Overconsumption and obesity: peptides and susceptibility to weight gain.

Physiological control of feeding is mediated by tonic and episodic signalling systems. These are sometimes thought of as long-term and short-term control. Tonic signals arise from tissue stores whereas episodic signals oscillate periodically with the consumption of food. These physiological controls are paralleled in the motivation to eat by long-acting enduring traits (such as disinhibition) and by short-acting states (such as hunger). Peptides are usually envisaged to exert an action on appetite control through the modulation of states such as hunger and satiety (fullness). Here we provide evidence that peptides involved in tonic regulation--such as leptin--may express a control over appetite motivation through an effect on traits that confer a constant readiness to eat, whereas episodic peptides such as GLP-1 influence appetite motivation through a state such as hunger. The distinction between tonic and episodic regulation, and between traits and states has implications for understanding overconsumption and the susceptibility to weight gain.

Characterization of obese individuals who claim to detect no relationship between their eating pattern and sensations of hunger or fullness.

OBJECTIVE: To study the phenomenon that obese subjects show considerable individual variability in their reported relationships between eating and sensations of hunger and fullness. DESIGN: A laboratory study of the relationship between eating behaviour traits and the episodic oscillations in sensations of hunger and fullness in response to obligatory, fixed energy breakfast (481 kcal) and lunch (675 kcal) meals. SUBJECTS: Obese subjects were divided into two groups based on their responses to four 'screening' questions associated with their habitual experience of hunger and fullness sensations before and after eating: those who experienced sensations of hunger and fullness related to eating (Related-R; n=20, body mass index (BMI)=42.4 kg/m(2)) and those for whom eating was not related to hunger or fullness sensations (Unrelated - UR; n=19, BMI=41.3 kg/m(2)). In addition, a control, lean group (Control - C; n=14, BMI=22.6 kg/m(2)) who experienced sensations of hunger and fullness related to eating was studied. MEASUREMENTS: The Three-Factor Eating Questionnaire (TFEQ) was used to measure the eating behaviour traits, disinhibition, restraint and hunger. Profiles of subjective appetite sensations were continuously monitored across the day using visual analogue scales. RESULTS: All groups displayed clear meal-related oscillations in subjective sensations of hunger, fullness, desire to eat and prospective consumption. In contrast, the TFEQ disinhibition and hunger scores (but not restraint scores) were significantly different (P<0.05) between the groups ((UR; D=13.5+/-0.5, H=10.0+/-0.5), R (D 7.5+/-0.6, H 6.1+/-0.4), C(D 3.7+/-0.5, H 3.7+/-0.5)). In addition, analysis of the intra-meal changes in subjective appetite sensations revealed that the UR group displayed a smaller meal-induced suppression of hunger and elevation of fullness. CONCLUSION: These data indicate that the reported relationship between eating and hunger/fullness was associated with obese individuals showing high or low disinhibition scores. In addition, the data suggest that the processes underlying disinhibition may be associated with a modulation of the recognition of meal-related satiety sensations.

Eating habits in relation to body fatness and gender in adolescents--results from the 'SWEDES' study.

OBJECTIVE: To investigate if eating habits among adolescents are related to body fatness and gender. DESIGN: Cross-sectional study. SETTING: Obesity Unit, Huddinge University Hospital, Sweden, 2001-2002. SUBJECTS: Two hundred and seventy-five girls and 199 boys, aged 16-17 years. METHOD: Questionnaires were used for dietary intake and meal frequency, BodPod for measuring body fatness (BF%). In all, 169 girls and 128 boys were classified as adequate reporters (AR) of energy intake, and were used in the dietary analyses. The whole sample was used in the meal frequency analyses. RESULTS: The correlation between reported energy intake and weight in the AR group was 0.23 (P<0.01) for girls and 0.36 for boys (P<0.001). The correlations were inverse or not significant in the whole sample. The following variables correlated significantly with a high BF% (r (s)=+/-0.2): a low intake of milk in both girls and boys, a high intake of fibre and alcohol and a low intake of sugar in girls and a low intake of breakfast cereals in boys. Those with regular breakfast habits had healthier food choices than others, but this was not related to BF%. Boys had more meals per day (4.9 vs 4.6, P=0.02), especially early in the morning and late at night, whereas girls reported a higher relative intake of light meals and fruit and a lower intake of milk than boys. CONCLUSIONS: A few associations between eating habits and body fatness were found, but without any obvious patterns. The true differences in eating habits between lean and overweight adolescents are probably very small.

A comparison of effects of fish and beef protein on satiety in normal weight men.

BACKGROUND: Previous studies have indicated that fish protein may have a greater effect on satiety compared to other protein sources of animal origin. OBJECTIVE: To compare the effects of fish protein and beef protein meals on hunger and satiety. DESIGN: Twenty-three normal non-smoking, healthy males aged 20-32 years, body mass index 22.5+/-1.8 (s.d.) kg/m(2) participated in a study, with within-subjects design and 1 week between test days. In the morning of the test days, subjects received a standardized breakfast. Four hours after breakfast, subjects were served an iso-energetic protein-rich (40 energy % protein) lunch meal, consisting of either a fish protein dish or a beef protein dish. Four hours after the start of the lunch meals, an ad libitum standardized evening meal was served and the intake of food was measured. Appetite was rated by visual analogue scales (VAS) immediately before and after the meals, as well as every hour between the meals. After the evening meal until bedtime, subjects were asked to record in detail foods and drinks consumed. RESULTS: The repeated VAS-ratings of hunger, satiety and prospective consumption were modelled in a random effects model, taking pre-lunch VAS-ratings into account. After the fish meal, the point estimates were lower for hunger (-2+/-4.8), higher for satiety (8.7+/-6.0) and lower for prospective consumption (-4.9+/-4.7), but they did not reach statistical significance (P satiety=0.88; P hunger=0.15; P prospective=0.30). However, the energy intake at the evening meal displayed significant differences with subjects eating less after the fish protein lunch (2765 vs 3080 KJ, P<0.01) without feeling less satiated. No later energy compensation after the evening meal was found on the test day. CONCLUSION: Although no significant differences in VAS-ratings of satiety or hunger were detected, subjects displayed an 11% reduction in energy intake at the subsequent evening meal.

Discrepancies between classification systems of childhood obesity.

Despite growing concern about weight-related problems among children, no universally accepted classification system for childhood obesity exists. There is a number of proposed international body mass index (BMI)-based systems in use and national variants also exist in many countries. The absence of a universally accepted standard and confusion concerning which classification system to use on national levels complicate monitoring of the development of the obesity epidemic, stratification for selective interventions in public health, screening in clinical practice and comparisons between studies. Some proposed international classification systems have not only been recommended for global monitoring and comparisons between studies, but also for clinical and national epidemiological use in some countries. Possible discrepancies may thereby lead to inefficiencies in health care delivery and prevention programmes. The problems associated with misclassification of individuals at risk may lead to overconsumption of health care resources by lower-risk individuals and underconsumption by higher-risk individuals, which is costly both in terms of foregone health improvements and in terms of wasteful monetary usage. The aim of this paper was to review the specific problems associated with BMI as a measure of adiposity in childhood, the most commonly used classification systems for childhood obesity based on BMI, and how their performance can be evaluated.

Weight development over time in parous women--the SPAWN study--15 years follow-up.

BACKGROUND: Weight gain is common after pregnancy. Most studies suggest that weight gain associated with a pregnancy is between 0.5 and 3.8 kg up to 2.5 y of follow-up. However, 73% of the female patients at our obesity clinic identified pregnancy as an important trigger for marked weight retention. The majority retained more than 10 kg after each pregnancy. The aim of this study was to examine long-term weight development after pregnancy in a 15 y follow-up of women who took part in the Stockholm Pregnancy And Women's Nutrition (SPAWN) study. METHOD AND SUBJECTS: The SPAWN study is a long-term follow-up study of women who delivered children in 1984-85 in Stockholm (n=2342). A total of 1423 participants (response rate=61%) completed questionnaires, which covered eating behaviour and exercise, demographic information including social situation and status and details of the pregnancy before, during and up to 1 y after pregnancy. After 15 y, these women were invited to take part in the follow-up study. Anthropometric measurements and the same questionnaire data were collected from the 563 women who participated (response rate=40%). The sample was divided into two main groups: those who were normal weight before pregnancy and remained normal weight, and those who were normal weight before pregnancy and had become overweight at 15 y follow-up. RESULTS: Those women who became overweight had a higher pre-pregnant body mass index (BMI) (22.3+/-1.5 vs 20.5+/-1.6 kg/m(2), P<0.001), gained more weight during pregnancy (16.3+/-4.3 vs 13.6+/-3.7 kg, P<0.001) and had retained more at 1 y follow-up. The women who became overweight had a steeper weight trajectory gaining more from 1 y follow-up to 15 y follow-up (11.1+/-6.5 vs 4.5+/-6.5 kg, P<0.001), with a higher BMI at 15 y follow-up of 27.5+/-2.6 vs 22.5+/-2.3 5 kg/m(2) (P<0.001). However, differences between those who became overweight and those who did not could not be explained by age, number of children and various socioeconomic factors. Features of pregnancy that did differ between the two groups were breastfeeding and smoking cessation. However, women who became overweight had lower lactation scores than women who remained normal weight. Relatively more subjects of the group that became overweight stopped smoking during pregnancy. DISCUSSION: Pregnancy is a vulnerability factor for some women to become overweight. This study attempted to identify those factors that place initially normal weight women on a steeper weight trajectory as a result of pregnancy. Demographic, behavioural, physical and psychological characteristics only partly explain the weight gain observed at 15 y follow-up. Further research is required to investigate the relative role of these characteristics in predicting postpregnancy weight development.

Short-term effects of sibutramine (Reductil) on appetite and eating behaviour and the long-term therapeutic outcome.

OBJECTIVE: To evaluate the short-term effects of sibutramine on appetite and eating behaviour and whether these effects are related to the long-term therapeutic outcome. STUDY DESIGN: Short-term: randomised, double-blind, placebo-controlled, within-subject design. Long-term: prospective open clinical trial. SUBJECTS: A total of 36 obese (nine men/27 women) with a body mass index of 39.3+/-4.3 (mean+/-s.d.) (range 30.2 - 45.2) kg/m(2) and age 44.4+/-12.1 y. PROCEDURE AND METHODS:: First phase-short-term effects: At baseline, the subjects were treated for 14 days with 15 mg sibutramine/placebo (period 1) followed by a 2 weeks single-blind placebo washout period, the subjects received the alternative therapy for another 14 days (period 2). At baseline, and at day 14 in each treatment period the subjects arrived fasting to the laboratory for a standardised breakfast and an ad libitum standardised lunch using the VIKTOR set-up (a universal eating monitor) to evaluate the microstructure of the eating behaviour (ie amount of food consumed and eating rate). Visual Analogue Scales were applied before and after the meals as well as every hour between the meals to monitor the appetite. During this first phase, subjects were encouraged to keep their habitual eating habits. Second phase-long-term effects: All subjects received 10 months open treatment with 15 mg sibutramine and dietary advice in monthly group sessions with a dietitian. On the last day of this treatment period, the subjects returned to repeat the measurements of appetite and eating behaviour using the same test procedure as during the first phase of the study. RESULTS: First phase: Sibutramine influenced appetite and eating behaviour that could be registered after only 14 days of treatment. The amount of food consumed at lunch on VIKTOR was reduced by 16% by sibutramine compared to placebo, 335+/-123 g vs 399+/-126 g (P<0.0001). Second phase: Responders and nonresponders were defined as those who ate less vs more food on VIKTOR when treated with sibutramine compared to the baseline food intake in the first phase of the study. The weight reduction was greater for responders 11.8+/-6.2 (mean+/-s.d.) kg compared to nonresponders 6.8+/-2.7 (mean+/-s.d.) kg (P<0.05). CONCLUSION: Short-term effects of sibutramine on appetite and eating behaviour were identified such as a reduction in food intake and in ratings of subjective motivation to eat. Short-term sibutramine effects on eating behaviour are to some extent related to the long-term therapeutic outcome in obese subjects.

Effects of glucocorticoids on leptin levels and eating behaviour in women.

OBJECTIVE: Long-term treatment with glucocorticoids induces weight gain and increased risk to develop obesity-related metabolic complications. The underlying mechanisms are not fully understood. Glucocorticoid therapy has previously been associated with increased levels of circulating leptin. In this study the eating behaviour was therefore studied in relation to leptin levels before and after short-term prednisolone treatment. DESIGN: Within-subject design. SUBJECTS: Twelve healthy postmenopausal women with a mean body mass index (BMI) of 28.9 kg m-2 (+/-0.8 SEM) volunteered after recruitment by an advertisement in the local paper. INTERVENTIONS: The subjects received 25 mg prednisolone daily for 7 days. MAIN OUTCOME MEASUREMENTS: Fasting serum samples were obtained before, during and after treatment for determination of leptin and insulin, glucose and fractionated lipoproteins in plasma. The microstructure of the eating behaviour was registered with a universal eating monitor, VIKTOR. Appetite was estimated by visual analogue rating scales and food intake by a 48-h recall. RESULTS: Serum leptin increased after 2 and 7 days of glucocorticoid administration (P < 0.01), and the food intake measured by VIKTOR after 7 days of treatment (P < 0.05). No statistically significant changes were however, found in the 48-h food- recall or in the subjective appetite registrations. Insulin levels were borderline elevated (P = 0.062) after treatment, but no significant changes of fasting glucose were seen. High density lipoprotein cholesterol (HDL) increased (P < 0.05), whilst low density lipoprotein cholesterol (LDL) decreased (P < 0.05). CONCLUSION: Food intake was elevated after glucocorticoid administration as observed with an objective, quantitative method, in spite of increased levels of circulating leptin.

Intake of sweet foods and counts of cariogenic microorganisms in relation to body mass index and psychometric variables in women.

OBJECTIVE: As a part of the SPAWN (Stockholm Pregnancy and Women's Nutrition) study, the intake of sweet foods (habitual and pre-menstrual intakes) and the number of cariogenic microorganisms in saliva was analysed in relation to body mass index (BMI) and psychometric variables. DESIGN: A cross-sectional study. SUBJECTS: Three hundred and sixty-two women with a median BMI of 24.2 kg/m(2) (range 17.5-47.8) and 45 y of age (range 34-64). METHODS: A questionnaire of sweet food intake, salivary counts of mutans streptococci and lactobacilli and a self-rating scale on psychometric variables (CPRS-S-A). RESULTS: The number of mutans streptococci correlated with BMI (P<0.05), indirectly indicating a higher intake of sweet foods in obese women. The reported energy intake of sweet foods (more specifically the intake of chocolate), correlated with CPRS scores (P<0.01), indicating that women with more severe psychiatric symptomatology have higher intakes of sweet foods. CONCLUSIONS: This study suggests that women with higher CPRS score have higher energy intakes of sweet foods, indicating a possible link between mood regulation and the intake of sweet food. SPONSORSHIP: Karolinska Institute Research Funds.

Long-term weight development after pregnancy.

For some women pregnancy is a trigger for developing overweight and obesity. Seventy-three per cent of 128 female patients at our Obesity Unit indicated that they had retained more than 10 kg after each of their pregnancies, and for this subgroup weight development after pregnancy was of crucial importance for their future health. Although mean weight increases after pregnancy generally are modest, there are wide individual variations. In studies at the Obesity Unit, weight retention ranging from up to 26.5 kg one year after pregnancy to a loss of 12.3 kg was reported, although the mean weight gained was only 0.5 kg. Numerous studies have analysed factors explaining weight development after pregnancy and delivery, with a range of subjects from several hundred thousand women to fewer than one-hundred, but overall it has been surprisingly difficult to identify strong predictors of weight development. Numerous confounders have been identified; in a review up to 31 such confounders were reported. Methodological problems include weight development over time also in non-pregnant women and problems of identifying the optimal time-point when the overall impact of the pregnancy on weight development should be evaluated. Lactation has consistently been found to play a small role in explaining weight retention up to one year after delivery. Few studies have examined the role of physical activity during pregnancy and after delivery to explain weight development. Our own ongoing follow-up of women who gave birth during 1984-85, the so-called SPAWN (Stockholm Pregnancy and Women's Nutrition) study, illustrates that 15 years after delivery, a significant proportion of the 1423 women initially studied were available for re-examination. Drop-out analyses indicate that for most variables under study, the remaining women were representative for the initial sample. Pregnancy and weight development are intertwined in a complex pattern, which includes a change in lifestyle factors, such as eating behaviour, physical activity, smoking cessation and degree of lactation, but which are still not fully understood.

Intake of sweet foods and counts of cariogenic microorganisms in obese and normal-weight women.

OBJECTIVE: To study the intake of sweet foods in obese and normal-weight women, while also taking menstrual cycle effects on eating behaviour into consideration. An objective test of the intake of sugar-containing foods was introduced by measuring salivary counts of mutans streptococci and lactobacilli. DESIGN: A cross-sectional comparison of the intake of sweet foods in obese and normal-weight women. The obese women were also studied longitudinally after 10 weeks in a weight reduction programme. SUBJECTS: Obese (n=72, body mass index (BMI) 42.0+/-5.2 kg/m2) and normal-weight women (n=67, BMI 22.2+/-1.6 kg/m2) participated. RESULTS: Mutans streptococci in saliva were higher in obese than in normal-weight women (P<0.0001), although the reported habitual daily intake of sweet foods did not differ. Of the menstruating women, 80% of the obese subjects and 62% of the normal-weight ones (P<0.05) reported periods during the menstrual cycle with an 'extra large' intake of sweet foods; these intakes were higher in obese than in normal-weight women (P<0.01). The obese women reduced their intake of sweet foods after 10 weeks of weight reduction, although these changes were not pronounced enough to significantly affect the counts of cariogenic microorganisms. CONCLUSIONS: In contrast to most previous cross-sectional studies, this study shows that obese women have a higher intake of sweet foods, especially pre-menstrually. This was indicated by higher salivary counts of cariogenic microorganisms. SPONSORSHIP: Karolinska Institute Research Funds.

Eating behavior in Prader-Willi syndrome, normal weight, and obese control groups.

OBJECTIVE: Hyperphagia in Prader-Willi syndrome (PWS) is hypothesized to be due to hypothalamic dysfunction; thus the study of individuals with PWS might illustrate how hypothalamic dysfunction affects eating behavior. The aim of this study was to document the microstructure of the eating behavior in patients with PWS and to compare it with that of members of obese and normal weight control groups of the same age. STUDY DESIGN: Nine subjects with PWS (age, 10 +/- 4 years), 20 normal weight subjects (age, 12 +/- 3 years), and 20 obese subjects (age, 12 +/- 4 years) were served an excess lunch meal (hash) on a hidden scale built into a table and connected to a computer. The plate of food is placed on top of the scale, and when the food is eaten, the change in food weight is registered continuously. An eating curve is displayed online. After the meal, the eating data are fitted to a polynomial, and the computer calculates the amount of food eaten, time of consumption, eating rate (initial and total), and rate of deceleration. RESULTS: Subjects with PWS were found to have a longer duration of eating (P =.04) and a slower initial eating rate (P =. 01) compared with members of both obese and normal weight groups. In subjects with PWS, 56% of the eating curves were non-decelerating (linear or accelerating) compared with 10% of the normal weight group and 30% of the obese group (P =.02). CONCLUSION: The microstructure of the eating behavior in subjects with PWS differs from that of members of obese and normal weight control groups. Thus the eating behavior found in subjects with PWS might be due to decreased satiation rather than increased hunger.

Energy intake and appetite are suppressed by glucagon-like peptide-1 (GLP-1) in obese men.

BACKGROUND: Peripheral administration of glucagon-like peptide-1 (GLP-1) for four hours, to normal weight and obese humans, decreases food intake and suppresses appetite. OBJECTIVE: The aim of this study was to assess the effect of an eight hour infusion of GLP-1 on appetite and energy intake at lunch and dinner in obese subjects. DESIGN: Randomised, blinded cross-over design with intravenous infusion of GLP-1 (0.75 pmol x kg(-1) min(-1)) or saline. SUBJECTS: Eight obese (body mass index, BMI, 45.5 +/- 2.3 kg/m2) male subjects. MEASUREMENTS: Ad libitum energy intake at lunch (12.00 h) and dinner (16.00 h) after an energy fixed breakfast (2.4 MJ) at 08.00 h. Appetite sensations using visual analogue scales, (VAS) immediately before and after meals and hourly in-between. Blood samples for the analysis of glucose, insulin, C-peptide, GLP-1 and peptide YY. Gastric emptying after breakfast and lunch using a paracetamol absorption technique. RESULTS: Hunger ratings were significantly lower with GLP-1 infusion. The summed ad libitum energy intake at lunch and dinner was reduced by 1.7 +/- 0.5 MJ (21 +/- 6%) by GLP-1 infusion (P = 0.01). Gastric emptying was delayed by GLP-1 infusion, and plasma glucose concentrations decreased (baseline: 6.6 +/- 0.35 mmol/L; nadir: 5.3 +/- 0.15 mmol/L). No nausea was recorded during GLP-1 infusion. CONCLUSIONS: Our results demonstrate that GLP-1 decreases feelings of hunger and reduces energy intake in obese humans. One possible mechanism for this finding might be an increased satiety primarily mediated by gastric vagal afferent signals.

Changes in patients' eating behavior: in the uremic state, on continuous ambulatory peritoneal dialysis treatment, and after transplantation.

Nineteen predialysis patients (group A) were studied before and after 3 to 6 months on continuous ambulatory peritoneal dialysis (CAPD) treatment. Six patients (group B) were studied during CAPD treatment and 3 to 6 months after transplantation. Nine uremic patients (group C) were studied before and 3 to 6 months after transplantation. The patients were invited to a single test meal by means of the universal eating monitor VIKTOR. An excess portion of hash was served on a plate placed on a hidden scale that was connected to a computer registering the eating process on line. The patients filled out visual analogue scales concerning appetite and food preferences before and after the test meal. The feeling of fullness before meals was greater in patients on CAPD than in patients in the predialytic state. Transplanted patients felt less full before meals compared with their ratings during the dialysis period. The median total intake of food was lower during dialysis than after transplantation. The palatability of the food was rated lower during dialysis compared with the ratings in the uremic state. Poor appetite and low intake during dialysis is still a problem, but improves after transplantation.

Effects of weight loss on single meal eating behaviour in obese subjects.

In 22 obese patients the eating pattern during a single meal as evaluated by the universal eating monitor VIKTOR was assessed after one year of treatment, initially with VLCD (Nutrilett) followed by combined long term diet, exercise and behavioural modification, underscoring the importance of appropriate meal habits. A mean weight loss from 117 to 101 kg was achieved. Before treatment a decelerated eating curve was found; after treatment this curve changed significantly towards a flatter and more linear shape.

Methodological studies on single meal food intake characteristics in normal weight and obese men and women.

METHOD: The eating behaviour of 19 normal weight males, 19 obese males, 19 normal weight females and 19 obese females was measured by means of VIKTOR, our version of the universal eating monitor. The total food intake, the duration of consumption, the rate of consumption, the relative rate of consumption and the subjective motivation to eat were measured during five homogenous lunch meals to analyse how these variables were related to body weight or to sex. Furthermore, the stability of the eating characteristics over the five eating occasions were tested with pre-defined criteria of stability. The predictive validity of the variables measuring subjective motivation to eat and forthcoming food intake was also tested. RESULTS: Men ate more food than women; normal weight men by eating for a longer time and obese men by eating faster. Females did not slow down the eating rate towards the end of the meals as much as males did. The obese subjects described themselves as having less motivation to eat prior to meals than normal weight subjects. CONCLUSIONS: Total stability, i.e. both relative and absolute stability, for all subjects was present for the eating variables intake of food and eating rate. Of the variables measuring subjective motivation to eat (desire to eat, hunger, fullness and prospective consumption) on visual analogue scales, only the variables desire to eat and prospective consumption predicted forthcoming food intake.

Intravenous enterostatin does not affect single meal food intake in man.

Enterostatin, a pentapeptide released with colipase from pancreatic procolipase in man, affects eating behaviour in animals. We report the first phase II study of intravenous (i.v.) enterostatin (D3800) in obese but otherwise healthy men. Eighteen men (mean age 37 years, mean body mass index 34.9 kg/m2) completed a double-blind, randomized, crossover placebo controlled trial. After in initial session, each man received i.v. 4 mg D3800, 16 mg D3800 or placebo in random order over three sessions, immediately before a test meal served on a universal eating monitor. No statistically significant effect of i.v. enterostatin on any uptake or rating variable was observed. Several factors may explain the lack of effect, e.g. the inability of i.v. enterostatin to reach a site of action, the time between i.v. administration and eating, and the possibility that the only human responders are those who express particular fat preferences.

Eating behavior in continuous ambulatory peritoneal dialysis and hemodialysis patients.

Three groups consisting of 12 subjects each (continuous ambulatory peritoneal dialysis [CAPD] patients, hemodialysis patients, and healthy controls) matched for age, sex, and body weight were invited to a test meal for the study of hunger, fullness, and food preferences. They were served an excess portion of hash served on a plate placed on a hidden scale ("VIKTOR"), which was connected to a computer registering the eating process on-line. The patients filled in visual analogue scales (VAS) concerning appetite and food preferences before and after the test meal. Mean total intake of food (+/- SD) was significantly higher for healthy controls (357 +/- 175 g) compared with hemodialysis patients (295 +/- 105 g), which in turn was higher than in CAPD patients (206 +/- 70 g). Eating velocity was lower in both dialysis groups compared with controls. CAPD patients experienced less hunger and desire to eat compared with hemodialysis patients and controls. The reason for the low eating drive in CAPD patients despite their great need for protein and calories is unknown, but might be explained by gastric retention, insufficient dialysis, metabolic effects of the high sugar load from the dialysate, or combinations of these factors.

Eating behaviour in obese and normal weight 11-year-old children.

The eating behaviour of 23 normal weight and 20 obese 11-year-old children was measured by the computerized eating monitor VIKTOR. The total intake of food, duration of consumption, rate of consumption and the relative rate of consumption were measured during two lunch meals. Subjective motivation to eat and food preferences were also measured. The obese children ate faster (P less than 0.05) and did not slow down their eating rate towards the end of the meal (P less than 0.05) as much as normal weight children. The obese children also described themselves as having less motivation to eat before lunch than normal weight children (P less than 0.05). A deficient satiety signal or an impared response to such signals in obese subjects could possibly explain these differences found.