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Compression of the animal stomach gives rise to vagal discharges that could signal satiety. To test a noninvasive method of inducing compression of the human stomach, we first employed extra-abdominal pressure levels of 0, 10, and 20 Torr, counterbalanced for sequence, in six lean and obese subjects. A large blood pressure cuff was wrapped around the abdomen of the subject with the air bladder over the epigastrium. The bladder was inflated before ingestion of a liquid meal by the subject until satiated. Relative to 0 Torr, pressures of 10 and 20 Torr significantly reduced spontaneous food intake (P less than 0.03) without producing discomfort. In a second study, extra-abdominal pressure of 20 Torr also raised intragastric pressure by a mean of 5.5 Torr (P less than 0.03). In a third study, extra-abdominal pressure of 20 Torr did not alter gastric emptying rate during meal ingestion but ultimately enhanced emptying rate when this pressure was maintained for greater than 100 min after meal completion (P less than 0.01).

The accuracy of prediction equations for estimating lean body mass (LBM) from total-body electrical conductivity (TOBEC) was examined by cross-validation. Two samples of adults, aged 18-35 yr, were drawn from separate geographic locations. LBM was determined by densitometry and TOBEC was measured with TOBEC II instrument. LBM and TOBEC were highly correlated in both samples (r = 0.96 and 0.97). Cross-validation of LBM prediction equations was accomplished by exchanging equations and comparing predicted LBM values. There was a mean difference of 0.974 kg LBM between the two equations (p less than 0.0001). Thus, data from 157 subjects were pooled and one equation was developed that incorporated height (cm), sex (males = 0, females = 1), and the zero-, first-, and second-order Fourier coefficients (FC0, FC1, and FC2) of the TOBEC phase value: LBM, kg = -36.410 + (-1.324 X sex) + (0.01185 X (FC1(0.5)xht)) + (12.347 X FC2(0.5)) + (0.0627 X FC0)-(0.9232 X FC2) This equation, developed from 157 subjects, accounted for 96% of the variability in LBM and had a standard error of estimate of 2.17 kg LBM.

A significant proportion of the interindividual variance in human fatness is attributable to genetic factors. This fact is indicated (inter alia) by studies of identical twins demonstrating that the degree of efficiency with which the body uses excess dietary energy for fat storage is, to a considerable extent, inherited. Genetic factors also appear to render particular individuals or groups especially vulnerable to pervasive obesity-promoting influences (excess food and too little exercise) in the environment. If, indeed, much human obesity results from an interaction between a genetically determined disposition to store fat efficiently and a food-laden, overmechanized environment, then preventive and therapeutic strategies should be directed toward (a) helping the susceptible individual protect himself from the "calorie pollution" that surrounds him, and (b) finding pharmacologic agents to modify the inherited metabolic factors that favor excessive fat storage.

The effect of cyproheptadine on spontaneous energy intake was studied by means of an automated (liquid diet) food-dispensing apparatus in two nonobese adults confined to a metabolic ward. The experimental design included both single and double-blind periods. Throughout, the composition of daily weight change was determined by the energy-nitrogen balance method. While on cyproheptadine, both subjects exhibited increases in energy intake with the following average composition of weight gain: protein 16%, fat 14% and water 70% (first subject), and protein 5%, fat 49% and water 46% (second subject). The cyproheptadine-induced increase in energy intake was statistically significant in one of the subjects, who was at his desirable weight level at the outset. The other subject was underweight initially and tended to gain throughout the experiment, although rate of weight gain appeared to be more rapid during the periods of cyproheptadine administration. Energy output in both subjects remained fairly constant throughout. We conclude that cyproheptadine induces weight gain of 'normal' composition by stimulating increased energy intake.

A Consensus Development Conference on the Health Implications of Obesity was held in February 1985 at the National Institutes of Health in Bethesda, Maryland, USA. After presentations by 19 experts in relevant subject areas, a panel of 15 impartial senior level professionals presented their consensus of findings and recommendations. This paper summarizes the results of the conference and provides reference tables of body mass index (BMI) values and weight goals, along with nomograms of the BMI determined from height and weight scales, to show comparisons with weight goals. The goals are taken from two widely available tables of mortality data by weight. These reference aids are included to illustrate the potential clinical value of wider use of the BMI, as recommended in the conference.

Obese individuals maintained for 64 days on either of two low-calorie diets (600-800 kcal/day), consisting of protein alone or protein plus carbohydrate, varied widely in the extent of their cumulative nitrogen deficits. Rates of weight loss showed little correlation with rates of nitrogen loss after the first 28 days of the study. The low-calorie diet consisting entirely of protein increased blood beta-hydroxybutyrate concentrations far more than did a diet consisting of equal parts of protein and carbohydrate. The diet which consisted almost entirely of protein did not spare body protein better or induce a greater rate of weight loss than did the mixture of protein and carbohydrate.

In comparison with lean marathon runners whose fat content was 15%, obese subjects with a fat content of 55% showed a 36% reduction in intracellular potassium. It is hypothesized that as much as 60% of this decrease may have been due to the lower proportion of muscle (which has the highest intracellular potassium of any tissue) in the fat free mass of very obese subjects. The remainder of the decrease seems to have been a measurement artefact owing to self-absorption of gamma rays by adipose tissue, most of which is distributed over potassium rich lean tissue. The low intracellular potassium values found in obesity should not be interpreted as necessarily signifying potassium deficiency.

Serum insulin has been implicated as a determinant of blood pressure (BP) level in obese hypertensive individuals. We examined the relationships among fasting insulin, mean arterial pressure (MAP), body composition, and fat distribution in 204 subjects unselected for glucose tolerance. All met the criteria of taking no oral hypoglycemic agents, insulin or antihypertensive medications. 95 percent were considered obese and 78 percent were female. Mean age was 39 years (range 15-71), percent ideal body weight (IBW) 171 percent (109-332), BP 125/81 mmHg (80-181/50-110) and fasting insulin 44 microU/ml (4-196). Lean body mass (LBM) and body fat were measured by tritium dilution. The correlation coefficient between insulin and MAP was 0.32 (P less than 0.0001). Both insulin and MAP correlated highly with percentage IBW, percentage body fat, fat mass, LBM, body build and upper fat pattern. Controlling for these variables simultaneously eliminated the association between insulin and BP. By contrast, the correlations between MAP and measures of body composition and fat distribution retained significance after controlling for insulin level. These findings suggest that measures of body composition and fat distribution have a relationship with BP that is not entirely accounted for by serum insulin level, and the relationship between serum insulin and BP is indirect and largely accounted for by their mutual association with measures of body composition and fat distribution.

Of sixty-seven adult, non-selected patients admitted to the medical wards of two New York City teaching hospitals over a six-week period, 91 per cent were found to have overt or potential nutritional problems of clinical significance. While they usually received sophisticated diagnostic studies and complex drug therapy, their nutritional needs, for the most part, were not given comparable attention. Major examples of nutritional neglect included failure to: Obtain a dietary history when indicated; record body weight on admission and at appropriate intervals thereafter, ascertain "relative weight" or some similar measure of deviation from a desirable standard; provide appropriate dietary management, including nutrient supplements; and furnish nutritional counseling. At no time was a dietary history obtained by a dietitian, and no plans were made at discharge for follow-up nutritional care.

The effect of a medium chain triglyceride (MCT) preparation on blood ketones was determined in fourteen normal subjects and six patients with diabetes mellitus of the maturity-onset type. Ingestion of 100 gm. of the MCT (containing 86 per cent C8 and 14 per cent C10 fatty acids) was followed by a small but statistically significant rise in blood ketones in each of the groups. The rise in ketones was slightly but significantly higher in the diabetic patients than in the normal subjects. In all subjects, ketone rises were negligible after ingestion of 100 gm. of corn oil. The ketogenic effect of MCT may result in part from its rapid absorption from the gut, with a high proportion of the component fatty acids traveling in the portal vein directly to the liver in the free acid form. In the liver, these fatty acids appear to be rapidly degraded and converted in part to ketones. The predictable mild hyperketonemia induced by MCT makes this glyceride a useful tool in the study of ketogenesis.

SummaryRats with depot fat enriched with undecanoate maintain significantly higher concentrations of liver glycogen and plasma glucose during prolonged starvation than do conventionally fed controls. When food motivated behavior was tested by means of a progressive ratio schedule of reinforcement, the undecanoate-enriched rats exhibited a significantly lower drive for food after 48 hr of starvation than did their nonenriched controls.We thank K. Porikos for critical comments on the manuscript and C. Wang and K. Ellis for technical assistance.

ONE of the most frustrating features of primary biliary cirrhosis is pruritus, often so intense and unrelenting that the victim seriously contemplates suicide.1 Such patients suffer from chronic insomnia and irritability, and their bodies become covered with excoriations from uncontrollable scratching. Attempts to control the intolerable itching with sedatives, analgesics, glucocorticoids and methyltestosterone have met with little success. Recently, norethandrolone has been reported fairly effective in relieving the pruritus; however, its administration is associated with deepening jaundice and other side effects.2 3 4 Bile acids accumulate in the blood of patients with primary biliary cirrhosis, and it has been proposed that the . . .

Serum Lipids and Atherogenesis With this necessarily sketchy discussion of lipid physiology as a background, it is appropriate to consider what the relation of the serum lipids and atherosclerosis ...