Eating behavior dimensions. Associations with energy intake and body weight. A review

Individual differences in susceptibility to large portion sizes among obese and normal-weight children

OBJECTIVE

Determine the association of children's susceptibility to large food portion sizes with appetite regulation and obesity.

METHODS

Normal-weight and obese non-Hispanic black children (n = 100) aged 5-6 years were observed in four dinner conditions of varying portion size; portions of all foods (except milk) offered were: 100% (677 kcal), 150% (1015 kcal), 200% (1353 kcal), or 250% (1691 kcal) of those in the reference condition (100%). Condition order was randomly assigned to 2-4 children who ate together at each meal. Child height and weight were measured and caregiver reports of child appetite were obtained. Hierarchical growth curve models were used to estimate associations of meal energy intake with portion size condition, child weight status, and appetite regulation traits, controlling for demographics.

RESULTS

Total energy intake increased across conditions of increasing food portion size (P < 0.001). The effect of portion size condition on total energy intake varied with food responsiveness (P = 0.05) and satiety responsiveness (P < 0.05), but not weight status (P = 0.682). Children with lower satiety responsiveness and greater food responsiveness showed greater increases in meal energy across conditions.

CONCLUSIONS

Children with poorer appetite regulation may be more vulnerable to obesogenic dietary environments offering large food portions than other children.

Implication of corticotropic hormone axis in eating behaviour pattern in obese and type 2 diabetic participants

In Algeria, eating behaviour has been increasingly deviated from its traditional Mediterranean diet to modern fast food style. The present study examines the interactions between eating behaviour pattern (EBP), corticotropic hormone axis and the metabolic syndrome. Our Algerian population cohort comprised of 410 participants (130 obese, 170 type 2 diabetics and 110 healthy participants). The EBP was evaluated by the Three-Factor Eating Questionnaire test. The anthropometric and metabolic parameters (glucose, TAG, HDL, LDL and cholesterol) and the concentrations of hormones (insulin, adrenocorticotropin hormone (ACTH), cortisol and growth hormone) were determined by biometrics, spectrophotometry and RIA, respectively. Multivariate analyses showed a high correlation between the EBP and the metabolic syndrome, particularly between insulin-resistant state and hypertrophy of visceral adipose tissue. Compared with healthy participants, obese ones showed the hyperphagic type of EBP, i.e. disinhibition and hunger disorders. Conversely, the diabetics showed both the hypophagic and hyperphagic type of EBP. In diabetic and obese participants, cortisol and ACTH secretions were significantly altered, leading to metabolic disorders. The present study confirms the role of EBP in obesity and diabetes.

Origins of food reinforcement in infants

BACKGROUND

Rapid weight gain in infancy is associated with a higher risk of obesity in children and adults. A high relative reinforcing value of food is cross-sectionally related to obesity; lean children find nonfood alternatives more reinforcing than do overweight/obese children. However, to our knowledge, there is no research on how and when food reinforcement develops.

OBJECTIVE

This study was designed to assess whether the reinforcing value of food and nonfood alternatives could be tested in 9- to 18-mo-old infants and whether the reinforcing value of food and nonfood alternatives is differentially related to infant weight status.

DESIGN

Reinforcing values were assessed by using absolute progressive ratio schedules of reinforcement, with presentation of food and nonfood alternatives counterbalanced in 2 separate studies. Two nonfood reinforcers [Baby Einstein-Baby MacDonald shows (study 1, n = 27) or bubbles (study 2, n = 30)] were tested against the baby's favorite food. Food reinforcing ratio (FRR) was quantified by measuring the reinforcing value of food (Food Pmax) in proportion to the total reinforcing value of food and a nonfood alternative (DVD Pmax or BUB Pmax).

RESULTS

Greater weight-for-length z score was associated with a greater FRR of a favorite food in study 1 (FRR-DVD) (r = 0.60, P < 0.001) and FRR of a favorite food in study 2 (FRR-BUB) (r = 0.49, P = 0.006), primarily because of the strong association between greater weight-for-length z score and lower DVD Pmax (r = -0.71, P < 0.0001) and BUB Pmax (r = -0.53, P = 0.003). Infant monthly weight gain was positively associated with FRR-DVD (r = 0.57, P = 0.009) and FRR-BUB (r = 0.37, P = 0.047).

CONCLUSIONS

Our newly developed paradigm, which tested 2 different nonfood alternatives, demonstrated that lean infants find nonfood alternatives more reinforcing than do overweight/obese infants. This observation suggests that strengthening the alternative reinforcers may have a protective effect against childhood obesity.

Quantitative gastrointestinal and psychological traits associated with obesity and response to weight-loss therapy

BACKGROUND & AIMS

Weight loss after pharmacotherapy varies greatly. We aimed to examine associations of quantitative gastrointestinal and psychological traits with obesity, and to validate the ability of these traits to predict responses of obese individuals to pharmacotherapy.

METHODS

In a prospective study, we measured gastric emptying of solids and liquids, fasting and postprandial gastric volume, satiation by nutrient drink test (volume to fullness and maximal tolerated volume), satiety after an ad libitum buffet meal, gastrointestinal hormones, and psychological traits in 328 normal-weight, overweight, or obese adults. We also analyzed data from 181 previously studied adults to assess associations betwecen a subset of traits with body mass index and waist circumference. Latent dimensions associated with overweight or obesity were appraised by principal component analyses. We performed a proof of concept, placebo-controlled trial of extended-release phentermine and topiramate in 24 patients to validate associations between quantitative traits and response to weight-loss therapy.

RESULTS

In the prospective study, obesity was associated with fasting gastric volume (P = .03), accelerated gastric emptying (P < .001 for solids and P = .011 for liquids), lower postprandial levels of peptide tyrosine tyrosine (P = .003), and higher postprandial levels of glucagon-like peptide 1 (P < .001). In a combined analysis of data from all studies, obesity was associated with higher volume to fullness (n = 509; P = .038) and satiety with abnormal waist circumference (n = 271; P = .016). Principal component analysis identified latent dimensions that accounted for approximately 81% of the variation among overweight and obese subjects, including satiety or satiation (21%), gastric motility (14%), psychological factors (13%), and gastric sensorimotor factors (11%). The combination of phentermine and topiramate caused significant weight loss, slowed gastric emptying, and decreased calorie intake; weight loss in response to phentermine and topiramate was significantly associated with calorie intake at the prior satiety test.

CONCLUSIONS

Quantitative traits are associated with high body mass index; they can distinguish obesity phenotypes and, in a proof of concept clinical trial, predicted response to pharmacotherapy for obesity. ClinicalTrials.gov Number: NCT01834404.

Food reward. What it is and how to measure it

We investigated the contribution of hunger and food liking to food reward, and the relationship between food reward and food intake. We defined liking as the pleasantness of taste of food in the mouth, and food reward as the momentary value of a food to the individual at the time of ingestion. Liking and food reward were measured, respectively, by ratings of the pleasantness of the taste of a mouthful, and ratings of desire to eat a portion, of the food in question. Hunger, which we view as primarily the absence of fullness, was rated without food being present. Study 1 provided evidence that hunger and liking contribute independently to food reward, with little effect of hunger on liking. Food intake reduced liking and reward value more for the eaten food than uneaten foods. The results were ambiguous as to whether this food-specific decline in reward value ('sensory-specific satiety') involved a decrease in 'wanting' in addition to the decrease in liking. Studies 2 and 3 compared desire to eat ratings with work-for-food and pay-for-food measures of food reward, and found desire to eat to be equal or superior in respect of effects of hunger and liking, and superior in predicting ad libitum food intake. A further general observation was that in making ratings of food liking participants may confuse the pleasantness of the taste of food with the pleasantness of eating it. The latter, which some call 'palatability,' decreases more with eating because it is significantly affected by hunger/fullness. Together, our results demonstrate the validity of ratings of desire to eat a portion of a tasted food as a measure of food reward and as a predictor of food intake.

CE: The obesity epidemic, part 1: understanding the origins

OVERVIEW

The obesity epidemic remains a significant health problem in the United States and worldwide, with multiple associated physical and societal costs. To contribute to obesity's treatment and prevention, nurses must be conversant in a wide range of theoretical and clinical perspectives on the problem. This article, the first in a two-part series, defines the terms used in the treatment of obesity and outlines pathophysiologic, psychological, and social factors that influence weight control. Part 2, which will appear in next month's issue, presents a theoretical framework that can be used to guide nursing assessment of both patient and family, thereby informing intervention.

Right sizing prevention. Food portion size effects on children's eating and weight

Experimental findings provide consistent evidence that increasing the portion size of palatable, energy dense entrees relative to an age appropriate reference portion increases children's energy intake of the entree and the meal. Most of these studies have been conducted on preschool aged children between 2 and 6 years of age, in childcare or laboratory settings, using repeated measures designs. In these studies, children's intake is compared across a series of meals, where the size of the entrée portion is varied and other aspects of the meal, including the portion size of other items on the menu, are held constant. This paper provides an overview of what we know from this research, what is not known about the effects of portion size on children's intake and weight status, and points to some of the important unanswered questions and gaps in the literature. Lastly, we discuss how individual characteristics may make someone more or less susceptible to large portions of foods and how the palatability of foods may moderate observed associations among portion size, children's intake, and weight status. Future studies that address the gaps identified in this paper are needed to inform policy and to develop effective and efficient interventions to prevent childhood obesity.

Mechanisms of the portion size effect. What is known and where do we go from here?

Childhood obesity is a persistent problem worldwide, and of particular concern in the United States. Clarifying the role of the food environment in promoting overeating is an important step toward reducing the prevalence of obesity. One potential contributor to the obesity epidemic is the increased portion sizes of foods commonly served. Portion sizes of foods served both at home and away from home have dramatically increased over the past 40 years. Consistently, short-term studies have demonstrated that increasing portion size leads to increased food intake in adults and children, a phenomenon known as the portion size effect. However, the mechanisms underlying this effect are poorly understood. Understanding these mechanisms could assist in clarifying the relationship between portion size and weight status and help inform the development of effective obesity interventions. First, we review the role of visual cues, such as plate size, unit, and utensil size as a potential moderator of the portion size effect. In addition, we discuss meal microstructure components including bite size, rate, and frequency, as these may be altered in response to different portion sizes. We also review theories that implicate post-ingestive, flavor-nutrient learning as a key moderator of the portion size effect. Furthermore, we present preliminary data from an ongoing study that is applying neuroimaging to better understand these mechanisms and identify modifiable child characteristics that could be targeted in obesity interventions. Our tentative findings suggest that individual differences in cognitive (e.g. loss of control eating) and neural responses to food cues may be critical in understanding the mechanisms of the portion size effect. To advance this research area, studies that integrate measures of individual subject-level differences with assessment of food-related characteristics are needed.

Understanding eating in the absence of hunger among young children: a systematic review of existing studies

BACKGROUND

Eating in the Absence of Hunger (EAH), or consuming highly palatable foods when satiated, is one behavioral pathway that may lead to childhood obesity. EAH is an objective, laboratory-based measure. A more comprehensive understanding of potential determinants of EAH could inform childhood obesity programs outside of a laboratory setting.

OBJECTIVE

Systematic review of EAH experiments to identify individual, familial, and societal-level correlates of EAH among children 12 years of age or younger.

DESIGN

1487 studies were retrieved from five electronic databases (Medline [PubMed], Web of Science, Cochrane Library, CINAHL, PsycINFO). Eligible studies were those that measured EAH as initially operationalized in a laboratory setting enrolling children ≤12 years or reporting age-specific results for children ≤12 years. Only articles written in English were included.

RESULTS

12 cross-sectional, six prospective, and one behavioral-intervention studies were included in the review. EAH was observable among boys and girls; absolute levels of EAH increased with age; and maternal feeding styles were associated with EAH among girls. The most consistent evidence supported increased levels of EAH among overweight and obese versus normal weight children, both cross-sectionally and prospectively. Two studies supported a genetic component to EAH.

CONCLUSIONS

Studies enrolling independent samples support a positive association between weight status and EAH among children; studies addressing causality are needed. Other various individual, genetic, and familiar characteristics were associated with EAH, yet studies among more heterogeneous sample populations are needed to confirm findings. Studies addressing societal-level factors related to EAH were absent.

Metabolite profile deviations in an oral glucose tolerance test-a comparison between lean and obese individuals

OBJECTIVE

While impaired glucose tolerance diagnosed by the oral glucose tolerance test (OGTT) is a common trait in obese individuals, less is known about changes in levels of other metabolites. The aim was to reveal the complex alterations in metabolite levels provoked by an OGTT and its perturbation in obese individuals.

METHODS

Gas chromatography/mass spectrometry was used to profile metabolite levels in serum from 14 obese participants (body mass index [BMI] of 43.6 ± 1.5 kg m(-2) [mean ± SEM]) at 0, 30, and 120 min during a standard 2-h 75 g OGTT. Metabolite profiles from six lean individuals (BMI of 22.4 ± 2.4 kg m(-2) ), collected from a previous study, were included for comparison.

RESULTS

In the obese group, 59 metabolite profiles were determined. Among these, 16 deviated from profiles in the lean group. Deviating metabolites were categorized into three groups. Delayed reduction in levels of five fatty acids. Increased levels at 30 min of five amino acids, including isoleucine and leucine. A blunted increase at 30 min of six metabolites.

CONCLUSIONS

Metabolomics analysis revealed distinct differences in alterations of metabolite levels during an OGTT in obese and lean subjects. To this end, our data suggests a disrupted regulation of ketogenesis, lipolysis and proteolysis in obese individuals.

Eating behavior traits and sleep as determinants of weight loss in overweight and obese adults

Objective:

To examine the associations between eating behavior traits and weight loss according to sleep quality and duration in adults enrolled in common weight-loss interventions.

Methods:

Participants included overweight and obese men and women (n=150) (mean±s.d. age, 38.8±8.6 years; mean±s.d. body mass index (BMI), 33.3±3.5 kg m⁻²) who were subjected to a dietary intervention over a period of 12–16 weeks. Anthropometric measurements, eating behavior traits (Three-Factor Eating Questionnaire), sleep quality (total Pittsburgh Sleep Quality Index (PSQI) score) and sleep duration (hours per night, self-reported from the PSQI) were assessed at both baseline and post intervention. Linear regression analysis was used to quantify the relationships between eating behavior traits and changes in anthropometric markers for all subjects and by sleep categories (short sleep: <7 h per night vs recommended sleep: ⩾7 h per night; poor sleep quality: ⩾5 PSQI score vs good sleep quality: <5 PSQI score). We adjusted for age, sex and baseline BMI in analyses.

Results:

Baseline eating behavior traits were modest predictors of weight-loss success, but they were all significantly associated with their changes over the weight-loss intervention (P<0.01). The diet intervention induced significant changes in eating behavior traits and even more for those having a non-favorable eating behavior profile at baseline. We observed that changes in flexible control and strategic dieting behavior were constantly negatively associated with changes in body weight and fat mass (P<0.05) for recommended duration sleepers. The change in situational susceptibility to disinhibition was positively associated with the change in fat mass and body weight for those having healthy sleeping habits (P<0.05). For poor quality sleepers, the change in avoidance of fattening foods was negatively associated with changes in adiposity (P<0.05).

Conclusion:

Eating behavior traits and sleep may act together to influence the outcome of weight-loss programs.

Meal pattern of male rats maintained on amino acid supplemented diets: the effect of tryptophan, lysine, arginine, proline and threonine

The macronutrient composition of the diet has been shown to affect food intake, with proteins having distinct effects. The present study investigated the effect of diet supplementation with individual amino acids (tryptophan, lysine, arginine, proline and threonine) on meal pattern among male rats. Meal pattern and body weight were monitored for two weeks. Proline and threonine had minimal effects on meal pattern, while the most pronounced changes were observed in the tryptophan group. Both tryptophan and lysine decreased overall food intake, which was translated into a reduction in body weight. The reduced food intake of the tryptophan group was associated with an increase in meal size, intermeal intervals (IMI) and meal time and a decrease in meal number. The decrease in the food intake of the lysine group was associated with a reduction in both IMI and meal number, and this was accompanied by an increase in meal time. Arginine increased meal number, while decreasing IMI. Proline and threonine had a minimal effect on meal pattern. Lysine seems to increase satiety, and arginine seems to decrease it, while tryptophan seems to increase satiety and decrease satiation. Accordingly, changes in meal patterns are associated with the type of amino acid added to the diet.

A physiological perspective on the neuroscience of eating

I present the thesis that 'being physiological,' i.e., analyzing eating under conditions that do not perturb, or minimally perturb, the organism's endogenous processes, should be a central goal of the neuroscience of eating. I describe my understanding of 'being physiological' based on [i] the central neural-network heuristic of CNS function that traces back to Cajal and Sherrington, [ii] research on one of the simpler problems in the neuroscience of eating, identification of endocrine signals that control eating. In this context I consider natural meals, physiological doses and ranges, and antagonist studies. Several examples involve CCK. Next I describe my view of the cutting edge in the molecular neuroscience of eating as it has evolved from the discovery of leptin signaling through the application of optogenetic and pharmacogenetic methods. Finally I describe some novel approaches that may advance the neuroscience of eating in the foreseeable future. I conclude that [i] the neuroscience of eating may soon be able to discern 'physiological' function in the operation of CNS networks mediating eating, [ii] the neuroscience of eating should capitalize on methods developed in other areas of neuroscience, e.g., improved methods to record and manipulate CNS function in behaving animals, identification of canonical regional circuits, use of population electrophysiology, etc., and [iii] subjective aspects of eating are crucial aspects of eating science, but remain beyond mechanistic understanding.

Concurrent and convergent validity of the eating in the absence of hunger questionnaire and behavioral paradigm in overweight children

OBJECTIVE

This study aimed to assess the concurrent and convergent validity of the Eating in the Absence of Hunger (EAH) questionnaire parent report of child (EAH-PC) and child self-report (EAH-C) with the EAH behavioral paradigm (EAH%) and usual dietary intake.

METHOD

Data were obtained at baseline assessment for 117 treatment-seeking overweight and obese (BMI > 85th percentile) 8- to 12-year old children (53% female, 54% white) and their parents. Children participated in the EAH free access paradigm after a standardized ad libitum meal. Parents and children completed EAH questionnaires, and the children completed three 24 h recalls. EAH External Eating subscale and total scores were assessed.

RESULTS

EAH% was inversely associated with the EAH-PC total score (p < .04), however, it was not associated with the EAH-PC External Eating scale, EAH-C total score or EAH-C External Eating scale. Daily caloric intake was positively related to both the EAH-C total score (p < .02) and External Eating subscale (p < .007). Daily caloric intake was inversely related to EAH-PC total score (p < .05), but was not related to EAH-PC External Eating subscale or EAH%.

DISCUSSION

Concurrent validity was not supported for EAH questionnaires, but convergent validity was supported for EAH-C and child daily caloric intake. Further research is warranted to assess whether EAH questionnaires and paradigm are measuring different aspects of EAH in treatment-seeking children.

Fasting for 24 hours heightens reward from food and food-related cues

Introduction

We examined the impact of a 24 hour complete fast (vs. fed state) on two measures of food reward: 1) ‘wanting’, as measured by response to food images and by the relative-reinforcing value of food (RRV), and 2) ‘liking’, as measured by response to food images and the hedonic evaluation of foods consumed.

Methods

Utilizing a randomized crossover design, 15 subjects (9 male; 6 female) aged 28.6±4.5 yrs with body mass index 25.3±1.4 kg/m² were randomized and counterbalanced to normal feeding (FED) and 24-hour fast (FASTED) conditions. Trait characteristics were measured with the Three Factor Eating Questionnaire. Two computer tasks measured food reward: 1) RRV progressive ratio task, 2) explicit ‘liking’ and ‘wanting’ (Leeds Food Preference Questionnaire, LFPQ). Also measured were ad libitum energy intake (EI; buffet) and food ‘liking’ (visual analogue scale) of personalized stimuli.

Results

There were no significant anthropometric changes between conditions. Appetite scores, hedonic ratings of ‘liking’, and ad libitum EI all significantly increased under the FASTED condition (p<0.05). Under the FASTED condition there were significant increases in the RRV of snack foods; similarly, explicit ‘wanting’ and ‘liking’ significantly increased for all food categories. ‘Liking’ of sweet foods remained high across-meals under FASTED, but savory foods decreased in hedonic saliency.

Conclusion

Relative to a fed state, we observed an increase in hedonic ratings of food, the rewarding value of food, and food intake after a 24 hr fast. Alliesthesia to food and food cues is suggested by heightened hedonic ratings under the FASTED condition relative to FED.

Morningness-eveningness, depressive symptoms, and emotional eating: a population-based study

The aim of this study was to increase understanding of the associations between different dimensions of morningness-eveningness, depressive symptoms, and emotional eating in the general population. The participants were 25-to-74-year-old Finnish men (n = 2325) and women (n = 2699) from the National FINRISK Study conducted in 2007. The Center for Epidemiological Studies - Depression Scale and the Three-Factor Eating Questionnaire-R18 were used to measure depressive symptoms and emotional eating. Chronotype was assessed with a shortened version of Horne and Östberg's Morningness-Eveningness Questionnaire (MEQ). Structural equation modeling was used as an analytical approach. Confirmatory factor analysis indicated a two-factor structure for the six-item MEQ with separate factors for morning alertness and circadian preference for daily activities (r = 0.65). Higher alertness in the morning and preference for morning hours were both related to lower depressive symptoms (βtotal effect = -0.36 and -0.11, respectively) and emotional eating (βtotal effect = -0.20 and -0.09; βindirect effect through depressive symptoms = -0.12 and -0.04, respectively), even though the relationships with morning alertness were stronger. However, the associations of circadian preference with depressive symptoms and emotional eating were reversed after adjustment for morning alertness. Finally, among participants who rarely or never experienced sleeping sufficiently, those in the lowest (i.e. eveningness) and higher (i.e. morningness) circadian preference/morning alertness quartiles had the highest depressive symptom scores. In conclusion, the findings emphasize the importance of separating between different dimensions of chronotype when examining its relationships with psychological factors such as depressive symptoms and overeating tendencies.

Effectiveness of a cognitive behavioral therapy for dysfunctional eating among patients admitted for bariatric surgery: a randomized controlled trial

OBJECTIVE

To examine whether cognitive behavioral therapy (CBT) alleviates dysfunctional eating (DE) patterns and symptoms of anxiety and depression in morbidly obese patients planned for bariatric surgery.

DESIGN AND METHODS

A total of 98 (68 females) patients with a mean (SD) age of 43 (10) years and BMI 43.5 (4.9) kg/m(2) were randomly assigned to a CBT-group or a control group receiving usual care (i.e., nutritional support and education). The CBT-group received ten weekly intervention sessions. DE, anxiety, and depression were assessed by the TFEQ R-21 and HADS, respectively.

RESULTS

Compared with controls, the CBT-patients showed significantly less DE, affective symptoms, and a larger weight loss at follow-up. The effect sizes were large (DE-cognitive restraint, g = -.92, P ≤ .001; DE-uncontrolled eating, g = -.90, P ≤ .001), moderate (HADS-depression, g = -.73, P ≤ .001; DE-emotional eating, g = -.67, P ≤ .001; HADS-anxiety, g = -.62, P = .003), and low (BMI, g = -.24, P = .004).

CONCLUSION

This study supports the use of CBT in helping patients preparing for bariatric surgery to reduce DE and to improve mental health. This clinical trial is registered with NCT01403558.

Influence of feeding state on neurofunctional differences between individuals who are obese and normal weight: a meta-analysis of neuroimaging studies

Obesity is a complex disorder associated with serious health risks. Examining differences in brain activity between normal weight and obese populations in response to food cues may help researchers and clinicians understand the underlying causes of overeating and obesity and help prevent them. Multiple neuroimaging studies have investigated weight differences in functional activity to food cues but have found varying results. We performed six meta-analyses of functional neuroimaging studies of weight differences in response to food images and isolated differences in processing between normal weight and obese participants. Within this study, 7 papers and 3 sets of unpublished data on functional activation to food images were analyzed using an Activation Likelihood Estimation meta-analytic approach. These analyses also addressed how feeding state impacts functional activity between weight groups. Feeding state affected weight related differences in neurofunctional activity triggered by visual food cues. In the premeal state, greater activation in the amygdala/hippocampus was found in obese participants compared to normal weight participants and, in the postmeal state, obese individuals had greater activation in the caudate and medial prefrontal cortex (MPFC) as compared to normal weight individuals. Regions of the brain associated with caloric evaluation, arousal, and memory were more active in the obese before eating, while less activity was found in an area linked to interoceptive processing. In the postmeal state, greater activity was found in the obese in areas related to risk vs. reward evaluation and reward processing. These findings may help researchers and clinicians understand and treat obesity related behaviors by identifying the altered functional regions that lead to obesity, providing a guide for future research on which neural regions need to be the target of further investigation.

Aspiration therapy leads to weight loss in obese subjects: a pilot study

BACKGROUND & AIMS

Obese patients rarely achieve long-term weight loss with only lifestyle interventions. We evaluated the use of endoscopic aspiration therapy for obesity. Aspiration therapy involves endoscopic placement of a gastrostomy tube (A-Tube) and the AspireAssist siphon assembly (Aspire Bariatrics, King of Prussia, PA) to aspirate gastric contents 20 minutes after meal consumption.

METHODS

We performed a pilot study of 18 obese subjects who were randomly assigned (2:1) to groups that underwent aspiration therapy for 1 year plus lifestyle therapy (n = 11; mean body mass index, 42.6 ± 1.4 kg/m(2)) or lifestyle therapy only (n = 7; mean body mass index, 43.4 ± 2.0 kg/m(2)). Lifestyle intervention comprised a 15-session diet and behavioral education program.

RESULTS

Ten of the 11 subjects who underwent aspiration therapy and 4 of the 7 subjects who underwent lifestyle therapy completed the first year of the study. After 1 year, subjects in the aspiration therapy group lost 18.6% ± 2.3% of their body weight (49.0% ± 7.7% of excess weight loss [EWL]) and those in the lifestyle therapy group lost 5.9% ± 5.0% (14.9% ± 12.2% of EWL) (P < .04). Seven of the 10 subjects in the aspiration therapy group completed an additional year of therapy and maintained a 20.1% ± 3.5% body weight loss (54.6% ± 12.0% of EWL). There were no adverse effects of aspiration therapy on eating behavior and no evidence of compensation for aspirated calories with increased food intake. No episodes of binge eating in the aspiration therapy group or serious adverse were reported.

CONCLUSIONS

In a pilot study, aspiration therapy appears to be a safe and effective long-term weight loss therapy for obesity.

Questionnaire and laboratory measures of eating behavior. Associations with energy intake and BMI in a community sample of working adults

PURPOSE

The present research compared a self-report measure of usual eating behaviors with two laboratory-based behavioral measures of food reward and food preference.

METHODS

Eating behaviors were measured among 233 working adults. A self-report measure was the Three Factor Eating Questionnaire (TFEQ) Restraint, Disinhibition and Hunger subscales. Laboratory measures were the (RVF) and Explicit Liking (EL) and Implicit Wanting (IW) for high fat food. Outcome measures were body mass index (BMI), and energy intake measured using three 24-h dietary recalls.

RESULTS

Significant bivariate associations were observed between each of the eating behavior measures and energy intake, but only Disinhibition and Hunger were associated with BMI. Multiple regression results showed RVF and EL and IW predicted energy intake independent of the TFEQ scales but did not predict BMI.

CONCLUSION

Laboratory and self-report measures capture unique aspects of individual differences in eating behaviors that are associated with energy intake.

Facial affective reactions to bitter-tasting foods and body mass index in adults

Differences in food consumption among body-weight statuses (e.g., higher fruit intake linked with lower body mass index (BMI) and energy-dense products with higher BMI) has raised the question of why people who are overweight or are at risk of becoming overweight eat differently from thinner people. One explanation, in terms of sensitivity to affective properties of food, suggests that palatability-driven consumption is likely to be an important contributor to food intake, and therefore body weight. Extending this approach to unpalatable tastes, we examined the relationship between aversive reactions to foods and BMI. We hypothesized that people who have a high BMI will show more negative affective reactions to bitter-tasting stimuli, even after controlling for sensory perception differences. Given that hedonic reactions may influence consumption even without conscious feelings of pleasure/displeasure, the facial expressions were included in order to provide more direct access to affective systems than subjective reports. Forty adults (28 females, 12 males) participated voluntarily. Their ages ranged from 18 to 46 years (M=24.2, SD=5.8). On the basis of BMI, participants were classified as low BMI (BMI<20; n=20) and high BMI (BMI>23; n=20). The mean BMI was 19.1 for low BMI (SD=0.7) and 25.2 for high BMI participants (SD=1.8). Each subject tasted 5 mL of a grapefruit juice drink and a bitter chocolate drink. Subjects rated the drinks' hedonic and incentive value, familiarity and bitter intensity immediately after each stimulus presentation. The results indicated that high BMI participants reacted to bitter stimuli showing more profound changes from baseline in neutral and disgust facial expressions compared with low BMI. No differences between groups were detected for the subjective pleasantness and familiarity. The research here is the first to examine how affective facial reactions to bitter food, apart from taste responsiveness, can predict differences in BMI.

Sex differences in the physiology of eating

Hypothalamic-pituitary-gonadal (HPG) axis function fundamentally affects the physiology of eating. We review sex differences in the physiological and pathophysiological controls of amounts eaten in rats, mice, monkeys, and humans. These controls result from interactions among genetic effects, organizational effects of reproductive hormones (i.e., permanent early developmental effects), and activational effects of these hormones (i.e., effects dependent on hormone levels). Male-female sex differences in the physiology of eating involve both organizational and activational effects of androgens and estrogens. An activational effect of estrogens decreases eating 1) during the periovulatory period of the ovarian cycle in rats, mice, monkeys, and women and 2) tonically between puberty and reproductive senescence or ovariectomy in rats and monkeys, sometimes in mice, and possibly in women. Estrogens acting on estrogen receptor-α (ERα) in the caudal medial nucleus of the solitary tract appear to mediate these effects in rats. Androgens, prolactin, and other reproductive hormones also affect eating in rats. Sex differences in eating are mediated by alterations in orosensory capacity and hedonics, gastric mechanoreception, ghrelin, CCK, glucagon-like peptide-1 (GLP-1), glucagon, insulin, amylin, apolipoprotein A-IV, fatty-acid oxidation, and leptin. The control of eating by central neurochemical signaling via serotonin, MSH, neuropeptide Y, Agouti-related peptide (AgRP), melanin-concentrating hormone, and dopamine is modulated by HPG function. Finally, sex differences in the physiology of eating may contribute to human obesity, anorexia nervosa, and binge eating. The variety and physiological importance of what has been learned so far warrant intensifying basic, translational, and clinical research on sex differences in eating.

Dietary disinhibition modulates neural valuation of food in the fed and fasted states

BACKGROUND

Dietary disinhibition is a behavioral trait associated with weight gain and obesity. Because food choices are made according to the relative value assigned to each option, examination of valuation signals through functional magnetic resonance imaging (fMRI) may elucidate the neural basis for the association between dietary disinhibition and weight gain.

OBJECTIVE

We examined how food valuation signals differ in the fed and fasted states between persons with high dietary disinhibition (HD) and low dietary disinhibition (LD).

DESIGN

Sixteen men with HD and 14 with LD underwent fMRI once while fasted and once after being fed in a counterbalanced order. In-scanner preference to consume a test food relative to a neutral-tasting, neutral-health reference food was examined. The slope of magnetic resonance signal change corresponding to these food preferences constituted the food valuation signal that was compared across disinhibition group and satiety state.

RESULTS

Both the HD and LD participants reported being less hungry (F(1,28) = 113.11, P < 0.001) after being fed than when fasted. However, food valuation signals in the ventromedial prefrontal cortex (vmPFC) differed between the groups (F(1,28) = 21.34, P < 0.001). Although LD participants showed attenuated vmPFC activity after being fed (t(13) = 4.11, P < 0.001), HD participants showed greater vmPFC activity in the fed than in the fasted state (t(15) = -2.56, P < 0.05).

CONCLUSIONS

Despite reporting normal decreases in hunger ratings after being fed, persons with HD have an altered neural valuation of food. This may be a mechanism underlying their propensity to overeat and gain weight. This trial was registered at clinicaltrials.gov as NCT00988819.

Sociocultural pressures and adolescent eating in the absence of hunger

Parental feeding practices and sociocultural pressures theoretically influence eating behavior. Yet, whether these factors relate to eating in the absence of hunger (EAH) is unknown. We assessed if sociocultural pressures were associated with EAH among 90 adolescents (Mage=15.27, SD=1.39; 48% female). Parents completed the Child Feeding Questionnaire. Adolescents completed the Perceived Sociocultural Pressures Scale, Sociocultural Attitudes Towards Appearance Questionnaire-3, and Multidimensional Body Self-Relations Questionnaire-Appearance Scales. On two occasions, EAH was assessed as snack food intake after adolescents ate to satiety. Controlling for body composition and demographics, parental restriction and family pressure to be thin were associated with greater EAH. Media pressure was related to more EAH in girls. Appearance orientation and preoccupation with becoming overweight mediated links between sociocultural pressures and EAH. Findings support the notion that sociocultural pressures and their links to body image may contribute to the course of disinhibited eating behaviors during adolescence.