Eating frequency and energy regulation in free-living adults consuming self-selected diets

Nutritional Mechanisms of Cancer Cachexia

Cancer cachexia is a complex systemic wasting syndrome. Nutritional mechanisms that span energy intake, nutrient metabolism, body composition, and energy balance may be impacted by, and may contribute to, the development of cachexia. To date, clinical management of cachexia remains elusive. Leaning on discoveries and novel methodologies from other fields of research may bolster new breakthroughs that improve nutritional management and clinical outcomes. Characteristics that compare and contrast cachexia and obesity may reveal opportunities for cachexia research to adopt methodology from the well-established field of obesity research. This review outlines the known nutritional mechanisms and gaps in the knowledge surrounding cancer cachexia. In parallel, we present how obesity may be a different side of the same coin and how obesity research has tackled similar research questions. We present insights into how cachexia research may utilize nutritional methodology to expand our understanding of cachexia to improve definitions and clinical care in future directions for the field.

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.

Changes in eating patterns in response to chronic insufficient sleep and their associations with diet quality: a randomized trial

STUDY OBJECTIVES

Insufficient sleep leads to overconsumption, but the factors contributing to this effect are poorly understood. Therefore, we assessed the influence of prolonged curtailment of sleep on free-living eating patterns linked with overconsumption and explored associations of these eating patterns with diet quality under different sleep conditions.

METHODS

Sixty-five adults (47 females) participated in outpatient randomized crossover studies with two 6-week conditions: adequate sleep (7-9 h/night) and sleep restriction (-1.5 h/night relative to screening). Food records were collected over 3 nonconsecutive days, from which we ascertained data on eating frequency, midpoint, and window and intakes of energy and nutrients. Linear mixed models were used to assess the impact of sleep condition on change in eating pattern (sleep × week interaction) and the relation between eating patterns and dietary intakes (sleep × eating pattern interaction).

RESULTS

Sleep condition impacted the change in eating frequency across weeks, with eating frequency increasing in sleep restriction relative to adequate sleep (β = 0.3 ± 0.1; P = .046). Across conditions, eating more frequently tended to relate to higher energy intakes (β = 60.5 ± 34.6; P = .082). Sleep also influenced the relation of variability in eating midpoint with intakes of saturated fat (β = 6.0 ± 2.1; P = .005), polyunsaturated fat (β = -3.9 ± 2.0; P = .051), and added sugar (β = 17.3 ± 6.2; P = .006), with greater midpoint variability associated with more adverse changes in these diet quality components in sleep restriction vs adequate sleep.

CONCLUSIONS

Chronic short sleep increases eating frequency and adversely influences associations of variability in meal timing with components of diet quality. These findings help to explain how short sleep leads to overconsumption and obesity.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Impact of Sleep Restriction in Women; URL: https://clinicaltrials.gov/ct2/show/NCT02835261; Identifier: NCT02835261 and Name: Impact of Sleep Restriction on Performance in Adults; URL: https://clinicaltrials.gov/ct2/show/NCT02960776; Identifier: NCT02960776.

CITATION

Barragán R, Zuraikat FM, Tam V, RoyChoudhury A, St-Onge M-P. Changes in eating patterns in response to chronic insufficient sleep and their associations with diet quality: a randomized trial. J Clin Sleep Med. 2023;19(11):1867-1875.

Associations between dietary intake, physical activity, and obesity among public school teachers in Jeddah, Saudi Arabia

Objective

We aimed to assess the dietary intake of certain food groups in a representative sample of public-school teachers living in Jeddah city. We also, examined the association of dietary intake with physical activity and obesity among schoolteachers.

Methods

The study was a cross-sectional online survey, conducted among 640 (177 male, 463 female) schoolteachers aged between 20 and 62 years old and working in public primary, intermediate, and high schools in Jeddah. Measurements included gender, weight, height, body mass index (BMI), health problems, and lifestyle behaviours, including physical activity levels, smoking status, and dietary intake.

Results

Based on gender, number of non-smoking women (94%) was higher than number of non-smoking men (57.1%) (P < 0.001). However, men were more active than women (P = 0.03). Regarding BMI, there were more overweight men than women, while obese women numbered more than men (P = 0.003). There was no significant difference in dietary intake between men and women except that men consumed more soft drinks than women (P = 0.002). Lower physically active schoolteachers were less likely to consume salad (OR = 0.6, 95% CI 0.4-0.9; P = 0.02), vegetables (OR = 0.6, 95% CI 0.3-0.9; P = 0.01), beans and legumes (OR = 0.4, 95% CI 0.2-0.7; P = 0.005), wholegrain bread (OR = 0.6, 95% CI 0.4-0.9; P = 0.03), dairy products (OR = 0.6, 95% CI 0.4-0.9; P = 0.01), snacks (OR = 0.5, 95% CI 0.2-0.8; P = 0.01), and fish (OR = 0.4, 95% CI 0.2-0.9; P = 0.04) compared to those with high levels of physical activity. Only fruit intake was considered statistically significant (OR = 0.4, 95% CI 0.3-0.7; P = 0.003). The study found a relationship between the BMI of schoolteachers and food intake. Obese schoolteachers had lower consumption of fruits (OR = 0.3, 95% CI 0.2-0.7; P = 0.007) and white meat (OR = 0.5, 95%CI 0.3-0.9; P = 0.03) than schoolteachers in the normal weight group.

Conclusion

The high prevalence of physical activity, dietary intake and body weight among Saudi teachers is a major public health concern. The present study identified several lifestyle factors associated with body weight that may represent valid targets for the prevention and management of obesity among Saudi school teachers. Promoting active lifestyles and healthy diets would be primary targets for obesity prevention.

Neuronal GHS-R Differentially Modulates Feeding Patterns under Normal and Obesogenic Conditions

The orexigenic hormone ghrelin increases food intake and promotes obesity through its receptor, growth hormone secretagogue receptor (GHS-R). We previously reported two neuron-specific GHS-R knockout mouse lines, namely pan-neuronal deletion by Syn1-cre and hypothalamic deletion by AgRP-cre, exhibiting differential diet-dependent effects on body weight. GHS-R deficiency in neurons elicited less pronounced metabolic effects under regular diet (RD) than high fat diet (HFD). While there was no difference in total food intake of HFD in either mouse line, Syn1-cre; Ghsrf/f mice showed much greater anti-obesity effect than that of AgRP-cre; Ghsrf/f mice. Meal feeding pattern is known to have a major impact on energy homeostasis and obesity development. Here, we investigated the feeding behaviors of these two neuron-specific GHS-R knockout mice under RD and HFD feeding, by assessing meal number, meal size, meal duration, and feeding frequency. Under the normal diet, RD-fed Syn1-cre; Ghsrf/f mice showed a decreased meal size in dark phase, while RD-fed AgRP-cre; Ghsrf/f mice showed an increased meal duration in dark phase. Under the obesogenic diet, HFD-fed Syn1-cre; Ghsrf/f mice displayed reduced meal numbers in light phase and increased feeding in both light and dark phases, whereas HFD-fed AgRP-cre; Ghsrf/f mice showed a decreased meal duration in the light phase only. Consistently, the expression of neuropeptides (Neuropeptide Y and Orexin) was increased in the hypothalamus of RD-fed Syn1-cre; Ghsrf/f mice, whereas the expression of cannabinoid receptor type 1 (CB1) was increased in the hypothalamus of HFD fed Syn1-cre; Ghsrf/f mice. Overall, feeding pattern changes were more pronounced in Syn1-cre; Ghsrf/f mice than that in AgRP-cre; Ghsrf/f mice, and HFD elicited greater alteration than RD. While AgRP-cre; Ghsrf/f mice consumed HFD meals faster during the day (showing shorter meal duration), Syn1-cre; Ghsrf/f mice ate few HFD meals during the light phase and ate slowly throughout the day (showing longer meal duration in both phases). Our findings reveal that neuronal GHS-R regulates energy homeostasis by altering feeding patterns, and differentially modulates feeding patterns in a site- and diet-dependent manner. The distinctive data in these two mouse lines also suggest that eating slowly during the optimal feeding period (dark phase for mice) may be beneficial in combating obesity.

Face Validity of Observed Meal Patterns Reported with 7-Day Diet Diaries in a Large Population-Based Cohort Using Diurnal Variation in Concentration Biomarkers of Dietary Intake

In a cross-sectional analysis of a population-based cohort (United Kingdom, N = 21,318, 1993-1998), we studied how associations between meal patterns and non-fasting triglyceride and glucose concentrations were influenced by the hour of day at which the blood sample was collected to ascertain face validity of reported meal patterns, as well as the influence of reporting bias (assessed using formula of energy expenditure) on this association. Meal size (i.e., reported energy content), mealtime and meal frequency were reported using pre-structured 7-day diet diaries. In ANCOVA, sex-specific means of biomarker concentrations were calculated by hour of blood sample collection for quartiles of reported energy intake at breakfast, lunch and dinner (meal size). Significant interactions were observed between breakfast size, sampling time and triglyceride concentrations and between lunch size, sampling time and triglyceride, as well as glucose concentrations. Those skipping breakfast had the lowest triglyceride concentrations in the morning and those skipping lunch had the lowest triglyceride and glucose concentrations in the afternoon, especially among acceptable energy reporters. Eating and drinking occasion frequency was weakly associated with glucose concentrations in women and positively associated with triglyceride concentrations in both sexes; stronger associations were observed for larger vs. smaller meals and among acceptable energy reporters. Associations between meal patterns and concentration biomarkers can be observed when accounting for diurnal variation and underreporting. These findings support the use of 7-day diet diaries for studying associations between meal patterns and health.

Carbohydrate-dense snacks are a key feature of the nutrition transition among Ghanaian adults - findings from the RODAM study

BACKGROUND

African populations in sub-Saharan Africa and African migrants in Europe are facing a rapid upsurge in obesity. This trend has been related to urbanization, migration and associated shifts in lifestyle, including dietary habits. Whether changes in eating patterns contribute to the rising burden of obesity among African populations is currently unknown.

OBJECTIVE

Our aims in conducting this study were to characterize eating patterns among Ghanaian adults living in their country of origin and in Europe and to explore associations of meal patterns with body mass index (BMI).

DESIGN

Within the cross-sectional RODAM (Research on Obesity and Diabetes among African Migrants) study, data of single 24-h dietary recalls from Ghanaian adults in rural Ghana (n = 20), urban Ghana (n = 42), and Europe (n = 172) were recorded. Eating frequencies, energy intake, and macronutrient composition of eating occasions (EOs, i.e. meals or snacks) were compared between study sites based on descriptive statistics and χ 2-/Kruskal-Wallis tests.

RESULTS

A rising gradient of EO frequencies from rural Ghana through urban Ghana to Europe was observed, mainly reflecting the differences in snacking frequencies (≥1 snack per day: 20 vs. 48 vs. 52%, P = 0.008). Meal frequencies were similar across study sites (≥3 meals per day: 30 vs. 33 vs. 38%, P = 0.80). Meals were rich in carbohydrates (median 54.5, interquartile range (IQR): 43.2-64.0 energy%) and total fats (median: 27.0, IQR: 19.9-34.4 energy %); their protein content was lowest in rural Ghana, followed by urban Ghana and Europe (P = 0.0005). Snacks mainly contained carbohydrates (median: 75.7, IQR: 61.0-89.2 energy%). In linear regression analyses, there was a non-significant trend for an inverse association between snacking frequencies and BMI.

DISCUSSION AND CONCLUSIONS

The observed integration of carbohydrate-dense snacks into the diet supports the growing evidence for a nutrition transition among African populations undergoing socioeconomic development. This analysis constitutes a starting point to further investigate the nutritional implications of increased snacking frequencies on obesity and metabolic health in these African populations.

The Role of Snack Choices, Body Weight Stereotypes and Smoking Behavior in Assessing Risk Factors for Adolescent Overweight and Obesity

This study investigated the relationship of behavioral factors, such as snack choices, obesity stereotypes and smoking with adolescents’ body weight. Individual-level data for 1254 Greek youths were selected via a formal questionnaire. Snack choices seem to be gender specific with girls showing a stronger preference for healthier snacks. Frequent consumption of high-calorie and more filling snacks was found to increase Body Mass Index (BMI) in both genders. Fruit/vegetable snacks were associated with lower body weight in females, whereas cereal/nut snacks had a negative influence in males’ BMI. The majority of participants expressed anti-fat attitudes and more boys than girls assigned positive attributes to lean peers. The endorsement of the thin-ideal was positively associated with the BMI of both adolescent boys and girls. This study also revealed that neglecting potential endogeneity issues can lead to biased estimates of smoking. Gender may be a crucial moderator of smoking–BMI relationships. Male smokers presented a higher obesity risk, whereas female smokers were more likely to be underweight. Nutrition professionals should pay attention to increase the acceptance of healthy snack options. Gender differences in the influence of weight stereotypes and smoking on BMI should be considered in order to enhance the efficacy of obesity prevention interventions.

Daily Eating Frequency in US Adults: Associations with Low-Calorie Sweeteners, Body Mass Index, and Nutrient Intake (NHANES 2007-2016)

Studies of relationships between eating frequency and/or timing and energy intake have not examined associations with low-calorie sweeteners (LCS). We assessed the frequency of eating behavior related to LCS consumption emphasizing timing, calorie intake, and body mass index (BMI) among United States (US) adults aged ≥19 years. Using the National Health and Nutrition Examination Survey (NHANES) 2007-2016, we defined eating episodes as food and/or beverage intake within 15 min of one another over the first 24-h dietary recall. We coded items ingested during episodes (n = 136,938) and assessed LCS presence using US Department of Agriculture (USDA) food files. Episode analysis found intakes of foods only (27.4%), beverages only (29.5%), and foods with beverages (43.0%). LCS items were consumed without concurrent calories from other sources in fewer than 2.7% of all episodes. Within participants having normal weight (29.4%), overweight (33.6%) and obese (37.1%) BMIs, LCS consumers (35.2% overall) evidenced: more episodes/day; and fewer: calories, carbohydrates, fats, and protein per episode. Per person, those consuming LCS had lower total calories and higher fiber intake per day. LCS consumption was associated with higher BMI. Number of eating episodes/day and longer hours when eating episodes occurred were also consistently associated with higher BMI. Consuming LCS did not modify these relationships. These results did not show that LCS consumption was associated with increased caloric intake from other dietary sources.

Office cake culture

Purpose

The purpose of this paper is to explore the characteristics of office cake (OC) consumption and the associated attitudes and behaviours among UK office workers to gain insight into the implications for workplace health.

Design/methodology/approach

A cross-sectional online questionnaire was completed by 940 respondents. Data were analysed using descriptive statistics and cross-tabulation withχ2tests for between-group difference.

Findings

Respondents reported both positive social and negative health-related consequences of OC. OC influenced eating behaviour through increased salience and availability, and the effects of social influencing. Almost all (94.8 per cent) reported ideal OC frequency to be once/week or less. Gender and age significantly affected attitudes and behaviour.

Research limitations/implications

The questionnaire was not validated so data accuracy could have been diminished or biased. Portion size was not examined and consumption data were self-reported which could have resulted in under-reporting. Only office workers were investigated therefore results may not be applicable to other workplaces.

Practical implications

OC appears to influence both the workplace eating environment and employee eating behaviour. It could therefore affect employee health and workplace health promotion programme efficacy. However the findings suggest that nudge-based initiatives could reduce OC consumption to make workplaces healthier while retaining social benefits.

Originality/value

The present study provides the first data on OC culture and insights on how to address it sensitively. It also highlights that sweet treats used for celebration and employee recognition should be considered a relevant part of workplace food provision alongside canteens and vending.

Use of a Smartphone Application Can Improve Assessment of High-Fat Food Consumption in Overweight Individuals

BACKGROUND

We evaluated the feasibility of an application for measuring the frequency of consumption of high-fat foods and compared this application with standard methods.

METHODS

Twenty-six females and thirty six males aged 20⁻40 were enrolled in Poland. Participants completed the Block Screening Questionnaire for Fat Intake (BSQF; Q1) and a second questionnaire (Q2) with additional high-fat foods. The participants were then monitored for ten days in a real-time manner using a smartphone application that employed the same lists of food as Q2.

RESULTS

Most subjects (84%) gave replies to at least three prompts on at least 5 days. The results from Q1 and the application were correlated (r = 0.42, p < 0.001). Energy intake and the frequency of consumption of high-fat foods were correlated in the overweight/obese group (r = 0.83, p < 0.001). The mean differences between Q2 and the app were similar in both groups but the agreement limits were wider in the overweight/obese group than in the normal weight group.

CONCLUSIONS

An application for mobile devices is a feasible tool for capturing the frequency of high-fat food consumption and it seems to improve the measured variable, especially in overweight or obese people.

High orange juice consumption with or in-between three meals a day differently affects energy balance in healthy subjects

Sugar-containing beverages like orange juice can be a risk factor for obesity and type 2 diabetes although the underlying mechanisms are less clear. We aimed to investigate if intake of orange juice with or in-between meals differently affects energy balance or metabolic risk. Twenty-six healthy adults (24.7 ± 3.2 y; BMI 23.2 ± 3.2 kg/m²) participated in a 4-week cross-over intervention and consumed orange juice (20% of energy requirement) either together with 3 meals/d (WM) or in-between 3 meals/d (BM) at ad libitum energy intake. Basal and postprandial insulin sensitivity (primary outcome), daylong glycaemia, glucose variability and insulin secretion were assessed. Body fat mass was measured by air-displacement plethysmography. After BM-intervention, fat mass increased (+1.0 ± 1.8 kg; p < 0.05) and postprandial insulin sensitivity tended to decrease (ΔMatsuda_ISI: −0.89 ± 2.3; p = 0.06). By contrast, after WM-intervention fat mass and gamma-glutamyl transferase (GGT) decreased (−0.30 ± 0.65 kg; −2.50 ± 3.94; both p < 0.05), whereas glucose variability was higher (ΔMAGE: +0.45 ± 0.59, p < 0.05). Daylong glycaemia, insulin secretion, changes in basal insulin sensitivity, and triglycerides did not differ between WM- and BM-interventions (all p > 0.05). In young healthy adults, a conventional 3-meal structure with orange juice consumed together with meals had a favorable impact on energy balance, whereas juice consumption in-between meals may contribute to a gain in body fat and adverse metabolic effects.

The benefits of defining "snacks"

Whether eating a "snack" is considered a beneficial or detrimental behavior is largely based on how "snack" is defined. The term "snack food" tends to connote energy-dense, nutrient-poor foods high in nutrients to limit (sugar, sodium, and/or saturated fat) like cakes, cookies, chips and other salty snacks, and sugar-sweetened beverages. Eating a "snack food" is often conflated with eating a "snack," however, leading to an overall perception of snacks as a dietary negative. Yet the term "snack" can also refer simply to an eating occasion outside of breakfast, lunch, or dinner. With this definition, the evidence to support health benefits or detriments to eating a "snack" remains unclear, in part because relatively few well-designed studies that specifically focus on the impact of eating frequency on health have been conducted. Despite these inconsistencies and research gaps, in much of the nutrition literature, "snacking" is still referred to as detrimental to health. As discussed in this review, however, there are multiple factors that influence the health impacts of snacking, including the definition of "snack" itself, the motivation to snack, body mass index of snack eaters, and the food selected as a snack. Without a definition of "snack" and a body of research using methodologically rigorous protocols, determining the health impact of eating a "snack" will continue to elude the nutrition research community and prevent the development of evidence-based policies about snacking that support public health.

Associations between nutritional quality of meals and snacks assessed by the Food Standards Agency nutrient profiling system and overall diet quality and adiposity measures in British children and adolescents

OBJECTIVE

This cross-sectional study examined how the nutritional quality of meals and snacks was associated with overall diet quality and adiposity measures.

METHODS

Based on 7-d weighed dietary record data, all eating occasions were divided into meals or snacks based on time (meals: 06:00-09:00 h, 12:00-14:00 h, and 17:00-20:00 h; snacks: others) or contribution to energy intake (meals: ≥15%; snacks: <15%) in British children aged 4-10 (n = 808) and adolescents aged 11-18 (n = 809). The nutritional quality of meals and snacks was assessed as the arithmetical energy intake-weighted means of the Food Standards Agency (FSA) nutrient profiling system score of each food and beverage consumed, based on the contents of energy, saturated fatty acid, total sugar, sodium, fruits/vegetables/nuts, dietary fiber, and protein.

RESULTS

Regardless of the definition of meals and snacks, higher FSA score (lower nutritional quality) of meals was inversely associated with overall diet quality assessed by the Mediterranean diet score in both children and adolescents (P <0.0001), whereas the inverse associations for the FSA score of snacks did not reach statistical significance. The FSA score of meals based on time was inversely associated with body mass index z-score only in children, whereas that of snacks based on time showed a positive association.

CONCLUSION

Lower nutritional quality of meals, but not snacks, assessed by the FSA score was associated with lower overall diet quality, whereas no consistent associations were observed with regard to adiposity measures.

Nutritional quality of meals and snacks assessed by the Food Standards Agency nutrient profiling system in relation to overall diet quality, body mass index, and waist circumference in British adults

BACKGROUND

Studies examining meal and snack eating behaviors in relation to overall diet and health markers are limited, at least partly because there is no definitive consensus about what constitutes a snack, a meal, or an eating occasion. This cross-sectional study examined how nutritional quality of meals and snacks is associated with overall diet quality, body mass index (BMI), and waist circumference.

METHODS

Based on 7-d weighed dietary record data, all eating occasions were divided into meals or snacks based on time (meals: 0600-1000, 1200-1500, and 1800-2100 h; snacks: others) or contribution to energy intake (EI) (meals: ≥15%; snacks: <15%) in 1451 British adults aged 19-64 years participating in the National Diet and Nutrition Survey. Nutritional quality of meals and snacks was assessed as the arithmetic EI-weighted means of the British Food Standards Agency (FSA) nutrient profiling system score of each food and beverage consumed, based on the contents of energy, saturated fatty acid, total sugar, sodium, fruits/vegetables/nuts, dietary fiber, and protein per 100 g.

RESULTS

Irrespective of the definition of meals and snacks, higher FSA scores (lower nutritional quality) of both meals and snacks were associated with unfavorable profiles of individual components of overall diet, including lower intakes of fruits/vegetables/nuts and higher intakes of biscuits/cakes/pastries, total fat, and saturated fatty acid. The FSA scores of meals and snacks were also inversely associated with overall diet quality assessed by the healthy diet indicator (regression coefficient (β) = -0.22 to -0.17 and -0.06 to -0.03, respectively) and Mediterranean diet score (β = -0.25 to -0.19 and -0.08 to -0.05, respectively) in both sexes (P ≤ 0.005). However, the associations were stronger for meals, mainly due to their larger contribution to total EI (64% to 84%). After adjustment for potential confounders, only the FSA score of snacks based on EI contribution was positively associated with BMI and waist circumference in women (P ≤ 0.005).

CONCLUSIONS

Although lower nutritional quality of both meals and snacks assessed by the FSA score was associated with adverse profiles of overall diet quality (but not necessarily adiposity measures), stronger associations were observed for nutritional quality of meals.

Associations between energy density of meals and snacks and overall diet quality and adiposity measures in British children and adolescents: the National Diet and Nutrition Survey

This cross-sectional study examined how energy density (ED) of meals and snacks are associated with overall diet quality and adiposity measures in 1617 British children aged 4-18 years from the 1997 National Diet and Nutrition Survey. On the basis of data from 7-d weighed dietary record, all eating occasions were divided into meals or snacks on the basis of time (meals: 06.00-09.00, 12.00-14.00 and 17.00-20.00 hours; snacks: all others) or contribution to energy intake (EI) (meals: ≥15 %; snacks: <15 %). ED of meals and snacks was calculated on the basis of food only. Overall diet quality was assessed using the Mediterranean diet score (range 0-8). Irrespective of the definition of meals and snacks, ≥67 % of EI was derived from meals, whereas ED of meals was lower than ED of snacks (mean: 8·50-8·75 v. 9·69-10·52 kJ/g). Both ED of meals and ED of snacks were inversely associated with total intakes of vegetables, fruits, dietary fibre and overall diet quality and positively associated with total intakes of fat. However, the associations were stronger for ED of meals. The change in the Mediterranean diet score with a 1-unit increase of ED (kJ/g) was -0·35 to -0·30 for ED of meals and -0·09 to -0·06 for ED of snacks (all P<0·0001). After adjustment for potential confounders, all measures of ED of meals and snacks did not show positive associations with adiposity measures. In conclusion, although both ED of meals and ED of snacks were associated with adverse profiles of overall diet quality (but not adiposity measures), stronger associations were observed for ED of meals.

The mountainous Cretan dietary patterns and their relationship with cardiovascular risk factors: the Hellenic Isolated Cohorts MANOLIS study

OBJECTIVE

We carried out de novo recruitment of a population-based cohort (MANOLIS study) and describe the specific population, which displays interesting characteristics in terms of diet and health in old age, through deep phenotyping.

DESIGN

Cross-sectional study where anthropometric, biochemical and clinical measurements were taken in addition to interview-based completion of an extensive questionnaire on health and lifestyle parameters. Dietary patterns were derived through principal component analysis based on a validated FFQ.

SETTING

Geographically isolated Mylopotamos villages on Mount Idi, Crete, Greece.

SUBJECTS

Adults (n 1553).

RESULTS

Mean age of the participants was 61·6 years and 55·8 % were women. Of the population, 82·7 % were overweight or obese with a significantly different prevalence between overweight men and women (43·4 v. 34·7 %, P=0·002). The majority (70·6 %) of participants were married, while a larger proportion of women were widowed than men (27·8 v. 3·5 %, P<0·001). Smoking was more prevalent in men (38·7 v. 8·2 %, P<0·001), as 88·8% of women had never smoked. Four dietary patterns emerged as characteristic of the population; these were termed 'local', 'high fat and sugar, 'Greek café/tavern' and 'olive oil, fruits and vegetables'. Individuals more adherent to the local dietary pattern presented higher blood glucose (β=4·026, P<0·001). Similarly, individuals with higher compliance with the Greek café/tavern pattern had higher waist-to-hip ratio (β=0·012, P<0·001), blood pressure (β=1·015, P=0·005) and cholesterol (β=5·398, P<0·001).

CONCLUSIONS

Profiling of the MANOLIS elderly population identifies unique unhealthy dietary patterns that are associated with cardiometabolic indices.

Energy density of meals and snacks in the British diet in relation to overall diet quality, BMI and waist circumference: findings from the National Diet and Nutrition Survey

This cross-sectional study examined how energy density (ED) in meals and snacks is associated with overall diet quality, BMI and waist circumference (WC). On the basis of the data from 7-d weighed dietary record, all eating occasions were divided into meals or snacks based on time (meals: 06.00-10.00, 12.00-15.00 and 18.00-21.00 hours; snacks: others) or contribution to energy intake (EI) (meals: ≥15; snacks: <15%) in 1451 British adults aged 19-64 years. Irrespective of the definition of meals and snacks, both meal ED and snack ED (kJ/g; calculated on the basis of solid food only) were inversely associated with overall diet quality assessed by the healthy diet indicator (regression coefficient (β)=-0·29 to -0·21 and -0·07 to -0·04, respectively) and Mediterranean diet score (β=-0·43 to -0·30 and -0·13 to -0·06, respectively) in both sexes (P≤0·002), although the associations were stronger for meal ED. After adjustment for potential confounders, in both men and women, meal ED based on EI contribution showed positive associations with BMI (β=0·34; 95% CI 0·06, 0·62 and β=0·31; 95% CI 0·01, 0·61, respectively) and WC (β=0·96; 95% CI 0·27, 1·66 and β=0·67; 95% CI 0·04, 1·30, respectively). In addition, meal ED based on time was positively associated with WC in men (β=0·59; 95% CI 0·07, 1·10) and snack ED based on time was positively associated with BMI in women (β=0·15; 95% CI 0·04, 0·27). In analyses in which only acceptable EI reporters were included, similar results were obtained. In conclusion, the findings suggest stronger associations of meal ED with overall diet quality, BMI and WC compared with snack ED.

Relationship between frequency of eating and cardiovascular disease mortality in U.S. adults: the NHANES III follow-up study

PURPOSE

This study examined longitudinal relationship between baseline daily eating frequency and all-cause and cardiovascular disease (CVD) mortality among U.S. adults.

METHODS

The Third National Health and Nutrition Examination Survey (1988-1992) participants were followed through 2006. Nonpregnant adults >17 years old (n = 6884) whose dietary recall was of good quality and had fasted at least 8 hours before physical examinations were eligible for this analysis. Frequency of eating was derived from 24-hour dietary recalls. Main outcomes included all-cause and CVD mortality during follow-up, based on National Death Index data.

RESULTS

During follow-up (median time: 176 months), 1280 subjects died, 503 of them from CVD. Adults reporting eating ≥6 times/day had a lower hazard ratio for CVD mortality than those reporting eating 4 times/day (hazard ratio = 0.68; 95% confidence interval, 0.43-1.08; test for trend, P = .011). The gradient of CVD mortality risk by eating frequency was significant for the groups with ≥2500 kcal of total energy intake (test for trend, P = .037).

CONCLUSIONS

Eating frequency was inversely associated with CVD mortality, which was especially marked for people reporting high total energy intake. Nevertheless, public health recommendations should be cautious, as eating frequency was positively associated with total energy intake, which could promote weight gain.

What Is a Snack, Why Do We Snack, and How Can We Choose Better Snacks? A Review of the Definitions of Snacking, Motivations to Snack, Contributions to Dietary Intake, and Recommendations for Improvement

Around the world, adults consume energy outside of traditional meals such as breakfast, lunch, and dinner. However, because there is no consistent definition of a "snack," it is unclear whether those extra eating occasions represent additional meals or snacks. The manner in which an eating occasion is labeled (e.g., as a meal or a snack) may influence other food choices an individual makes on the same day and satiety after consumption. Therefore, a clear distinction between "meals" and "snacks" is important. This review aims to assess the definition of extra eating occasions, to understand why eating is initiated at these occasions, and to determine what food choices are common at these eating occasions in order to identify areas for dietary intervention and improvement. Part I of this review discusses how snacking is defined and the social, environmental, and individual influences on the desire to snack and choice of snack. The section concludes with a brief discussion of the associations of snacking with cardiometabolic health markers, especially lipid profiles and weight. Part II addresses popular snack choices, overall snacking frequencies, and the demographic characteristics of frequent snackers in several different countries. This review concludes with a recommendation for nutrition policymakers to encourage specific health-promoting snacks that address nutrient insufficiencies and excesses.

Associations between meal and snack frequency and overweight and abdominal obesity in US children and adolescents from National Health and Nutrition Examination Survey (NHANES) 2003–2012

The association between eating frequency (EF) and adiposity in young populations is inconsistent. This cross-sectional study examined associations of EF, meal frequency (MF) and snack frequency (SF) with adiposity measures in US children aged 6–11 years (n 4346) and adolescents aged 12–19 years (n 6338) participating in the National Health and Nutrition Examination Survey 2003–2012. Using data from two 24-h dietary recalls, all eating occasions providing ≥210 kJ of energy were divided into meals or snacks based on contribution to energy intake (≥15 or <15 %), self-report and time (06.00–09.00, 12.00–14.00 and 17.00–20.00 hours or others). When analysed without adjustment for the ratio of reported energy intake:estimated energy requirement (EI:EER), all measures of EF, MF and SF showed inverse or null associations with overweight (BMI≥85th percentile of BMI-for-age) and abdominal obesity (waist circumference≥90th percentile) in both children and adolescents. After adjustment for EI:EER, however, EF and SF, but not MF, showed positive associations in children, irrespective of the definition of meals and snacks. In adolescents, after adjustment for EI:EER, positive associations were observed for EF (abdominal obesity only), SF based on energy contribution and MF based on self-report, whereas there was an inverse association between MF based on energy contribution and overweight. In conclusion, higher SF and EF, but not MF, were associated with higher risks of overweight and abdominal obesity in children, whereas associations varied in adolescents, depending on the definition of meals and snacks. Prospective studies are needed to establish the associations observed here.

Deletion of G-protein-coupled receptor 55 promotes obesity by reducing physical activity

BACKGROUND/OBJECTIVES

Cannabinoid receptor 1 (CB1) is the best-characterized cannabinoid receptor, and CB1 antagonists are used in clinical trials to treat obesity. Because of the wide range of CB1 functions, the side effects of CB1 antagonists pose serious concerns. G-protein-coupled receptor 55 (GPR55) is an atypical cannabinoid receptor, and its pharmacology and functions are distinct from CB1. GPR55 regulates neuropathic pain, gut, bone, immune functions and motor coordination. GPR55 is expressed in various brain regions and peripheral tissues. However, the roles of GPR55 in energy and glucose homeostasis are unknown. Here we have investigated the roles of GPR55 in energy balance and insulin sensitivity using GPR55-null mice (GPR55(-/-)).

METHODS

Body composition of the mice was measured by EchoMRI. Food intake, feeding behavior, energy expenditure and physical activity of GPR55(-/-) mice were determined by indirect calorimetry. Muscle function was assessed by forced treadmill running test. Insulin sensitivity was evaluated by glucose and insulin tolerance tests. Adipose inflammation was assessed by flow cytometry analysis of adipose tissue macrophages. The expression of inflammatory markers in adipose tissues and orexigenic/anorexigenic peptides in the hypothalamus was also analyzed by real-time PCR.

RESULTS

GPR55(-/-) mice had normal total energy intake and feeding pattern (i.e., no changes in meal size, meal number or feeding frequency). Intriguingly, whereas adult GPR55(-/-) mice only showed a modest increase in overall body weight, they exhibited significantly increased fat mass and insulin resistance. The spontaneous locomotor activity of GPR55(-/-) mice was dramatically decreased, whereas resting metabolic rate and non-shivering thermogenesis were unchanged. Moreover, GPR55(-/-) mice exhibited significantly decreased voluntary physical activity, showing reduced running distance on the running wheels, whereas muscle function appeared to be normal.

CONCLUSIONS

GPR55 has an important role in energy homeostasis. GPR55 ablation increases adiposity and insulin resistance by selectively decreasing physical activity, but not by altering feeding behavior as CB1.

Dietary patterns in weight loss maintenance: results from the MedWeight study

PURPOSE

The dietary habits contributing to weight loss maintenance are not sufficiently understood. We studied weight loss maintainers in comparison with regainers, to identify the differentiating behaviors.

METHODS

The MedWeight study is a Greek registry of weight loss maintainers and regainers. Participants had intentionally lost ≥10 % of their weight and either had maintained this loss for over a year, or had regained weight. Questionnaires on demographics and lifestyle habits were completed online. Dietary assessment was carried out by two telephone 24-h recalls.

RESULTS

Present analysis focused on 361 participants (32 years old, 39 % men): 264 maintainers and 97 regainers. Energy and macronutrient intake did not differ by maintenance status (1770 ± 651 kcal in maintainers vs. 1845 ± 678 kcal in regainers, p = 0.338), although protein intake per kg of body weight was higher in maintainers (1.02 ± 0.39 vs. 0.83 ± 0.28 g/kg in regainers, p < 0.001). Physical activity energy expenditure was greater for maintainers in men (by 1380 kcal per week, p = 0.016), but not women. Salty snacks, alcohol and regular soda were more frequently consumed by men regainers. Principal component analysis identified a healthy dietary pattern featuring mainly unprocessed cereal, fruit, vegetables, olive oil and low-fat dairy. Male maintainers were 4.6 times more likely to follow this healthy pattern compared to regainers (OR 4.6, 95 % CI 2.0-11.0). No similar finding was revealed in women. Other characteristics of maintainers but not of regainers were: involvement in meal preparation and eating at home for men, and a higher eating frequency and slower eating rate for women.

CONCLUSIONS

Men maintaining weight loss were much more likely to adhere to a healthy eating pattern. Eating at home, involvement in meal preparation, higher eating frequency and slower eating rate were also associated with maintenance. These lifestyle habits of successful maintainers provide target behaviors to improve obesity treatment.

Eating Frequency Is Positively Associated with Overweight and Central Obesity in U.S. Adults

BACKGROUND

Evidence of the association between eating frequency (EF) and adiposity is inconsistent.

OBJECTIVE

With the use of data from the NHANES 2003-2012, this cross-sectional study examined the associations between EF, meal frequency (MF), and snack frequency (SF) and overweight/obesity and central obesity.

METHODS

Dietary intake was assessed with the use of two 24-h dietary recalls in 18,696 US adults ≥20 y of age. All eating occasions providing ≥50 kcal of energy were divided into meals or snacks on the basis of contribution to energy intake (≥15% or <15%), self-report, and time (0600-1000, 1200-1500, 1800-2100, or other). Multivariable logistic regression was used to compute ORs and 95% CIs.

RESULTS

When analyzed without adjustment for the ratio of energy intake to estimated energy requirement (EI:EER), all measures of EF, MF, and SF showed inverse or null associations. After adjustment for EI:EER, however, EF was positively associated with overweight/obesity (body mass index ≥25 kg/m2) and central obesity (waist circumference ≥102 cm in men and ≥88 cm in women). Compared with the lowest category (≤3 times/d), the OR (95% CI) for overweight/obesity in the highest category (≥5 times/d) was 1.54 (1.23, 1.93) in men (P-trend = 0.003) and 1.45 (1.17, 1.81) in women (P-trend = 0.001). The corresponding value for central obesity was 1.42 (1.15, 1.75) in men (P-trend = 0.002) and 1.29 (1.05, 1.59) in women (P-trend = 0.03). The self-report-based MF and time-based MF were positively associated with overweight/obesity, central obesity, or both, although MF based on energy contribution showed no associations. There were positive associations for all SF measures in men and for the energy-contribution-based SF in women.

CONCLUSIONS

This cross-sectional study suggests that higher EF, MF, and SF are associated with an increased likelihood of overweight/obesity and central obesity in US adults. Prospective studies are needed to confirm the associations observed in this study.

Decreasing the number of small eating occasions (<15 % of total energy intake) regardless of the time of day may be important to improve diet quality but not adiposity: a cross-sectional study in British children and adolescents

Evidence of associations between meal frequency (MF) and snack frequency (SF) and diet and obesity in young populations is limited. This cross-sectional study examined MF and SF in relation to dietary intake and adiposity measures in British children aged 4-10 years (n 818) and adolescents aged 11-18 years (n 818). Based on data from a 7-d weighed dietary record, all eating occasions were divided into meals or snacks on the basis of contribution to energy intake (≥15 or <15 %) or time (06.00-10.00, 12.00-15.00 and 18.00-21.00 hours or others). All measures of MF and SF showed positive associations with energy intake, except for MF based on energy contribution in children. Irrespective of the definition of snacks, SF was associated with higher intakes of soft drinks, confectionery and total sugar, lower intakes of cereals, fish, meat, protein, PUFA, starch and dietary fibre, and a lower diet quality (assessed by the Mediterranean diet score, except for SF based on energy contribution in adolescents). MF based on time, but not based on energy contribution, was associated with higher intakes of confectionery and total sugar, lower intakes of fish, protein, PUFA and starch, and, only in children, a lower diet quality. All measures of MF and SF showed no association with adiposity measures. In conclusion, this cross-sectional study in British children and adolescents suggests that decreasing the number of small eating occasions (<15 % of total energy intake) regardless of the time of day may be important to improve diet quality but not adiposity.

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 34.5years, mean BMI 23.9kg/m(2), 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 Frequency, Food Intake, and Weight: A Systematic Review of Human and Animal Experimental Studies

Eating frequently during the day, or "grazing," has been proposed to assist with managing food intake and weight. This systematic review assessed the effect of greater eating frequency (EF) on intake and anthropometrics in human and animal experimental studies. Studies were identified through the PubMed electronic database. To be included, studies needed to be conducted in controlled settings or use methods that carefully monitored food intake, and measure food intake or anthropometrics. Studies using human or animal models of disease states (i.e., conditions influencing glucose or lipid metabolism), aside from being overweight or obese, were not included. The 25 reviewed studies (15 human and 10 animal studies) contained varying study designs, EF manipulations (1-24 eating occasions per day), lengths of experimentation (230 min to 28 weeks), and sample sizes (3-56 participants/animals per condition). Studies were organized into four categories for reporting results: (1) human studies conducted in laboratory/metabolic ward settings; (2) human studies conducted in field settings; (3) animal studies with experimental periods <1 month; and (4) animal studies with experimental periods >1 month. Out of the 13 studies reporting on consumption, 8 (61.5%) found no significant effect of EF. Seventeen studies reported on anthropometrics, with 11 studies (64.7%) finding no significant effect of EF. Future, adequately powered, studies should examine if other factors (i.e., disease states, physical activity, energy balance and weight status, long-term increased EF) influence the relationship between increased EF and intake and/or anthropometrics.

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.

Eating in moderation and the essential role of awareness. A Dutch longitudinal study identifying psychosocial predictors

BACKGROUND

Eating in moderation, i.e. the attempt to monitor and limit the intake of energy-dense foods, is a promising strategy in the prevention of weight gain. The purpose of this study was to examine which psychosocial factors derived from the I-Change Model (ICM) were associated with eating in moderation, and whether these factors differed between adults with a correct (aware) or incorrect (unaware) perception of their dietary behaviour.

METHODS

This study used a longitudinal design with measurements at baseline (N = 483) and six-month follow-up (N = 379). Eating in moderation was defined as the average daily energy intake from energy-dense food products and was measured by a validated food frequency questionnaire. Linear regression analyses were used to assess the associations between the ICM factors and eating in moderation. The moderating role of awareness was examined by including interactions between awareness and the ICM factors in the regression analyses using the pick-a-point approach to further examine the associations for aware and unaware participants.

RESULTS

Participants who were aware of their dietary behaviour had a significantly lower average daily energy intake compared to those who were unaware. Eating in moderation was predicted by awareness, risk perception, social influence and intention. Among the aware participants, eating in moderation was predicted by risk perception, attitude, social influence and intention. Among the unaware participants, only risk perception and self-efficacy were significantly associated with eating in moderation.

CONCLUSIONS

Our findings show that psychosocial factors may only predict eating in moderation when people are aware of their risk behaviour. Therefore, interventions aimed at promoting complex behaviours, such as eating in moderation, should first focus on improving individuals' awareness of their risk behaviour before targeting motivational factors.

Energy compensation in the real world: good compensation for small portions of chocolate and biscuits over short time periods in complicit consumers using commercially available foods

While investigations using covert food manipulations tend to suggest that individuals are poor at adjusting for previous energy intake, in the real world adults rarely consume foods of which they are ill-informed. This study investigated the impact in fully complicit consumers of consuming commercially available dark chocolate, milk chocolate, sweet biscuits and fruit bars on subsequent appetite. Using a repeated measures design, participants received four small portions (4 × 10-11 g) of either dark chocolate, milk chocolate, sweet biscuits, fruit bars or no food throughout five separate study days (counterbalanced in order), and test meal intake, hunger, liking and acceptability were measured. Participants consumed significantly less at lunch following dark chocolate, milk chocolate and sweet biscuits compared to no food (smallest t(19) = 2.47, p = 0.02), demonstrating very good energy compensation (269-334%). No effects were found for fruit bars (t(19) = 1.76, p = 0.09), in evening meal intakes (F(4,72) = 0.62, p = 0.65) or in total intake (lunch + evening meal + food portions) (F(4,72) = 0.40, p = 0.69). No differences between conditions were found in measures of hunger (largest F(4,76) = 1.26, p = 0.29), but fruit bars were significantly less familiar than all other foods (smallest t(19) = 3.14, p = 0.01). These findings demonstrate good compensation over the short term for small portions of familiar foods in complicit consumers. Findings are most plausibly explained as a result of participant awareness and cognitions, although the nature of these cognitions cannot be discerned from this study. These findings however, also suggest that covert manipulations may have limited transfer to real world scenarios.

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.

Ghrelin receptor regulates appetite and satiety during aging in mice by regulating meal frequency and portion size but not total food intake

Aging is often associated with overweight and obesity. There exists a long-standing debate about whether meal pattern also contributes to the development of obesity. The orexigenic hormone ghrelin regulates appetite and satiety by activating its receptor, growth hormone secretagogue receptor (GHS-R). In mice, circulating ghrelin concentrations and brain GHS-R expression were shown to increase with aging. To assess whether GHS-R regulates feeding pattern during aging, we studied meal patterns for the following cohorts of male mice fed a normal unpurified diet: 1) 3-4 mo, young wild-type (WT) mice; 2) 3-4 mo, young Ghsr-null (Ghsr(-/-)) mice; 3) 12-14 mo, middle-aged WT (WT-M) mice; 4) 12-14 mo, middle-aged Ghsr(-/-) (Ghsr(-/-)-M) mice; 5) 24-26 mo, old WT (WT-O) mice; and 6) 24-26 mo, old Ghsr(-/-) (Ghsr(-/-)-O) mice. Although the total daily food intake of Ghsr(-/-) mice was similar to that of WT controls, Ghsr(-/-)-M and Ghsr(-/-)-O mice had 9% (P = 0.07) and 16% (P < 0.05) less body weight compared with WT-M and WT-O mice, respectively, primarily due to reduced fat mass (P < 0.05, WT-M vs. Ghsr(-/-)-M and WT-O vs. Ghsr(-/-)-O). Intriguingly, Ghsr(-/-)-M mice ate larger meals (on average, Ghsr(-/-)-M mice ate 0.117 g/meal and WT-M mice ate 0.080 g/meal; P < 0.01) and took a longer time to eat (Ghsr(-/-)-M, 196.0 s and WT-M, 128.9 s; P < 0.01), but ate less frequently (Ghsr(-/-)-M, 31.0 times/d and WT-M, 42.3 times/d; P < 0.05) than WT-M controls. In addition, we found that expression of hypothalamic orexigenic peptides, neuropeptide Y (NPY) and agouti-related peptide (AgRP), was relatively lower in aged WT mice (P = 0.09 for NPY and P = 0.06 for AgRP), but anorexic peptide pro-opiomelanocortin (POMC) expression remained unchanged between the WT age groups. Interestingly, old Ghsr(-/-) mice had greater hypothalamic NPY expression (102% higher; P < 0.05) and AgRP expression (P = 0.07) but significantly lower POMC expression (P < 0.05) when compared with age-matched WT-O controls. Thus, our results indicate that GHS-R plays an important role in the regulation of meal pattern and that GHS-R ablation may modulate feeding behavior through the regulation of hypothalamic neuropeptides. Our results collectively suggest that ghrelin receptor antagonism may have a beneficial effect on metabolism during aging.

Body weight regulation and obesity: dietary strategies to improve the metabolic profile

This review discusses dietary strategies that may improve the metabolic profile and body weight regulation in obesity. Recent evidence demonstrated that long-term health effects seem to be more beneficial for low-glycemic index (GI) diets compared to high-protein diets. Still, these results need to be confirmed by other prospective cohort studies and long-term clinical trials, and the discrepancy between these study designs needs to be explored in more detail. Furthermore, the current literature is mixed with regard to the efficacy of increased meal frequency (or snacking) regimens in causing metabolic alterations, particularly in relation to body weight control. In conclusion, a growing body of evidence suggests that dietary strategies with the aim to reduce postprandial insulin response and increase fat oxidation, and that tend to restore metabolic flexibility, have a place in the prevention and treatment of obesity and associated metabolic disorders.

Associations of eating frequency with adiposity measures, blood lipid profiles and blood pressure in British children and adolescents

Several epidemiological studies in adults have suggested a favourable effect of frequent eating on blood lipid profiles, but evidence in younger populations is lacking. In the present cross-sectional study, we examined the associations of eating frequency (EF) with metabolic risk factors in British children aged 4-10 years (n 818) and adolescents aged 11-18 years (n 818). Dietary intake was assessed using a 7 d weighed dietary record. EF was calculated based on all eating occasions, except for those providing < 210 kJ of energy. Metabolic risk factors examined were total, HDL-cholesterol and LDL-cholesterol concentrations, TAG concentration, BMI z-score, waist:height ratio (WHtR; only adolescents), and systolic and diastolic blood pressures. Adjustment was made for age, sex, social class, physical activity levels, intakes of protein, fat, total sugar and dietary fibre, ratio of reported energy intake to estimated energy requirement (EI:EER) and BMI z-score (except for BMI z-score and WHtR). In children, EF was inversely associated with total cholesterol and LDL-cholesterol concentrations (n 324, P= 0·01 and 0·04, respectively). Conversely, EF was positively associated with BMI z-score in adolescents (P= 0·004). There were no associations between EF and other metabolic risk factors. In analyses in which only plausible energy reporters (EI:EER: 0·72-1·28) were included, similar results were obtained, except for an inverse association between EF and diastolic blood pressure in children. In conclusion, a higher EF is associated with lower total cholesterol and LDL-cholesterol concentrations in children but with a higher BMI z-score in adolescents.

Meals and snacking, diet quality and energy balance

The present obesity "epidemic" has been attributed to a growing trend for snacking. Snacking may contribute to excess energy intake and weight gain through different ways, for example: context/environment of eating, frequency of consumption and quality of food choices. The present article reviews data and hypotheses about the role of snacks in diet quality and body weight control. One obvious difficulty in this field is the diversity of definitions and approaches used in cross-sectional, longitudinal, and intervention studies. A brief paragraph reviews the prevalence of snacking in various countries and its recent evolution. The literature addressing the contribution of snacks to daily energy and nutrient intake presents two contrasting pictures. In many reports, snacking appears to facilitate the adjustment of energy intake to needs, and to contribute carbohydrates, rather than fats, to the diet, in addition to valuable micronutrients. Such results are usually reported in healthy, normal-weight children and adults. By contrast, snacking often appears to contribute much energy but little nutrition in the diet of other consumers, particularly obese children and adults. In addition to selecting energy-dense foods, eating in the absence of hunger in response to external non-physiological cues, in an irregular fashion, in contexts (e.g. while watching television) that do not favor attention to the act of eating, might be crucial factors determining the nutritional effects of snacking. While efforts should be continued to harmonize definitions and minimize the influence of under-reporting, interventions aimed at decreasing detrimental snacking should address both food-related aspects and behavioral components.

Healthy snacking recommendations: one size does not fit all

An underlying factor contributing to a lack of consensus in the scientific literature regarding the health effects of snacking may be the diversity of study populations. In fact, the influence of snacking likely varies with different target populations. Accordingly, the purpose of this paper is to demonstrate that snacking may make important contributions to a healthy diet, especially among older adults (≥65 years). However, these dietary behaviors may have a different consequence among adults (18-60 years) experiencing psychosocial stress as measured by food insecurity. Food insecurity refers to the condition in which individuals do not have access at all times to enough food for an active, healthful life. Another reason for a lack of consensus regarding the effects of snacking is that reports describing the contribution of snacking to the diet of adults have generally focused on single nutrients. Because of the complexity of dietary intake and the possible interaction of nutrients, it is often difficult to attribute health outcomes to the effects of a single dietary component. Thus, the relationship between snacking frequency and overall dietary quality among adults (≥20 years) will be described. Developing recommendations regarding snacking and meal frequency is extremely problematic for numerous reasons. One universal dietary recommendation regarding snacking and meal frequency is not appropriate for every life-stage group. Also, research has demonstrated that individuals view snacking as an unhealthy behavior. Because individuals are more likely to acknowledge, integrate, and act on nutrition knowledge that corresponds with their existing knowledge, changing dietary behaviors with messages containing the term snacking may be ill-conceived. Descriptive alternatives to the term snacking are needed in developing messages for health promotion campaigns.

Eating frequency in relation to body mass index and waist circumference in British adults

BACKGROUND

Inconsistent associations between eating frequency (EF) and adiposity may be mainly due to measurement errors of EF.

OBJECTIVE

This cross-sectional study examined the association of EF with body mass index (BMI) and waist circumference (WC), by focusing on the confounding of energy misreporting and the effect of exclusion of underreporters (URs).

DESIGN

Dietary intake was assessed using a 7-day weighed dietary record in 1487 British adults aged 19-64 years. EF was calculated based on all eating occasions (EF(all)), after excluding those providing no energy (EF(energy)), and after excluding those providing <210 kJ of energy (EF(⩾210 kJ)). Energy misreporting was assessed as reported energy intake divided by estimated energy requirement (EI:EER).

RESULTS

The mean values (1st and 99th percentiles) of EF(all), EF(energy) and EF(⩾210 kJ) were, respectively, 7.8 (3.1, 15.3), 7.2 (2.9, 12.7), and 5.6 (2.3, 10.7) times/day in men and 7.6 (3.0, 13.9), 6.7 (2.7, 12.1), and 4.8 (1.9, 9.1) times/day in women. In the univariate analyses of the entire male population, EF(⩾210 kJ), but not EF(all) and EF(energy), was inversely associated with BMI and WC. After full adjustment (including EI:EER), all three measures of EF were positively associated with BMI and WC. In the univariate analyses of the entire female population, all three measures of EF were inversely associated with BMI and WC. After full adjustment, EF(⩾210 kJ) was positively associated with BMI and WC while EF(all) and EF(energy) showed null associations. When URs (EI:EER <0.665) were excluded, the multivariate analyses showed that EF(all) and EF(energy) were positively associated with BMI in men while EF(⩾210 kJ) was positively associated with BMI and WC in both sexes.

CONCLUSIONS

We showed positive associations of EF with BMI and WC. Adjustment for EI:EER and the exclusion of URs, as well as definitions of EF, radically affected the results of the analysis.

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.

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.

An isocaloric increase of eating episodes in the morning contributes to decrease energy intake at lunch in lean men

The effects of increasing eating frequency on human health are unclear. This study used an integrated approach to assess the short-term consequences on appetite and metabolism. Twenty normal-weight men participated in: (i) two sessions consisting of a breakfast consumed in one eating episode at T0 (F1), or in four isocaloric eating episodes at T0, T60, T120, and T180 min (F4), and followed by an ecological ad libitum buffet meal (T240) designed in an experimental restaurant. Intakes were assessed for the whole buffet meal and for each temporal quarter of the meal. (ii) two sessions consisting of the same two breakfasts F1 and F4 in a Clinical Investigation Centre. Blood sampling was performed to study the kinetics of ghrelin, glucagon-like peptide-1 (GLP-1), glucose, insulin, triglycerides and non-esterified fatty acids (NEFA). Substrate oxidation was measured by indirect calorimetry. During each of the 4 sessions, participants rated their appetite throughout the experiment. After F4, at T240 min, GLP-1 concentration was higher (P=0.006) while ghrelin concentration and hunger ratings were lower (P<0.001). We showed a trend for subjects to consume less energy (-88±61 kcal, P=0.08) at the buffet after F4, explained by a decrease in lipid intake (P=0.04). Marked differences in consumption were observed during the last temporal quarter of the meal for total energy and lipid intake (P=0.03). Mixed models highlighted differences between F1 and F4 for the kinetics of glucose, insulin and NEFA (P<0.001). The area under the curve was lower for insulin (P<0.001) and NEFA in F4 (P=0.03). Diet induced thermogenesis was reduced in F4 (P<0.05). This study demonstrated the beneficial short-term effect of increasing eating frequency on appetite in lean men considering subjective, physiological and behavioral data. However, the loss of the inter-prandial fast was associated with an inhibition of lipolysis, reflected by NEFA profiles, and a decrease in energy expenditure.

Effects of meal frequency on metabolic profiles and substrate partitioning in lean healthy males

Introduction

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.

Methods

Twelve (BMI:21.6±0.6 kg/m²) 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.

Results

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.

Conclusion

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.

Trial Registration

ClinicalTrails.gov NCT01034293

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

Eating frequency has been inversely related to BMI but the impact of eating frequency on weight loss is unclear. This randomized controlled trial pilot study examined the effect of eating frequency on hunger, energy intake, and weight loss during a 6-month behavioral weight loss intervention. Participants (age: 51.0 ± 9.9 years, BMI: 35.5 ± 4.8 kg/m(2), 57.8% female, 94.1% white) were randomized to one of two eating frequency prescriptions: Three meal (n = 25): three eating bouts/day; or grazing (n = 26): eat at least 100 kcals every 2-3 h. Both groups attended 20 sessions and had identical dietary (1,200-1,500 kcals/day, <30% kcals from fat) and physical activity goals (200 min/week). Assessments were conducted at 0, 3, and 6 months. Using intent-to-treat analyses, grazing reported a greater eating frequency than three meal at 6 months (5.8 ± 1.1 eating bouts/day vs. 3.2 ± 0.6 eating bouts/day, P < 0.001). Grazing reported a significant reduction in hunger from 0 to 6 months (56.3 ± 15.7 mm vs. 47.9 ± 18.5 mm, P < 0.05). Energy intake and BMI were significantly (P < 0.001) reduced from 0 to 6 months (energy intake: 2,198 ± 692 kcals/day vs. 1,266 ± 353 kcals/day; BMI: 35.5 ± 4.8 kg/m(2) vs. 30.6 ± 4.9 kg/m(2)). There were no significant differences in energy intake or BMI between the groups. While eating more frequently reduced hunger, it may not be related to greater reductions in energy intake or BMI during a behavioral weight loss intervention.