Ghrelin concentration as an indicator of eating-disorder risk in obese women

The moderating role of eating behaviour traits in the association between exposure to hot food takeaway outlets and body fatness

BACKGROUND

Previous studies demonstrated a relation between takeaway outlet exposure and health outcomes. Individual characteristics, such as eating behaviour traits, could make some people more susceptible to the influence of the food environment. Few studies have investigated this topic. We aimed to investigate the moderating role of eating behaviour traits (cognitive restraint, uncontrolled eating and emotional eating) in the association between neighbourhood exposure to hot food takeaway outlets (hereafter referred to as takeaway outlets), and takeaway food consumption and adiposity.

METHODS

We used cross-sectional data from a cohort in Cambridgeshire, UK (The Fenland study). Takeaway outlet exposure was derived using participants' residential address and data from local authorities and divided into quarters. The Three Factor Eating questionnaire (TFEQ-R18) was used to measure eating behaviour traits. Primary outcomes were consumption of takeaway-like foods (derived from food frequency questionnaire), and body fat percentage (measured using dual-energy X-ray absorptiometry).

RESULTS

Mean age of participants (n = 4791) was 51.0 (SD = 7.2) and 53.9% were female. Higher exposure to takeaway outlets in the neighbourhood and higher eating behaviour trait scores were independently associated with greater takeaway consumption and body fat percentage. Uncontrolled eating did not moderate the associations between takeaway outlet exposure and takeaway consumption or body fat percentage. The association between takeaway outlet exposure and takeaway consumption was slightly stronger in those with higher cognitive restraint scores, and the association between takeaway outlet exposure and body fat percentage was slightly stronger in those with lower emotional eating scores.

CONCLUSION

Eating behaviour traits and exposure to takeaway outlets were associated with greater takeaway consumption and body fat, but evidence that individuals with certain traits are more susceptible to takeaway outlets was weak. The findings indicate that interventions at both the individual and environmental levels are needed to comprehensively address unhealthy diets.

TRIAL REGISTRY

ISRCTN72077169.

Differences in gastrointestinal hormones and appetite ratings between individuals with and without obesity-A systematic review and meta-analysis

Determining if gastrointestinal (GI) hormone response to food intake differs between individuals with, and without, obesity may improve our understanding of obesity pathophysiology. A systematic review and meta-analysis of studies assessing the concentrations of GI hormones, as well as appetite ratings, following a test meal, in individuals with and without obesity was undertaken. Systematic searches were conducted in the databases MEDLINE, Embase, Cochrane Library, PsycINFO, Web of Science, and ClinicalTrials.gov. A total of 7514 unique articles were retrieved, 115 included in the systematic review, and 70 in the meta-analysis. The meta-analysis compared estimated standardized mean difference in GI hormones' concentration, as well as appetite ratings, between individuals with and without obesity. Basal and postprandial total ghrelin concentrations were lower in individuals with obesity compared with controls, and this was reflected by lower postprandial hunger ratings in the former. Individuals with obesity had a lower postprandial concentration of total peptide YY compared with controls, but no significant differences were found for glucagon-like peptide 1, cholecystokinin, or other appetite ratings. A large methodological and statistical heterogeneity among studies was found. More comprehensive studies are needed to understand if the differences observed are a cause or a consequence of obesity.

NUCB2/nesfatin-1 is associated with severity of eating disorder symptoms in female patients with obesity

BACKGROUND

Nesfatin-1 has been described as an anorexigenic peptide. Comprehensive evidence also points towards an involvement of nesfatin-1 in the modulation of emotional pathways with a sex-specific regulation of nesfatin-1 in association with anxiety. Although the implication of nesfatin-1 in the regulation of food intake is well-established in animals, data in humans are lacking. Therefore, we investigated a possible association of circulating NUCB2/nesfatin-1 with eating disorder symptoms in female and male patients displaying a wide range of body weight.

METHODS

We enrolled 243 inpatients (177 female, 66 male) hospitalized due to anorexia nervosa (n = 66) or obesity (n = 144) or with normal weight and suffering from somatoform, adjustment, depressive or anxiety disorders (n = 33). Plasma samples (NUCB2/nesfatin-1 levels measured by ELISA) and measures of eating disorder symptoms (by EDI-2, range 0-100) were obtained within three days after admission.

RESULTS

The study population displayed a distinct prevalence of eating disorder symptoms with female patients with anorexia nervosa (+ 77.0%, p < 0.001) and obesity (+ 87.9%, p < 0.001) reported significantly higher EDI-2 scores than normal weight patients of the same sex. Accordingly, males with anorexia nervosa (+ 39.7%, p < 0.05) and obesity (+ 51.7%, p < 0.001) had significantly higher EDI-2 scores than males with normal weight. Within the same BMI group, women displayed significantly higher scores than men (+ 21.4%, p < 0.05 in patients with anorexia nervosa, + 18.8%, p < 0.001 in participants with obesity). We observed a positive correlation between NUCB2/nesfatin-1 levels and EDI-2 total scores in female patients with obesity (r = 0.285, p = 0.015), whereas no associations were found in other subgroups. A positive correlation between NUCB2/nesfatin-1 levels and BMI was only observed in the male study population (r = 0.315, p = 0.018).

CONCLUSIONS

NUCB2/nesfatin-1 plasma levels were positively associated with EDI-2 total scores in women with obesity, while no association was observable in men. The lacking association of NUCB2/nesfatin-1 and EDI-2 total scores in female patients with anorexia nervosa might be due to already low NUCB2/nesfatin-1 plasma levels. Whether NUCB2/nesfatin-1 is selectively involved in eating behavior in women with obesity will have to be further investigated.

Ghrelin deficiency sex-dependently affects food intake, locomotor activity, and adipose and hepatic gene expression in a binge-eating mouse model

Binge-eating disorder is the most prevalent eating disorder diagnosed, affecting three times more women than men. Ghrelin stimulates appetite and reward signaling, and loss of its receptor reduces binge-eating behavior in male mice. Here, we examined the influence of ghrelin itself on binge-eating behavior in both male and female mice. Five-wk-old wild-type (WT) and ghrelin-deficient (Ghrl^-/-) mice were housed individually in indirect calorimetry cages for 9 wks. Binge-like eating was induced by giving mice ad libitum chow, but time-restricted access to a Western-style diet (WD; 2 h access, 3 days/wk) in the light phase (BE); control groups received ad libitum chow (CO), or ad libitum access to both diets (CW). All groups of BE mice showed binge-eating behavior, eating up to 60% of their 24-h intake during the WD access period. Subsequent dark phase chow intake was decreased in Ghrl^-/- mice and remained decreased in Ghrl^-/- females on nonbinge days. Also, nonbinge day locomotor activity was lower in Ghrl^-/- than in WT BE females. Upon euthanasia, Ghrl^-/- BE mice weighed less and had a lower lean body mass percentage than WT BE mice. In BE and CW groups, ghrelin and sex altered the expression of genes involved in lipid processing, thermogenesis, and aging in white adipose tissue and livers. We conclude that, although ghrelin deficiency does not hamper the development of binge-like eating, it sex-dependently alters food intake timing, locomotor activity, and metabolism. These results add to the growing body of evidence that ghrelin signaling is sexually dimorphic.NEW & NOTEWORTHY Ghrelin, a peptide hormone secreted from the gut, is involved in hunger and reward signaling, which are altered in binge-eating disorder. Although sex differences have been described in both binge-eating and ghrelin signaling, this interaction has not been fully elucidated. Here, we show that ghrelin deficiency affects the behavior and metabolism of mice in a binge-like eating paradigm, and that the sex of the mice impacts the magnitude and direction of these effects.

Circulating acyl and des-acyl ghrelin levels in obese adults: a systematic review and meta-analysis

Ghrelin is the only known orexigenic gut hormone, and its synthesis, secretion and degradation are affected by different metabolic statuses. This meta-analysis aimed to investigate the potential differences in plasma acyl ghrelin (AG) and des-acyl ghrelin (DAG) concentrations between normal weight and obese adults. Systematic literature searches of PubMed, Embase and Web of Science through October 2021 were conducted for articles reporting AG or DAG levels in obesity and normal weight, and 34 studies with 1863 participants who met the eligibility criteria were identified. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated to evaluate group differences in circulating AG and DAG levels. Pooled effect size showed significantly lower levels of baseline AG (SMD: - 0.85; 95% CI: - 1.13 to - 0.57; P_SMD < 0.001) and DAG (SMD: - 1.06; 95% CI: - 1.43 to - 0.69; P_SMD < 0.001) in obese groups compared with healthy controls, and similar results were observed when subgroup analyses were stratified by the assay technique or storage procedure. Postprandial AG levels in obese subjects were significantly lower than those in controls when stratified by different time points (SMD _30 min: - 0.85, 95% CI: - 1.18 to - 0.53, P_SMD < 0.001; SMD _60 min: - 1.00, 95% CI: - 1.37 to - 0.63, P_SMD < 0.001; SMD _120 min: - 1.21, 95% CI: - 1.59 to - 0.83, P_SMD < 0.001). In healthy subjects, a postprandial decline in AG was observed at 120 min (SMD: - 0.42; 95% CI: - 0.77 to - 0.06; P_SMD = 0.021) but not in obese subjects (SMD: - 0.28; 95% CI: - 0.60 to 0.03; P_SMD = 0.074). The mean change in AG concentration was similar in both the obese and lean health groups at each time point (ΔSMD_30min: 0.31, 95% CI: - 0.35 to 0.97, P_SMD = 0.359; ΔSMD_60min: 0.17, 95% CI: - 0.12 to 0.46, P_SMD = 0.246; ΔSMD_120min: 0.21, 95% CI: - 0.13 to 0.54, P_SMD = 0.224). This meta-analysis strengthens the clinical evidence supporting the following: lower baseline levels of circulating AG and DAG in obese individuals; declines in postprandial circulating AG levels, both for the healthy and obese individuals; a shorter duration of AG suppression in obese subjects after meal intake. These conclusions have significance for follow-up studies to elucidate the role of various ghrelin forms in energy homeostasis.

A questionnaire to assess eating behavior: Structure, validity and responsiveness of a new German eating behavior scale (SEV)

Numerous weight-loss interventions promoting healthy and weight-reducing eating behavior have been developed over the past years. To evaluate the effectiveness of such interventions for eating behavior change, short, validated and sensitive instruments are needed. In this study series, we developed and validated a new outcome measure to assess health-conscious and weight-controlling eating behavior for the evaluation of weight-loss interventions. The preliminary version of the German eating behavior scale (Skala zumErnährungsverhalten [SEV]) included 40 items. Three studies were conducted to (a) reduce the preliminary item pool, (b) investigate structural validity and internal consistency using exploratory and confirmatory factor analyses (EFA, CFA), as well as McDonald's ω, and (c) test construct validity with physiological and behavioral parameters. Responsiveness to change was also assessed after a 12-week weight-loss intervention. EFA indicated a two-factor solution with health-conscious (hc-EB) and weight-controlling eating behavior (wc-EB) as subscales, CFA confirmed the two-factor solution with acceptable model fit. Internal consistencies of both subscales were also acceptable to good (hc-EB: ω = 0.88; wc-EB: ω = 0.78). Significantly small to moderate correlations to the Healthy Eating Index (r = 0.51) as well as blood glucose (r = 0.31), blood lipids (r = 0.23), and vascular age (r = 0.31) were found, supporting the construct validity of the SEV and its subscales. Both subscales detected intervention-related changes in eating behavior among subjects of a weight-loss intervention with Standardized Response Means of 0.52 and 0.67, indicating good responsiveness of the SEV. In sum, findings provide evidence that the SEV is a valid and responsive measure to assess health-conscious and weight-controlling eating behavior.

Obesity and Eating Disturbance: the Role of TFEQ Restraint and Disinhibition

PURPOSE OF REVIEW

Literature from the past five years exploring roles of Three-Factor Eating Questionnaire (TFEQ) Restraint and Disinhibition in relation to adult obesity and eating disturbance (ED) was reviewed.

RECENT FINDINGS

Restraint has a mixed impact on weight regulation, diet quality, and vulnerability to ED, where it is related detrimentally to weight regulation, diet, and psychopathology, yet can serve as a protective factor. The impact of Disinhibition is potently related to increased obesity, poorer diet, hedonically driven food choices, and a higher susceptibility to ED. Restraint and Disinhibition have distinct influences on obesity and ED and should be targeted differently in interventions. Further work is required to elucidate the mechanisms underlying TFEQ eating behavior traits.