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Biomedical subjects

Allan Geliebter

Publications and source records attributed to Allan Geliebter.

At least 19 recordsLinked to original sources
PubMed2006

Coffee, diabetes, and weight control.

Several prospective epidemiologic studies over the past 4 y concluded that ingestion of caffeinated and decaffeinated coffee can reduce the risk of diabetes. This finding is at odds with the results of trials in humans showing that glucose tolerance is reduced shortly after ingestion of caffeine or caffeinated coffee and suggesting that coffee consumption could increase the risk of diabetes. This review discusses epidemiologic and laboratory studies of the effects of coffee and its constituents, with a focus on diabetes risk. Weight loss may be an explanatory factor, because one prospective epidemiologic study found that consumption of coffee was followed by lower diabetes risk but only in participants who had lost weight. A second such study found that both caffeine and coffee intakes were modestly and inversely associated with weight gain. It is possible that caffeine and other constituents of coffee, such as chlorogenic acid and quinides, are involved in causing weight loss. Caffeine and caffeinated coffee have been shown to acutely increase blood pressure and thereby to pose a health threat to persons with cardiovascular disease risk. One short-term study found that ground decaffeinated coffee did not increase blood pressure. Decaffeinated coffee, therefore, may be the type of coffee that can safely help persons decrease diabetes risk. However, the ability of decaffeinated coffee to achieve these effects is based on a limited number of studies, and the underlying biological mechanisms have yet to be elucidated.

Animals↗
PubMed2005

Responsivity to food stimuli in obese and lean binge eaters using functional MRI.

Functional neuroimaging was employed to study 10 obese and 10 lean healthy young right-handed women, divided equally into binge and non-binge eaters. Subjects were presented with visual and auditory stimuli of binge type foods, non-binge type foods, and non-food stimuli in the fMRI scanner. Brain areas activated by both the visual and auditory stimuli across all individual subjects within a particular group was observed only for the binge food stimuli in the obese binge eaters, in the right premotor area, involved in planning of motor behavior. For four of the five obese binge eaters, the activation was in the ventral premotor cortex adjacent to the oral region, and may reflect past or concurrent motor planning about eating binge foods. Because a random effects group analysis has not yet been completed, this should be considered a preliminary report.

Adult↗
PubMed2005

Air displacement plethysmography: validation in overweight and obese subjects.

OBJECTIVE: Patients with moderate and severe obesity, because of their physical size, often cannot be evaluated with conventional body composition measurement systems. The BOD POD air displacement plethysmography (ADP) system can accommodate a large body volume and may provide an opportunity for measuring body density (D(b)) in obese subjects. D(b) can be used in two- or three-compartment body composition models for estimating total body fat in patients with severe obesity. The purpose of this study was to compare D(b) measured by ADP to D(b) measured by underwater weighing (UWW) in subjects ranging from normal weight to severely obese. RESEARCH METHODS AND PROCEDURES: D(b) was measured with UWW and BOD POD in 123 subjects (89 men and 34 women; age, 46.5 +/- 16.9 years; BMI, 31.5 +/- 7.3 kg/m2); 15, 70, and 10 subjects were overweight (25 < or = BMI < 30 kg/m2), obese (30 < or = BMI < 40 kg/m2), and severely obese (BMI > or = 40 kg/m2), respectively. RESULTS: There was a strong correlation between D(b) (kilograms per liter) measured by UWW and ADP (r = 0.94, standard error of the estimate = 0.0073 kg/L, p < 0.001). Similarly, percent fat estimates from UWW and ADP using the two-compartment Siri equation were highly correlated (r = 0.94, standard error of the estimate = 3.58%, p < 0.001). Bland-Altman analysis showed no significant bias between D(b) measured by UWW and ADP. After controlling for D(b) measured by ADP, no additional between-subject variation in D(b) by UWW was accounted for by subject age, sex, or BMI. DISCUSSION: Body density, an important physical property used in human body composition models, can be accurately measured by ADP in overweight and obese subjects.

Adipose Tissue↗
PubMed2005

Plasma ghrelin concentrations are lower in binge-eating disorder.

Binge-eating disorder (BED), characterized by binge meals without purging afterward, is found in about 30% of obese individuals seeking treatment. The study objective was to ascertain abnormalities in hormones influencing appetite in BED, especially ghrelin, an appetite-stimulating peptide, which was expected to be elevated. Measurements were made of plasma insulin, leptin, glucagon, cholecystokinin, and ghrelin, as well as glucose following an overnight 12-h fast, prior to and after ingestion (from 0 to 5 min) of a nutritionally complete liquid meal (1254 kJ) at 0830 h, at -15, 0, 5, 15, 30, 60, 90, and 120 min. Appetite ratings including hunger and fullness were also obtained. An acetaminophen tracer was used to assess gastric emptying rate. Three groups of comparably obese women (BMI = 35.9 +/- 5.5; % body fat = 44.9 +/- 4.7) participated: 12 nonbinge eating normals (NB), 14 subthreshold BED, and 11 BED. The BED subjects, compared to NB subjects, had lower baseline ghrelin concentrations prior to the meal, a lower area under the curve (AUC), with lower levels at 5, 15, 30, 90, and 120 min, and a smaller decline in ghrelin postmeal (all P < 0.03). The other blood values did not differ among groups, and neither did gastric emptying rate nor ratings of fullness. The BED subjects were then randomly assigned to treatment with cognitive-behavior therapy and diet (n = 5) or to a wait-list control (n = 4). Baseline ghrelin (P = 0.01) and AUC increased (P = 0.02), across both conditions, in which most subjects (7 of 9) stopped binge eating. The lower fasting and postmeal plasma ghrelin levels in BED are consistent with lower ghrelin levels in obese compared to lean individuals and suggests downregulation by binge eating.

Adult↗
PubMed2004

Impulsivity and test meal intake in obese binge eating women.

Greater impulsivity has been observed in those with chemical (cocaine, marijuana, alcohol) and behavioral addictions (gambling, sex, shopping), as well as in individuals with personality and conduct disorders. Greater impulsivity has also been described in those with Bulimia Nervosa and attributed to aberrations in serotonin, as has eating in response to negative affect. However, less is known about the impact of impulsivity on eating behavior in obese humans in general, and in those who meet sub-clinical and full clinical criteria for Binge Eating Disorder (BED) in particular. Using a laboratory test meal paradigm, we demonstrated: (1) greater Motor Impulsivity (Barratt Impulsivity Scale (BIS) (p = 0.05) in those with BED (n = 11) as compared to those without BED (n = 11) (2) a positive correlation between BED criteria and BIS scores (p < 0.01) (3) a positive correlation between test meal duration and Zung Depression Score, and (4) a positive correlation between Motor Impulsivity and mood rated before consuming the test meal. These associations suggest potential aberrations in serotonin transmission in BED, and a possible target for pharmacotherapy of BED especially in those who are resistant to Cognitive Behavioral Therapy.

Adult↗
PubMed2004

Exposure to appetitive food stimuli markedly activates the human brain.

OBJECTIVE: The increased incidence of obesity most likely reflects changes in the environment that had made food more available and palatable. Here we assess the response of the human brain to the presentation of appetitive food stimuli during food presentation using PET and FDG. METHOD: Metabolic changes in response to food presentation were done in 12 healthy normal body weight subjects who were food deprived before the study. RESULTS: Food presentation significantly increased metabolism in the whole brain (24%, P < 0.01) and these changes were largest in superior temporal, anterior insula, and orbitofrontal cortices. The increases in the right orbitofrontal cortex were the ones that correlated significantly with the increases in self-reports of hunger and desire for food. DISCUSSION: The marked increase in brain metabolism by the presentation of food provides evidence of the high sensitivity of the human brain to food stimuli. This high sensitivity coupled with the ubiquitousness of food stimuli in the environment is likely to contribute to the epidemic of obesity. In particular, the activation of the right orbitofrontal cortex, a brain region involved with drive, may underlie the motivation to procure food, which may be subjectively experienced as "desire for food" and "hunger" when exposed to food stimuli.

Adult↗
PubMed2004

Gastric capacity, test meal intake, and appetitive hormones in binge eating disorder.

Binge eating disorder (BED), characterized by ingestion of very large meals without purging afterwards, is found in a subset of obese individuals. We showed previously that stomach capacity is greater in obese than in lean subjects, and in this study, we investigated capacity in obese individuals with BED. We also determined ad-libitum intake of a test meal until extremely full. Furthermore, we measured various appetitive hormones (insulin, leptin, glucagon, CCK, ghrelin) and glucose before a fixed meal and for 120 min afterwards. An acetaminophen tracer was used to assess gastric emptying rate. We compared three groups of overweight women: 11 BED, 13 BE (subthreshold BED), and 13 non-binge-eating normals. The BED individuals had the largest stomach capacity as assessed by either maximum volume tolerated (P=.05) or by gastric compliance to pressure (P=.02) using an intragastric balloon. Although test meal intake did not differ between groups, it correlated (P=.03) with gastric capacity. The BED group showed a tendency (P=.06) to have greater area under the curve (AUC) and had higher values at 5 and 60 min (P<.05) for insulin compared to normals. Moreover, the BED subjects had lower ghrelin baselines premeal, and lower AUC for ghrelin, which then declined less postmeal than for the normals (P<.05). None of the other blood values differed, including glucose, leptin glucagon, and CCK, as well as acetaminophen, reflecting gastric emptying. The lower ghrelin in BED, although contrary to what was expected, is consistent with lower ghrelin in obesity, and suggests down-regulation of ghrelin by overeating. The lack of differences in CCK is consistent with the lack of differences in gastric emptying rate, given that CCK is released when nutrients reach the intestine. The results show that BED subjects have a large gastric capacity as well as abnormalities in meal-related ghrelin and insulin patterns that may be factors in binge eating.

Adult↗
PubMed2004

Peripheral and central signals in the control of eating in normal, obese and binge-eating human subjects.

The worldwide increase in the incidence of obesity is a consequence of a positive energy balance, with energy intake exceeding expenditure. The signalling systems that underlie appetite control are complex, and the present review highlights our current understanding of key components of these systems. The pattern of eating in obesity ranges from over-eating associated with binge-eating disorder to the absence of binge-eating. The present review also examines evidence of defects in signalling that differentiate these sub-types. The signalling network underlying hunger, satiety and metabolic status includes the hormonal signals leptin and insulin from energy stores, and cholecystokinin, glucagon-like peptide-1, ghrelin and peptide YY3-36 from the gastrointestinal tract, as well as neuronal influences via the vagus nerve from the digestive tract. This information is routed to specific nuclei of the hypothalamus and brain stem, such as the arcuate nucleus and the solitary tract nucleus respectively, which in turn activate distinct neuronal networks. Of the numerous neuropeptides in the brain, neuropeptide Y, agouti gene-related peptide and orexin stimulate appetite, while melanocortins and alpha-melanocortin-stimulating hormone are involved in satiety. Of the many gastrointestinal peptides, ghrelin is the only appetite-stimulating hormone, whereas cholecystokinin, glucagon-like peptide-1 and peptide YY3-36 promote satiety. Adipose tissue provides signals about energy storage levels to the brain through leptin, adiponectin and resistin. Binge-eating has been related to a dysfunction in the ghrelin signalling system. Moreover, changes in gastric capacity are observed, and as gastric capacity is increased, so satiety signals arising from gastric and post-gastric cues are reduced. Understanding the host of neuropeptides and peptide hormones through which hunger and satiety operate should lead to novel therapeutic approaches for obesity; potential therapeutic strategies are highlighted.

Adipocytes↗
PubMed2004

Cortisol stress response is positively correlated with central obesity in obese women with binge eating disorder (BED) before and after cognitive-behavioral treatment.

Stress is the most commonly reported trigger of binge eating, and high cortisol levels are positively related to both central body fat and food intake after laboratory stress. We therefore examined waist circumference (WHR) and cortisol stress responsivity after a cold pressor stress test (CPT) in 22 obese (BMI > 27) women (11 BED, 11 non-BED). BMI and WHR did not differ between groups. The BED group had higher morning basal cortisol than the non-BED group (P = .03) and greater AUC cortisol after CPT, after controlling for AUC insulin (P = .04). In the BED group, WHR was related to AUC cortisol (P = .002) and peak cortisol stress responsivity (P = .003). Twenty (10 non-BED, 10 BED) were randomized to a 6-week treatment program (CBT + Diet) or Wait-List (WL) control group. There were no BED group or treatment-group differences in WHR, morning basal cortisol, or AUC cortisol after CPT. The relationship between WHR and both AUC cortisol (P = .002) and peak cortisol stress responsivity after CPT (P = .008) remained significant in the BED group. In BED, there is a hyperactive HPA axis related to abdominal obesity that persists even after treatment, suggesting that cortisol might be a primary factor in the disorder.

Adipose Tissue↗
PubMed2003

Cholecystokinin and stomach distension combine to reduce food intake in humans.

The aim of this study was to test the hypothesis that gastric distension can enhance the effect of cholecystokinin (CCK) on reduction of food intake in men and women. Eight normal-weight subjects of each gender were tested four times each with either CCK or saline infusion crossed with gastric distension or no distension. Intravenous infusion of a low dose of CCK octapeptide (CCK-8; 112 ng/min for 23 min) combined with a subthreshold gastric distension induced by a water-filled balloon (300 ml) resulted in a significant (means +/- SED: 191 +/- 61 g in men, 209 +/- 61 g in women, and 200 +/- 43 g combined) reduction in intake of a liquid meal compared with saline infusion and unfilled gastric balloon. This combined effect was the result of a large and significant CCK effect when the stomach was distended (CCK vs. saline with distension: 169 +/- 43 g) and a small and insignificant distension effect (distension vs. no distension without CCK: 31 +/- 43 g). The CCK effect alone on intake (CCK vs. saline) without distension was not significant in men (72 +/- 61 g) but was significant in women (121 +/- 61 g). These results are consistent with the hypothesis that CCK's suppression of food intake is enhanced when the stomach is distended.

Adult↗
PubMed2003

Emotional eating in overweight, normal weight, and underweight individuals.

Emotional states and situations can affect food intake. We predicted that underweight individuals would eat less and overweight individuals would eat more during negative as well as positive emotional states and situations. Questionnaires to assess eating during emotional states and situations were distributed and collected in person in several major university and public libraries. Ninety questionnaires, representing for each gender the 15 most overweight, the 15 closest to normal weight, and the 15 most underweight, were analyzed. Gender had only minor effects on the eating ratings, and therefore the results are presented for the sexes combined. Underweight individuals reported eating less (P=.000) than both the normal and overweight groups during negative emotional states and situations. More surprisingly, underweight individuals also reported eating more (P=.01) than the other groups during positive emotional states and situations. Thus, part of the prediction was confirmed: the relative undereating by the underweight group, and the relative overeating by the overweight group during negative emotional states and situations. As compared to their usual eating behavior, undereating by underweight individuals during negative emotional states and situations was of a greater magnitude than their own overeating during positive states and situations (P=.01). Undereating by underweight individuals when experiencing negative emotions may contribute to their low body weight.

Journal Article↗
PubMed2003

Obese patients have inadequate protein intake related to protein intolerance up to 1 year following Roux-en-Y gastric bypass.

BACKGROUND: Inadequate protein intake is a concern following Roux-en-Y gastric bypass (RYGBP). The small gastric pouch and bypass restrict energy intake and may lead to insufficient protein intake and absorption, and excess loss of lean tissue. METHODS: We evaluated protein intake in 93 (77 F, 16 M) morbidly obese individuals (BMI = 52.0 +/- 12.9 [SD]) who underwent RYGBP at our medical center. Participants completed 24-hr food recalls and received nutritional counseling at 3, 6, and 12 months following surgery. RESULTS: Daily energy intake (kcal/day) increased from 849 +/- 329 (SD) at 3 months to 1,101 +/- 400 at 12 months (P = .009). Protein intake also increased (g/day) from 45.6 +/- 14.2 at 3 months to 58.5 +/- 17.1 at 12 months (P = .04), and as a percentage of goal protein intake from 55.1% +/- 23.0 at 3 months to 73.5% +/- 38.0 at 12 months (P = .02). Although energy and protein intake increased significantly over the 12-month period, protein intake at 12 months remained significantly lower (P = .01) than the daily recommended guidelines (1.5 g/kg IBW) for a low-energy restrictive diet. Energy intake did not differ in those who reported food intolerances at 3 months (P = .77) or 6 months (P = .65), but was lower in them at 12 months (trend, P = .06). Also at 12 months, protein intake (P = .02) and percentage of protein intake goal (P = .04) were significantly lower in those with protein intolerance. CONCLUSIONS: These results suggest that postoperative patients consume insufficient amounts of protein, possibly mediated by protein intolerance. Protein supplementation following RYGBP deserves further consideration.

Adult↗
PubMed2003

Depression score predicts weight loss following Roux-en-Y gastric bypass.

BACKGROUND: The prevalence of obesity is increasing in the United States. Bariatric surgery is the only intervention that can reliably induce and maintain significant weight loss in obese patients. The association between pre-surgical severity of depression and success at weight loss following Roux-en-Y gastric bypass (RYGBP) has not yet been fully elucidated. METHODS: 145 charts of patients who underwent RYGBP for morbid obesity were reviewed. 47 patients who filled out the Beck Depression Inventory (BDI) before surgery and completed 1 year of follow-up were studied. The relationship between pre-surgical severity of depression and success at weight loss was examined through multivariate regression analysis using percent excess weight loss (%EWL) as a dependent variable and BDI score as one of the predictors. RESULTS: Weight loss at 1 year was significantly related to the BDI score before surgery (P =0.014). BDI score was also found to be a significant predictor of the amount of weight lost (kg) 1 year after surgery (P =0.027). Age (P =0.03) and initial body mass index (BMI) (P =0.011) were the only other variables with significant independent relations to %EWL. CONCLUSIONS: Our data show a positive correlation between pre-surgical severity of depression as measured by BDI score and the 1-year success at weight loss after RYGBP as measured by %EWL. More depressed individuals tend to lose greater amounts of weight compared with less depressed individuals. Future prospective studies should examine possible mechanisms and effects of depression and other psychiatric disturbances on long-term weight loss after RYGBP.

Adult↗
PubMed2002

Body image disturbance in obese outpatients before and after weight loss in relation to race, gender, binge eating, and age of onset of obesity.

OBJECTIVE: To assess body image disturbance as a composite of three aspects (distortion, discrepancy, and dissatisfaction) in obese subjects before and after weight loss. Disturbance was then related to race, gender, binge eating behavior, and age of onset of obesity. METHODS: Eighty-two obese outpatients (24 males, 58 females) completed the Stunkard Figure Rating Scale (FRS). A Disturbance score was derived from the weighted sum of distortion, discrepancy, and dissatisfaction. The measures were repeated 4 weeks after starting a medically supervised liquid formula diet. RESULTS: Prior to weight loss, race (r =.28, p =.01) and gender (r =.25, p =.02) were each predictive of disturbance, with Caucasians and men having the most disturbance. Binge eaters exhibited more discrepancy (p =.03) and dissatisfaction (p =.005) than non-binge eaters. Early-onset subjects demonstrated more discrepancy than adult-onset subjects (p =.02). Following weight loss, disturbance scores decreased for all groups (p =.009). However, early-onset subjects still showed more discrepancy (p =.002) and more dissatisfaction (p =.005) than adult-onset subjects. DISCUSSION: Body image disturbance was viewed as a composite of three aspects. Prior to weight loss, the high disturbance score in Caucasians may be due to them experiencing greater cultural pressure to be thin. The men may have exaggerated their degree of obesity because of less denial of being overweight than women. Following weight loss, disturbance decreased for all groups but remained elevated for those with early onset, possibly because of a persistent self-image from adolescence.

Adolescent↗
PubMed2002

Racial/ethnic differences in body image and eating behaviors.

There is a growing literature on the relationship between race/ethnicity and body image and eating disorders, but the conclusions are still unclear. We therefore examined racial/ethnic influences on body image and eating behaviors in 108 Caucasian, 46 African American, and 40 Asian female undergraduates. Participants completed the Figure Rating Scale (FRS) and the Eating Habits Questionnaire (EHQ) to assess body image and eating pathology. Caucasians had greater body discrepancy (difference between current and ideal) than Asians (P=.05) and higher EHQ scores (P<.0001) than both Asians and African Americans. African Americans chose a larger ideal body size than the other groups (P=.005). However, Asian women had a significantly lower body mass index (BMI) than both groups (P<.0001). After controlling for BMI, ideal body size differences were minimized (P=.08). Also, now, both Caucasians and Asians had greater body discrepancy (P<.0001) and EHQ scores (P<.0001) than African Americans. Our findings help reconcile inconsistencies in the literature by demonstrating the impact of controlling for BMI when comparing body image and eating behaviors in individuals from different racial/ethnic backgrounds.

Journal Article↗