Appetite sensations and eating behaviors to complete fasting in obese and non-obese individuals

Influence of anti-obesity strategies on brain function in health and review: A review

The aim of this review was to investigate in the literature the application of strategies such as low carbohydrate diet (LCD), ketogenic diet (KD) and intermittent fasting (IF) and their effects on the CNS. We performed a narrative review of the literature. The search was specifically carried out in PubMed, selecting articles in English, which had the following keywords: obesity, central nervous system, low carb diet, ketogenic diet and intermittent fasting, using the narrative review methodology. The studies found show that the benefits of the LCD, KD and IF strategies, at the CNS level, have a strong influence on the mechanisms of hunger and satiety, as well as on the reduction of food reward and show improvement in memory and mood influenced by the interventions.

Sleeve gastrectomy effects on hunger, satiation, and gastrointestinal hormone and motility responses after a liquid meal test

BACKGROUND

The relation between hunger, satiation, and integrated gastrointestinal motility and hormonal responses in morbidly obese patients after sleeve gastrectomy has not been determined.

OBJECTIVE

The objective was to assess the effects of sleeve gastrectomy on hunger, satiation, gastric and gallbladder motility, and gastrointestinal hormone response after a liquid meal test.

DESIGN

Three groups were studied: morbidly obese patients (n = 16), morbidly obese patients who had had sleeve gastrectomy (n = 8), and nonobese patients (n = 16). The participants fasted for 10 h and then consumed a 200-mL liquid meal (400 kcal + 1.5 g paracetamol). Fasting and postprandial hunger, satiation, hormone concentrations, and gastric and gallbladder emptying were measured several times over 4 h.

RESULTS

No differences were observed in hunger and satiation curves between morbidly obese and nonobese groups; however, sleeve gastrectomy patients were less hungry and more satiated than the other groups. Antrum area during fasting in morbidly obese patients was statistically significant larger than in the nonobese and sleeve gastrectomy groups. Gastric emptying was accelerated in the sleeve gastrectomy group compared with the other 2 groups (which had very similar results). Gallbladder emptying was similar in the 3 groups. Sleeve gastrectomy patients showed the lowest ghrelin concentrations and higher early postprandial cholecystokinin and glucagon-like peptide 1 peaks than did the other participants. This group also showed an improved insulin resistance pattern compared with morbidly obese patients.

CONCLUSIONS

Sleeve gastrectomy seems to be associated with profound changes in gastrointestinal physiology that contribute to reducing hunger and increasing sensations of satiation. These changes include accelerated gastric emptying, enhanced postprandial cholecystokinin and glucagon-like peptide 1 concentrations, and reduced ghrelin release, which together may help patients lose weight and improve their glucose metabolism after surgery. This trial was registered at clinicaltrials.gov as NCT02414893.

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.

The Three-Factor Eating Questionnaire-R18 is able to distinguish among different eating patterns in a general population

A revised version of the Three-Factor Eating Questionnaire (TFEQ) was developed in an obese population, but its applicability to the general population was not assessed. We aimed to define the relationship between eating behavior and reported food intake. This was a cross-sectional study of 529 middle-aged adults and 358 teenagers and young adults recruited on a geographical basis. The TFEQ-R18 measures 3 aspects of eating behavior: cognitive restraint (CR), uncontrolled eating (UE), and emotional eating. Reported food intake was calculated from a food frequency questionnaire. Girls who scored higher on restrained eating had a lower energy intake than the other girls (9164 kJ vs. 13,163 kJ, P < 0.001). In adult men, energy intake increased with UE (9663 kJ vs. 11,029 kJ in the lower and higher UE tertiles, respectively, P < 0.05). When specific food groups were analyzed, higher CR was positively associated in adults with healthy food groups like green vegetables [OR = 1.92 (0.68-2.44)] and negatively associated with French fries [OR = 0.35 (0.22-0.57)] and sugar [OR = 0.38 (0.23-0.61)]. Energy-dense foods, such as fat, were positively associated with UE [OR = 2.28 (1.46-3.57) for dietary fat]. Finally, emotional eaters had a higher snacking food intake. In teenagers and young adults, most associations were seen with CR. Converse to observations in adults, teenagers and young adults who exhibited a high cognitive restraint reported consumption of fewer energy-dense foods rather than more "healthy foods." The TFEQ-R18 was therefore able to distinguish among different eating patterns in our sample of a French general population.

Effect of an acute fast on energy compensation and feeding behaviour in lean men and women

AIM

Humans appear to defend against energy deficit to a greater extent than energy surplus. Severe dietary energy restriction resulting in 5-30% weight loss often leads to hyperphagia and weight regain in lean subjects. However, the period of time over which fasting is often endured in Western society are far shorter, approximately 1-2 days. This study examined how a 36 h fast effected the subsequent day's energy and nutrient intake in a group of 24 healthy, lean men and women.

METHOD

Subjects underwent two 2 day treatments, termed 'fast' and 'maintenance'. During the 'fast' treatment, subjects were fed a maintenance diet on the day prior to the fast (day -1) to prevent overeating. They then consumed non-energy drinks only, from 20:00 h on day -1 to 08:00 h on day 2 (ad libitum feeding day), thus fasting for 36 h. On the 'maintenance' protocol, subjects received a maintenance diet throughout day 1. Throughout day 2 they had ad libitum access to a range of familiar foods, which were the same for both treatments. Body weight, blood glucose and respiratory quotient were used as compliance checks. Hunger was monitored on day's -1, 1 and 2 for the fast treatment only.

RESULTS

On day 2, average energy intake was 10.2 vs 12.2 MJ/day (s.e.d. 1.0) on the post-maintenance and post-fast periods, respectively (P=0.049). Subjects altered feeding behaviour, in response to the fast, only at breakfast time, selecting a higher-fat meal (P<0.005). Compared to day -1, motivation to eat was elevated during the fast (P<0.05). This continued until breakfast was consumed during the re-feeding period (day 2), when values then returned to baseline.

CONCLUSION

These data suggest that a 36 h fast, which generated a negative energy balance of approximately 12 MJ, did not induce a powerful, unconditioned stimulus to compensate on the subsequent day.