Effects of Meal Frequency on Metabolic Profiles and Substrate Partitioning in Lean Healthy Males

The daily number of meals has an effect on postprandial glucose and insulin responses, which may affect substrate partitioning and thus weight control. This study investigated the effects of meal frequency on 24 h profiles of metabolic markers and substrate partitioning.Twelve (BMI:21.6 ± 0.6 kg/m(2)) healthy male subjects stayed after 3 days of food intake and physical activity standardization 2 × 36 hours in a respiration chamber to measure substrate partitioning. All subjects randomly received two isoenergetic diets with a Low meal Frequency (3 ×; LFr) or a High meal Frequency (14 ×; HFr) consisting of 15 En% protein, 30 En% fat, and 55 En% carbohydrates. Blood was sampled at fixed time points during the day to measure metabolic markers and satiety hormones.Glucose and insulin profiles showed greater fluctuations, but a lower AUC of glucose in the LFr diet compared with the HFr diet. No differences between the frequency diets were observed on fat and carbohydrate oxidation. Though, protein oxidation and RMR (in this case SMR + DIT) were significantly increased in the LFr diet compared with the HFr diet. The LFr diet increased satiety and reduced hunger ratings compared with the HFr diet during the day.The higher rise and subsequently fall of insulin in the LFr diet did not lead to a higher fat oxidation as hypothesized. The LFr diet decreased glucose levels throughout the day (AUC) indicating glycemic improvements. RMR and appetite control increased in the LFr diet, which can be relevant for body weight control on the long term.ClinicalTrials.gov NCT01034293

Should snacks be recommended in obesity treatment? a 1-year randomized clinical trial

Objective:To study the effect to recommend no snacks vs three snacks per day on 1-year weight loss. The hypothesis was that it is easier to control energy intake and lose weight if snacks in between meals are omitted.Subjects/Method:In total 140 patients (36 men, 104 women), aged 18-60 years and body mass index>30 kg/m(2) were randomized and 93 patients (27 men, 66 women) completed the study. A 1-year randomized intervention trial was conducted with two treatment arms with different eating frequencies; 3 meals/day (3M) or 3 meals and 3 snacks/day (3+3M). The patients received regular and individualized counseling by dieticians. Information on eating patterns, dietary intake, weight and metabolic variables was collected at baseline and after 1 year.Results:Over 1 year the 3M group reported a decrease in the number of snacks whereas the 3+3M group reported an increase (-1.1 vs +0.4 snacks/day, respectively, P<0.0001). Both groups decreased energy intake and E% (energy percent) fat and increased E% protein and fiber intake but there was no differences between the groups. Both groups lost weight, but there was no significant difference in weight loss after 1 year of treatment (3M vs 3+3M=-4.1+/-6.1 vs -5.9+/-9.4 kg; P=0.31). Changes in metabolic variables did not differ between the groups, except for high-density lipoprotein that increased in the 3M group but not in 3+3M group (P<0.033 for group difference).Conclusion:Recommending snacks or not between meals does not influence 1-year weight loss.European Journal of Clinical Nutrition advance online publication, 15 August 2007; doi:10.1038/sj.ejcn.1602860

Changes in eating behaviour and meal pattern following Roux-en-Y gastric bypass

Background: Little is known about eating behaviour and meal pattern subsequent to Roux-en-Y gastric bypass (RYGB), knowledge important for the nutritional care process. The objective of the study was to obtain basic information of how meal size, eating rate, meal frequency and eating behaviour change upon the RYGB surgery. Materials and methods: Voluntary chosen meal size and eating rate were measured in a longitudinal, within subject, cohort study of 43 patients, 31 women and 12 men, age 42.6 (s.d. 9.7) years, body mass index (BMI) 44.5 (4.9) kg m(-2). Thirty-one non-obese subjects, 37.8 (13.6) years, BMI 23.7 (2.7) kg m(-2) served as a reference group. All subjects completed a meal pattern questionnaire and the Three-Factor Eating Questionnaire (TFEQ-R21). Results: Six weeks postoperatively meal size was 42% of the preoperative meal size, (P<0.001). After 1 and 2 years, meal size increased but was still lower than preoperative size 57% (P<0.001) and 66% (P<0.001), respectively. Mean meal duration was constant before and after surgery. Mean eating rate measured as amount consumed food per minute was 45% of preoperative eating rate 6 weeks postoperatively (P<0.001). After 1 and 2 years, eating rate increased to 65% (P<0.001) and 72% (P<0.001), respectively, of preoperative rate. Number of meals per day increased from 4.9 (95% confidence interval, 4.4,5.4) preoperatively to 6 weeks: 5.2 (4.9,5.6), (not significant), 1 year 5.8 (5.5,6.1), (P=0.003), and 2 years 5.4 (5.1,5.7), (not significant). Emotional and uncontrolled eating were significantly decreased postoperatively, (both P<0.001 at all-time points), while cognitive restraint was only transiently increased 6 weeks postoperatively (P=0.011). Conclusions: Subsequent to RYGB, patients display markedly changed eating behaviour and meal patterns, which may lead to sustained weight loss

Psychological predictors of opportunistic snacking in the absence of hunger

Increased frequency of eating in the absence of homeostatic need, notably through snacking, is an important contributor to overconsumption and may be facilitated by increased availability of palatable food in the obesogenic environment. Opportunistic initiation of snacking is likely to be subject to individual differences, although these are infrequently studied in laboratory-based research paradigms. This study examined psychological factors associated with opportunistic initiation of snacking, and predictors of intake in the absence of homeostatic need. Fifty adults (mean age 34.5 years, mean BMI 23.9 kg/m2 , 56% female) participated in a snack taste test in which they ate a chocolate snack to satiation, after which they were offered an unanticipated opportunity to initiate a second eating episode. Trait and behavioural measures of self control, sensitivity to reward, dietary restraint and disinhibited eating were taken. Results showed that, contrary to expectations, those who initiated snacking were better at inhibitory control compared with those who did not initiate. However, amongst participants who initiated snacking, intake (kcal) was predicted by higher food reward sensitivity, impulsivity and BMI. These findings suggest that snacking initiation in the absence of hunger is an important contributor to overconsumption. Consideration of the individual differences promoting initiation of eating may aid in reducing elevated eating frequency in at-risk individuals

Eating Beyond Satiety and Body Mass Index

Objective: To examine discrete eating behaviours as predictors of body mass and psychological processes through which these behaviours might lead to increased body mass. Method: Three hundred and twenty-nine undergraduate females filled out questionnaires on eating beyond satiety (EBS), snacking, night eating, and hunger as well as the process variables — eating expectancies and self-reported cue reactivity — in an online study. The eating behaviours were regressed on body mass index and mediation analyses were conducted for the process variables. Results: EBS was the strongest predictor of body mass when the other eating behaviours were controlled. The process variables did not mediate the relationship between EBS and body mass. Discussion: EBS may be a discrete variable on which to intervene to prevent and treat overweight and obesity. Further research is needed to elucidate the situational and affective antecedents of EBS