Comparison of gastric emptying of a solid and a liquid nutritional rehabilitation food

OBJECTIVE: To compare gastric emptying of a solid and a liquid nutritional rehabilitation food. DESIGN: Cross-over trial. Eight volunteers took, in random order at least 1 week apart, 2100 kJ of a solid and a liquid nutritional rehabilitation food with added labelled [13C] glycine. SETTING: Research ward for healthy volunteers. SUBJECTS: Eight healthy volunteers. METHODS: Appearance of 13CO2 was monitored in expired gas every 15 min for 240 min after meal intake and compared between solid and liquid meals. Parameters of gastric emptying were then calculated. RESULTS: Gastric half-emptying time was slightly longer for solid meal compared to liquid meal (101+/-6.0 vs 88+/-9.8 min, P=0.24). 13CO2 excretion peaked 138+/-5.3 min after the solid meal compared with 119+/-8.6 min with liquid meal (P=0.06). 13CO2 excretion was higher for the liquid food up to 110 min after the meal but then became higher for the solid food. Analysis of variance for repeated measures of 13CO2 excretion showed a significant interaction term between the type of food and time indicating a delayed elimination of 13CO2 for the solid food (P=0.018). CONCLUSIONS: Attempts to replace liquid nutritional rehabilitation foods by a solid food in malnourished patients should take into account a possible slower gastric emptying. SPONSORSHIP: Supported by a grant from Nutriset (Malaunay, France) and ANVAR (Agence Nationale de la Valorisation de la Recherche, contract no. A9703021P).     

Long-term effects of dietary fiber on glucose tolerance and gastric emptying in noninsulin-dependent diabetic patients

Effects of long-term (2 months) supplementation of diet with 20 g of guar gum and 10 g of wheat bran on metabolic control was studied in 12 obese, poorly controlled noninsulin-dependent diabetic patients. Addition of fiber reduced urinary excretion of glucose from 30.5 +/- 6 to 8.3 +/- 2 g/24 h, (p less than 0.025), fasting plasma glucose concentration from 301 +/- 24 to 184 +/- 15 mg/dl (p less than 0.025), and plasma cholesterol concentration from 277 +/- 24 to 193 +/- 9 mg/dl (p less than 0.025). No significant changes were observed in the patients weight and serum concentrations of triglycerides, high-density lipoproteins, free fatty acids, and insulin. Addition of fiber also delayed gastric emptying of liquids and solids. This effect became statistically significant 60 and 90 min after intake of a test meal for liquids and solids, respectively. We conclude that addition of guar and bran to the diet resulted in long-term improvement of metabolic control in these patients and that delayed gastric emptying may be one of the mechanisms responsible for this beneficial effect.     

Investigation into the role of cephalic stimulation of acid secretion on gastric emptying and appetite following a soup meal using the gastric acid inhibitor omeprazole

We previously showed that oral administration of a liquid soup preload was associated with a slower rate of gastric emptying and suppressed appetite more compared with intragastric administration of the same soup [Appetite 31(1998)377]. The present study was designed to investigate whether these results could be explained by the cephalic stimulation of acid secretion induced by oral administration. Eight healthy male subjects took part in a double-blind placebo controlled study comparing the effects of omeprazole and placebo on gastric emptying, appetite ratings and subsequent food intake following the ingestion of a liquid soup. Subjects were administered with a single oral dose of 80 mg omeprazole or placebo 3 h prior to ingesting the radiolabelled soup preload (400 kcal; 425 ml) over 15 min. Ratings of hunger, desire to eat and fullness were recorded over 135 min and gastric emptying was measured by scintigraphy. Food intake was evaluated from a test meal (yoghurt drink) given 120 min after the end of the soup ingestion. Analysis of data showed that there was no significant difference between omeprazole and placebo in gastric emptying, appetite or subsequent energy intake from the test meal. The results suggest that gastric acid secretion is not responsible for the differences in gastric emptying and appetite observed between intragastrically infused and orally administered soup preloads.     

The addition of soybean phosphatidylcholine to triglyceride increases suppressive effects on food intake and gastric emptying in rats

The physiologic roles of dietary lecithin have not yet been clearly defined. We examined the effects of soybean lecithin on gastric emptying (Experiments 1 and 2) and food intake (Experiment 3) in rats. Male Wistar rats were fed 2 g of a 20 g lipid/100 g diet containing various levels of lecithin after 24 h of food deprivation; gastric contents were collected 3 h after feeding (Experiment 1). In Experiment 2, the effects of lecithin and a CCK-A receptor antagonist on gastric emptying were examined using a modified phenol red recovery technique. In Experiment 3, their effects on food intake were examined after an intraduodenal infusion of an oil emulsion containing 50 mg soybean oil (SO) or SO partially replaced by lecithin (14-50%). Gastric emptying rates of the lipid and protein in the test diet (Experiment 1) or of phenol red (Experiment 2) were lower in the groups administered lecithin. Food intake for 60 min was lower in rats infused with the oil emulsion containing lecithin (25, 50%) than in rats not administered lecithin. The suppressive effects of lecithin on gastric emptying and food intake were largely reduced by devazepide. These results demonstrate that oil containing lecithin inhibits gastric emptying and food intake, and the effects are associated in part with CCK release.     

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.     

Reproducibility of energy intake, gastric emptying, blood glucose, plasma insulin and cholecystokinin responses in healthy young males

Gastric emptying, as well as intragastric meal distribution, and gastrointestinal hormones, including cholecystokinin (CCK), play an important role in appetite regulation. The evaluation of gastrointestinal factors regulating food intake is commonly performed in healthy, lean, young male participants. It has, however, been suggested that there is a marked interindividual variability in the effects of nutrient 'preloads' on energy intake in this group. Whether there is significant intraindividual variation in acute energy intake after a nutrient preload, and, if so, how this relates to day-to-day differences in gastric emptying and gastrointestinal hormone release, is unclear. The purpose of the present paper is to evaluate the hypothesis that energy intake after a nutrient preload would be reproducible and associated with reproducible patterns of gastric emptying, intragastric distribution and gastrointestinal hormone release. Fifteen healthy men (age 25 (sem 5) years) consumed a glucose preload (50 g glucose in 300 ml water; 815 kJ) on three occasions. Gastric emptying and intragastric meal distribution (using three-dimensional ultrasound), blood glucose, plasma insulin and CCK concentrations and appetite perceptions were evaluated over 90 min, and energy intake from a cold buffet-style meal was then quantified. Energy intake was highly reproducible within individuals between visits (intraclass correlation coefficient, ri = 0.9). Gastric emptying, intragastric meal distribution, blood glucose, plasma insulin and CCK concentrations and appetite perceptions did not differ between visits (ri>0.7 for all). In healthy males, energy intake is highly reproducible, at least in the short term, and is associated with reproducible patterns of gastric emptying, glycaemia, insulinaemia and CCK release.     

Xylitol vs glucose: effect on the rate of gastric emptying and motilin, insulin, and gastric inhibitory polypeptide release

The effect of xylitol and glucose on the rate of gastric emptying and intestinal transit and on motilin, gastric inhibitory polypeptide (GIP), and insulin release were studied in human volunteers. A single oral dose of 200 mL water containing 30 g glucose or 30 g xylitol, mixed with a 99mtechnetium-tin (99mTc-Sn) colloid, was used. Similar dosing without the label was used in motilin, GIP, and insulin studies. Xylitol decreased the rate of gastric emptying but concomitantly accelerated intestinal transit compared with glucose. The half-times for gastric emptying were 77.5 +/- 4.6 and 39.8 +/- 3.4 min after ingestion of xylitol and glucose solutions, respectively. Glucose suppressed motilin and stimulated GIP secretion; xylitol stimulated motilin secretion but had no effect on GIP, which is currently the main candidate for the role of enterogastrone. The accelerated intestinal transit and increase in plasma motilin observed after xylitol ingestion were thought to be causally related to the diarrhea and gastrointestinal discomfort produced by it.     

Insoluble cereal fiber reduces appetite and short-term food intake and glycemic response to food consumed 75 min later by healthy men

BACKGROUND: Insoluble fiber consumption is associated with reduced risk of obesity and diabetes, but its mechanisms of action are unknown. OBJECTIVE: The objective was to describe the effect of insoluble fiber on appetite, short-term food intake, and blood glucose (BG) before and after a meal 75 min later in healthy men. DESIGN: In a crossover design, high-fiber (HF; 33 g insoluble fiber) cereal, low-fiber (LF) cereal, white bread (WB), and water control were administered to young men after an overnight fast. Caloric treatments had similar energy, macronutrient content, volume, and weight. In the first experiment, subjective appetite and BG were measured at 15-min intervals before and after an ad libitum meal at 75 min. In the second experiment, a preset pizza meal (850 kcal) was consumed at 75 min. Appetite and blood glucose were measured for 150 min at fasting and at 15-min intervals before and after the fixed meal. RESULTS: In experiment 1, ad libitum food intake was lower after the HF cereal and WB than after the LF cereal and water (937 +/- 86, 970 +/- 65, 1109 +/- 90, 1224 +/- 89 kcal, respectively; P < 0.001). Appetite was lower (P < 0.05) after the HF cereal than after the WB but not different from the LF cereal. The BG area under the curve (AUC) did not differ among the HF cereal, WB, and LF cereal from 0 to 75 min, but the postmeal BG increased after the WB and LF cereal but not after the HF cereal. In experiment 2, the HF cereal, but not the LF cereal or WB, increased fullness before and prevented an increase in the BG AUC after the preset meal (P < 0.05). CONCLUSION: A serving of 33 g insoluble fiber reduced appetite, lowered food intake, and reduced glycemic response to a meal consumed 75 min later.     

The effects of fiber enrichment of pasta and fat content on gastric emptying,GLP-1, glucose,and insulin responses to a meal

OBJECTIVE: To assess whether the addition of viscous fiber at an amount recommended by the US FDA to allow a 'low saturated fat, cholesterol, soluble fiber and coronary heart disease', health claim label on a food package (1.7 g psyllium) and/or fat (30 g sunflower oil and 3 g sodium propionate) to a pasta meal would affect gastric emptying, postprandial glucose, insulin and GLP-1 concentrations. DESIGN: Ten subjects participated in a two-by-two single blind randomized crossover study. Four meals containing 50 g of available carbohydrate were consumed: pasta with or without psyllium enrichment served with a tomato sauce with (520 kcal per meal) and without (240 kcal per meal) fat. Blood samples were taken for 240 min following the meal and all subjects consumed a buffet meal at the end of the study. Gastric emptying was measured using the paracetamol absorption test. Blood was analysed for glucose, insulin, GLP-1. Visual analog scales were used to record feelings of hunger, pleasantness and nausea. RESULTS: The psyllium-enriched pasta had no significant effect on gastric emptying or the incremental area under the curve (IAUC) for GLP-1, insulin or glucose compared with the control pasta. The addition of polyunsaturated fat and sodium propionate significantly increased the IAUC for GLP-1 (P<0.001), delaying gastric emptying (P<0.002), and decreasing glucose (P<0.002). CONCLUSIONS: A dose of 1.7 g psyllium did not evoke measurable effects on gastric emptying, postprandial GLP-1, insulin or glucose metabolism. However the addition of 30 g of oil and 3 g of sodium propionate to the pasta did reduce gastric emptying, increase GLP-1 and reduce glucose and insulin concentrations. While this short-term study may have implications in terms of reducing the risk of diabetes and improving coronary risk factor profiles the long term effects of these nutrients need to be studied.     

Physical state of meal affects gastric emptying, cholecystokinin release and satiety

To verify the influence of food consistency on satiety mechanisms we evaluated the effects of the same meal in solid-liquid (SM) and homogenized (HM) form on satiety sensation, gastric emptying rate and plasma cholecystokinin (CCK) concentration. Eight healthy men, aged 21-28 (mean 24.5) years were given two meals (cooked vegetables 250 g, cheese 35 g, croutons 50 g and olive oil 25 g, total energy 2573 kJ, with water 300 ml) differing only in physical state: SM and HM. The subjects consumed the meals in randomized order on non-consecutive days. The sensations of fullness, satiety and desire to eat were evaluated by means of a questionnaire, gastric emptying was assessed by ultrasonographic measurement of antral area, and plasma CCK concentration was measured by radioimmunoassay. The vegetable-rich meal was significantly more satiating (P < 0.05) when in the HM form than when eaten in a SM state. Furthermore, the overall gastric emptying time was significantly slowed (255 (SEM 11) min after HM v. 214 (SEM 12) min after SM; P < 0.05) and CCK peak occurred later (94 (SEM 12) min after HM v. 62 (SEM 11) min after SM; NS) when the food was consumed in the HM form. Independently of the type of meal, antral area was significantly related to fullness sensations (r2 0.46, P = 0.004). These results demonstrate that meal consistency is an important physical food characteristic which influences both gastric emptying rate and satiety sensation. Moreover, the relationship observed between antral area and fullness sensation confirms that antral distension plays a part in the regulation of eating behaviour.     

Dietary restriction delays gastric emptying in rats

In rats allowed to eat for only 2 h per day, gastric emptying of three different meals [poached egg white, glucose (0.5 kcal/ml) and physiological saline, each labelled with 60 MBq of technetium-99m tin colloid visualized using a gamma camera] was markedly slowed 8 h after the last meal. Mean body weight in rats on the restricted feeding schedule was 80% of the weight of free-feeding controls. Gastric emptying curves for all three meals in controls were best described using loge transformed counts. Other models used were linear and square root. For each of the three meals, the percentage remaining in the stomach at 120 min was estimated using linear regression of gastric contents, transformed if necessary to yield the best curve against time. At 120 min, % gastric contents (mean +/- SEM) were 19.5 +/- 5.6 (egg), 15.5 +/- 6.27 (glucose) and 27.1 +/- 7.48 (saline) in control rats. After 4 months restriction, the corresponding figures were 75.2 +/- 4.04, 81.5 +/- 4.75 and 70.3 +/- 5.83. After 3 months of free feeding, emptying rates of the three meals were not significantly different from control values. We conclude that dietary restriction causes profound changes in gastric emptying by unknown mechanisms which may be operating in patients with anorexia nervosa.     

Camel's milk and gastric emptying

BACKGROUND & AIM: Gastric emptying is determined by food consistency, pH, osmolality, lipid and calorie content as well as the presence of different nutrients in the duodenal lumen. Control of gastric emptying is essential for ensuring optimal digestion. The present study tested the hypothesis that due to its different precipitation properties, gastric emptying of camel's milk may be quicker than that of bovine's milk with the same caloric and fat content. METHODS: Gastric emptying was studied by a scintigraphic technique in a randomized, double blind fashion in 8 volunteers after drinking 450 mL of either cow's milk or camel's milk. RESULTS: No differences in gastric emptying rates were found between the two types of milk. The percentage of retention of the meal after 60 min was 74.6+/-13.2% for cow's milk and 79.8+/-10.8% for camel's milk. The 50% emptying time (T(1/2)) was 131.8+/-37.4 min for cow's milk and 136.8+/-55.8 min for camel's milk. CONCLUSIONS: Camel's milk is most probably not a useful substitute for other types of milk to shorten gastric emptying.     

The effect of incorporating fat into different components of a meal on gastric emptying and postprandial blood glucose and insulin responses

1. Three studies were carried out in each of six normal volunteers to investigate how lipid, when given at different stages during the course of a meal, affects gastric emptying and postprandial blood glucose and insulin concentrations. 2. The control meal consisted of 300 ml beef consommé (50 kJ, 12 kcal), followed 20 min later by 300 g mashed potato (908 kJ, 217 kcal). In the two test meals, 60 g margarine were incorporated into either the soup or the mashed potato. 3. The addition of margarine to either component of the meal delayed gastric emptying of the mashed potato (P less than 0.05), but the pattern varied according to the component to which the fat was added. 4. Incorporation of fat into the soup increased the lag phase (P less than 0.05) but did not influence the slope of emptying of the mashed potato, while incorporation of fat into the mashed potato reduced the slope of emptying of the mashed potato (P less than 0.05) but did not influence the lag phase. 5. Addition of fat to either component of the meal reduced postprandial blood glucose (P less than 0.05) and insulin responses, but when the fat was incorporated in the soup, peak glucose and insulin responses were delayed as well (P less than 0.05). 6. The results show that the effect of fat on gastric emptying and absorption of nutrients depends on when, in relation to the other components of the meal, the fat is consumed.     

The effect of ethanol and alcoholic beverages on gastric emptying of solid meals in humans

AIMS: The systematic study of the effect of pure ethanol, alcoholic beverages, and their non-alcoholic components on gastric emptying of solid meals in humans. METHODS: 16 fasting healthy male subjects received once weekly 300 ml of the following solutions in random order: 4 and 10% (v/v) ethanol, beer, red wine, 5.5 and 11.4% (w/v) glucose, and water. The test solutions were given either together with a low caloric (270 kcal, n = 8) or a high caloric (740 kcal, n = 8) solid meal. Ultrasonography of the antrum was used to determine gastric emptying. RESULTS: Gastric half emptying time (t(1/2) ) of the high caloric solid meal with water was 131.3 +/- 7 min. The ingestion of 4 and 10% (v/v) ethanol (158.8 +/- 9.3 and 165.6 +/- 6.2 min, respectively), beer (163.1 +/- 11 min), and red wine (186.3 +/- 8.4 min) resulted in a significantly longer t(1/2) than water. The lag phases after 4 and 10% (v/v) ethanol, beer, and red wine were not significantly different from that of water (48.1 +/- 6.5 min). Compared with water, the ingestion of 5.5 and 11.4% (w/v) glucose resulted in a significantly longer t(1/2) (153.8 +/- 5 and 168.1 +/- 14.4 min, respectively) by increasing the duration of the lag phase. The high caloric meals resulted in a 2-fold prolongation of t(1/2) when compared with the low caloric meals. The effect of the solutions on the gastric emptying times, however, was similar for both test meals. CONCLUSIONS: (i) Ethanol in low concentrations of 4 and 10% (v/v) prolongs gastric emptying of solid meals; this inhibitory effect is not dose-dependent. (ii) Alcoholic beverages (beer and red wine) also result in a prolongation of gastric emptying. The inhibitory effect of red wine, but not of beer, is more pronounced than that of the corresponding ethanol concentration and amount. (iii) The inhibitory effect of ethanol and alcoholic beverages is mainly induced by a prolongation of the gastric emptying phase (without affecting the lag phase), whereas 5.5 and 11.4% (w/v) glucose prolong the lag phase in a dose-dependent manner. (iv) The inhibitory effect of ethanol, beer, and red wine on gastric emptying does not depend on the caloric content of the meal.     

Thermic effect of feeding carbohydrate, fat, protein and mixed meal in lean and obese subjects

The thermic effect of 1.67 MJ (400 kcal) of carbohydrate (glucose), fat, protein and mixed meal were examined in 11 lean and 11 obese subjects by indirect calorimetry. The changes in metabolic rate in response over 90 min period (30-120 min after the meal) to the different meals were compared with that seen after a similar volume of low calorie drink. The thermic effects of glucose and protein were not significantly different between lean and obese subjects. Obese subjects showed very little increase in metabolic rate following ingestion of fat (-0.9 +/- 2.0%, mean +/- SEM) and this was significantly different from that seen in lean subjects (14.4 +/- 3.4%). The thermogenic response to mixed meal was also significantly lower in obese subjects when expressed as percentage change (12.9 +/- 2.3% compared to 25.0 +/- 4.8%). There was no evidence for delay in gastric emptying times for glucose and fatty meal in the six obese subjects in whom these were measured. We conclude that obese subjects show a reduced thermogenic response to fat.     

Metabolic responses to high-fat or low-fat meals and association with sympathetic nervous system activity in healthy young men

The present study was designed to investigate the metabolic and sympathetic responses to a high-fat meal in humans. Fourteen young men (age: 23.6 +/- 0.5 y, BMI: 21.3 +/- 0.4 kg/m2) were examined for energy expenditure and fat oxidation measured by indirect calorimetry for 3.5 h after a high-fat (70%, energy from fat) or an isoenergetic low-fat (20% energy from fat) meal served in random order. The sympathetic nervous system (SNS) activity was assessed using power spectral analysis of heart rate variability (HRV). After the high-fat meal, increases in thermoregulatory SNS activity (very low-frequency component of HRV, 0.007-0.035 Hz, 577.4+/-45.9 vs. 432.0+/-49.3 ms2, p<0.05) and fat oxidation (21.0+/-5.3 vs. 13.3+/-4.3 g, p<0.001) were greater than those after the low-fat meal. However, thermic effects of the meal (TEM) were lower after the high-fat meal than after the low-fat meal (27.5+/-11.2 vs. 36.1+/-10.9 kcal, p<0.05). In conclusion, the high-fat meal can stimulate thermoregulatory SNS and lipolysis, but resulted in lower TEM, suggesting that a high proportion of dietary fat intake, even with a normal daily range of calories, may be a potent risk factor for further weight gain.     

Frequent feeding delays the gastric emptying of a subsequent meal

To assess the suitability of the 13C-octanoic acid breath test for measuring gastric emptying in circumstances other than the post-absorptive state, a preliminary study was performed where 6 hourly spaced isoenergetic meals preceded the determination of gastric emptying of a subsequent 2 MJ meal. Emptying was measured in three individuals on four separate occasions, with a reproducibility of 8%. A crossover study was then conducted to test the hypothesis that meal frequency can modulate the gastric emptying of a subsequent meal, with the potential to influence appetite regulation. Sixteen subjects were fed to energy balance, receiving food either as 2 isoenergetic meals 3 h apart or 6 isoenergetic meals fed hourly. Gastric emptying of a subsequent 2 MJ meal was investigated. Visual analogue scales were used throughout to assess appetite. The maximum rate of gastric emptying was unchanged but the onset of emptying was delayed by the more frequent feeding pattern. There was no significant difference in subjective appetite before or after the test meal. In conclusion, short-term increases in feeding frequency delayed the gastric emptying of a subsequent meal, but significant effects on post-meal appetite could not be demonstrated.     

Eating slowly led to decreases in energy intake within meals in healthy women

Although reducing eating rate is frequently advocated for control of food intake and thus body weight, empirical evidence is extremely limited and inconsistent. We sought to compare the impact of slow and quick eating rates on development of satiation in healthy women. In a randomized design, 30 healthy women (22.9+/-7.1 years; body mass index [calculated as kg/m(2)] 22.1+/-2.9) were studied on two test visits to compare slow and quick eating rates. Satiation was examined as the main outcome, using the objective measure of energy intake during ad libitum meals. At designated times, subjects also rated perceived hunger, satiety, desire to eat, thirst and meal palatability on visual analogue scales. Slow rates of ingestion led to significant decreases in energy intake (quick: 645.7+/-155.9 kcal; slow: 579.0+/-154.7 kcal; P<0.05) and significant increases in water consumption (quick: 289.9+/-155.1 g; slow: 409.6+/-205.8 g; P<0.05). Despite higher energy intake upon meal completion under the quick condition, satiety was significantly lower than the slow condition (P<0.05). Accordingly, the quick condition showed a lower Satiating Efficiency Index (quick: 0.1; slow: 0.2; P<0.05). After meal completion, pleasantness ratings tended to be higher under the slow condition (P=0.04; but not significant after Bonferroni adjustment). Ad libitum energy intake was lower when the meal was eaten slowly, and satiety was higher at meal completion. Although more study is needed, these data suggest that eating slowly may help to maximize satiation and reduce energy intake within meals.     

Circadian eating and sleeping patterns in the night eating syndrome

OBJECTIVE: To compare the eating and sleep-wake patterns of persons with the night eating syndrome (NES) with those of matched control subjects. RESEARCH METHODS AND PROCEDURES: Forty-six overweight/obese NES subjects (mean age 43.3 +/- 9.8 years; 32 women) and 43 similar controls (mean age 39.0 +/- 11.0 years; 28 women) wore wrist actigraphs for 7 days and completed sleep and food diaries at home. RESULTS: There was no difference between the total energy intake of the NES and the control subjects, but the pattern of energy intake differed greatly. Relative to control subjects, the temporal pattern of food intake of night eaters was delayed. Food intake after the evening meal, as a proportion of the 24-hour intake, was more than 3-fold greater in NES subjects than in controls (34.6 +/- 10.1% vs. 10.0 +/- 6.9%, p = 0.001). NES subjects had sleep onset, offset, and total sleep duration times comparable with those of controls. NES subjects reported more nocturnal awakenings than did controls (1.5 +/- 1.0 per night vs. 0.5 +/- 0.5; p < 0.001), and their actigraphically monitored arousals occurred earlier during sleep (at 128 minutes after sleep onset vs. 193 minutes, p = 0.01). NES subjects consumed food on 74% of the awakenings vs. 0% for the controls. DISCUSSION: The pattern of cumulative energy intake of the night eaters suggests a phase delay in energy consumption relative to sleep-wake times. NES may involve a dissociation of the circadian control of eating relative to sleep.     

Evening ready-to-eat cereal consumption contributes to weight management

OBJECTIVES: Post dinner snacking may constitute a significant proportion of total daily energy intake and contribute to overweight and obesity in some individuals (night snackers). This study tested the hypothesis that providing a structured snack in the form of a "ready-to-eat" breakfast cereal would help regulate excess energy intake and contribute to weight loss in night snackers. METHODS: Adults (18 to 65 years of age, BMI kg/m2 > or = 25), with self-reported night snacking behaviors, were randomized into a cereal group (CR) and a no-cereal group (NC). During a period of 4 weeks, the cereal group was instructed to consume a serving of ready-to-eat cereal with low-fat milk 90 minutes after their evening meal. Concurrently, the non-cereal group continued their regular diet ad libitum. RESULTS: At baseline, there were no significant differences between groups for age, body weight, body mass index, daily caloric intake, or evening caloric intake. There was a correlation between number of days of compliance with post-dinner cereal consumption and weight loss (r = -0.36, p = 0.057). After 4 weeks, the compliant subjects (cereal intake > or = 20 d) lost -1.85 +/- 3.56 lbs vs. -0.39 +/- 3.1 lb for the NC group (p = 0.06). Compared to baseline, the compliant CR group reduced their total daily caloric intake by -396.50 +/- 641.6 kcal (p < 0.02), whereas, the NC group experienced a reduction of -23.22 +/- 889.60 kcal/day during the same period (p = ns). Reduction in post-dinner calorie intake for the compliant CR group was significantly greater compared to the NC group (-141.74 +/- 385.58 kcal vs. 85.82 +/- 374.70 kcal; p = 0.042). CONCLUSION: Eating ready-to-eat cereal after the evening meal may attenuate caloric intake in night snackers and promote weight loss in compliant individuals.