Protein intake and body-weight regulation

Body-weight management requires a multi-factorial approach. Recent findings suggest that an elevated protein intake seems to play such a key role in body-weight management, through (i) increased satiety related to increased diet-induced thermogenesis, (ii) its effect on thermogenesis, (iii) body composition, and (iv) decreased energy-efficiency. Supported by these mechanisms a relatively larger weight loss and stronger body-weight maintenance thereafter have been observed

Effects of oral fat perception by modified sham feeding on energy expenditure, hormones and appetite profile in the postprandial state.

Previously, we have shown that satiety and metabolites increased after high-fat modified sham feeding (MSF). We assessed possible metabolic effects due to oral stimulation with a high-fat sham-fed 'meal', in comparison with a high-fat fed meal and with water, in the postprandial state. Fourteen healthy women (aged 18-40 years; BMI 22.5 (sd 3) kg/m2) were fed in energy balance during 4 d with a 50 % enegy as carbohydrate, 15 % energy as protein and 35 % energy as fat menu. On day 4, subjects were given one out of three test lunches, 5 h after a high-fat breakfast, in random order: a high-fat MSF lunch, water (W) or the same lunch to be eaten (E), during their 36 h stay in the respiration chamber, where substrate oxidation, 24 h energy expenditure (EE) and appetite profile were measured. Oral fat stimulation by MSF increased EE (W 6.3 (sd 0.8) v. MSF 6.9 (sd 1.0) kJ/min and E 6.8 (sd 0.7) kJ/min; P < 0.04) for 1 h, increased plasma insulin concentrations (t = 15; W 10.0 (sd 3.4) v. MSF 13.2 (sd 4.0) v. E 22.3 (sd 3.3) units/l; P < 0.0001), attenuated changes in plasma NEFA concentrations (t = 15, W 432 (sd 108) v. MSF 418 (sd 146) v. E 282 (sd 72) mumol/l; P < 0.0001), plasma TAG concentrations (t = 60; W 1092 (sd 548) v. MSF 1116 (sd 493) mumol/l and E 1350 (sd 352) mumol/l; P < 0.02) and plasma glycerol concentrations (t = 15, W 87 (sd 29) v. MSF 74 (sd 34) mumol/l and E 67 (sd 18) mumol/l; P < 0.03). Over a longer period of time, MSF had no effects on substrate oxidation, diet-induced thermogenesis or total EE. In addition to the previously observed metabolic effects of oral stimulation with fat, EE is stimulated up to 1 h after the MSF meal

Sensory and gastrointestinal satiety effects of capsaicin on food intake

BACKGROUND: Decreased appetite and increased energy expenditure after oral consumption of red pepper has been shown. OBJECTIVE: The aim of the present study was to assess the relative oral and gastrointestinal contribution to capsaicin-induced satiety and its effects on food intake or macronutrient selection. METHODS: For 24 subjects (12 men and 12 women; age: 35+/-10 y; BMI: 25.0+/-2.4 kg/m2; range 20-30), 16 h food intake was assessed four times during 2 consecutive days by offering macronutrient-specific buffets and boxes with snacks, in our laboratory restaurant. At 30 min before each meal, 0.9 g red pepper (0.25% capsaicin; 80,000 Scoville Thermal Units) or a placebo was offered in either tomato juice or in two capsules that were swallowed with tomato juice. Hunger and satiety were recorded using Visual Analogue Scales. RESULTS: Average daily energy intake in the placebo condition was 11.5+/-1.0 MJ/d for the men and 9.4+/-0.8 MJ/d for the women. After capsaicin capsules, energy intake was 10.4+/-0.6 and 8.3+/-0.5 MJ/d (P<0.01); after capsaicin in tomato juice, it was 9.9+/-0.7 and 7.9+/-0.5 MJ/d, respectively (compared to placebo: P<0.001; compared to capsaicin in capsules: P<0.05). En % from carbohydrate/protein/fat (C/P/F): changed from 46+/-3/15+/-1/39+/-2 to 52+/-4/15+/-1/33+/-2 en% (P<0.01) in the men, and from 48+/-4/14+/-2/38+/-3 to 42+/-4/14+/-2/32+/-3 en% (P<0.01) in the women, in both capsaicin conditions. Satiety (area under the curve) increased from 689 to 757 mmh in the men and from 712 to 806 mmh in the women, both (P<0.01). Only in the oral exposure condition was the reduction in energy intake and the increase in satiety related to perceived spiciness. CONCLUSION: In the short term, both oral and gastrointestinal exposure to capsaicin increased satiety and reduced energy and fat intake; the stronger reduction with oral exposure suggests a sensory effect of capsaicin

Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation

OBJECTIVE: Investigation of the effect of a green tea-caffeine mixture on weight maintenance after body weight loss in moderately obese subjects in relation to habitual caffeine intake. RESEARCH METHODS AND PROCEDURES: A randomized placebo-controlled double blind parallel trial in 76 overweight and moderately obese subjects, (BMI, 27.5 +/- 2.7 kg/m2) matched for sex, age, BMI, height, body mass, and habitual caffeine intake was conducted. A very low energy diet intervention during 4 weeks was followed by 3 months of weight maintenance (WM); during the WM period, the subjects received a green tea-caffeine mixture (270 mg epigallocatechin gallate + 150 mg caffeine per day) or placebo. RESULTS: Subjects lost 5.9 +/-1.8 (SD) kg (7.0 +/- 2.1%) of body weight (p < 0.001). At baseline, satiety was positively, and in women, leptin was inversely, related to subjects' habitual caffeine consumption (p < 0.01). High caffeine consumers reduced weight, fat mass, and waist circumference more than low caffeine consumers; resting energy expenditure was reduced less and respiratory quotient was reduced more during weight loss (p < 0.01). In the low caffeine consumers, during WM, green tea still reduced body weight, waist, respiratory quotient and body fat, whereas resting energy expenditure was increased compared with a restoration of these variables with placebo (p < 0.01). In the high caffeine consumers, no effects of the green tea-caffeine mixture were observed during WM. DISCUSSION: High caffeine intake was associated with weight loss through thermogenesis and fat oxidation and with suppressed leptin in women. In habitual low caffeine consumers, the green tea-caffeine mixture improved WM, partly through thermogenesis and fat oxidation

Effects of very low calorie diet induced body weight loss with or without human pegylated recombinant leptin treatment on changes in ghrelin and adiponectin concentrations

The aim of the study was to investigate the effects of energy restriction with or without pegylated recombinant leptin (PEG-leptin) treatment on ghrelin, adiponectin, insulin and glucose concentrations. A randomized double-blind placebo-controlled trial was performed in 24 moderately overweight/obese men. PEG-leptin or placebo was administered weekly for 6 weeks, combined with a restricted energy intake of 2.1 MJ/d. At days 1, 25, and 46 a blood sample was taken and body-weight (BW) was measured. Days 1-25 was named phase 1, and days 25-46 phase 2. During phase 1 the rate of BW loss was significantly higher in the PEG-leptin compared to the placebo group (0.38+/-0.07 vs 0.32+/-0.06 kg/d, p<0.05). The rate of BW loss during phase 2 was 0.24+/-0.08 and 0.18+/-0.09 kg/d, respectively (p=0.07). In both groups the rate of BW loss during phase 1 was significantly higher than during phase 2 (p<0.001). Energy balance (EB) was significantly more negative during phase 1 than during phase 2 in both groups (p<0.0005). During phase 1 insulin, glucose and adiponectin decreased significantly in both groups. Adiponectin and ghrelin concentrations changed in the opposite direction between phase 1 and phase 2 (p<0.05). Initial BW loss due to a considerable negative EB induced decreased ghrelin, adiponectin, insulin and glucose levels. However, when EB became less negative and the rate of BW loss decreased, these changes were reversed for adiponectin and ghrelin. The PEG-leptin injections did not have an effect on the changes in insulin, glucose and adiponectin, but had an effect on the changes in ghrelin concentrations. AD - Department of Human Biology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands

Sex differences in energy homeostatis following a diet relatively high in protein exchanged with carbohydrate, assessed in a respiration chamber in humans

CONTEXT: Obesity prevalence is generally higher in women than in men, and a paucity of research with sex-specific approaches exists. The question arises whether current weight loss programmes, largely developed and tested on women, are appropriate for men. OBJECTIVE: Investigate 24 h energy metabolism, satiety and related hormones during a diet relatively high in protein (HP), exchanged with carbohydrate compared to an adequate-protein (AP) diet, in a respiration chamber in men, in comparison with previous outcomes in women. DESIGN: Ten healthy males (BMI: 22.5+/-1.6 kg/m(2), age: 25+/-3.5 y) were fed in energy balance with an AP (10/60/30% of energy of protein/carbohydrate/fat) or a HP (30/40/30% of energy of protein/carbohydrate/fat) diet in a randomized cross-over design. RESULTS: During the HP diet, 24 h Energy Expenditure (10.5+/-0.5 versus 10.0+/-0.5 MJ/d; p<0.05), Sleeping Energy Expenditure (7.1+/-0.3 vs 6.9+/-0.2 MJ/d;p<0.05), protein balance (0.5+/-0.02 vs 0.0+/-0.01 MJ/d;p<0.05), satiety (AUC) p<0.05, and plasma GLP-1 concentrations (42+/-23 versus 28+/-16 AUC; p<0.005) were significantly higher and 24 hRQ (0.80 vs 0.85;p<0.01), fat balance (-0.85+/-0.03 vs 0.05 vs 0.03 MJ/d;p<0.01) and hunger (AUC) p<0.05, were significantly lower. Comparisons reveal a stronger reaction in men in energy expenditure and substrate oxidation, whereas satiety reacted stronger in the women. CONCLUSIONS: Effects of a diet relatively high in protein exchanged with carbohydrate, versus an adequate protein diet are a stronger increased energy expenditure, fat oxidation, protein anabolism in men, and a stronger increased satiety in women, thereby creating sex-specific conditions for long-term use for body-weight management

Surveillance parasitologique des eaux usées urbaines : recherche des amibes libres potentiellement pathogènes

Les auteurs ont analysé les eaux usées d'une station d'épuration de Brest, sous trois angles : parasitologiques, bactériologiques et physico-chimique. Les constantes physico-chimiques et bactériologiques sont satisfaisantes par contre les amibes libres sont retrouvées à tous les niveaux, sans toutefois d'espèces pathogènes. Leur indépendance à l'égard des autres critères retenus reste à prouver