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Biomedical subjects

A Astrup

Publications and source records attributed to A Astrup.

At least 55 records · Page 3Linked to original sources
PubMed2001

Twenty-four hour energy expenditure and substrate oxidation before and after 6 months' ad libitum intake of a diet rich in simple or complex carbohydrates or a habitual diet.

OBJECTIVE: To investigate 24 h energy expenditure (24 h EE) and substrate oxidations in overweight and obese subjects before and after 6 months' ad libitum intake of a low-fat, high-simple carbohydrate diet (SCHO), a low-fat, high-complex carbohydrate diet (CCHO), or a habitual control diet (CD). SUBJECTS: Twenty-four healthy overweight and obese subjects (11 males and 13 females; body mass index 30.7+/-0.6 kg/m(2); age 42.2+/-1.8 y). MEASUREMENTS: Twenty-four hour EE, substrate oxidation rates and spontaneous physical activity (SPA) measured in a respiration chamber, and food intake. RESULTS: After the intervention no differences were seen in 24 h EE, postprandial thermogenesis, basal metabolic rate or SPA. Carbohydrate oxidation, adjusted for energy balance, increased on both carbohydrate-rich diets (SCHO 13.0%, CCHO 11.5%) and decreased on the CD diet (6.5%); however, the changes were not significantly different between diets. The opposite pattern was seen for fat oxidation, which increased by 2.9% on the CD diet and decreased by 17.1 and 25.6% on the SCHO and CCHO, respectively. The changes only differed between the CD and CCHO diet (P=0.03). CONCLUSION: Six months' ad libitum intake of a diet rich in simple or complex carbohydrates or a habitual diet induced a shift in the oxidation pattern to closely reflect the diet composition in overweight and obese subjects. No differences between diets were seen in 24 h EE.

Adult↗
PubMed2001

The role of postprandial releases of insulin and incretin hormones in meal-induced satiety--effect of obesity and weight reduction.

BACKGROUND: Previous studies have indicated that the secretion of the intestinal satiety hormone glucagon-like peptide-1 (GLP-1) is attenuated in obese subjects. OBJECTIVE: To compare meal-induced response of GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) in obese and lean male subjects, to investigate the effect of a major weight reduction in the obese subjects, and to look for an association between these hormones and ad libitum food intake. METHOD: Plasma concentrations of intestinal hormones and appetite sensations were measured prior to, and every 30 min for 180 min after, ingestion of a 2.5 MJ solid test meal. Gastric emptying was estimated scintigraphically. An ad libitum lunch was served 3 h after the test meal. SUBJECTS: Nineteen non-diabetic obese (body mass index (BMI) 34.1--43.8 kg/m(2)) and 12 lean (BMI 20.4--24.7 kg/m(2)) males. All obese subjects were re-examined after a mean stabilised weight loss of 18.8 kg (95% CI 14.4--23.2). RESULTS: Total area under the GLP-1 response curve (AUC(total, GLP-1)) was lower in obese before and after the weight loss compared to lean subjects (P<0.05), although weight loss improved the response from 80 to 88% of that of the lean subjects (P=0.003). The GIP response was similar in obese and lean subjects. However, after the weight loss both AUC(total, GIP) and AUC(incremental, GIP) were lowered (P<0.05). An inverse correlation was observed between AUC(incremental, GIP) and energy intake at the subsequent ad libitum meal in all groups. In lean subjects ad libitum energy intake was largely predicted by the insulin response to the preceding meal (r(2)=0.67, P=0.001). CONCLUSION: Our study confirmed previous findings of a reduced postprandial GLP-1 response in severely obese subjects. Following weight reduction, GLP-1 response in the obese subjects apparently rose to a level between that of obese and lean subjects. The data suggests that postprandial insulin and GIP responses are key players in short-term appetite regulation.

Absorptiometry, Photon↗
PubMed2001

The role of dietary fat in the prevention and treatment of obesity. Efficacy and safety of low-fat diets.

BACKGROUND: Does dietary fat play a central role in weight gain and development of obesity? Do low-fat diets have adverse effects on blood lipids? OBJECTIVE AND DESIGN: To answer these questions we have reviewed the evidence linking the dietary fat content to energy balance and obesity, and examined the efficacy and safety of ad libitum low fat, high carbohydrate/protein diets in the prevention and management of obesity. RESULTS: Physiological studies have provided insight into the mechanisms by which the macronutrients differ in their effect on energy balance: (1) energy from fat is less satiating than energy from carbohydrate, and a high fat/carbohydrate ratio in the diet promotes passive overconsumption, a positive energy balance and weight gain in susceptible individuals; (2) fat is more readily absorbed from the intestine and fecal energy loss is much lower with a high dietary fat/carbohydrate ratio; (3) carbohydrate is more thermogenic than fat and energy expenditure is lower during positive energy balance produced by a diet with a high fat/carbohydrate ratio than during positive energy balance produced by a diet with a low fat/carbohydrate ratio. Randomized intervention studies comparing low fat diets to normal fat diets show that low fat diets prevent weight gain in normal weight subjects and produce weight loss in overweight individuals. In our meta-analysis of ad libitum low fat interventions we included 16 trials involving 1728 individuals. The difference in weight loss between intervention and control groups was 2.5 kg (95% CI, 1.5-3.5; P<0.0001). Weight loss was positively related to pre-treatment body weight (r=0.52, P<0.05) and to reduction in percentage energy as fat (0.37 kg/%, P<0.005). Extrapolated to a body mass index (BMI) approximately 30 kg/m(2), and assuming a 10% reduction in dietary fat, the predicted weight loss would be 4.4 kg (95% CI, 2.0-6.8 kg), which has been confirmed in subsequent studies. Newer studies have shown that replacing some carbohydrate with protein may enhance weight loss. CONCLUSION: The American Paradox, the observation that obesity prevalence is increasing despite a slight decrease in population dietary fat consumption, is easily explained by the concomitantly decreasing physical activity, which reduces fat requirements and counteracts the beneficial effect of a slight reduction in dietary fat. Low fat diets with a high content of complex carbohydrates and protein do not produce any adverse effect on cardiovascular risk factors when weight loss is allowed to occur, and they have been shown to decrease mortality among high risk subjects.

Diet, Fat-Restricted↗
PubMed2001

When, for whom and how to use sibutramine?

Sibutramine is the first of a new generation of weight management drugs, and offers long-term control of weight when used as an adjunct to diet and exercise. This paper considers the criteria set down by the European Union's regulatory agency for its use and how this relates to the information now available on its efficacy, side-effect profile and benefits in different patient groups. The data presented relate to 18-65y olds; its use in other age groups has not been established. The EU licence permits continuous treatment for periods of up to 1 y; the STORM study has now led the US Food and Drug Administration to extend clearance to 2 y. The addition of sibutramine to a regimen of diet, exercise and lifestyle modification results in 3-5 times more patients responding to a weight-reduction programme, ie achieving more than 5% weight maintenance. Sibutramine is indicated for use in obese patients (BMI > 30 kg/m2) and also overweight patients with a BMI > 27 kg/m2 who have additional obesity-related risk factors such as type 2 diabetes or dyslipidaemia.

Adolescent↗
PubMed2001

Healthy lifestyles in Europe: prevention of obesity and type II diabetes by diet and physical activity.

The prevalence of obesity is increasing rapidly in all age groups in most EU-countries and is one of the fastest growing epidemics, now affecting 10-40% of the adult population. Obesity increases the risk of serious co-morbidities such as type 2 diabetes, cardiovascular disease, certain cancers and reduced life expectancy, and these complications may account for 5-10% of all health costs in EU countries. The risk of diabetes is particularly increased by obesity, and 80-95% of the increase in diabetes can be attributed to obesity and overweight with abdominal fat distribution. There is robust evidence from cross-sectional and longitudinal studies to support that an energy-dense, high fat diet and physical inactivity are independent risk factors for weight gain and obesity. Furthermore, interaction between dietary fat and physical fitness determine fat balance, so that the obesity promoting effect of a high fat diet is enhanced in susceptible subjects, particularly in sedentary individuals with a genetic predisposition to obesity. Ad libitum consumption of diets low in fat and high in protein and complex carbohydrates, with a low glycaemic index, contributes to the prevention of weight gain in normal weight subjects. It also causes a spontaneous weight loss of 3-4 kg in overweight subjects, and has beneficial effects on risk factors for diabetes and CVD. To prevent obesity and diabetes there are grounds for recommending the combination of increasing daily physical activity level to a PAL-value of at least 1.8 and reducing dietary fat content to 20-25 energy-% in sedentary subjects, and to 25-35% in more physically active individuals.

Adipose Tissue↗
PubMed2001

Diurnal metabolic profiles after 14 d of an ad libitum high-starch, high-sucrose, or high-fat diet in normal-weight never-obese and postobese women.

BACKGROUND: The influence of the amount and type of carbohydrates in the diet on risk factors for obesity, diabetes, and cardiovascular disease remains unclear. OBJECTIVE: We investigated the effects of 2 low-fat diets (high-sucrose and high-starch) and a high-fat diet on glycemia, lipidemia, and hormonal responses in never-obese and postobese women. DESIGN: Eighteen normal-weight women (8 postobese and 10 never-obese) consumed 3 ad libitum diets (high-fat, high-starch, and high-sucrose) for 14 d each. On day 15, we measured fasting and postprandial glucose, lactate, insulin, triacylglycerol, nonesterified fatty acids (NEFA), glycerol, glucagon, glucose-dependent insulinotropic polypeptide, and glucagon-like peptide 1. RESULTS: The high-sucrose diet induced significantly lower total areas under the curve (AUCs) for glucose and NEFA and a significantly higher lactate AUC than did the high-fat and high-starch diets; there were no significant differences in the insulin AUCs. The triacylglycerol AUC was greater with the high-fat and high-sucrose diets than with the high-starch diet. Gastrointestinal hormone concentrations differed between diets, but not between the 2 subject groups. Comparisons between subject groups for all diets combined showed lower relative insulin resistance and lower AUCs for glucose, insulin, and triacylglycerol in the postobese group. CONCLUSIONS: High-starch and high-sucrose diets had no adverse effects on postprandial glycemia, insulinemia, or lipidemia compared with a high-fat diet. A sucrose-rich diet may improve glucose metabolism, but may have an adverse effect on lipidemia, compared with a starch-rich diet. Postobese women seemed to be more insulin-sensitive and more efficient at storing triacylglycerol than were never-obese women, regardless of dietary composition.

Adult↗
PubMed2001

A meta-analysis of the effect of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake in humans.

Seven studies have now been published pertaining to the acute effect of iv administration of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake. In four of these studies energy intake was significantly reduced following the glucagon-like peptide-1 infusion compared with saline. In the remaining studies, no significant effect of glucagon-like peptide-1 could be shown. Lack of statistical power or low glucagon-like peptide-1 infusion rate may explain these conflicting results. Our aim was to examine the effect of glucagon-like peptide-1 on subsequent energy intake using a data set composed of subject data from previous studies and from two as yet unpublished studies. Secondly, we investigated whether the effect on energy intake is dose dependent and differs between lean and overweight subjects. Raw subject data on body mass index and ad libitum energy intake were collected into a common data set (n = 115), together with study characteristics such as infusion rate, duration of infusion, etc. From four studies with comparable protocol the following subject data were included if available: plasma concentrations of glucagon-like peptide-1, subjective appetite measures, well-being, and gastric emptying rate of a meal served at the start of the glucagon-like peptide-1 infusion. Energy intake was reduced by 727 kJ (95% confidence interval, 548-908 kJ) or 11.7% during glucagon-like peptide-1 infusion. Although the absolute reduction in energy intake was higher in lean (863 kJ) (634-1091 kJ) compared with overweight subjects (487 kJ) (209-764 kJ) (P = 0.05), the relative reduction did not differ between the two groups (13.2% and 9.3%, respectively). Stepwise regression analysis showed that the glucagon-like peptide-1 infusion rate was the only independent predictor of the reduction in energy intake during glucagon-like peptide-1 (7-36) amide infusion (r = 0.4, P < 0.001). Differences in mean plasma glucagon-like peptide-1 concentration on the glucagon-like peptide-1 and placebo day (n = 43) were related to differences in feelings of prospective consumption (r = 0.40, P < 0.01), fullness (r = 0.38, P < 0.05), and hunger (r = 0.26, P = 0.09), but not to differences in ad libitum energy intake. Gastric emptying rate was significantly lower during glucagon-like peptide-1 infusion compared with saline. Finally, well-being was not influenced by the glucagon-like peptide-1 infusion. Glucagon-like peptide-1 infusion reduces energy intake dose dependently in both lean and overweight subjects. A reduced gastric emptying rate may contribute to the increased satiety induced by glucagon-like peptide-1.

Adult↗
PubMed2000

The role of dietary fat in body fatness: evidence from a preliminary meta-analysis of ad libitum low-fat dietary intervention studies.

The role of high-fat diets in weight gain and obesity has been questioned because of inconsistent reports in the literature concerning the efficacy of ad libitum low-fat diets to reduce body weight. We conducted a meta-analysis of weight loss occurring on ad libitum low-fat diets in intervention trials, and analysed the relationship between initial body weight and weight loss. We selected controlled trials lasting more than 2 months comparing ad libitum low-fat diets with a control group consuming their habitual diet or a medium-fat diet ad libitum published from 1966 to 1998. Data were included from 16 trials with a duration of 2-12 months, involving 1728 individuals. No trials on obese subjects fulfilled the inclusion criteria. The weighted difference in weight loss between intervention and control groups was 2.55 kg (95% CI, 1.5-3.5; P < 0.0001). Weight loss was positively and independently related to pre-treatment body weight (r = 0.52, P < 0.05) and to reduction in the percentage of energy as fat (0.37 kg/%, P < 0.005) in unweighted analysis. Extrapolated to a BMI of about 30 kg/m2 and assuming a 10% reduction in dietary fat, the predicted weight loss would be 4.4 kg (95% CI, 2.0 to -6.8 kg). Because weight loss was not the primary aim in 12 of the 16 studies, it is unlikely that voluntary energy restriction contributed to the weight loss. Although there is no evidence that a high intake of simple sugars contributes to passive overconsumption, carbohydrate foods with a low glycaemic index may be more satiating and exert more beneficial effects on insulin resistance and cardiovascular risk factors. Moreover, an increase in protein content up to 25% of total energy may also contribute to reducing total energy intake. In conclusion, a low-fat diet, high in protein and fibre-rich carbohydrates, mainly from different vegetables, fruits and whole grains, is highly satiating for fewer calories than fatty foods. This diet composition provides good sources of vitamins, minerals, trace elements and fibre, and may have the most beneficial effect on blood lipids and blood-pressure levels. A reduction in dietary fat without restriction of total energy intake prevents weight gain in subjects of normal weight and produces a weight loss in overweight subjects, which is highly relevant for public health.

Body Mass Index↗
PubMed2000

Effect of 8 week intake of probiotic milk products on risk factors for cardiovascular diseases.

OBJECTIVE: To investigate the effect of a probiotic milk product containing the culture CAUSIDO(R) and of two alternative products on risk factors for cardiovascular disease in overweight and obese subjects. DESIGN: An 8 week randomized, double-blind, placebo- and compliance-controlled, parallel study. SUBJECTS: Seventy healthy, weight-stable, overweight and obese (25.0<BMI<37.5 kg/m2) males (n=20) and females (n=50), 18-55 y old, were randomly assigned into five groups. INTERVENTION: Four groups consumed 450 ml fermented milk products (yoghurt) daily. Group 1: a yoghurt fermented with two strains of Streptococcus thermophilus and two strains of Lactobacillus acidophilus (StLa). Group 2: a placebo yoghurt fermented with delta-acid-lactone (PY). Group 3: a yoghurt fermented with two strains of Streptococcus thermophilus and one strain of Lactobacillus rhamnosus (StLr). Group 4: a yoghurt fermented with one strain of Enterococcus faecium and two strains of Streptococcus thermophilus (CAUSIDO(R) culture), GAIO(R) (G). The dietary composition of the yoghurt was otherwise similar. The fifth group was given two placebo pills (PP) daily. RESULTS: When comparing all five treatment groups, unadjusted for changes in body weight, no statistical effects were observed in week 8 in the G-group on low density lipoproteins (LDL)-cholesterol (P=0.29). After adjustment for small changes in body weight, LDL-cholesterol decreased by 8.4% (0.26+/-0.10 mmol/l; P<0.05) and fibrinogen increased (0.74+/-0.32 mmol/l; P<0.05) after 8 weeks in the G-group. This was significantly different from the group consuming chemically fermented yoghurt and the group consuming placebo pills (P<0.05). After 8 weeks, systolic blood pressure was significantly more reduced in the StLa and G-group compared to StLr. No other differences were found. CONCLUSION: The CAUSIDO(R) culture reduced LDL-cholesterol and increased fibrinogen in the overweight subjects at a 450 ml consumption daily for 8 weeks. The effect on LDL-cholesterol confirms previous studies. An immunostimulation by one of the strains in the product might explain the effect on fibrinogen in the G-group. SPONSORSHIP: MD Foods A/S, Denmark.

Adult↗
PubMed2000

The effect of a probiotic milk product on plasma cholesterol: a meta-analysis of short-term intervention studies.

INTRODUCTION: Certain fermented dairy milk products may have beneficial effects on plasma cholesterol levels. However, a number of studies have produced conflicting results as to whether dietary supplementation by a probiotic dairy product containing the bacteria culture Causido(R) reduces plasma cholesterol. OBJECTIVE: To conduct a meta-analysis of intervention studies to evaluate the effect of the Causido(R) culture on plasma total cholesterol and low-density lipoprotein (LDL)-cholesterol. THE PROBIOTIC MILK PRODUCT: The yoghurt product Gaio(R) is fermented with Causido(R), composed of one strain of Enterococcus faecium (human species) with the proposed cholesterol-lowering effect, and two strains of Streptococcus thermophilus. STUDY INCLUSION AND DATA EXTRACTION: Six studies were identified from a literature search and from the yoghurt producer. All studies met the inclusion criteria. Summary data for plasma concentrations of total cholesterol and LDL-cholesterol were extracted from the original publications or by personal request to the authors. Data from 4-8 weeks of treatment duration was used. STATISTICAL ANALYSIS: We performed a traditional meta-analysis where mean differences between intervention and control of the pre-post changes in total cholesterol and LDL-cholesterol were calculated, as well as 95% confidence intervals (CIs). RESULTS: In the six studies included in the meta-analysis, the Gaio(R) interventions produced changes in total cholesterol above those of the control groups ranging from -0.02 to -1.02 mmol/l and in LDL-cholesterol ranging from -0.02 to -1.15 mmol/l. After inclusion of an open-label study, the meta-analysis of the double-blind studies showed that Gaio(R) as compared to the control group changed total cholesterol by -0.22 mmol/l (95% CI: -0.35 to -0.08, P<0.01) and LDL-cholesterol by -0.20 mmol/l (95% CI: -0.33 to -0.06, P<0.005). The outcome was essentially the same if all studies were included. CONCLUSIONS: The present meta-analysis of controlled short-term intervention studies shows that the fermented yoghurt product produced a 4% decrease in total cholesterol and a 5% decrease in LDL-cholesterol when the open-label study is excluded. To demonstrate sustained effects on blood lipids, long-term studies are required. SPONSORSHIP: MD Foods A/S, Denmark.

Adult↗
PubMed2000

Reproducibility, power and validity of visual analogue scales in assessment of appetite sensations in single test meal studies.

OBJECTIVE: To examine reproducibility and validity of visual analogue scales (VAS) for measurement of appetite sensations, with and without a diet standardization prior to the test days. DESIGN: On two different test days the subjects recorded their appetite sensations before breakfast and every 30 min during the 4.5 h postprandial period under exactly the same conditions. SUBJECTS: 55 healthy men (age 25.6+/-0.6 y, BMI 22.6+/-0.3 kg¿m2). MEASUREMENTS: VAS were used to record hunger, satiety, fullness, prospective food consumption, desire to eat something fatty, salty, sweet or savoury, and palatability of the meals. Subsequently an ad libitum lunch was served and energy intake was recorded. Reproducibility was assessed by the coefficient of repeatability (CR) of fasting, mean 4.5 h and peak/nadir values. RESULTS: CRs (range 20-61 mm) were larger for fasting and peak/nadir values compared with mean 4.5 h values. No parameter seemed to be improved by diet standardization. Using a paired design and a study power of 0.8, a difference of 10 mm on fasting and 5 mm on mean 4.5 h ratings can be detected with 18 subjects. When using desires to eat specific types of food or an unpaired design, more subjects are needed due to considerable variation. The best correlations of validity were found between 4.5 h mean VAS of the appetite parameters and subsequent energy intake (r=+/-0.50-0.53, P<0.001). CONCLUSION: VAS scores are reliable for appetite research and do not seem to be influenced by prior diet standardization. However, consideration should be given to the specific parameters being measured, their sensitivity and study power. International Journal of Obesity (2000)24, 38-48

Adult↗
PubMed2000

The effect of glucagon-like peptide-1 on energy expenditure and substrate metabolism in humans.

OBJECTIVE: To investigate the effects of a near-physiological peripheral glucagon-like peptide-1 (GLP-1) infusion, during and after a breakfast of fixed energy content, on resting energy expenditure, substrate oxidation and metabolism and the desire to eat specific types of food in humans. DESIGN: A placebo-controlled, randomized, blinded, cross-over study. Infusion (GLP-1, 50 pmol/kg x h or saline) was started simultaneously with initiation of the test meals. SUBJECTS: 20 healthy, normal weight (body mass index 20.3-25.7 kg/m2) men of 20-31 y of age. MEASUREMENTS: Energy expenditure and substrate oxidations were measured before and for 4 h after standard breakfast (20% of calculated daily energy requirements, 50% of energy from carbohydrates, 37% of energy from fat and 13% of energy from protein) using a ventilated hood system. Visual analogue scales were used throughout the experiment to assess the desire to eat specific types of food and the palatability of the test meals. Blood was sampled throughout the day for analysis of plasma hormone and substrate concentrations. RESULTS: Diet-induced thermogenesis (DIT) was lower (47%) on the GLP-1 infusion than on the saline infusion (P < 0.0001). This was due to a lower carbohydrate oxidation (P < 0.01). No differences in fat oxidation or total 4 h protein oxidation were observed. All hormone and substrate profiles except non-esterified fatty acids (NEFA) and cholecystokinin (CCK) were significantly suppressed (GLP-2 completely suppressed) during the GLP-1 infusion, whereas profiles of NEFA and CCK differed in time course during the two treatments (treatment x time effect), P < 0.0001). GLP-1 infusion also suppressed the desire to eat all food types following the breakfast (treatment effect: P < 0.05). CONCLUSION: Peripheral GLP-1 decreased DIT and carbohydrate oxidation, probably secondary to a delayed absorption of nutrients, since substrate and hormone concentrations in plasma were suppressed during GLP-1 infusion. Endogenous secretion of GLP-1 and GLP-2 was completely suppressed by GLP-1 infusion. Finally, the desire to eat any type of food was decreased by exogenous administrated GLP-1.

Adult↗
PubMed2000

Leptin is influenced both by predisposition to obesity and diet composition.

OBJECTIVE: (1) To investigate whether plasma leptin concentrations differ between subjects with and without the genetic predisposistion to obesity, and (2) to investigate the effect of dietary manipulations on plasma leptin in these subjects. DESIGN: Fasting and postprandial plasma leptin concentrations were measured before and after 14 days' ad libitum intake of a fat-rich (FAT), starch-rich (STARCH) or sucrose-rich (SUCROSE) diet. On day 15 ad libitum breakfast and lunch were given and blood sampled regularly until 6 p.m. SUBJECTS: Eight normal-weight, post-obese women and 10 matched controls (body mass index, 23.5+/-0.5 and 22.9 +/- 0.3 kg/m2). MEASUREMENTS: Leptin, glucose, insulin, appetite ratings, dietary intake, body weight and composition. RESULTS: Fasting leptin concentration on day 1 or 15 did not differ between post-obese and controls. However, after meal intake leptin increased in post-obese compared with controls on all three diets. In both groups fasting and postprandial leptin concentrations were greater after SUCROSE compared with FAT and STARCH. CONCLUSION: A larger postprandial leptin concentration was observed in post-obese subjects than in controls. This may be related to greater insulin sensitivity in adipose tissue in the post-obese. Furthermore, increased leptin concentrations were found after a sucrose-rich diet in both groups, possibly related to larger postprandial insulin peaks on this diet. Both contentions should, however, be validated by further studies.

Adult↗
PubMed2000

Effect of obesity and major weight reduction on gastric emptying.

BACKGROUND: An enhanced gastric emptying rate might reduce the satiating effect of food and thereby promote obesity. Gastric emptying rate has previously been compared between obese and lean subjects with conflicting outcome. OBJECTIVE: Comparison of gastric emptying rate in lean and obese subjects before and after a major weight reduction. DESIGN: The study was designed as a case-control study comparing obese and lean subjects and a subsequent comparison of obese subjects before and after a dietary induced major weight reduction. METHOD: Gastric emptying rate following a solid test meal was estimated scintigraphically for 3 h using the left anterior oblique projection. SUBJECTS: Nineteen non-diabetic obese (mean BMI=38.7 kg/m2) and 12 lean (mean BMI=23.1 kg/m2) males matched for age and height. All obese subjects were re-examined after a mean weight loss of 18.8 kg (95% CI, 14.4-23.2) achieved by 16 weeks of dietary intervention followed by 8 weeks of weight stability. RESULTS: When comparing obese and lean subjects no differences were seen in overall 3 h emptying rate (30.3% per hour vs 30.5% per hour). However, a trend towards a higher percentage gastric emptying during the initial 30 min was seen in the obese when compared to lean subjects (24.0% vs 17.8% of the test meal; P=0.08). Weight loss was associated with a reduction in percentage gastric emptying during the initial 30 min (from 24.0% to 18.3% of the test-meal; P<0. 02), whereas the overall 3 h emptying rate was unaffected (30.3% vs 30.9% per hour). Neither initial or overall emptying rate differed between reduced-obese and lean subjects. CONCLUSION: Overall 3 h gastric emptying rate was similar in obese and normal weight males, and unaffected by a major weight loss. However, percentage gastric emptying during the initial 30 min for a solid meal appeared to be increased in obese males and was normalized after a major weight reduction.

Adolescent↗