Effects of manipulating eating frequency during a behavioral weight loss intervention: a pilot randomized controlled trial

Meal Frequency Does Not Affect Weight Loss in Overweight/Obese Women but Affects the Body Composition: A Randomized Controlled Trial

OBJECTIVES

Studies showing the relationship between meal frequency, weight loss and anthropometric measurements are contradictory. This study aims to determine the effect of meal frequency on weight loss, anthropometric measurements, and body composition.

METHODS

This is a parallel designed randomized control trial that was conducted with 40 female volunteers between the ages of 19-64 years, with a Body Mass Index (BMI) ≥27 who applied to a private clinic. Participants were randomized in two treatment arms (3 meals + 3 snacks/day (n = 20) vs 3 meals/day (n = 20)) and same dietary energy restriction (-500kcal) was applied for 3 months. Food consumption was questioned with 3 day food records, and anthropometric measurements and body composition were measured before the study and repeated each week till the end of the study by the researcher.

RESULTS

All of the participants completed the study period. Body weight (kg), BMI (kg/m2), total body fat (kg), body fat percentage (%), fat free mass (kg) and waist circumference (cm) decreased, while fat free mass percentage (%) increased significantly in both of the groups at the end of the study (p < 0.05). The rate of difference for body weight, BMI (kg/m2) and waist circumference (cm) were similar among the groups. When difference in body composition analyses was examined, the rate of reduction in total body fat (-18.82 ± 4.97% vs -14.87 ± 7.44%) and body fat percentage (%)(-10.79 ± 4.63% vs -7.68 ± 7.04%) and the rate of increase in fat free mass percentage (%)(7.65 ± 3.16% vs 5.04 ± 3.44%) were significantly higher in 3 meals + 3 snacks group (p < 0.05).

CONCLUSION

When energy restricted and balanced weight loss programs are applied, alteration in body weight, BMI and waist circumference is not affected from meal frequency, but body composition does.

CLINICAL TRIAL NUMBER

NCT05581862 (Date of Trial Registration: 13/10/2022).

Interindividual variability in appetitive sensations and relationships between appetitive sensations and energy intake

BACKGROUND

Appetitive sensations (AS) are signals that guide eating behaviors. Marked short-term inter-individual variability in AS has been reported but the long-term stability of individual ratings and their dietary implications are not well characterized.

OBJECTIVES

This study explored the stability of inter-individual ratings of hunger, fullness and thirst for 17 weeks; determined the relationships between these sensations, eating patterns and energy intake (EI); as well as the associations between ratings and selected individual characteristics (age, gender, BMI).

METHODS

A 17-week observational study collected hourly appetitive ratings and dietary intake data from 97 (90 completers, 7 partial completers) healthy adults at weeks 1, 9, and 17.

RESULTS

There were marked and stable inter-individual differences over the 17 weeks for hunger (week 1 vs. week 9, r = 0.72 (p < 0.001); week 1 vs. week 17, r = 0.67 (p < 0.001); week 9 vs. week 17, r = 0.77 (p < 0.001)); fullness (week 1 vs. week 9 r = 0.74 (p < 0.001); week 1 vs. week 17, r = 0.71 (p < 0.001); week 9 vs. week 17, r = 0.81 (p < 0.001)); and thirst (week 1 vs. week 9 r = 0.82 (p < 0.001); week 1 vs. week 17, r = 0.81 (p < 0.001); week 9 vs. week 17, r = 0.88 (p < 0.001)). Cross-correlation functions revealed EI and eating pattern exerted stronger effects on AS than the reverse. However, the absolute effect sizes were small. Path analyses also indicated that there were weak relationships between AS and EI. No robust effects of the studied individual characteristics were observed.

CONCLUSION

This study found that acute and chronic sensations of hunger, fullness and thirst are relatively stable within individuals but vary markedly between individuals. In addition, the present data indicate AS are poorly associated with dietary patterns or with EI under conditions of relatively stable energy balance.

The effects of eating frequency on changes in body composition and cardiometabolic health in adults: a systematic review with meta-analysis of randomized trials

BACKGROUND

Eating frequency may affect body weight and cardiometabolic health. Intervention trials and observational studies have both indicated that high- and low-frequency eating can be associated with better health outcomes. There are currently no guidelines to inform how to advise healthy adults about how frequently to consume food or beverages.

AIM

To establish whether restricted- (≤ three meals per day) frequency had a superior effect on markers of cardiometabolic health (primary outcome: weight change) compared to unrestricted-eating (≥ four meals per day) frequency in adults.

METHODS

We searched Medline (Ovid), Embase, CINAHL (EBSCO), Cochrane Central Register of Controlled Trials (CENTRAL), CAB Direct and Web of Science Core Collection electronic databases from inception to 7 June 2022 for clinical trials (randomised parallel or cross-over trials) reporting on the effect of high or low-frequency eating on cardiometabolic health (primary outcome: weight change). Trial interventions had to last for at least two weeks, and had to have been conducted in human adults. Bias was assessed using the Cochrane Risk of Bias tool 2.0. Standardized mean differences (SMD) and 95% confidence intervals were calculated for all outcomes. Certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Seventeen reports covering 16 trials were included in the systematic review. Data from five trials were excluded from meta-analysis due to insufficient reporting. 15 of 16 trials were at high risk of bias. There was very low certainty evidence of no difference between high- and low-frequency eating for weight-change (MD: -0.62 kg, CI95: -2.76 to 1.52 kg, p = 0.57).

CONCLUSIONS

There was no discernible advantage to eating in a high- or low-frequency dietary pattern for cardiometabolic health. We cannot advocate for either restricted- or unrestricted eating frequency to change markers of cardiometabolic health in healthy young to middle-aged adults.

PROTOCOL REGISTRATION

CRD42019137938.

Association of Eating and Sleeping Intervals With Weight Change Over Time: The Daily24 Cohort

Background We aim to evaluate the association between meal intervals and weight trajectory among adults from a clinical cohort. Methods and Results This is a multisite prospective cohort study of adults recruited from 3 health systems. Over the 6-month study period, 547 participants downloaded and used a mobile application to record the timing of meals and sleep for at least 1 day. We obtained information on weight and comorbidities at each outpatient visit from electronic health records for up to 10  years before until 10 months after baseline. We used mixed linear regression to model weight trajectories. Mean age was 51.1 (SD 15.0) years, and body mass index was 30.8 (SD 7.8) kg/m²; 77.9% were women, and 77.5% reported White race. Mean interval from first to last meal was 11.5 (2.3) hours and was not associated with weight change. The number of meals per day was positively associated with weight change. The average difference in annual weight change (95% CI) associated with an increase of 1 daily meal was 0.28 kg (0.02-0.53). Conclusions Number of daily meals was positively associated with weight change over 6 years. Our findings did not support the use of time-restricted eating as a strategy for long-term weight loss in a general medical population.

Eating frequency has an inverse correlation with adiposity measures and non-invasive arterial stiffness parameters in healthy adult people

BACKGROUND

Lifestyle modifications have been recommended as an essential treatment approach for cardiovascular diseases. Recent studies have shown that eating frequency (EF) correlates with hypertension and related risk of organ damage. This study aimed to examine critical clinical implications to evaluate the association of EF with arterial stiffness parameters as an early marker of atherosclerosis manifestations.

METHODS

A cross-sectional descriptive study was performed on 658 participants of the PERSIAN Organizational Cohort study in Mashhad, aged 30-70 years. Arterial stiffness was assessed by measurement markers of arteriosclerosis, including arterial age, augmentation index (AIx), augmentation pressure (AP), carotid-femoral pulse wave velocity (Cf-PWV), and central blood pressure. Differences in anthropometric indices, blood indices, and arterial stiffness parameters were evaluated across EF groups.

RESULTS

Our data demonstrate that EF was positively correlated with total daily energy intake, and favourable profiles of adiposity and blood lipids. Subjects with an increased EF, had significantly lower AIx, AP, Arterial Age and Central blood pressure (P for trend<0.001) as compared to Lowest EF and not significant with PWV (P for trend, 0.19). Arterial stiffness was also significantly lower in those with increased EF compared with subjects with low EF. By Linear regression analysis, after adjustment for Confounding factors, except PWV, EF showed the associations with all of the non-invasive arterial stiffness parameters.

CONCLUSION

Increased EF is associated with a lower wave reflection and blood pressure in the central arteries.

Effect of changes in children's bedtime and sleep period on targeted eating behaviors and timing of caloric intake

Short sleep is associated with obesity risk. Experimental studies with adults and observational studies with children demonstrate that changes in eating, including increased caloric intake from energy-dense foods and sugar-sweetened beverages as well as increased caloric intake in the evening, may partially account for this increased risk. We therefore examined whether experimental changes in children's sleep period lead to changes in reported caloric intake from energy-dense snack foods and sugar-sweetened beverages, and in the evening. Thirty-seven children, 8-11 years old, completed a three-week study that used a within-subject randomized cross-over design. Children slept their typical amount for one week and were subsequently randomized to either increase or decrease their typical amount by 1.5 h/night for one week; the alternate schedule was completed during the third week of the study, creating a 3-h time in bed difference between the increase and decrease conditions. Sleep was monitored with actigraphy, and dietary intake was assessed with 24-hour dietary recalls. Participants reported consuming 35 kcal per day more from sugar-sweetened beverages during the decrease sleep than the increase sleep condition, p = .033. There were no reported differences between conditions from energy-dense snack foods. Although no differences in reported intake were observed earlier in the day, from 2000 h (8:00 PM) and later, children reported consuming 132 kcal more during the decrease sleep condition than the increase condition, p < 0.001. Shortened sleep achieved by delaying bedtimes led to increased caloric intake in the evening and from sugar-sweetened beverages. Clinical Trials Registration: clinicaltrials.gov Identifier: NCT01030107.

Systematic Review and Meta-Analysis on the Effect of Portion Size and Ingestive Frequency on Energy Intake and Body Weight among Adults in Randomized Controlled Feeding Trials

Energy intake is the product of portion size (PS)-the energy content of an ingestive event-and ingestive frequency (IF)-the number of ingestive events per unit time. An uncompensated alteration in either PS or IF would result in a change in energy intake and body weight if maintained over time. The objective of this meta-analysis was to assess the independent effects of PS and IF on energy intake and body weight among healthy adults in randomized controlled trials (RCTs). A total of 9708 articles were identified in PubMed, Web of Science, Cochrane, and CINAHL databases. The articles were divided among 10 researchers; each article was screened for eligibility by 2-3 independent reviewers. Exclusion criteria included: populations <19 y and >65 y, unhealthy populations (i.e. participants with an acute or chronic disease), assessments <24 h and <4 wk in duration for trials investigating energy intake or body weight, respectively. Controlled feeding trials (i.e. fixed energy intake) that manipulated IF and PS in the same study intervention (IF/PS) were evaluated separately and for the body weight outcome only. Twenty-two studies (IF = 4, PS = 14, IF/PS = 4) met the inclusion criteria. There was an insufficient number of studies to assess the effect of IF, PS, or IF/PS on body weight. There was heterogeneity in the effect sizes among all comparisons (I2 ≥75%). Consuming larger portion sizes was associated with higher daily energy intake [295 kcal (202, 388), n = 24; weighted mean differences (WMD) (95% CI), n = comparisons], and increased frequency of ingestive events was associated with higher energy intake [203 kcal (76, 330), n = 10]. Results from RCTs support that larger PS and greater IF are both associated with higher energy consumption. However, there is insufficient information to determine chronic effects on body weight. This protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42018104757.

The effect of meal frequency on biochemical cardiometabolic factors: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Although several randomized controlled trials (RCTs) have supported the beneficial effects of higher meal frequency (MF) on cardiometabolic risk factors, the putative effects of higher MF on health remain inconclusive. This study systematically reviewed the evidence from RCTs of the effect of higher compared with lower MF on the blood lipid profile, glucose homeostasis, and adipokines.

METHODS

PubMed, Scopus, ISI Web of Science, and the Cochrane database were searched up to October 2020 to retrieve relevant RCTs. A DerSimonian and Laird random effects model was used to pool mean differences and 95% CI for each outcome. The quality of studies and evidence was assessed through standard methods.

RESULTS

Twenty-one RCTs (686 participants) were included in this meta-analysis. Overall results showed a significant improvement in total cholesterol [weighted mean difference (WMD) = -6.08 mg/dl; 95% CI: -10.68, -1.48; P = 0.01; I² = 88%], and low-density cholesterol (LDL-C) (WMD = -6.82 mg/dl; 95% CI: -10.97, -1.60; P = 0.009; I² = 85.7%), while LDL-C to high-density cholesterol ratio (LDL-C: HDL-C) increased (WMD = 0.22; 95% CI: 0.07, 0.36; P = 0.003; I² = 0.0%) in higher MF vs. lower MF. No significant effects were found on measures of glycemic control, apolipoproteins-A1 and B, or leptin. In subgroup analyses, higher MF significantly reduced serum triglyceride (TG), and increased HDL-C, compared with lower MF in interventions > 12 weeks, and decreased serum TC and LDL-C in healthy participants. A significant reduction in LDL-C also was observed in studies where the same foods given both arms, simply divided into different feeding occasions, and in feeding studies, following higher MF compared to lower MF.

CONCLUSION

Our meta-analysis found that higher, compared with lower MF may improve total cholesterol, and LDL-C. The intervention does not affect measures of glycemic control, apolipoproteins-A1 and B, or leptin. However, the GRADE ratings of low credibility of the currently available evidence highlights the need for more high-quality studies in order to reach a firm conclusion.

Effect of a school-based intervention in eating habits among school children: quasi experimental study, Tunisia

OBJECTIVE

The present study aimed to assess whether six months intervention program with parents' implication in primary schools is able to decrease morning snack consumption among children aged 6-12 years.

METHODS

We carried out a quasi-experimental study with two groups of schoolchildren in the region of Sousse (Tunisia) from 2015 to 2016. One primary school in each group was selected. In each school, we randomly selected a sample size of schoolchildren and their parents. The intervention was based on healthy eating habits promotion.

RESULTS

The consumption of morning snacks the day before data collection, reported by children, decreased significantly in post-intervention in both intervention and control groups. The decrease of consumption of morning snacks was significantly higher in intervention group (p=0.009). According to parents, the proportion of children who had the habit of eating morning snack decreased significantly from pre to post-intervention in intervention group (p<0.001).

CONCLUSION

A healthy environment should be created through effective school policies to prevent obesity.

Impact of Meal Frequency on Anthropometric Outcomes: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

The relation between meal frequency and measures of obesity is inconclusive. Therefore, this systematic review and network meta-analysis (NMA) set out to compare the isocaloric effects of different meal frequencies on anthropometric outcomes and energy intake (EI). A systematic literature search was conducted in 3 electronic databases (Medline, Cochrane Library, Web of Science; search date, 11 March 2019). Randomized controlled trials (RCTs) were included with ≥2 wk intervention duration comparing any 2 of the eligible isocaloric meal frequencies (i.e., 1 to ≥8 meals/d). Random-effects NMA was performed for 4 outcomes [body weight (BW), waist circumference (WC), fat mass (FM), and EI], and surface under the cumulative ranking curve (SUCRA) was estimated using a frequentist approach (P-score: value is between 0 and 1). Twenty-two RCTs with 647 participants were included. Our results suggest that 2 meals/d probably slightly reduces BW compared with 3 meals/d [mean difference (MD): -1.02 kg; 95% CI: -1.70, -0.35 kg) or 6 meals/d (MD: -1.29 kg; 95% CI: -1.74, -0.84 kg; moderate certainty of evidence). We are uncertain whether 1 or 2 meals/d reduces BW compared with ≥8 meals/d (MD1 meal/d vs. ≥8 meals/d: -2.25 kg; 95% CI: -5.13, 0.63 kg; MD2 meals/d vs. ≥8 meals/d: -1.32 kg; 95% CI: -2.19, -0.45 kg) and whether 1 meal/d probably reduces FM compared with 3 meals/d (MD: -1.84 kg; 95% CI: -3.72, 0.05 kg; very low certainty of evidence). Two meals per day compared with 6 meals/d probably reduce WC (MD: -3.77 cm; 95% CI: -4.68, -2.86 cm; moderate certainty of evidence). One meal per day was ranked as the best frequency for reducing BW (P-score: 0.81), followed by 2 meals/d (P-score: 0.74), whereas 2 meals/d performed best for WC (P-score: 0.96). EI was not affected by meal frequency. In conclusion, our findings indicate that there is little robust evidence that reducing meal frequency is beneficial.

Eating frequency is inversely associated with BMI, waist circumference and the proportion of body fat in Korean adults when diet quality is high, but not when it is low: analysis of the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV)

The role of eating frequency (EF) in obesity development has been debated, and few studies have investigated Asian populations. Diet quality might affect the association between EF and obesity. Therefore, we investigated the association between EF and obesity indicators in a representative sample of Korean adults with consideration to diet quality. This cross-sectional study used data of 6951 participants aged 19-93 years (male 49·8 %, female 50·2 %) from the Fourth Korean National Health and Nutrition Examination Survey. EF was assessed using a questionnaire, and diet quality was defined as mean adequacy ratio (MAR). To explore the association between EF and obesity indicators, we used multiple linear regression analyses with and without interaction terms between diet quality and EF. EF was inversely associated with each obesity indicator, including body fat percentage (BF%), BMI and waist circumference (WC), showing a significant linear trend (P<0·001 for BF%, WC and BMI). In addition, the association between EF and each obesity indicator was significantly altered according to diet quality (P value of the interaction term EF×diet quality=0·008 in the regression model for BF%, <0·001 for BMI and 0·043 for WC). In the stratified analyses according to diet quality, EF had a significant inverse association with BF%, WC and BMI in the high diet quality groups, but not in the low diet quality groups. This study suggests that EF is inversely associated with the obesity indicators when diet quality is high, but not when it is low in Korean adults.

Effects of 6 vs 3 eucaloric meal patterns on glycaemic control and satiety in people with impaired glucose tolerance or overt type 2 diabetes: A randomized trial

BACKGROUND/OBJECTIVES

The study aimed to compare the effects of two eucaloric meal patterns (3 vs 6 meals/day) on glycaemic control and satiety in subjects with impaired glucose tolerance and plasma glucose (PG) levels 140-199mg/dL at 120min (IGT-A) or PG levels 140-199mg/dL at 120min and >200mg/dL at 30/60/90min post-oral glucose load on 75-g OGTT (IGT-B), or overt treatment-naïve type 2 diabetes (T2D).

SUBJECTS/METHODS

In this randomized crossover study, subjects with IGT-A (n=15, BMI: 32.4±5.2kg/m²), IGT-B (n=20, BMI: 32.5±5kg/m²) or T2D (n=12, BMI: 32.2±5.2kg/m²) followed a weight-maintenance diet (45% carbohydrates, 20% proteins, 35% fats) in 3 or 6 meals/day (each intervention lasting 12 weeks). Anthropometrics, diet compliance and subjective appetite were assessed every 2 weeks. OGTT and measurements of HbA1c and plasma lipids were performed at the beginning and end of each intervention period.

RESULTS

Body weight and physical activity levels remained stable throughout the study. In T2D, HbA1c and PG at 120min post-OGTT decreased with 6 vs 3 meals (P<0.001 vs P=0.02, respectively). The 6-meal intervention also improved post-OGTT hyperinsulinaemia in IGT-A subjects and hyperglycaemia in IGT-B subjects. In all three groups, subjective hunger and desire to eat were reduced with 6 vs 3 meals/day (P<0.05). There were no differences in HOMA-IR or plasma lipids between interventions.

CONCLUSION

Although weight loss remains the key strategy in hyperglycaemia management, dietary measures such as more frequent and smaller meals may be helpful for those not sufficiently motivated to adhere to calorie-restricted diets. Our study shows that 6 vs 3 meals a day can increase glycaemic control in obese patients with early-stage T2D, and may perhaps improve and/or stabilize postprandial glucose regulation in prediabetes subjects.

Longitudinal associations of away-from-home eating, snacking, screen time, and physical activity behaviors with cardiometabolic risk factors among Chinese children and their parents

Background: Little is known about intergenerational differences in associations of urbanization-related lifestyle behaviors with cardiometabolic risk factors in children and their parents in rapidly urbanizing China.Objective: We tested the intergenerational differences in longitudinal associations of away-from-home eating, snacking, screen time, and leisure-time sports with high waist-to-height ratio (WHtR), elevated blood pressure (BP), elevated glycated hemoglobin (HbA1c), and elevated C-reactive protein (CRP) among Chinese children and their parents.Design: We studied children enrolled in the longitudinal China Health and Nutrition Survey (1991-2009, 7 surveys) aged 7-17 y in ≥2 surveys (average follow-up: 2.3 surveys out of a possible 4 surveys with the age restriction; n = 3875, including 1175 siblings) and their parents (2947 mothers, 2632 fathers) living in the same household. We used 3 consecutive interviewer-administered 24-h dietary recalls to derive a 3-d average for away-from-home eating (nonconsumer, >0 and <1 meal/d, or ≥1 meals/d) and consumption of fruit or vegetable snacks (any or none) and other snacks (any or none) and a self-reported 7-d physical activity recall for screen time (≤1, >1 and ≤2, or >2 h/d) and leisure-time sports (any or none). Random-effects logistic regression was used to examine the associations of lagged (average: 3 y) behaviors with cardiometabolic risk factors (WHtR, BP, HbA1c, and CRP).Results: We detected intergenerational differences in associations between lagged behaviors and risk factors (P-interaction < 0.1). Generation-specific models showed that lagged away-from-home eating of ≥1 meal/d (compared with none) was negatively associated with parents' high WHtR (OR: 0.68; 95% CI: 0.53, 0.88) but positively associated with children's high WHtR (OR: 1.46; 95% CI: 1.01, 2.12). Lagged fruit and vegetable snack consumption was negatively related to parents' (OR: 0.76; 95% CI: 0.59, 0.97) and children's (OR: 0.58; 95% CI: 0.33, 1.00) high WHtR. Lagged screen time (>2 compared with ≤1 h/d) was positively associated with parents' (OR: 2.58; 95% CI: 1.56, 4.28) and children's high WHtR (OR: 2.26; 95% CI: 1.06, 4.83).Conclusion: Parent-offspring differences in associations between lifestyle behaviors and cardiometabolic risk factors provide insight into intergenerational differences in cardiometabolic risk with urbanization.

Effects of breakfast eating and eating frequency on body mass index and weight loss outcomes in adults enrolled in an obesity treatment program

This study examined the effects of breakfast eating and eating frequency on objectively assessed BMI and weight loss outcomes among adults enrolled in obesity treatment. Participants completed measures of breakfast eating and eating frequency before and after treatment and had their height and weight measured. Baseline breakfast eating and eating frequency were not associated with baseline BMI (p = .34, p = .45, respectively) and did not predict weight loss during treatment (p = .36, p = .58, respectively). From pre- to post-treatment, there was no significant change in eating frequency (p = .27) and changes in eating frequency had no impact on weight loss (r = -.08, p = .23). However, increases in breakfast eating during treatment were associated with significantly better weight loss outcomes (r = .26, p < .001). Among participants who increased breakfast eating, those who had either no change or a decrease in daily eating frequency were more likely to achieve a 5% weight loss compared to those who had an increase in daily eating frequency (p = .04). These results suggest that increasing breakfast eating, while simultaneously reducing or keeping eating frequency constant, may improve outcomes in obesity treatment. Experimental studies are needed to further elucidate these effects.

Randomized Trial Testing the Effects of Eating Frequency on Two Hormonal Biomarkers of Metabolism and Energy Balance

BACKGROUND

Eating frequency (EF) may influence obesity-related disease risk by attenuating postprandial fluctuations in hormones involved in metabolism, appetite regulation, and inflammation.

MATERIALS/METHODS

This randomized crossover intervention trial tested the effects of EF on fasting plasma insulin-like growth factor-I (IGF-1) and leptin. Fifteen subjects (4 males, 11 females) completed two eucaloric intervention phases lasting 21 days each: low EF ("low-EF"; 3 eating occasions/day) and high EF ("high-EF"; 8 eating occasions/day). Subjects were free-living and consumed their own meals using individualized structured meal plans with instruction from study staff. Subjects completed fasting blood draws and anthropometry on the first and last day of each study phase. The generalized estimated equations modification of linear regression tested the intervention effect on fasting serum IGF-1 and leptin.

RESULTS

Mean (± SD) age was 28.5 ± 8.70 years, and mean (± SD) Body Mass Index was 23.3 (3.4) kg/m². We found lower mean serum IGF-1 following the high-EF condition compared to the low-EF condition (P < 0.001). There was no association between EF and plasma leptin (P = 0.83).

CONCLUSION

These results suggest that increased EF may lower serum IGF-1, which is a hormonal biomarker linked to increased risk of breast, prostate, and colorectal cancer.

Dietary Strategies Implicated in the Prevention and Treatment of Metabolic Syndrome

Metabolic syndrome (MetS) is established as the combination of central obesity and different metabolic disturbances, such as insulin resistance, hypertension and dyslipidemia. This cluster of factors affects approximately 10%-50% of adults worldwide and the prevalence has been increasing in epidemic proportions over the last years. Thus, dietary strategies to treat this heterogenic disease are under continuous study. In this sense, diets based on negative-energy-balance, the Mediterranean dietary pattern, n-3 fatty acids, total antioxidant capacity and meal frequency have been suggested as effective approaches to treat MetS. Furthermore, the type and percentage of carbohydrates, the glycemic index or glycemic load, and dietary fiber content are some of the most relevant aspects related to insulin resistance and impaired glucose tolerance, which are important co-morbidities of MetS. Finally, new studies focused on the molecular action of specific nutritional bioactive compounds with positive effects on the MetS are currently an objective of scientific research worldwide. The present review summarizes some of the most relevant dietary approaches and bioactive compounds employed in the treatment of the MetS to date.

Energy and Nutrient Timing for Weight Control: Does Timing of Ingestion Matter?

Over the past 40 years, meal skipping and snacking in US adults have increased, and currently most eating occasions occur later in the day than previously. Whether these changes have played a causal role in the obesity epidemic is poorly understood. Observational studies are largely inconclusive due to methodological limitations. Experimental evidence does not support a causal role for eating frequency or breakfast skipping in weight control. Emerging evidence suggests that eating irregularity and eating later in the day may be detrimental for weight control, but more studies are needed. This article summarizes studies and highlights areas needing attention.

Snacking Is Longitudinally Associated with Declines in Body Mass Index z Scores for Overweight Children, but Increases for Underweight Children

BACKGROUND

Few studies, to our knowledge, have examined the longitudinal association of snacking with child body mass index (BMI), especially in China, where the incidence of overweight and obesity has increased rapidly.

OBJECTIVES

Our objective was to examine the longitudinal association between snacking and BMI z score and to test whether this association differs by baseline weight status.

METHODS

Using data from the China Health and Nutrition Survey (2006, 2009, and 2011), we characterized snack intake for 9 provinces and 3 megacities. We used linear mixed-effects models to examine longitudinally the association between snacking (none, low, medium, and high tertiles according to energy) and BMI z score in children aged 2-13 y at baseline, controlling for sex, urbanicity, parental education, physical activity, and foods consumed at meals (n = 2277 observations). We tested whether this association differed by baseline underweight, normal weight, or overweight/obese.

RESULTS

Snacking is prevalent in Chinese children, with fruit being the most common snack. Snacking was not associated with meaningful BMI z score changes in normal-weight children. However, in children who were underweight at baseline, snacking in the top tertiles was associated with increases in BMI z scores from 2006 to 2011 (+1.2 and +1.1 BMI z score units for ages 2-6 and 7-13 y, respectively) (P < 0.05). In overweight/obese 2- to 6-y-old children at baseline, being in the lowest snacking tertile was associated with declines in BMI z score (-3.3), whereas in overweight 7- to 13-y-old children, being in the top tertile of snacking was associated with the greatest decline in BMI z score (-2.1) (P < 0.05). The direction and magnitude of associations did not vary regardless of adjustment for total energy intake.

CONCLUSIONS

Snacking in China, dominated by fruit consumption, is associated with decreased BMI in overweight/obese children and increased BMI in underweight children. More work will be needed to monitor this relation as Chinese diets continue to westernize.

Associations between eating frequency and energy intake, energy density, diet quality and body weight status in adults from the USA

To investigate associations between eating frequency and energy intake, energy density, diet quality and body weight status in adults from the USA, combined data from the 2009–2010 and 2011–2012 National Health and Nutrition Examination Survey (NHANES) were used in this study. The first 24-h dietary recall data from eligible participants (4017 men and 3774 women) were used to calculate eating frequency, as well as energy intake, energy density and the Healthy Eating Index 2010 (HEI-2010), as a measure of diet quality. BMI and waist circumference were obtained from the NHANES body measures data. Adjusting for confounding socio-demographic characteristics and lifestyle factors, a higher eating frequency was significantly associated with higher energy intake in both men and women (bothP<0·001). A higher eating frequency was also significantly associated with lower energy density in both men and women, regardless of whether beverage or water intake was included in the calculation of energy density (allP<0·01). Moreover, there was a significant positive association between eating frequency and the HEI-2010 total score in both men and women (bothP<0·001). Eating frequency was inversely associated with BMI in women (P=0·003), as well as waist circumference in both men (P=0·032) and women (P=0·010). Results from the present study suggested that adults with a higher eating frequency in the USA had a healthier diet with lower energy density and better diet quality, and eating frequency was inversely associated with body weight status.

Weight discrimination and unhealthy eating-related behaviors

Individuals with obesity often experience unfair treatment because of their body weight. Such experiences are associated with binge eating, but less is known about its association with other eating-related behaviors and whether these relations are specific to discrimination based on weight or extend to other attributions for discrimination. The present research uses a large national sample (N = 5129) to examine whether weight discrimination is associated with diet and meal rhythmicity, in addition to overeating, and whether these associations generalize to nine other attributions for discrimination. We found that in addition to overeating, weight discrimination was associated with more frequent consumption of convenience foods and less regular meal timing. These associations were generally similar across sex, age, and race. Discrimination based on ancestry, gender, age, religion, and physical disability were also associated with overeating, which suggests that overeating may be a general coping response to discrimination. Unfair treatment because of body weight is associated with unhealthy eating-related behaviors, which may be one pathway through which weight discrimination increases risk for weight gain and obesity.

Effect of meal frequency on glucose and insulin levels in women with polycystic ovary syndrome: a randomised trial

BACKGROUND/OBJECTIVES

The aim of the study was to compare the effect of two-meal patterns (three vs six meals per day) on glucose and insulin levels in women with polycystic ovary syndrome (PCOS).

SUBJECTS/METHODS

In a randomised, crossover, 24-week study, 40 women with PCOS, aged 27±6 years, body mass index 27±6 kg/m(2), followed a weight maintenance diet (% carbohydrates:protein:fat, 40:25:35), consumed either as a three- or a six-meal pattern, with each intervention lasting for 12 weeks. Anthropometric measurements, diet compliance and subjective hunger, satiety and desire to eat were assessed biweekly. All women underwent an oral glucose tolerance test (OGTT) with 75 g glucose for measurement of plasma glucose and insulin at the beginning and end of each intervention. HaemoglobinA1c (HbA1c), blood lipids and hepatic enzymes were measured at the beginning and end of each intervention.

RESULTS

Body weight remained stable throughout the study. Six meals decreased significantly fasting insulin (P=0.014) and post-OGTT insulin sensitivity (Matsuda index, P=0.039) vs three meals. After incorporation of individual changes over time, with adjustment for potential confounders, the only variable that remained significant was the Matsuda index, which was then used in multivariate analysis and general linear models. Six meals improved post-OGTT insulin sensitivity independently of age and body weight vs three meals (P=0.012). No significant differences were found between six and three meals for glucose, HbA1c, blood lipids, hepatic enzymes, subjective desire to eat and satiety.

CONCLUSIONS

Six meals had a more favourable effect on post-OGTT insulin sensitivity in women with PCOS compared with isocaloric three meals.

Effects of meal frequency on weight loss and body composition: a meta-analysis

It has been hypothesized that eating small, frequent meals enhances fat loss and helps to achieve better weight maintenance. Several observational studies lend support to this hypothesis, with an inverse relationship noted between the frequency of eating and adiposity. The purpose of this narrative review is to present and discuss a meta-analysis with regression that evaluated experimental research on meal frequency with respect to changes in fat mass and lean mass. A total of 15 studies were identified that investigated meal frequency in accordance with the criteria outlined. Feeding frequency was positively associated with reductions in fat mass and body fat percentage as well as an increase in fat-free mass. However, sensitivity analysis of the data showed that the positive findings were the product of a single study, casting doubt as to whether more frequent meals confer beneficial effects on body composition. In conclusion, although the initial results of this meta-analysis suggest a potential benefit of increased feeding frequencies for enhancing body composition, these findings need to be interpreted with circumspection.

Mental Health Professionals and Behavioral Interventions for Obesity: A Systematic Literature Review

Adult obesity in the United States has risen to epidemic proportions, and mental health professionals must be called to action. The objectives of this article were to (a) synthesize outcomes of behavioral health interventions for adult obesity in recent meta-analyses and systematic reviews (MAs/SRs) as well as randomized controlled trials (RCTs) and further, (b) evaluate the role of mental health professionals in these behavioral health interventions. Articles were included if published in English between January 1, 2004, and May 1, 2014, in peer-reviewed journals examining behavioral health interventions for adults with obesity. Data were subsequently extracted and independently checked by two authors. Included MAs/SRs utilized motivational interviewing, financial incentives, multicomponent behavioral weight management programs, as well as dietary and lifestyle interventions. Behavioral health interventions in randomized controlled trials (RCTs) were discussed across 3 major intervention types (educational, modified caloric intake, cognitive-based). Regarding the 1st study objective, multiple positive primary (e.g., weight loss) and secondary outcomes (e.g., quality of life) were found in both MAs/SRs and RCTs. However, the majority of included studies made no mention of interventionist professional background and little inference could be made regarding the effects of professional background on behavioral health intervention outcomes for adults facing obesity; an important limitation and direction for future research. Future studies should assess the effects of interventionist profession in addition to primary and secondary outcomes for adults facing obesity. Implications for mental health professionals' educational curricula, assessment, and treatment strategies are discussed.

Effective Diet and Exercise Interventions to Improve Body Composition in Obese Individuals

Because higher body fat and lower lean mass is associated with excess morbidity and mortality, health care teams need specific science-based recommendations to advise clients on lifestyle approaches to alter body composition. Combining exercise with modest energy restriction is recommended to cause up to 20% more weight and fat loss, improved function, and reduced lean mass loss than modification of diet alone. The optimal diet for developing a leaner body composition is one that is modestly reduced in energy and contains lower fat and higher protein than average. Aerobic exercise alone may cause minimal change in body weight (1%-3%) and fat if greater than 250 min/wk. Higher intensity or duration of exercise can cause more substantial fat loss but may have poor long-term compliance. Resistance exercise boosts lean body mass and improves some health indicators but generally does not cause fat loss. In summary, consumption of a low-fat (20%-25% of energy), moderately high-protein (>1.2 g/kg and up to 20%-25% of energy) diet with modestly reduced energy (500-1000 kcal/d) combined with aerobic (3-5 d/wk, at least 250 min/wk) and resistance exercise (2 d/wk) can improve body composition to reduce clinically relevant risks associated with obesity.

Evidence for efficacy and effectiveness of changes in eating frequency for body weight management

In self-reported diets of free living individuals, frequent eating is associated with higher energy intake, yet beliefs about the possible beneficial effect of higher eating frequency for managing body weight persist. Prospective cohort studies and controlled trials of manipulation of eating frequency published by 31 December 2012 were reviewed to assess whether variation in eating frequency may be an adjunct to weight management. Four prospective cohort studies were identified; 2 of these included adults followed for 10 y and 2 followed pre-adolescent/adolescent girls for 6 or 10 y. Within each age category, the findings of the 2 studies were contradictory. Six controlled trials with adult subjects serving as their own controls found no significant changes in body weight due to manipulation of eating frequency interventions lasting 6-8 wk. In 6 additional intervention trials of 8-52 wk duration, free-living adults were counseled to change the eating frequency of self-selected food intake with no significant differences in weight loss attributable to eating frequency. Overall, the consistency of the null findings from controlled trials of manipulation of eating frequency for promoting weight loss suggests that beliefs about the role of higher eating frequency in adult weight management are not supported by evidence. Interpretation of the evidence from published observational studies is complicated by differences in definition of eating frequency and limited knowledge of systematic and random errors in measurement of eating frequency.

Meal timing influences daily caloric intake in healthy adults

The role that meal pattern plays in weight regulation is a popular topic of scientific and common debate. The goal of this study was to evaluate the relationship between meal timing with caloric intake and body mass index (BMI). We hypothesized that late meal timing and eating closer to sleep onset time would be associated with greater energy intake and higher BMI. Participants included 59 individuals recruited from the community. Rest/activity patterns were assessed using 7 days of wrist actigraphy, and caloric intake was evaluated using 7 days of diet logs. Results demonstrated that the timing of meals was associated with overall energy intake but not with BMI. In multivariate analyses controlling for age, sex, sleep duration, and timing, eating more frequently, later timing of the last meal, and a shorter duration between last meal and sleep onset predicted higher total caloric intake. In a mediational model, eating frequency explained the relationship between eating closer to sleep onset and total caloric intake. Results suggest that later relative timing of meals, particularly eating close to sleep, could lead to weight gain due to a greater number of eating occasions and higher total daily caloric intake. These findings have important implications for the development of novel, time-based interventions for weight management.

Eating two larger meals a day (breakfast and lunch) is more effective than six smaller meals in a reduced-energy regimen for patients with type 2 diabetes: a randomised crossover study

AIMS/HYPOTHESIS

The aim of the study was to compare the effect of six (A6 regimen) vs two meals a day, breakfast and lunch (B2 regimen), on body weight, hepatic fat content (HFC), insulin resistance and beta cell function.

METHODS

In a randomised, open, crossover, single-centre study (conducted in Prague, Czech Republic), we assigned 54 patients with type 2 diabetes treated with oral hypoglycaemic agents, both men and women, age 30-70 years, BMI 27-50 kg/m(2) and HbA1c 6-11.8% (42-105 mmol/mol), to follow two regimens of a hypoenergetic diet, A6 and B2, each for 12 weeks. Randomisation and allocation to trial groups (n = 27 and n = 27) were carried out by a central computer system. Individual calculations of energy requirements for both regimens were based on the formula: (resting energy expenditure × 1.5) - 2,092 kJ. The diet in both regimens had the same macronutrient and energy content. HFC was measured by proton magnetic resonance spectroscopy. Insulin sensitivity was measured by isoglycaemic-hyperinsulinaemic clamp and calculated by mathematical modelling as oral glucose insulin sensitivity (OGIS). Beta cell function was assessed during standard meal tests by C-peptide deconvolution and was quantified with a mathematical model. For statistical analysis, 2 × 2 crossover ANOVA was used.

RESULTS

The intention-to-treat analysis included all participants (n = 54). Body weight decreased in both regimens (p < 0.001), more for B2 (-2.3 kg; 95% CI -2.7, -2.0 kg for A6 vs -3.7 kg; 95% CI -4.1, -3.4 kg for B2; p < 0.001). HFC decreased in response to both regimens (p < 0.001), more for B2 (-0.03%; 95% CI -0.033%, -0.027% for A6 vs -0.04%; 95% CI -0.041%, -0.035% for B2; p = 0.009). Fasting plasma glucose and C-peptide levels decreased in both regimens (p < 0.001), more for B2 (p = 0.004 and p = 0.04, respectively). Fasting plasma glucagon decreased with the B2 regimen (p < 0.001), whereas it increased (p = 0.04) for the A6 regimen (p < 0.001). OGIS increased in both regimens (p < 0.01), more for B2 (p = 0.01). No adverse events were observed for either regimen.

CONCLUSIONS/INTERPRETATION

Eating only breakfast and lunch reduced body weight, HFC, fasting plasma glucose, C-peptide and glucagon, and increased OGIS, more than the same caloric restriction split into six meals. These results suggest that, for type 2 diabetic patients on a hypoenergetic diet, eating larger breakfasts and lunches may be more beneficial than six smaller meals during the day. Trial registration ClinicalTrials.gov number, NCT01277471, completed. Funding Grant NT/11238-4 from Ministry of Health, Prague, Czech Republic and the Agency of Charles University - GAUK No 702312.

Increased eating frequency linked to decreased obesity and improved metabolic outcomes

BACKGROUND

We previously reported that more frequent eating in overweight minority youth was linked to lower visceral adiposity and circulating triglycerides. The aim of this study was to examine this issue in more detail by assessing the relationship between eating frequency and adiposity and metabolic disease risk in a cohort of exclusively overweight Hispanic youth.

METHODS

This analysis included 191 overweight (⩾ 85th percentile body mass index (BMI)) Hispanic youth (8-18 years) with the following cross-sectional measures: height, weight, BMI, dietary intake via multiple 24 h recalls, body composition via dual-energy X-ray absorptiometry, lipids and insulin action (insulin sensitivity, acute insulin response (AIR) and disposition index, a measure of β-cell function) via a frequently sampled intravenous glucose tolerance test. Each eating occasion (EO) was defined as ⩾ 50 calories and ⩾ 15 min from any prior EO. Infrequent eaters (IEs) were classified as any subject who ate <3 EOs on any dietary recall (n = 32), whereas frequent eaters (FEs) always consumed ⩾ 3 EOs (n = 159).

RESULTS

Using analyses of covariance, FEs compared with IEs consumed 23% more calories per day (P ⩽ 0.01), ate 40% more often and consumed 19% less calories per EO (P ⩽ 0.01). FEs also exhibited 9% lower BMI Z-scores (P ⩽ 0.01), 9% lower waist circumferences (P ⩽ 0.01), 29% lower fasting insulin (P = 0.02), 31% lower HOMA-IR (Homeostatic Model Assessment: Insulin Resistance) values (P = 0.02) and 19% lower triglycerides (P ⩽ 0.01), as well as an 11% higher AIR (P = 0.02) and 31% higher disposition index (P=0.01). The following a priori covariates were included: Tanner, sex, body fat and reported energy intake.

CONCLUSION

These findings suggest that increased eating frequency is related to decreased obesity and metabolic disease risk in overweight Hispanic youth, despite increases in energy intake.

Mechanisms and effects of "fat taste" in humans

Evidence supporting a "taste" cue from fat in the oral cavity continues to accrue. The proposed stimuli for fat taste, non-esterified fatty acids (NEFA), are released from food through hydrolytic rancidity and lipase activity derived from foods or saliva. NEFA must then be released from the food matrix, negotiate the aqueous environment to reach taste cell surfaces, and interact with receptors such as CD36 and GPR120 or diffuse across cell membranes to initiate a taste signal. Knowledge of these processes in non-gustatory tissues should inform understanding of taste responses to NEFA. Additionally, downstream effects of oral triglyceride exposure have been observed in numerous studies. Data specific to effects of NEFA versus triglyceride are scarce, but modified sham feeding trials with triglyceride document cephalic phase responses including elevations in serum lipids and insulin as well as potential, but debated, effects on gut peptides, appetite, and thermogenesis. In this review, we highlight the mechanisms by which NEFA migrate to and interact with taste cells, and then we examine physiological responses to oral fat exposure.

"At 150 kg, you can't run" men's weight loss stories in a popular health magazine provide appropriate examples of good health practice

We explore weight loss stories from 47 men collected from the Australian edition of Men's Health magazine between January 2009 and December 2012. Our analysis uses a mixed methods approach that combines thematic analysis and descriptive statistics to examine weight loss strategies against clinical practice guidelines for the management of overweight and obesity. All the stories reported the use of physical activity for weight loss and most stories detailed dietary changes for weight loss. Our findings indicate that most of the men reportedly used some form of behavioural strategies to assist them in their behaviour change efforts. The weight loss methods used were consistent with clinical practice guidelines, with the exception of some dietary practices. As narratives may assist with behaviour change, stories like those examined in this study could prove to be very useful in promoting weight loss to men.

Potential role of meal frequency as a strategy for weight loss and health in overweight or obese adults

Improved dietary strategies for weight loss are necessary to decrease metabolic disease risk in overweight or obese adults. Varying meal frequency (MF; i.e., increasing or decreasing eating occasions beyond the traditional pattern of three meals daily) has been thought to have an influence on body weight regulation, hunger control, and blood markers of health. It is common practice for weight management clinicians to recommend increasing MF as a strategy for weight management and to improve metabolic parameters. However, limited research exists investigating the effect of MF during controlled hypocaloric dietary interventions. Furthermore, MF literature often speculates with regard to efficacy of MF treatments based on research using normal weight, overweight/obese, or some combination, where much diversity exists within these various populations. In this review, we suggest that normal-weight and overweight/obese populations, as well as free-living versus investigator-controlled research trials, should be studied independently. Therefore, the objective of the present review is to survey the literature to assess whether the alteration of MF influences body weight regulation, hunger control, and/or blood markers of health in overweight/obese participants undergoing a controlled hypocaloric diet to induce weight loss. Findings of this review indicate that there is uncertainty in the literature when interpreting the optimal MF for obesity treatment, where reduced MF may even show more favorable lipid profiles in obese individuals compared with increased MF. Furthermore, the simple relationship of comparing MF with body fatness or body mass index should also consider whether eating frequency is associated with other healthy factors (e.g., increased physical activity).

Behavioral lifestyle intervention in the treatment of obesity

This article provides an overview of research regarding adult behavioral lifestyle intervention for obesity treatment. We first describe two trials using a behavioral lifestyle intervention to induce weight loss in adults, the Diabetes Prevention Program (DPP) and the Look AHEAD (Action for Health in Diabetes) trial. We then review the three main components of a behavioral lifestyle intervention program: behavior therapy, an energy- and fat-restricted diet, and a moderate- to vigorous-intensity physical activity prescription. Research regarding the influence of dietary prescriptions focusing on macronutrient composition, meal replacements, and more novel dietary approaches (such as reducing dietary variety and energy density) on weight loss is examined. Methods to assist with meeting physical activity goals, such as shortening exercise bouts, using a pedometer, and having access to exercise equipment within the home, are reviewed. To assist with improving weight loss outcomes, broadening activity goals to include resistance training and a reduction in sedentary behavior are considered. To increase the accessibility of behavioral lifestyle interventions to treat obesity in the broader population, translation of efficacious interventions such as the DPP, must be undertaken. Translational studies have successfully altered the DPP to reduce treatment intensity and/or used alternative modalities to implement the DPP in primary care, worksite, and church settings; several examples are provided. The use of new methodologies or technologies that provide individualized treatment and real-time feedback, and which may further enhance weight loss in behavioral lifestyle interventions, is also discussed.

Prevalence and energy intake from snacking in Brazil: analysis of the first nationwide individual survey

BACKGROUND/OBJECTIVES

Snacking has increased globally. We examine snacking patterns and common snack foods in Brazil.

SUBJECTS/METHODS

Data from the first of two non-consecutive food diaries from 34,003 individuals (aged ≥ 10 years) in the first Brazillian nationally representative dietary survey (2008-2009) were used. Meals were defined as the largest (kcal) eating event reported during select times of the day (Breakfast, 0600-1000 hours; Lunch, 1200-1500 hours; Dinner, 1800-2100 hours); all other eating occasions were considered snacks. We estimate daily energy intake, percentage of persons consuming snacks, number of daily snacks and per capita and per consumer energy from snacks (kcal/day, kcal/snack and % of daily energy from snacks).

RESULTS

In all, 74% of Brazilians (≥ 10 years) snacked, reporting an average 1.6 snacks/day. Also, 23% of the sample were heavy snackers (≥ 3 snacks/day). Snacking accounted for 21% of daily energy intake in the full sample but 35.5% among heavy snackers. Compared with non-snackers (1548 kcal/day), light (1-2 snacks/day) and heavy snackers consumed more daily energy (1929 and 2334 kcal/day, respectively). Taking into account time of day, the largest percentage of persons reported afternoon/early evening snacking (1501-1759 hours, 47.7%). Sweetened coffee and tea, sweets and desserts, fruit, sugar-sweetened beverages, and high-calorie salgados (fried/baked dough with meat/cheese/vegetable) were the top five most commonly consumed snacks. Differences were observed by age groups. Trends in commercial sales were observed, especially for sugar-sweetened beverages.

CONCLUSIONS

Many commonly consumed snack foods in Brazil are classified, in the US, as being high in solid fats and added sugars. The public health impact of snacking in Brazil requires further exploration.

Bibliotherapy and food cravings control

The use of self-help manuals or bibliotherapy could be an effective resource to treat obesity, but their effects on the elaborative processes of food cravings remain unclear. The present study examined whether bibliotherapy can effectively reduce food cravings in an overweight and obese adult population. 80 participants were randomly allocated either to the Self-help Manual group or the Intention-control group. They had to apply each resource over a period of 3 months whenever they felt a craving arise. During the baseline period most of the participants reported grazing as the main cause of their weight gain. Compared to baseline, the results of the third month of the follow-up revealed that intentions had paradoxical effects on food thought suppression, preoccupation with food, negative affect and guilty feelings; but the Self-help Manual promoted positive changes on the food cravings trait and its dimensions, food thoughts suppression, emotional and behavioural reactions to intrusions and BMI. These findings suggest that the Self-help Manual could be useful in reducing food cravings.

Effects of increased meal frequency on fat oxidation and perceived hunger

OBJECTIVE

Consuming smaller, more frequent meals is often advocated as a means of controlling body weight, but studies demonstrating a mechanistic effect of this practice on factors associated with body weight regulation are lacking. The purpose of this study was to compare the effect of consuming three (3M) vs. six meals (6M) per day on 24-h fat oxidation and subjective ratings of hunger.

DESIGN AND METHODS

Lean (body mass index <25 kg/m(2) ) subjects (7M, 8F) were studied in a whole-room calorimeter on two occasions in a randomized cross-over design. Subjects were provided isoenergetic, energy balanced diets with a 1- to 2-week washout between conditions. Hunger, fullness, and "desire to eat" ratings were assessed throughout the day using visual analog scales and quantified as area under the curve (AUC).

RESULTS

There were no differences (P < 0.05) in 24-h energy expenditure (8.7 ± 0.3 vs. 8.6 ± 0.3 mj d(-1) ), 24-h respiratory quotient (0.85 ± 0.01 vs. 0.85 ± 0.01), or 24-h fat oxidation (82 ± 6 vs. 80 ± 7 g day(-1) ) between 3M and 6M, respectively. There was no difference in fullness 24-h AUC, but hunger AUC (41850 ± 2255 vs. 36612 ± 2556 mm.24 h, P = 0.03) and "desire to eat" AUC (47061 ± 1791 vs. 41170 ± 2574 mm.24 h, P = 0.03) were greater during 6M than 3M.

CONCLUSION

We conclude that increasing meal frequency from three to six per day has no significant effect on 24-h fat oxidation, but may increase hunger and the desire to eat.