0.03 microgram (mean +/- SEM) and nearly identical for 27 male subjects, 0.17 +/- 0.02 microgram. Minimum Cr absorption calculated from urinary Cr excretion was about 0.4 percent. Increasing intake fivefold by Cr supplementation led to a nearly fivefold increase in Cr excretion suggesting that the extent of absorption of supplemental inorganic chromium was similar to that from normal dietary sources. Correlations between 24-hour Cr excretion and urine volume, age, total creatinine and body weight were not found. Urinary Cr concentration of samples obtained following a morning void correlated with creatinine and Cr concentration following a glucose challenge but not with serum glucose, insulin, lipid parameters, age or body weight. Similar results were obtained for urine samples obtained from subjects during Cr supplementation. These results suggest that urinary Cr excretion does not appear to be a meaningful indicator of Cr status but is a meaningful indicator of Cr intake and that the absorption of supplemental inorganic Cr was similar to that of Cr from normal dietary sources.

Direct regulation of rat liver glycogen metabolism by glucose and galactose was studied using an isolated liver perfusion system. Activation of glycogen synthase and net glycogen synthesis increased linearly when perfusate glucose concentration was increased from 125 to 500 mg/100 ml. Galactose, rapidly taken up by isolated rat liver regardless of circulating glucose concentration, increased these responses to glucose. In the presence of galactose (greater than or equal to 5 mg/100 ml), activation of synthase and glycogen synthesis were 1.5-fold higher at any given glucose concentration. The addition of insulin did not appreciably after synthase activation by glucose and galactose. Phosphorylase activity, low at circulating glucose levels above 125 mg/100 ml, was further decreased as glucose was increased or when galactose was added to the perfusate. Release of glucose into the perfusate in response to aglycemia was increased in the presence of galactose.

A critical review composed of two parts: estimates of present levels of sugars intake and of recent trends in nutritive carbohydrate sweetener content of the food supply and a review of recent scientific literature addressing potentially adverse health effects associated with sugars consumption. The review contains an executive summary, an appendix with 75 tables summarizing the estimation of sugars intake of U.S. population groups, and over one thousand citations.

Blood galactose concentrations were measured in 55 neonates consuming at least 80 ml/kg/day of lactose-containing formula. The range of galactose concentration immediately after feeding was 0.8 to 4.2 mg/dl, with a mean of 1.5 +/- 0.2 mg/dl. Galactose concentration fell rapidly after feeding, and normal values for the population fell with a half-life of 45 minutes. Considering galactose as a potential intravenous nutrient, six glucose-intolerant premature infants were given galactose-containing solutions intravenously using a double-blind randomized crossover protocol. Infants were chosen who had sustained hyperglycemia (150 mg/dl) and glucosuria (2+ Clinitest) requiring glucose infusion at a rate below 7 mg/kg/minute for more than 24 hours. Compared to the control glucose period, intravenous alimentation with a solution containing carbohydrate as 50% glucose and 50% galactose resulted in a 65% increase in total carbohydrate infusion rate, normalization of the blood glucose concentration, and decreased glucosuria. Blood galactose concentration averaged 15 mg/dl, and no clinical or biochemical evidence of galactose toxicity was noted.

In fetal rat liver in utero, an increase in glycogen and the glycogen synthetic enzyme glycogen synthetase (EC 2.4.1.11) occurs between gestational days 17 and 19. We used an organ culture system for finding the stimulus for increased enzyme activity and defining the relationship of this increase to glycogen synthesis. In fetal-liver explants from an earlier period (gestational day 16), hydrocortisone causes an elevation in total glycogen synthetase activity. This effect, which can be blocked by actinomycin D, is strikingly similar in time course and magnitude to the normal increase in utero. However, in order for glycogen synthesis to proceed after hydrocortisone increases glycogen synthetase levels, insulin is required. Unlike hydrocortisone, insulin does not increase total glycogen synthetase; it appears to act by converting the b or phospho form of synthetase to the a or dephospho form. Insulin alone does not stimulate glycogen synthesis in explants from 16-day fetal liver, although no defect in insulin binding was demonstrable. These findings support the hypothesis that the increase in liver-glycogen synthesis during the last trimester requires glucocorticoids for the developmental induction of glycogen synthetase and insulin for activation of the enzyme.

It is generally accepted that human T-cell lymphotropic virus type III (HTL VIII) is the causative agent of acquired immunodeficiency syndrome (AIDS), but, asyet, there are no clear reasons for the different clinical manifestations of AIDS among individuals. In this article Douglas Archer and Walter Glinsmann discuss the history of AIDS and propose a link between HTLV-III infection and gastrointestinal disease processes with attendant malabsorption. They further propose that maximizing the nutritional status and minimizing the incidence of gastrointestinal infection of individuals infected with HTLV-III may prevent development of the full-blown AIDS., (Copyright © 1985. Published by Elsevier B.V.)

Administration of adrenaline to an isolated rat hindlimb preparation rapidly decreased muscle phosphorylase phosphatase (EC 3.1.3.17) activity and increased heat-stable and trypsin-labile phosphatase inhibitor activity. This was associated with increased tissue cyclic AMP concentrations, phosphorylase (EC 2.4.1.1) activation and glycogen synthase (EC 2.4.1.11) inactivation.

Two heat-stable and trypsin-labile inhibitors of phosphorylase phosphatase, designated inhibitor-1 and inhibitor-2, were partially purified from extracts of rabbit skeletal muscle by heating and coloumn chromatography using DEAE-dellulose and Bio-gel P-60. Inhibitor-1 exists in an active phosphorylated form and an inactive dephosphorylated form. The interconversion of phosphorylated inhibitor-1 and dephosphorylated inhibitor-1 is mediated by protein kinase dependent on adenosine 3':5'-monophosphate (cyclic AMP) and a Mn2+-stimulated phosphoprotein phosphatase. Inhibitory activity of inhibitor-2 is not influenced by treatment with either the kinase or the Mn2+-stimulated phosphatase. The molecular weights of inhibitor-1 and inhibitor-2 estimated by sodium dodecylsulfate-polyacrylamide gel electrophoresis are 26000 and 33000 respectively. Both inhibitor-1 and inhibitor-2 inhibit phosphorylase phosphatase by a mechanism which appears to be non-competitive with respect to the substrate phosphorylase a. Inhibitor fractions at early stages of purification also inhibit cyclic-AMP-dependent histone phosphorylation, but this kinase inhibitory activity resides with a protein moiety which is separable from inhibitor-1 and inhibitor-2.

Sharp increases in the concentration of chromium in plasma were found in five subjects with normal glucose utilization after administration of glucose by mouth. This rise was not observed in two diabetics when glucose tolerance was impaired; however, it appeared when glucose tolerance was improved and when trace amounts of trivalent chromium were given as a dietary supple-ment. The source of chromium which became elevated was most likely an internal pool. Possibly there is a relation between chromium and insulin function.