Serum leptin and total dietary energy intake: the INTERLIPID Study

Purpose

It has been hypothesized that leptin-induced appetite suppression is impaired in obese individuals, but little human evidence is available documenting this. We investigated relations between serum leptin and total energy intake using INTERLIPID/INTERMAP data on Japanese–Americans in Hawaii and Japanese in Japan.

Methods

Serum leptin and nutrient intakes were examined by standardized methods in men and women aged 40–59 years from two population samples, one Japanese–American in Hawaii (88 men, 94 women), the other Japanese in central Japan (123 men, 111 women). Multiple linear regression analyses stratified by BMI category (<25 kg/m², 25–29.9 kg/m², and ≥30 kg/m²) with adjustment for possible confounders were used to examine the relation between log-leptin and total dietary energy intake.

Results

In multivariate regression analyses, in those with BMI < 25 kg/m² and in those with BMI between 25 and 29.9 kg/m², log-leptin was not significantly related to total dietary energy intake; in those with BMI ≥ 30 kg/m², it was significantly inversely related to total dietary energy intake (P = 0.029), independent of body weight and physical activity. Physical activity score was significantly positively related to total dietary energy intake only in participants with BMI < 25 kg/m² (P < 0.001).

Conclusion

Leptin was significantly inversely associated with dietary energy intake in obese persons, but not in overweight and normal-weight persons.     

Serum apolipoprotein A-II as a marker of change in alcohol intake in male drinkers

The relative usefulness of high-density lipoprotein cholesterol (HDL-C) and the HDL components, apolipoproteins A-I and A-II (Apo A-I and Apo A-II), as prospective markers of change in alcohol intake was compared to gamma-glutamyl transferase (gamma GT) and erythrocyte mean corpuscular volume (MCV) in a controlled crossover trial of 46 moderate male drinkers whose alcohol intake was reduced by approximately 80% for six weeks by the substitution of their normal drinking habits for a low alcohol content beer only. Only serum Apo A-II levels correlated significantly with self-reported alcohol intake at the commencement of the study (r = 0.46; P less than 0.001). All five indices fell significantly with reduction of alcohol intake. The change in these indices between normal and low alcohol intake periods correlated directly with change in alcohol intake, the highest correlation being with delta Apo A-II (r = 0.72; P less than 0.001). Using discriminant analysis this variable was found to achieve an accuracy of 96% in classifying subjects into the correct drinking category (either normal or low alcohol intake). The relative percentages for the other variables were delta Apo A-I 78%, delta HDL-C 82%, delta gamma GT 78% and delta MCV 76%. We conclude that Apo A-II may prove a valuable marker of alcohol intake in cross-sectional epidemiological studies, while delta Apo A-II may be a sensitive marker of change in alcohol intake in the prospective management of the heavy drinker.     

No effect of glucagon-like peptide-1 on short-term satiety and energy intake in man

Centrally administered glucagon-like peptide-1 (GLP-1) inhibits feeding in fasted rats, but its role in human satiety has been largely unexplored. The present study investigated the effect of peripheral GLP-1 infusion on gastric emptying and satiety in man. Ten non-obese male subjects were infused in a randomized single-blind within-subject crossover study using saline infusion as control. They received either a GLP-1 infusion (1.2 pmol/kg per min) or a saline infusion for 1 h, at 18.00 hours. At 20 min after starting the infusion the gastric emptying of a 400 ml water load was measured. Subjects completed behavioural self-rating scales to assess hunger and satiety. After 40 min subjects were given a buffet meal ad libitum and their food intake was recorded. GLP-1 infusion raised circulating GLP-1 concentrations to approximately twice those seen following a meal. It did not affect circulating insulin levels but caused a small fall in glucose levels. Gastric emptying of the water load was significantly delayed by the GLP-1 infusion. Energy intake from the buffet was unaffected by GLP-1 infusion. Self-assessment of hunger and satiety was similarly unaffected by the infusion before the buffet meal, although subjects tended to be less hungry after the buffet meal following GLP-1 infusion (P < 0.09). GLP-1 infusion delayed gastric emptying but had a minimal effect on food intake and satiety. This study casts doubts on whether GLP-1 is a major satiety factor in man, although a raised circulating plasma glucose level, as would normally occur postprandially, might be necessary for GLP-1 to increase satiety.     

Failure to reduce short-term appetite following alcohol is independent of beliefs about the presence of alcohol

Previously, it has been reported that energy consumed as alcohol prior to lunch does not result in subsequent reductions in voluntary food intake, and in some situations alcohol can increase subsequent appetite. The present study extends these findings by examining the effects of beliefs about alcohol content. Eighteen unrestrained men ate lunch 20 min after a preload of either water, an alcoholic beer or a non-alcoholic beer matched for energy content. Food intake was significantly less following the non-alcoholic beer than after alcohol or water, but when preload energy was included subjects had a higher overall energy intake on the day they consumed alcohol compared with both water and no-alcohol conditions. There were no significant differences in hunger or fullness ratings following the three drinks before or after the test meal, but the specific relationship between rated hunger and intake within the test meal was altered by the drink manipulation. The rate at which hunger decreased, and fullness increased, was slower after alcohol than after water or no-alcohol. The drinks did not alter the pleasantness of the test meal or increase hunger at the start of eating. When contrasted with previous work, these data confirm that alcohol consumed before lunch fails to reduce subsequent food intake, but also suggests that changes in rated appetite are influenced by beliefs about alcohol content.     

Contribution of energy density and food quantity to short-term fluctuations of energy intake in normal weight and obese subjects

Background  

In normal weight subjects it is known that day-to-day energy intake (EI) can vary substantially while this question has not been examined in obese subjects. From acute feeding experiments one would assume that these perturbations are mainly due to differences in food energy density (ED). However, food quantity (FQ) during single meals, number of meals, cognitive and sensory mechanisms may also contribute to the modification of EI.     

营养不良儿童血清瘦素水平与BMI、能量摄入的相关性分析

【目的】　探讨营养不良儿童血清瘦素水平的变化及其与能量摄入的相关性。　【方法】　检测32例营养不良患儿的空腹血清瘦素水平、体质指数(body mass index,BMI)、能量摄入量,并与32例健康儿童比较,同时分析血清瘦素水平与BMI、能量摄入的相关性。　【结果】　①病例组与对照组间的血清瘦素水平比较有统计学差异(F=4.574,P<0.05),病例组明显降低;②病例组中患儿的血清瘦素水平与BMI、能量摄入均有显著相关性(P<0.05);对照组中血清瘦素水平与BMI存在显著相关性(P<0.05), 但血清瘦素与能量摄入无显著相关性(P>0.05) 。　【结论】　营养不良儿童血清瘦素水平明显降低;其低下的原因,除了患儿脂肪含量下降致瘦素分泌减少外,还与能量摄入的减少有关。     

Changes in the basal metabolic rate of a normal woman induced by short-term and long-term alterations of energy intake

A long-term experiment was carried out to study the effects of alterations in energy intake and meal contents on basal metabolic rate (BMR) of a normal woman. Alterations of energy intake induced changes in BMR and pulse rate in addition to body weight changes. Whether BMR was expressed per whole body, per unit body weight, or per unit body surface area, it increased progressively during long-term overeating periods, and decreased markedly during long-term undereating periods. These results suggest that there exists 'Luxuskonsumption', or adaptive diet-induced thermogenesis, during an overeating period and hypometabolism during an undereating period. BMR was affected significantly by the menstrual cycle but not by nutrient composition when daily energy intake was fixed at 2000 kcal for a long time.     

Gastric leptin: a putative role in the short-term regulation of food intake

The discovery of the production of leptin by the stomach, in addition to its production by adipose tissue, has initiated new investigation into the possible role of this protein in the digestive physiology, in particular in the short-term control of energy balance. Leptin has been identified in the lower half of the stomach glands both in the pepsinogen granules of chief cells and in the granules of a specific endocrine cell type, suggesting that leptin action is exerted by both exocrine and endocrine pathways. Gastric leptin is sensitive to the nutritional state, being rapidly mobilized in response to food intake following fasting, or after the administration of satiety factors; this suggests a role for this protein in the short-term regulation of feeding, acting in collaboration with satiety peptides such as cholecystokinin. Leptin, produced by gastric cells and by adipocytes, could act on both acute and chronic regulation of feeding behaviour respectively, giving information to the brain on the availability of external (food) and internal (fat depots) energy resources, thus participating in short- and long-term satiation.     

Effect of short-duration physical activity and ventilation threshold on subjective appetite and short-term energy intake in boys

The purpose of this investigation was twofold: (1) to examine the role of low- to moderate-intensity, short-duration physical activity on subjective appetite and (2) to identify the role of and associations between ventilation threshold (VeT) and energy intake at a pizza lunch 30 min after glucose and whey protein drinks in normal weight boys. In 14 boys (age: 12.5+/-0.4 years) subjective appetite was measured before and after a 12 min walking protocol designed to determine physical fitness based on the VeT. On a separate occasion food intake (FI) and subjective appetite were measured in response to sweetened preloads of either a SPLENDA Sucralose control, glucose or whey protein made up to 250 ml with water, given in random order to each boy, 2h after a standardized breakfast. Subjective average appetite and prospective food consumption scores increased after physical activity. VeT was positively associated with FI at a pizza lunch consumed 30 min after glucose and whey protein drinks. Glucose and whey protein reduced FI similarly at lunch compared with control. In conclusion, appetite is increased by low- to moderate-intensity, short-duration physical activity and FI following glucose and protein preloads is positively associated with fitness levels in boys.     

Effects of short-term overfeeding on hunger, satiety, and energy intake in thin and reduced-obese individuals

BACKGROUND: Certain individuals appear to be resistant to weight gain in an obesigenic environment, yet the mechanisms for this adaptation are unclear. These individuals may sense positive energy balance more appropriately than those individuals prone to weight gain. RESEARCH METHODS AND PROCEDURES: Thirteen thin (7 women, 6 men) and 9 reduced-obese (5 women, 4 men) individuals were studied. Measures of intake were obtained using visual analog scales before and after each meal during eucaloric feeding and during three days of 50% overfeeding. Ad libitum energy intake was measured post-overfeeding. RESULTS: Overfeeding resulted in a significant reduction in pre-meal hunger in the thin (68+/-6 to 41+/-6 mm, p<0.0001) compared to the reduced-obese individuals (63+/-7 to 65+/-7 mm, p=0.67). There was a significantly greater increase (p=0.0016) in post-meal satiety scores during overfeeding in the thin (65+/-4 to 88+/-4 mm, p<0.0001) compared to the reduced-obese individuals (72+/-5 to 80+/-5 mm, p=0.04). Thin women had a 30% reduction in daily energy intake (1831+/-47 to 1273+/-79 kcal/day, p=0.005) after overfeeding while no difference was seen in the thin men or reduced-obese group. DISCUSSION: Thin individuals appear to sense positive energy balance more appropriately with changes in measures of intake than reduced-obese individuals. These findings are especially true in thin women.     

An intervention study targeting energy and nutrient intake in worksite cafeterias

Modifying the food environment is a promising strategy for promoting healthier eating behavior. This study aimed to evaluate nutritional and weight changes in a program that used worksite cafeterias to reduce employees’ calorie content of purchased foods and improve their macronutrient intake. Participants were randomly assigned to one of two conditions: 1) only environmental change (i.e., the introduction of 10 new low-energy-density (ED) foods and provision of labels for all foods sold at lunch, which listed ED, calories, and macronutrient content) or 2) the environmental change plus pricing incentives for purchasing low-ED foods and education about low-ED eating delivered in four, 1-hour group sessions. Participant lunch choices were monitored electronically at the point of purchase for 3 months before the intervention was instituted (i.e., the baseline period) and for 3 months afterward (i.e., intervention period). Participants were adults (n = 96, BMI = 29.7 ± 6.0 kg/m²) who regularly ate lunch at their workplace cafeteria. There was no difference between groups in total energy intake over the study period. Across groups, energy and percent of energy from fat decreased and percent of energy from carbohydrate increased from baseline to the intervention period (all p < .01). Follow-up analyses, conducted by averaging Baseline Months 1 and 2 and comparing them to Intervention Month 3 as a conservative estimate of overall impact of the intervention, indicated that change in energy, carbohydrate, and fat intake remained significant (p < .001). Providing nutrition labels and reducing the ED of selected foods was associated with improved dietary intake.     

Energy expenditure, energy intake, and weight loss in Alzheimer disease

Alzheimer disease is one of the leading causes of death among older individuals. Unexplained weight loss and cachexia are frequent clinical findings in patients with Alzheimer disease. Thus, it has been postulated that Alzheimer disease may be associated with dysfunction in body weight regulation. This brief review examines the interrelations among energy intake, energy expenditure, and body composition in Alzheimer disease. We explored whether abnormally high daily energy expenditures, low energy intakes, or both contribute to unexplained weight loss and a decline in nutritional status. Specifically, we considered studies that examined energy intake, body composition, and daily energy expenditure and its components. The application of doubly labeled water and indirect calorimetry to understand the etiology of wasting has increased our knowledge regarding the relation among energy expenditure, physical activity levels, and body composition in Alzheimer disease patients. Although the number of studies are limited, results do not support the notion that a hypermetabolic state contributes to unexplained weight loss in Alzheimer disease, even in cachectic patients. Recent findings are presented suggesting an association between abnormally elevated levels of physical activity energy expenditure and elevated appendicular skeletal muscle mass and energy intake in Alzheimer disease patients. Clinical strategies aimed at developing lifestyle and dietary interventions to maintain adequate energy intake, restore energy balance, and maintain skeletal muscle mass should be a future area of investigation in Alzheimer disease research.     

Modulatory factors in the effect of energy density on energy intake

The effect of energy density (ED) on energy intake (EI) has been assessed in short-term and long-term experiments. In the short term, it was found that ED affects EI directly in situations when the subjects cannot estimate the ED of the food; then subjects mainly monitor the weight of the food ingested. In the long term, the effects of ED on EI are modulated. Average daily EI appears to be related to ED of the food and drinks when ED is determined by specific macronutrients, but not when ED is only determined by the weight of water. Thus, the short-term effect ED has on EI cannot be extrapolated to the long term, because a possible dominating effect of the weight of water determining ED undoes the relationship of ED with EI. Moreover, in the long-term portion sizes are used to compensate for correctly estimated ED, resulting in less variation in EI than ED alone would imply. Finally, dietary restraint compensates for the effect of a relatively high ED on daily EI, whereas dietary unrestraint compensates for the effect of relatively low ED on daily EI. We conclude that the short-term effect of ED on EI is modulated by the effect of water on ED, and compensated for by the effect of dietary restraint and adapted portion sizes.     

Feeding problems in children with congenital heart disease: the impact on energy intake and growth outcome.

Cross-sectional data on growth outcome, upper-arm measurements and energy intake have been analysed according to the presence or absence of early feeding problems and poor appetite in 40 children (0.9-13 years) with congenital heart disease (CHD). At the time of study, refusal to eat or poor appetite was reported as a significant problem in 19 children and subnormal height and/or weight were recorded in 11 children. The children ate considerably less calories than recommended for healthy children. The cross-sectional analyses showed that children with poor appetite had significantly (P less than 0.05 and P less than 0.01) lower outcome values of growth and upper-arm measurements than their disabled counterparts with no feeding problems and good appetite. Children with feeding problems also tended to eat less than children without feeding problems. For most parents (65%) feeding of infants and children with CHD involves difficulties, time and anxiety. This study has shown that the parents' experience about feeding problems may be a good predictor for low growth outcome and low voluntary food intake of the child. Whenever feeding problems are reported, nutritional intervention should be offered in order to increase the caloric intake of the child and to develop a sound feeding relationship in the family.     

Phylloquinone intake as a marker for coronary heart disease risk but not stroke in women

OBJECTIVE: To examine the feasibility of using phylloquinone intake as a marker for coronary heart disease (CHD) and stroke risk in women. DESIGN AND SETTING: Nurses' Health Study, a prospective cohort study during 1984-2000. Dietary data were collected in 1984, 1986, 1990, and 1994 using a validated semiquantitative food frequency questionnaire. SUBJECTS: A total of 72 874 female nurses, aged 38-65 y, without previously diagnosed angina, myocardial infarction (MI), stroke, or cancer at baseline. MAIN OUTCOME MEASURES: Incidence of nonfatal MI, CHD deaths, total CHD events, ischemic, and total strokes. RESULTS: There were 1679 CHD events (1201 nonfatal) and 1009 strokes (567 ischemic). After adjustment for age and lifestyle factors associated with cardiovascular disease risk, the multivariate relative risks (RR) (95% CI) of total CHD from the lowest to the highest quintile category of phylloquinone intake were 1 (reference), 0.80 (0.69-0.94), 0.86 (0.74-1.00), 0.77 (0.66-0.99), and 0.79 (0.68-0.92), P for trend=0.01. Further adjustment for dietary intakes of saturated fat, polyunsaturated fat, trans fatty acids, eicosapentaenoic, and docosahexaenoic acids, cereal fiber, and folate attenuated the association (RR comparing extreme quintiles 0.84 [0.71-1.00], P for trend=0.12). Incidence rates of total or ischemic strokes were not associated with phylloquinone intake. CONCLUSION: The data suggest that high phylloquinone intake may be a marker for low CHD risk. Dietary and lifestyle patterns associated with phylloquinone intakes, rather than intake of the nutrient itself, might account for all or part of the weak association. .