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Biomedical subjects

M Apfelbaum

Publications and source records attributed to M Apfelbaum.

At least 37 records · Page 2Linked to original sources
PubMed1994

Recovery of initial body weight and composition after long-term massive overfeeding in men.

To verify the existence of a set point for body mass, the spontaneous evolution of body weight and composition after massive overfeeding was observed in nine lean young Cameroonian (Massa) men participating in a 4-6 mo traditional fattening session (Guru). Anthropometry (skinfold thicknesses) was used to estimate body composition. Peak weight and fat gains were found to be 19 +/- 3.2 (mean +/- SD) kg and 11.8 +/- 2.5 kg, respectively. Two and one-half years after cessation of fattening and a return to daily life and food habits, there was a spontaneous return to initial body weight and body composition of the overfed subjects. Because the subjects were not under social or other stimuli to lose weight, this finding argues in favor of the existence of a biological control of energy balance at a "preferred" level in nonobese individuals.

Adipose Tissue↗
PubMed1994

Effect of postgastric energy loads on intake of sham meals of different palatability in rats.

Food intake depends on the palatability of the diet and on the energy delivered to the body. It is not known, however, whether the palatability of a diet is able to modulate the inhibitory effect of energy input on food intake. To address this question, we have measured intake during sham feeding for diets of different palatabilities in rats receiving varying levels of duodenal energy load. Rats were offered sucrose solutions (6, 10, or 30%) or mixed liquid diets without or with physiological duodenal energy loads using a mixed liquid diet. Compared with that seen during real feeding, meal size during sham feeding was increased for palatable diets but not for less palatable diets. Intraduodenal infusion of the mixed liquid diet inhibited the intake of all diets given by sham feeding. This inhibition was dependent on the level of duodenal energy load and was significantly greater for more palatable diets than for less palatable ones. We conclude that the inhibitory effects of intestinal nutrient load on intake are significant for all diets but have a more pronounced effect on the intake of highly palatable diets.

Animals↗
PubMed1994

Xmn1 restriction polymorphism of apolipoprotein AI gene and lipoprotein levels in obesity.

The aim of this study was to assess any association between an Xmn1 restriction site polymorphism of the apo AI gene and lipoprotein levels in obesity. A cross sectional study was made of lipid variables in relation to genetic and anthropometric factors in obese people at the Nutrition Outpatient Clinic of Bichat Hospital in Paris, France. The subjects were 97 unrelated French Caucasian subjects (65 women and 32 men) selected on the basis of 20% over-weight. The following main outcome measures were recorded: body mass index (BMI) and waist to hip ratio (WHR), cholesterol (C) and triglyceride (TG) concentrations in serum and lipoproteins (including HDL subfractions), apolipoproteins AI and B, determination of apo AI Xmn1 genotypes. Three alleles, designated X1, X2, X3, could be detected with frequencies 0.84, 0.12, and 0.04 respectively. The X2 carriers had higher concentrations of LpA-I, A-II (HDL particles containing both Apo AI and Apo AII) in the whole group: 0.90 vs 0.77 and 0.72 g/l in X1X1 and X1X3 respectively (P < 0.01). The genotype X1X2 was also associated with higher HDL-C in obese men (0.47 vs 0.36 g/l in X1X1, P < 0.05). In X1X1 women, BMI was positively correlated with serum and VLDL-TG (P < 0.05) and negatively with HDL2-C (P < 0.05), WHR being positively correlated with serum TG (P < 0.05), VLDL-TG (P < 0.01) and negatively with HDL-(P < 0.05) and HDL2-C (P < 0.01). These correlations were not found in subjects carrying the X2 allele.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The effects of aspartame versus sucrose on motivational ratings, taste preferences, and energy intakes in obese and lean women.

This study examined the effects of four breakfast preloads of different sweetness and energy content on motivational ratings, taste preferences, and energy intakes of 12 obese and 12 lean women. The preloads consisted of creamy white cheese (fromage blanc) and were either plain, sweetened with sucrose or aspartame, or sweetened with aspartame and supplemented with maltodextrin. Their energy content was either 300 kcal (1,255 kJ) or 700 kcal (2,929 kJ). Motivational ratings of hunger and the desire to eat were obtained prior to and at 30 min intervals after breakfast. Taste preferences were measured prior to and 150 min after breakfast. The subjects ate buffet-style lunch, snack, and dinner meals in the laboratory. Obese women consumed significantly more energy at meals (2,596 kcal or 10,862 kJ) than did lean women (1,484 kcal or 6,209 kJ); derived a greater proportion of energy from fat (39.9% vs. 35.5%), and had lower dietary carbohydrate-to-fat ratios. Consumption of low-energy as opposed to high-energy breakfast preloads was associated with elevated motivational ratings by noon. However, energy intakes at lunch, snack, or dinner did not vary as a function of preload type, and no compensation was observed for the energy consumed at breakfast. Taste preferences were not affected by preload ingestion or by preload type. The study provided no evidence that aspartame promotes hunger or results in increased energy intakes in obese or in lean women.

Adult↗
PubMed1993

Tritium dilution space measurement is not modified by a doubling in fluid intake.

The purpose of this study was to examine the effects of a doubling in water intake on the total body water measured by the tritium dilution technique. Overdrinking was obtained by presenting tap water and sweet water to the rats. Total body water was measured twice, tritium dilution vs. dessication. Body water volumes differed between the two methods but not between the two groups. Thus the isotopic dilution technique can be used to measure total body water regardless of the flux of fluid through the subject.

Adipose Tissue↗
PubMed1992

Effect of a moderate alcohol intake on the lipoproteins of normotriglyceridemic obese subjects compared with normoponderal controls.

Moderate alcohol intake is frequently associated with an elevated concentration of high-density lipoprotein (HDL), which is one of the potential causes for the relative decrease in cardiovascular risk reported in moderate drinkers. Conversely, low HDL concentrations, particularly HDL2, in obese subjects may be a risk factor. The effect of 30 g alcohol daily (wine) during 14 days following a period of abstinence was studied in seven normolipidemic obese subjects (body mass index [BMI], 30 +/- 1.7 kg/m2) compared with seven normoponderal controls (BMI, 22 +/- 1.2 kg/m2). Alcohol caused apolipoprotein (apo) AI and apo AII concentrations to increase in all controls by 12% and 16% (P less than .05), but not in obese subjects. Lipoprotein (Lp) AI HDL particles (without AII) were initially in the same proportions in the two groups. Their increase in controls only (P less than .03) was not matched by an increase in HDL2 in all subjects. In obese subjects, neither Lp AI nor HDL2 were increased by alcohol, but their HDL-triglyceride (TG) contents, initially elevated, were normalized. Cholesterol ester (CE) transfer activity was not different in controls and obese subjects during abstinence (105.7 +/- 40.8 v 104.8 +/- 34.5 mmol/mg protein/h). It was notably depressed by alcohol in controls (74.2 +/- 27.4, P less than .002), but not in obese subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Underreporting of food intake in obese "small eaters".

Thirty sedentary and stable weight obese women were classified as small, normal or large eaters depending on their report of 24 h energy intake (EI) through a dietary history questionnaire. For each subject, resting metabolic rate (RMR) was assessed through indirect calorimetry, physical activity through a self-administered questionnaire and psychological evaluation through psychometric tests. Neither RMR nor indices of physical activity were different between the three groups; however for small eaters, RMR was higher than reported EI (p < 0.001). Thus, the low EI reported by obese small eaters reflected an underreporting of food intake. Psychometric evaluation was not different between normal and large eaters. Small eaters exhibited a better perception of food size than normal or large eaters, and no difference in tests assessing memory or attention; their score (2.8 +/- 1.3) in a nutritional dissimulation test was higher (p = 0.015) than that of normal (1.0 +/- 0.7) or large eaters (1.5 +/- 0.09). This suggests that underreporting in obese small eaters might be due to specific nutritional concealment; because small eaters reported a low intake particularly in foods which are often perceived as unhealthy (fats, sugars, extra-prandial consumption), they probably reported what, in their opinion, they should have eaten, instead of what they did eat.

Adult↗
PubMed1992

Massive overfeeding and energy balance in men: the Guru Walla model.

To determine the magnitude of the thermogenic response to a massive long-term overfeeding, an energy-balance study was carried out in nine lean, young Cameroonian men participating in a traditional fattening session: the Guru Walla. Food intake, body weight, body composition, activity, and metabolic rates were recorded during a 10-d baseline period and over the 61-65 d of fattening. Total energy expenditure (TEE) was measured by using doubly labeled water during the baseline period and the final 10 d of Guru Walla. Cumulative overfeeding consisted of 955 +/- 252 MJ (chi +/- SD) mainly as carbohydrate. Body-weight increase was 17 +/- 4 kg, 64-75% as fat. Metabolic rates increased but TEE did not. However, when accounting for the reduction in physical activity, substantial thermogenesis was observed but its amplitude was not greater than that observed under less extreme carbohydrate-overfeeding conditions. If luxuskonsumption does exist, it is not related to the magnitude of the cumulative overfeeding.

Adaptation, Physiological↗
PubMed1992

Association of a DNA polymorphism of the apolipoprotein A-I/C-III/A-IV gene cluster with hypertriglyceridemia in obese people.

Hypertriglyceridemia is frequently associated with obesity. In the general Caucasian population, an association of the uncommon S2 allele of a DNA polymorphism of the apolipoprotein (apo) A-I/C-III/A-IV gene cluster with hypertriglyceridemia has been reported. To assess the risk of hypertriglyceridemia associated with the S2 allele in obesity, lipid status and apo A-I/C-III/A-IV genotypes were studied in 90 unrelated Caucasian obese subjects. Age, body mass index, percentage body fat and waist-hip ratio were comparable between genotypes. The frequency of S1/S2 genotype was 35% in the hypertriglyceridemic group versus 11.4% in the normotriglyceridemic group (P < 0.05). The odds ratio of hypertriglyceridemia was 3.7 for obese subjects with the S2 allele and 26.7% of hypertriglyceridemias could be attributed to the S2 allele. Women with the S1/S2 genotype had also significantly higher VLDL- and LDL-cholesterol concentrations. These results suggest that the S2 allele modulates the effects of obesity on lipoproteins and increases the risk of hypertriglyceridemia when obese.

Adult↗
PubMed1992

Thymulin activity during very-low-calorie diet.

The potential use of thymulin levels as a sensitive and functional marker of energy deficiency was investigated in 13 obese women during a 3-week very-low-calorie diet. Mean weight loss was 8.92 +/- 0.52 kg after 21 days of treatment. The patients were free from infection as assessed by serum orosomucoid and C-reactive protein measurements. Serum albumin levels were not decreased throughout the experiment whereas transthyretin concentrations fell significantly during the first 2 weeks and remained fairly stable thereafter. Orosomucoid levels dropped only after 3 weeks of dieting. Serum zinc concentrations were within the normal range on admission and at the end of the experiment. Thymulin activity was not altered throughout the study, suggesting that this thymic hormone cannot be used as a functional marker of short-term energy restriction.

Adult↗
PubMed1991

Effects of ovarian steroids on energy balance in rats fed a highly palatable diet.

The effects of progesterone and estradiol on body weight, energy intake, energy expenditure, body composition, and brown adipose tissue activity were investigated in female rats fed a highly palatable diet (association of chow and full milk with sugar), which, by itself, induced an increase in food intake and energy expenditure. Progesterone and estradiol were administered in the form of implants. Ovariectomized animals were used in the estradiol studies. Energy expenditure was assessed through oxygen consumption, body composition through carcass analysis, brown adipose tissue activity through measurements of uncoupling-protein, guanosine diphosphate (GDP) binding capacity, and assay of uncoupling-protein mRNA. Body weight and food intake were increased by progesterone and decreased by estradiol. Energy expenditure was not altered by progesterone. Indirect evidence showed that estradiol increased energy expenditure, but direct measurements showed no modification. Changes in body weight under progesterone or under estradiol were not due to brown adipose tissue activity. The results indicate that ovarian hormones act on energy balance mainly by altering food intake, and possibly in the case of estradiol by increasing energy expenditure. These effects persist in rats fed a highly palatable diet, despite increases in energy intake and expenditure induced by the diet alone.

Adipose Tissue, Brown↗
PubMed1991

Lack of plasmic beta-endorphin response to a gastronomic meal in healthy humans.

In order to study the relationship between the endogenous opiate system and food intake in man, plasma concentrations of beta-endorphin were measured in ten healthy subjects. Time course of beta-endorphinemia was compared under the following conditions: basal (fasting), after an injection of pentagastrin (6 micrograms/kg), or after a gastronomic meal. No changes in plasma beta-endorphin or ACTH concentrations were observed with pentagastrin nor after the meal, despite the combination of very high sensory pleasure with intake of a very large amount of food. It is concluded that blood beta-endorphin concentration is not a sensitive index of the effects of food intake on the endogenous opioid system in man.

Adult↗
PubMed1991

Immunoreactive beta-endorphin increases after an aspartame chocolate drink in healthy human subjects.

It has been claimed that sucrose intake induces a rise in beta-endorphins. In an attempt to discriminate between the sensorial and metabolic effects of sucrose intake in this process, the effects of two chocolate drinks were compared: one sweetened with 50 g of sucrose, the other with 80 mg of aspartame. Plasma beta-endorphin concentrations were more elevated after the aspartame drink than after sucrose or fasting, while insulin increased after drinking as much with aspartame as with sucrose. We suggest that the increase in beta-endorphin after aspartame edulcorated chocolate is related with insulin secretion in the absence of marked changes in blood glucose or with a direct effect of aspartame itself on beta-endorphin liberation.

Adolescent↗