Weekly rhythms of spontaneous nutrient intake and meal pattern of humans

Temporal patterns in taste sensitivity

Individuals vary in their ability to taste, and some individuals are more sensitive to certain tastes than others. Taste sensitivity is a predictor of various factors, such as diet, eating behavior, appetite regulation, and overall health. Furthermore, taste sensitivity can fluctuate within an individual over short to long periods of time: for example, in daily (diurnal) cycles, monthly (menstrual) cycles (in females), and yearly (seasonal) cycles. Understanding these temporal patterns is important for understanding individual eating habits and food preferences, particularly in the context of personalized and precision nutrition. This review provides a summary of the literature on taste sensitivity patterns across 3 temporal dimensions: daily, monthly, and yearly. Good evidence for diurnal patterns has been observed for sweet taste and fat taste, although the evidence is limited to rodent studies for the latter. Obese populations showed limited variation to sweet and fat taste sensitivities over a day, with limited variation in sweet taste sensitivity being linked to insulin resistance. There were mixed observations of temporal variation in sensitivity to sour and umami tastes, and there were no patterns in sensitivity to bitter taste. Menstrual patterns in sweet taste sensitivity were consistent with patterns in food intake. Other taste modality investigations had mixed findings that had little agreement across studies. Hormonal changes in females influence taste sensitivity to some degree, although the overall patterns are unclear. Seasonal patterns have been less well studied, but there is weak evidence that sweet, salty, and bitter taste sensitivities change across seasons. Differences in seasonal taste patterns have been observed in subgroups susceptible to mental health disorders, requiring further investigation. Patterns of taste sensitivity are evident across multiple temporal dimensions, and more research is needed to determine the influence of these patterns on food intake. Dysregulation of these patterns may also be a marker of certain diseases or health conditions, warranting further investigation. Notably, the alimentary tastes (umami, fat, and carbohydrate) are underrepresented in this research area and require additional investigation.

Analysis of nutrient intake and dietary adequacy on weekdays and weekends among undergraduate students

Objective: To comparatively analyze nutrient intake and dietary adequacy on weekdays (WKDs) and weekends (WKNs) among undergraduate students. Participants: University students (N = 210), 18-30 years old. Methods: A two-day food record was used. Intake of energy, macronutrients, micronutrients and fiber were calculated, without and with an adjustment for 2000 kcal of energy and compared to the corresponding nutritional requirements. Results: Energy and macronutrients' intake was higher on WKNs (1,776.84 ± 40.68 vs. 2,025.76 ± 52.46 kcal; p < .05). There was a high predominance of hypocaloric diet on both WKDs (72%) and WKNs (57%). A low prevalence (<50%) of favorable intake level of most micronutrients and fiber was found on WKDs, WKNs, or both. There was a lower favorable intake of vitamins A, C, iron, and magnesium on WKNs, after adjusting for 2000 kcal. Conclusion: Undergraduate students showed an unfavorable nutrient intake and poor dietary quality on WKNs. Interventions that promote healthy eating are needed.

Quantitative analysis of the minimum days of dietary survey to estimate dietary pesticide exposure: Implications for dietary pesticide sampling strategy

Populations are exposed to pesticides through diet on a daily basis. However, there is no research guiding how to evaluate dietary pesticide exposure, and researchers used 1-day, 3-days, 7-days or even longer dietary survey to evaluate without any consensus. It is important for dietary pesticide evaluation to identify the minimum survey days. To increase knowledge of this, a data combination was applied between a two-wave consecutive repeated-measures study in Baoding City and the Fifth China Total Diet Study. Further policy consistency on pesticides were evaluated to explain its credibility. We computed the sensitivity and specificity to evaluate how well different days of dietary survey classify participants with high exposure, and calculated the minimum days required to estimate the participant-specific mean at different acceptable error range. With 1 day of dietary survey, the classification sensitivity was low (<0.6) for total HCH, endosulfan, chlordane, cyhalothrin, allethrin, and prallethrin; that for the other pesticides was high sensitivity (≥0.6). Sensitivity increased as the number of days increased, and the maximum marginal sensitivity increase (≥0.039) occurred from 1 to 2 days for all pesticides except phenothrin, whose maximum marginal sensitivity increase (0.042) occurred from 2 to 3 days. The specificity increased gradually from 0.8 to 0.9 from 1 to 7 days. Under the acceptable error range of 0.5%, 3-28 days were required for participant-specific mean estimation and 1-7 days were required when acceptable error range was shrunk in 1%. Only 1 day was enough if 5% error range was acceptable. In conclusion, 3 days in the study period was cost-effective to distinguish high exposure group, and it rose to 7 when estimating participant-specific mean from a conservative perspective. This study can serve as a reference to determine the minimum survey days for epidemiological studies employing dietary surveys.

Obesogenic Diet Cycling Produces Graded Effects on Cognition and Microbiota Composition in Rats

SCOPE

The effects of diet cycling on cognition and fecal microbiota are not well understood.

METHOD AND RESULTS

Adult male Sprague-Dawley rats were cycled between a high-fat, high-sugar "cafeteria" diet (Caf) and regular chow. The impairment in place recognition memory produced by 16 days of Caf diet was reduced by switching to chow for 11 but not 4 days. Next, rats received 16 days of Caf diet in 2, 4, 8, or 16-day cycles, each separated by 4-day chow cycles. Place recognition memory declined from baseline in all groups and was impaired in the 16- versus 2-day group. Finally, rats received 24 days of Caf diet continuously or in 3-day cycles separated by 2- or 4-day chow cycles. Any Caf diet access impaired cognition and increased adiposity relative to controls, without altering hippocampal gene expression. Place recognition and adiposity were the strongest predictors of global microbiota composition. Overall, diets with higher Caf > chow ratios produced greater spatial memory impairments and larger shifts in gut microbiota species richness and beta diversity.

CONCLUSION

Results suggest that diet-induced cognitive deficits worsen in proportion to unhealthy diet exposure, and that shifting to a healthy chow for at least a week is required for recovery under the conditions tested here.

Reliability estimates for assessing meal timing derived from longitudinal repeated 24-hour dietary recalls

BACKGROUND

Regulating meal timing may have efficacy for improving metabolic health for preventing or managing chronic disease. However, the reliability of measuring meal timing with commonly used dietary assessment tools needs characterization prior to investigating meal timing and health outcomes in epidemiologic studies.

OBJECTIVES

To evaluate the reliability of estimating meal timing parameters, including overnight fasting duration, the midpoint of overnight fasting time, the number of daily eating episodes, the period with the largest percentage of daily caloric intake, and late last eating episode (> 09:00 pm) from repeated 24-h dietary recalls (24HRs).

METHODS

Intraclass correlation coefficients (ICC), Light's Kappa estimates, and 95% CIs were calculated from repeated 24HR administered in 3 epidemiologic studies: The United States-based Interactive Diet and Activity Tracking in AARP (IDATA) study (n = 996, 6 24HR collected over 12-mo), German EPIC-Potsdam Validation Study (European Prospective Investigation into Cancer and Nutrition Potsdam Germany cohort) (n = 134, 12 24HR collected over 12-mo) and EPIC-Potsdam BMBF-II Study (Federal Ministry of Education and Research, "Bundesministerium für Bildung und Forschung") (n = 725, 4 24HR collected over 36 mo).

RESULTS

Measurement reliability of overnight fasting duration based on a single 24HR was "poor" in all studies [ICC range: 0.27; 95% CI: 0.23, 0.32 - 0.46; 95% CI: 0.43, 0.50]. Reliability was "moderate" with 3 24HR (ICC range: 0.53; 95% CI: 0.47, 0.58 in IDATA, 0.62; 95% CI: 0.52, 0.69 in the EPIC-Potsdam Validation Study, and 0.72; 95% CI: 0.70-0.75 in the EPIC-Potsdam BMBF-II Study). Results were similar for the midpoint of overnight fasting time and the number of eating episodes. Reliability of measuring late eating was "fair" in IDATA (Light's Kappa: 0.30; 95% CI: 0.21, 0.39) and "slight" in the EPIC-Potsdam Validation study and the EPIC-Potsdam BMBF-II study (Light's Kappa: 0.19; 95% CI: 0.15, 0.25 and 0.09; 95% CI: 0.06, 0.12, respectively). Reliability estimates differed by sex, BMI, weekday, and season of 24HR administration in some studies.

CONCLUSIONS

Our results show that ≥ 3 24HR over a 1-3-y period are required for reliable estimates of meal timing variables.

Highly processed food intake and immediate and future emotions in everyday life

Increased consumption of highly processed foods may result in lower diet quality, and low diet quality is associated with elevated risk of cardiovascular disease, type 2 diabetes, and cancer. One mechanism driving highly processed food intake is the expectation that eating these foods will improve emotional experiences, particularly in individuals with elevated "highly processed food addiction" symptoms. However, experimental findings about the emotional experiences following highly processed food intake are mixed. Furthermore, prior studies have generally failed to capture the potentially prolonged emotional effects of eating highly processed foods and not tested for individual differences. The present study was a preregistered archival data analysis of an ambulatory electronic diary study that captured real-life emotions following highly processed food intake. Multilevel modeling was used to predict the effects of highly processed food intake on subsequent positive and negative emotions immediately, 1 h, and 3 h after consumption. Intake of sweet high-fat foods, fast foods, and non-alcoholic sugary drinks was associated with greater positive emotions immediately after eating, and sweet high-fat food intake remained associated with greater positive emotions 1 h later. Sweet high-fat food and non-alcoholic sugary drink intake were associated with fewer negative emotions 1 h after consumption, and the negative association between non-alcoholic sugary drink intake and negative emotions was stronger for those with elevated highly processed food addiction symptoms. Overall, results suggest that highly processed food intake results in small alterations in positive and negative emotions immediately and up to 1 h after intake; however, these do not persist through 3 h after intake. The ability of highly processed foods to briefly alter emotions may be key to their reinforcing nature.

What Is the Impact of Energy Expenditure on Energy Intake?

Coupling energy intake (EI) to increases in energy expenditure (EE) may be adaptively, compensatorily, or maladaptively leading to weight gain. This narrative review examines if functioning of the homeostatic responses depends on the type of physiological perturbations in EE (e.g., due to exercise, sleep, temperature, or growth), or if it is influenced by protein intake, or the extent, duration, timing, and frequency of EE. As different measures to increase EE could convey discrepant neuronal or humoral signals that help to control food intake, the coupling of EI to EE could be tight or loose, which implies that some ways to increase EE may have advantages for body weight regulation. Exercise, physical activity, heat exposure, and a high protein intake favor weight loss, whereas an increase in EE due to cold exposure or sleep loss likely contributes to an overcompensation of EI, especially in vulnerable thrifty phenotypes, as well as under obesogenic environmental conditions, such as energy dense high fat—high carbohydrate diets. Irrespective of the type of EE, transient elevations in the metabolic rate seem to be general risk factors for weight gain, because a subsequent decrease in energy requirement is not compensated by an adequate adaptation of appetite and EI.

Unravelling the impacts of western-style diets on brain, gut microbiota and cognition

The steady rise in the prevalence of obesity has been fostered by modern environments that reduce energy expenditure and encourage consumption of 'western'-style diets high in fat and sugar. Obesity has been consistently associated with impairments in executive function and episodic memory, while emerging evidence indicates that high-fat, high-sugar diets can impair aspects of cognition within days, even when provided intermittently. Here we review the detrimental effects of diet and obesity on cognition and the role of inflammatory and circulating factors, compromised blood-brain barrier integrity and gut microbiome changes. We next evaluate evidence for changing risk profiles across life stages (adolescence and ageing) and other populations at risk (e.g. through maternal obesity). Finally, interventions to ameliorate diet-induced cognitive deficits are discussed, including dietary shifts, exercise, and the emerging field of microbiome-targeted therapies. With evidence that poor diet and obesity impair cognition via multiple mechanisms across the human lifespan, the challenge for future research is to identify effective interventions, in addition to diet and exercise, to prevent and ameliorate adverse effects.

People serve themselves larger portions before a social meal

One of the most powerful influences on food intake yet identified is the presence of familiar others at an eating occasion: people eat much more when they eat with friends/family than when they eat alone. But why this is the case is unclear. Across two studies (Study 1: N = 98; Study 2: N = 120), we found that the mere anticipation of social interaction is all that is needed to promote the selection of larger meals, and that this occurs even when a person is alone when they make their decision. Adult women served themselves larger portions when they knew they were going to eat socially versus when they knew they were going to eat alone. These data suggest that how other people influence our food intake reaches beyond the specific eating context to affect pre-meal portion size decisions, suggesting that a fundamental shift is required in our thinking about social influences on eating.

Weekly variation in diet and physical activity among 4-75-year-old Danes

OBJECTIVE

To compare dietary intake and physical activity (PA) between days of the week in a large sample of the Danish population; furthermore, to investigate the influence of gender and age as determinants for weekly variation.

DESIGN

Analysis was based on cross-sectional data from the Danish National Survey of Diet and Physical Activity 2011-2013. Dietary intake and PA were assessed by 7 d of pre-coded food diaries and pedometer-determined step counts. Dietary intake and PA on weekdays (Monday-Thursday), Friday, and weekend days (Saturday and Sunday) were compared using linear mixed models.

SETTING

Survey with national representation, conducted in Denmark between 2011 and 2013.

PARTICIPANTS

A random sample of 4-75-year-old Danes, n 3934 and n 3530 in analysis of dietary intake and PA, respectively.

RESULTS

Energy intake during Friday and weekend days was 7-20 % higher compared with weekdays, while step counts were 10 and 17 % lower on Saturday and Sunday, respectively (all P < 0·001). Energy density of liquids and solids, consumption of added sugar, alcohol, discretionary foods, beer, wine and sugar-sweetened beverages were substantially higher, and consumption of dietary fibre, vegetables, fruit and wholegrain products were lower, during Friday and weekend days compared with weekdays (all P < 0·001). The observed patterns were present across gender and age, although weekly variation was most pronounced among children and relatively modest among the elderly.

CONCLUSIONS

Weekend health behaviours of Danes display less favourable eating and PA behaviour compared with weekdays, making the weekend an important target for public health interventions aiming to improve dietary intake and PA behaviour.

Associations Between Habitual School-Day Breakfast Consumption Frequency and Academic Performance in British Adolescents

Studies indicate that breakfast positively affects learning in children. The present study aimed to examine associations between habitual school-day breakfast consumption frequency and academic performance, as measured by the General Certificate of Secondary Education (GCSE). The GCSE is a national academic qualification obtained by most British children during secondary education. Adolescents aged 16-18 years (n = 294; females: 77.2%) completed a retrospective 7-day food diary to report breakfast intake and a questionnaire to report GCSE grades. Breakfast was defined as any food or drink containing ≥5% of total energy expenditure (TEE) consumed up to 10:00 a.m. on school days. Habitual weekly school-day breakfast consumption frequency was categorized as rare (0-1 school days), occasional (2-3 school days), or frequent (4-5 school days). GCSE grades were aggregated into point scores and linear regression models were applied. Participants' GCSE grades in Mathematics and English were analyzed using ordinal logistic regression. Adolescents who rarely consumed breakfast on school days had a significantly lower capped point score (β = -0.13, p < 0.05) and mean point score (β = -0.14, p < 0.05) compared with frequent consumers. Low/middle socio-economic status (SES) adolescents who rarely consumed breakfast were significantly less likely to achieve higher Mathematics grades compared to low/middle SES adolescents who frequently consumed breakfast [adjusted cumulative odds ratio (OR): 0.35 95% confidence interval (CI): 0.17-0.72]. This cross-sectional study demonstrates that habitual school-day breakfast consumption amongst adolescents is a significant correlate of GCSE attainment. The results offer promising associative evidence which warrants further exploration in well controlled studies.

Within- and Between-Subject Variation in Dietary Intake of Fermentable Oligo-, Di-, Monosaccharides, and Polyols Among Patients with Irritable Bowel Syndrome

BACKGROUND

A diet low in fermentable carbohydrates, fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) is a promising treatment option for patients with irritable bowel syndrome (IBS). In order to correctly estimate and study the intake of FODMAPs, information about within- and between-subject variations in intakes is needed, but is currently lacking.

OBJECTIVES

The aim was to characterize the variation in FODMAP intake among patients with IBS and to calculate how many days of observations are required to capture absolute intakes as well as to rank individuals.

METHODS

Food intake was recorded during 4 consecutive days, and intakes of energy and FODMAPs were calculated. The coefficient of variation within subjects (CVw), coefficient of variation between subjects (CVb), number of days required to estimate an individual's intake, and number of observations required to correctly rank individuals into quartiles of consumption were calculated.

RESULTS

Diet records were provided from 151 women and 46 men with IBS. The reported mean energy intake was 2039 ± 502 kcal among women and 2385 ± 573 kcal among men, and the median FODMAP intakes were 18.7 g (range 3.7-73.4) and 22.8 g (range 3.6-165.7), respectively. The ratio of CVw/CVb for total FODMAP intake was 0.83 for women and 0.67 for men, and below 1 for all FODMAPs. To capture intake of FODMAPs at the individual level, 19 d of observations are required. Ranking individuals within a group would require 2-6 d of observations.

CONCLUSION

There is more variation between subjects than within subjects regarding FODMAP intake. To correctly estimate an individual's absolute intake of FODMAPs, the number of days of diet records required exceeds what is reasonable for a participant to accomplish. However, ranking individuals into quartiles of FODMAP consumption can be achieved using a 4-d food record. This trial was registered at www.clinicaltrials.gov as NCT02107625 and NCT01252550.

Food Consumption According to the Days of the Week - National Food Survey, 2008-2009

OBJECTIVE

Evaluate the variations in energy, nutrients, and food groups intake between days of the week and weekend days in the Brazilian population.

METHODS

We used data from the first National Food Survey (2008-2009) of a one-day food log of a representative sample of the Brazilian population aged 10 years or older (n = 34,003). For the analyses, we considered the sample weights and the effect of the study design. The mean (and standard deviations) and frequencies (%) of energy, nutrients, and food groups consumption were estimated for weekdays (Monday to Friday) and weekend (Saturday and Sunday), we then estimated the differences according to the days of the week for the population strata analyzed.

RESULTS

The average daily energy intake for the weekend was 8% higher than the one observed for weekdays. The average percentage contribution of carbohydrate to the daily energy intake was higher during the week compared to Saturday and Sunday (56.3% versus 54.1%, p < 0.01). The inverse was observed for averages of the contribution to the daily intake of energy from total fat (26.8% versus 28.4%), saturated fat (9.1% versus 9.9%) and trans fat (1.4% versus 1.6%). The most significant changes between weekdays and weekend days were observed for eggs, sugar-added beverages, puff snacks and chips, beans, and pasta. During weekends, the frequency of beverage with added sugar consumption increased by 34%, the amount consumed increased by 42%, and the contribution to energy intake increased by 62% when compared to weekdays.

CONCLUSIONS

The Brazilian population increases energy intake and unhealthy food markers on weekends compared to weekdays.

One-year assessment of physical activity level in adult Qatari females: a pedometer-based longitudinal study

BACKGROUND

Physical inactivity is a growing health concern and has been identified as the fourth leading risk factor for global mortality. The Arab region includes countries with some of the world's highest physical inactivity levels, such as Qatar, more specifically the Qatari female population.

OBJECTIVE

The objective of this study is to assess the physical activity levels of Qatari national female adults during a 1-year pedometer-based program.

MATERIALS AND METHODS

A total of 549 Qatari national females aged between 18 years and 64 years were included. Data extracted from "Step into Health" program web database in Qatar were used for analyses. Daily habitual physical activity (daily total step count and aerobic steps) was assessed through the Omron HJ-324U pedometer. Step counts were classified as follows: <5,000 steps/d, sedentary; 5,000-7,499 steps/d, low active; and ≥7,500 steps/d, physically active. Statistical significance was set at P-value ≤0.05. Descriptive statistics were used, and habitual physical activity was calculated through repeated measures analysis of variance to determine the difference across the monitored days.

RESULTS

Mean age was 37.4±11.7 years, and median body mass index of 28.8 kg/m(2) (interquartile range 24.8-33.5). Daily steps for the overall population ranged from 3,505 steps/d to 10,010 steps/d, with a median of 6,008 steps/d. A total of 242 (44.1%) females were sedentary, 178 (32.4%) were low active, and 129 (23.5%) were physically active. The physically active group showed a median of 927 aerobic steps/d (interquartile range 0-4,248).

CONCLUSION

Based on the results of this study, Qatari females are not meeting the global recommendations of physical activity. Future research might need to consider barriers to physical activity as well as social, cultural, and environmental factors.

Environmental Strategies to Promote Food Intake in Older Adults: A Narrative Review

Aging is often accompanied by lower intakes of food energy and consequent negative effects on health. To some extent this is due to declines in physiological ability, including the sensory responsiveness to regulate food intake. Fortunately, environmental factors may still influence food intake in older adults. Factors such as social facilitation, modeling, and nutrition knowledge and skills have been shown to stimulate their food intake. While environmental factors such as the eating location, portion size, food presentation, and labeling are known to influence eating behavior, their effectiveness in stimulating food intake in older persons is not well delineated. It is suggested that improving the environmental stimuli that promote food intake is a viable strategy to overcome age-related declines in nutrient intakes. This strategy is so promising that further research is warranted.

Dietary assessment among women with overweight and obesity in early postpartum

BACKGROUND

The present study aimed to assess dietary intake and evaluate the degree of agreement of group-level dietary intake as measured by 24-h recall against a 4-day diet record among postpartum women with overweight and obesity.

METHODS

A cross-sectional study was conducted of 110 Swedish women with a body mass index of ≥27 kg m(-2) at 6-15 weeks postpartum who were recruited to a weight loss trial and randomised to diet intervention or control. One 24-h recall was conducted among all women prior to randomisation. In addition, women subsequently randomised to diet intervention also conducted a 4-day diet record before receiving dietary treatment (n = 54). Paired tests were used to evaluate agreement of group-level dietary intake as measured by 24-h recall against 4-day diet record among women randomised to diet intervention.

RESULTS

Women reported a median (25th and 75th percentiles) energy intake of 9.1 (6.9, 11.7) MJ day(-1) and an intake of fibre, vitamin D, folate and iron below the recommended intake as assessed by 24-h recall prior to randomisation (n = 110). Group-level median intakes of energy (9.9 versus 10.0 MJ day(-1) ), fibre (21.9 versus 21.3 g day(-1) ), vitamin D (4.8 versus 6.5 μg day(-1) ), folate (296 versus 287 μg day(-1) ), iron (11.0 versus 11.3 mg day(-1) ) and calcium (915 versus 968 mg day(-1) ) did not differ significantly between the methods; however, the record captured a higher energy-adjusted intake of fat, saturated fat and alcohol, as well as a lower intake of carbohydrates, compared to the recall (n = 54).

CONCLUSIONS

We found no difference in group-level estimates of energy or micronutrients between the recall and the record; however, there were some differences for macronutrients.

The Influence of Portion Size and Timing of Meals on Weight Balance and Obesity

This review focuses on the influence of portion size and temporal distribution of food intake on weight balance and obesity in adults. The inconsistency of definitions in the area of meal patterns is also discussed. The conclusion is that regular eating habits might facilitate weight balance, while unplanned snacking as well as consuming the major part of the energy intake at the end of the day seem to be unfavourable. Altogether, the research suggests that large portions promote over-consumption and, therefore, limiting portion size of energy dense foods and drinks with added sugar could be recommended. Even if more research is needed, these factors should be taken into consideration in recommendations for obesity prevention.

Evidence for daily and weekly rhythmicity but not lunar or seasonal rhythmicity of physical activity in a large cohort of individuals from five different countries

BACKGROUND

Biological rhythmicity has been extensively studied in animals for many decades. Although temporal patterns of physical activity have been identified in humans, no large-scale, multi-national study has been published, and no comparison has been attempted of the ubiquity of activity rhythms at different time scales (such as daily, weekly, monthly, and annual).

METHODS

Using individually worn actigraphy devices, physical activity of 2,328 individuals from five different countries (adults of African descent from Ghana, South Africa, Jamaica, Seychelles, and the United States) was measured for seven consecutive days at different times of the year.

RESULTS

Analysis for rhythmic patterns identified daily rhythmicity of physical activity in all five of the represented nationalities. Weekly rhythmicity was found in some, but not all, of the nationalities. No significant evidence of lunar rhythmicity or seasonal rhythmicity was found in any of the groups.

CONCLUSIONS

These findings extend previous small-scale observations of daily rhythmicity to a large cohort of individuals from around the world. The findings also confirm the existence of modest weekly rhythmicity but not lunar or seasonal rhythmicity in human activity. These differences in rhythm strength have implications for the management of health hazards of rhythm misalignment.

Examining differences in nutrient intake and dietary quality on weekdays versus weekend days in Canada

This study examined differences in dietary intake on weekdays versus weekends in Canada (n = 34,402) and found that energy intake was 62 ± 23 kcal higher, and dietary quality was slightly lower on weekends (p < 0.05). After energy adjustment, Canadians consumed 66% more alcohol, 10% more cholesterol, and significantly lower intakes of carbohydrates, protein, and most micronutrients (ranging from 2.0%-6.9% lower) on weekends. Findings suggest that Canadians consume a slightly less favourable nutrient profile and poorer dietary quality on weekends.

Peers and Obesity during Childhood and Adolescence: A Review of the Empirical Research on Peers, Eating, and Physical Activity

Obesity during childhood and adolescence is a growing problem in the United States, Canada, and around the world that leads to significant physical, psychological, and social impairment. In recent years, empirical research on factors that contribute to the development and maintenance of obesity has begun to consider peer experiences, such as peer rejection, peer victimization, and friendship. Peer experiences have been theoretically and empirically related to the “Big Two” contributors to the obesity epidemic, eating and physical activity, but there has not been a comprehensive review of the extant empirical literature. In this article, we review and synthesize the emerging theoretical and empirical literatures on peer experiences in relation to: (a) eating (food consumption and food selection); and (b) physical activity, during childhood and adolescence. A number of limitations and issues in the theoretical and empirical literatures are also discussed, along with future research directions. In conclusion, we argue that the involvement of children and adolescents’ peer networks in prevention and intervention efforts may be critical for promoting and maintaining positive behavioral health trajectories.

Weight rhythms: weight increases during weekends and decreases during weekdays

BACKGROUND/AIMS

The week's cycle influences sleep, exercise, and eating habits. An accurate description of weekly weight rhythms has not been reported yet - especially across people who lose weight versus those who maintain or gain weight.

METHODS

The daily weight in 80 adults (BMI 20.0-33.5 kg/m(2); age, 25-62 years) was recorded and analysed to determine if a group-level weekly weight fluctuation exists. This was a retrospective study of 4,657 measurements during 15-330 monitoring days. Semi-parametric regression was used to model the rhythm.

RESULTS

A pattern of daily weight changes was found (p < 0.05), with higher weight early in the week (Sunday and Monday) and decreasing weight during the week. Increases begin on Saturday and decreases begin on Tuesday. This compensation pattern was strongest for those who lost or maintained weight and weakest for those who slowly gained weight.

CONCLUSION

Weight variations between weekends and weekdays should be considered as normal instead of signs of weight gain. Those who compensate the most are most likely to either lose or maintain weight over time. Long-term habits may make more of a difference than short-term splurges. People prone to weight gain could be counselled about the importance of weekday compensation.

Association of food form with self-reported 24-h energy intake and meal patterns in US adults: NHANES 2003-2008

BACKGROUND

Laboratory studies suggest that food form (beverages compared with solid foods) evokes behavioral and physiologic responses that modify short-term appetite and food intake. Beverage energy may be less satiating and poorly compensated, which leads to higher energy intake.

OBJECTIVE

We examined associations between 24-h energy consumed in beverages and a variety of meal and dietary attributes to quantify the contribution of beverage consumption to the energy content of diets in free-living individuals consuming their self-selected diets.

DESIGN

We used dietary recall data for adults (n = 13,704) in NHANES 2003-2008 to examine the multiple covariate-adjusted associations between 24-h energy from beverages and nonbeverages and associations between beverage intake, eating behaviors, and the energy density of beverage and nonbeverage foods.

RESULTS

In the highest tertile of 24-h beverage energy intake, beverages provided >30% of energy. Total 24-h energy and nonbeverage energy consumption and energy density (kcal/g) of both beverage and nonbeverage foods increased with increasing energy from beverages (P < 0.0001). With increasing 24-h beverage energy consumption, the reported frequency of all, snack, and beverage-only ingestive episodes and length of the ingestive period increased, whereas the percentage of energy from main meals decreased (P < 0.0001).

CONCLUSIONS

Higher 24-h beverage energy intake was related to higher energy intake from nonbeverage foods, quality of food selections, and distribution of 24-h energy into main meal and snack episodes. Moderation of beverage-only ingestive episodes and curtailing the length of the ingestion period may hold potential to lower uncompensated beverage energy consumption in the US population.

Assessing dietary intake: Who, what and why of under-reporting

Under-reporting of food intake is one of the fundamental obstacles preventing the collection of accurate habitual dietary intake data. The prevalence of under-reporting in large nutritional surveys ranges from 18 to 54% of the whole sample, but can be as high as 70% in particular subgroups. This wide variation between studies is partly due to different criteria used to identify under-reporters and also to non-uniformity of under-reporting across populations. The most consistent differences found are between men and women and between groups differing in body mass index. Women are more likely to under-report than men, and under-reporting is more common among overweight and obese individuals. Other associated characteristics, for which there is less consistent evidence, include age, smoking habits, level of education, social class, physical activity and dietary restraint. Determining whether under-reporting is specific to macronutrients or food is problematic, as most methods identify only low energy intakes. Studies that have attempted to measure under-reporting specific to macronutrients express nutrients as percentage of energy and have tended to find carbohydrate under-reported and protein over-reported. However, care must be taken when interpreting these results, especially when data are expressed as percentages. A logical conclusion is that food items with a negative health image (e.g. cakes, sweets, confectionery) are more likely to be under-reported, whereas those with a positive health image are more likely to be over-reported (e.g. fruits and vegetables). This also suggests that dietary fat is likely to be under-reported. However, it is necessary to distinguish between under-reporting and genuine under-eating for the duration of data collection. The key to understanding this problem, but one that has been widely neglected, concerns the processes that cause people to under-report their food intakes. The little work that has been done has simply confirmed the complexity of this issue. The importance of obtaining accurate estimates of habitual dietary intakes so as to assess health correlates of food consumption can be contrasted with the poor quality of data collected. This phenomenon should be considered a priority research area. Moreover, misreporting is not simply a nutritionist's problem, but requires a multidisciplinary approach (including psychology, sociology and physiology) to advance the understanding of under-reporting in dietary intake studies.

Fruit and vegetable intake is associated with frequency of breakfast, lunch and evening meal: cross-sectional study of 11-, 13-, and 15-year-olds

Background

Frequency of eating breakfast, lunch and evening meal as a determinant of fruit and vegetable intake among young people is little studied. We investigated whether irregular meal consumption was associated with fruit and vegetable intake among adolescents. We used separate analyses, and special emphasis was on the potentially modifying effect of sex and age.

Methods

Data were from the Danish contribution to the international collaborative Health Behavior in School-Aged Children Study (HBSC) in 2002. We used a questionnaire-based, cross-sectional design to study schoolchildren aged 11, 13 and 15 years (n = 3913) selected from a random sample of schools in Denmark. Fruit intake and vegetable intake were measured by a food frequency questionnaire and analyses were conducted using multivariate logistic regression.

Results

Overall, statistically significant associations were found between irregular breakfast, lunch and evening meal consumption and low frequency of fruit intake and vegetable intake (breakfast: fruit OR = 1.42, vegetables OR = 1.48; lunch: fruit OR = 1.68, vegetables OR = 1.83; evening meal: vegetables OR = 1.70). No association was found for irregular evening meal consumption and low frequency of fruit intake. Analyses stratified by sex showed that the associations between irregular breakfast consumption and both fruit and vegetable intake remained statistically significant only among girls. When analyses were stratified by both sex and age, different patterns appeared. Overall, skipping meals seemed to be a less serious risk factor for low frequency of fruit and vegetable intake among younger participants compared with those who were older. This was especially evident for skipping breakfast. The same tendency was also seen for skipping lunch and evening meal, although the age pattern varied between boys and girls and between fruit and vegetable intake.

Conclusion

Our results showed that irregular breakfast, lunch and evening meal consumption among adolescents was associated with a low frequency of fruit and vegetable intake and that sex and age may play a modifying role. The different associations observed in different age and sex groups indicate the importance of analysing fruit and vegetable intake and meal types separately. The results highlight the importance of promoting regular meal consumption when trying to increase the intake of fruit and vegetables among adolescents.

Beverage consumption and BMI of British schoolchildren aged 9-13 years

OBJECTIVE

Adequate fluid intake has been well documented as important for health but whether it has adverse effects on overall energy and sugar intakes remains under debate. Many dietary studies continue to refrain from reporting on beverage consumption, which the present study aimed to address.

DESIGN

A cross-sectional survey investigated self-reported measures of dietary intake and anthropometric measurements.

SETTING

Primary and secondary schools in south-west London, UK.

SUBJECTS

Boys and girls (n 248) aged 9–13 years.

RESULTS

Boys consumed 10 % and girls consumed 9 % of their daily energy intake from beverages and most children had total sugar intakes greater than recommended. Beverages contributed between a quarter and a third of all sugars consumed, with boys aged 11–13 years consuming 32 % of their total sugar from beverages. There was a strong relationship between consumption of beverages and energy intake; however, there was no relationship between beverage type and either BMI or BMI Z-score. Fruit juices and smoothies were consumed most frequently by all girls and 9–10-year-old boys; boys aged 11–13 years preferred soft drinks and consumed more of their daily energy from soft drinks. Milk and plain water as beverages were less popular.

CONCLUSIONS

Although current health promotion campaigns in schools merit the attention being given to improving hydration and reducing soft drinks consumption, it may be also important to educate children on the energy and sugar contents of all beverages. These include soft drinks, as well as fruit juices and smoothies, which are both popular and consumed regularly.

Body mass, frequency of eating and breakfast consumption in 9-13-year-olds

BACKGROUND

Unhealthy eating patterns in childhood can lead to adverse health conditions, particularly obesity. However, debate remains around the precise eating behaviours that lead to these conditions. The present study aimed to address this lack of evidence by reporting on the eating frequency, breakfast consumption and body mass index (BMI, kg m(-2) ) of youth in the UK.

METHODS

A total of 264 (133 boys and 131 girls) participants, aged 10-13years, completed self-report measures of dietary intake via 3-day food/drink diaries (Friday to Sunday). Trained researchers recorded height and weight to calculate the BMI. Diaries were analysed using dietplan 6 nutritional analysis software (Forestfield Software, Horsham, UK) and multivariate linear regression was used to examine any association between breakfast consumption, frequency of eating and BMI.

RESULTS

No relationship existed between BMI Z-score, eating frequency and breakfast consumption. However, frequent breakfast consumers had significantly lower mean (SD) BMI Z-scores [0.18(1.06) versus 0.57(1.23)] and higher intakes of iron, calcium and vitamin E than those who did not eat breakfast regularly. Those aged ≥11years consumed breakfast less frequently [0.92(0.20)] and were less likely to eat regularly [4.6(1.4)] than those aged ≤10years.

CONCLUSIONS

Older boys were the least likely to eat regularly and the least likely to consume breakfast. Promoting the importance of regular eating, particularly breakfast consumption to these boys, may be essential to ensure healthier, long-term eating patterns. Furthermore, the lower breakfast intakes in 11-13-year-olds and higher BMI Z-scores of those who did not eat breakfast regularly should be monitored.

Use of a mobile phone diary for observing weight management and related behaviours

We studied self-observations related to weight management recorded with a Wellness Diary application on a mobile phone. The data were recorded by 27 participants in a 12-week study, which included a short weight management lecture followed by independent usage of the Wellness Diary. We studied the validity of self-observed weight, and behavioural changes and weight patterns related to weight management success. Self-observed weight data tended to underestimate pre- and poststudy measurements, but there were high correlations between the measures (r >or= 0.80). The amount of physical activity correlated significantly with weight loss (r = 0.44) as did different measures representing healthy changes in dietary behaviours (r >or= 0.45). Weight changes and the weekly rhythms of weight indicated a strong tendency to compensate for high-risk periods among successful weight-losers compared to unsuccessful ones. These preliminary results suggest that the mobile phone diary is a valid tool for observing weight management and related behaviours.

Breakfast trends in children and adolescents: frequency and quality

Objective

Although breakfast is important for obesity prevention and dietary quality, breakfast skipping is a common behaviour. Knowledge of changes in breakfast habits may provide potential behaviour targets for intervention programmes. The present study describes the actual data on trends in breakfast habits and composition.

Design

A total of 7800 3 d dietary records of 1081 participants aged 2–18 years collected between 1986 and 2007 in the DONALD (Dortmund Nutritional and Anthropometric Longitudinally Designed) Study were analysed using mixed linear models.

Results

Breakfast was eaten at 78 % of all record days; regular breakfast (breakfast was eaten on all three recorded weekdays) was eaten in 75 % of records. During the study period, the number of records with regular breakfast decreased significantly in 6–12- and 13–18-year-olds (P= 0·0084 and 0·0350, respectively). Of all breakfast meals, 62 % were bread meals and 21 % were ready-to-eat cereal (RTEC) meals. RTEC meals nearly doubled from the youngest to the oldest age group (P< 0·0001). During the study period, the percentage of bread meals decreased, whereas the percentage of RTEC meals increased (P< 0·0001). A higher percentage of RTEC meals than the bread meals was in accordance with the food-based guidelines (36 %v. 20 %,P< 0·0001), i.e. a breakfast including grain, dairy and fruit/vegetables.

Conclusions

In the DONALD Study sample, a negative age and time trend in breakfast consumption was verified. Interventions regarding breakfast habits should be aimed at adolescents and should focus on fruit/vegetables.

Validation of the Danish 7-day pre-coded food diary among adults: energy intake v. energy expenditure and recording length

Under-reporting of energy intake (EI) is a well-known problem when measuring dietary intake in free-living populations. The present study aimed at quantifying misreporting by comparing EI estimated from the Danish pre-coded food diary against energy expenditure (EE) measured with a validated position-and-motion instrument (ActiReg). Further, the influence of recording length on EI:BMR, percentage consumers, the number of meal occasions and recorded food items per meal was examined. A total of 138 Danish volunteers aged 20-59 years wore the ActiReg and recorded their food intake for 7 consecutive days. Data for 2504 participants from the National Dietary Survey 2000-2 were used for comparison of characteristics and recording length. The results showed that EI was underestimated by 12 % on average compared with EE measured by ActiReg (PreMed AS, Oslo, Norway). The 95 % limits of agreement for EI and EE were - 6.29 and 3.09 MJ/d. Of the participants, 73 % were classified as acceptable reporters, 26 % as under-reporters and 1 % as over-reporters. EI:BMR was significantly lower on 1-3 consecutive recording days compared with 4-7 recording days (P < 0.03). Percentage consumers of selected food items increased with number of recording days. When recording length was 7 d, the number of reported food items per meal differed between acceptable reporters and under-reporters. EI:BMR was the same on 4 and 7 consecutive recording days. This was, however, a result of under-reporting in the beginning and the end of the 7 d reporting. Together, the results indicate that EI was underestimated at group level and that a 7 d recording is preferable to a 4 d recording period.

Evaluating energy intake measurement in free-living subjects: when to record and for how long?

OBJECTIVE

To nutritionally analyse mean energy intake (EI) from different 3 d intervals within a 7 d recording period and to evaluate the seasonal effect on energy and nutrient intake.

DESIGN

Cross-sectional study of dietary intake collected with 7 d food diaries.

SETTING

Aberdeen, north-east Scotland, UK, between 2002 and 2004.

SUBJECTS

Participants from two long-term trials were pooled. These trials, investigating genetic and environmental influences on body weight, were the Genotyping And Phenotyping (GAP) study and a cohort observational study, Rowett Assessment of Childhood Appetite and metaboLism (RASCAL). There were 260 Caucasian adults, BMI range 16.7-49.3 kg/m2, age range 21-64 years.

RESULTS

Mean EI for Wednesday, Friday and Saturday had the closest approximation to the 7 d mean (0.1 % overestimate). A gender x season interaction (P = 0.019) with a different intake pattern for females and males was observed. For females, lower mean (se) EI was recorded in summer (8117 (610) kJ) and autumn (7941 (699) kJ) compared with spring (8929 (979) kJ) and winter (8132 (1041) kJ). For males, higher mean (se) EI was recorded in summer (10 420 (736) kJ) and autumn (10 490 (1041) kJ) compared with spring (9319 (1441) kJ) and winter (9103 (1505) kJ).

CONCLUSIONS

The study results indicate that 3 d weighed intakes recorded from Wednesday, Friday and Saturday are most representative of 7 d habitual intake in free-living subjects. They also indicate that seasonality has a limited effect on EI and no effect on macronutrient intake.

Number of 24-hour diet recalls needed to estimate energy intake

PURPOSE

Twenty-four-hour diet recall interviews (24HRs) are used to assess diet and to validate other diet assessment instruments. Therefore it is important to know how many 24HRs are required to describe an individual's intake.

METHOD

Seventy-nine middle-aged white women completed seven 24HRs over a 14-day period, during which energy expenditure (EE) was determined by the doubly labeled water method (DLW). Mean daily intakes were compared to DLW-derived EE using paired t tests. Linear mixed models were used to evaluate the effect of call sequence and day of the week on 24HR-derived energy intake while adjusting for education, relative body weight, social desirability, and an interaction between call sequence and social desirability.

RESULTS

Mean EE from DLW was 2115 kcal/day. Adjusted 24HR-derived energy intake was lowest at call 1 (1501 kcal/day); significantly higher energy intake was observed at calls 2 and 3 (2246 and 2315 kcal/day, respectively). Energy intake on Friday was significantly lower than on Sunday. Averaging energy intake from the first two calls better approximated true energy expenditure than did the first call, and averaging the first three calls further improved the estimate (p=0.02 for both comparisons). Additional calls did not improve estimation.

CONCLUSIONS

Energy intake is underreported on the first 24HR. Three 24HRs appear optimal for estimating energy intake.

Effects of peer influence on dietary intake and physical activity in schoolchildren

Objective

To investigate the dietary intake and physical activity of boys and girls aged 9–13 years, and the influence of peers on these behaviours.

Design

Cross-sectional study.

Setting

Nine primary and secondary schools in south-west London.

Subjects

A total of 315 children wore sealed pedometers, provided self-report measures of dietary intake and answered a questionnaire relating to peer influence. Anthropometric measures of height and weight were also obtained.

Results

Obese children had the lowest reported energy intakes and the lowest step counts per day. Boys took significantly more steps per day than girls, however girls were closer to achieving their recommended cut-offs for physical activity. Girls had lower energy intakes per day and lower BMI Z-scores than boys, however both genders, across all age groups, had higher than recommended intakes of saturated fat. There were significant associations between peer influence and physical activity levels but not between peer influence and dietary intake.

Conclusions

Low energy intake and physical activity levels but high saturated fat intakes among boys and girls across all age groups highlight the importance of promoting both physical activity and healthy food choices. The finding that peers have a significant effect on physical activity levels but not on dietary intake offers an important approach for the design of health promotion interventions and obesity prevention programmes. Such designs may be particularly beneficial for obese youth, since the low physical activity levels found could be a major contributing factor to the maintenance of the condition.

When, how much and what foods are eaten are related to total daily food intake

Intake in the morning is associated with a reduction in the total intake for the day, while intake at night is associated with greater overall daily intake. These associations are macronutrient specific, with morning carbohydrate intake associated with reduced daily carbohydrate intake, morning fat intake associated with reduced daily fat intake and morning protein intake associated with reduced daily protein intake. Since different types of foods contain differing proportions of macronutrients, the present study investigated the associations of different types of foods ingested at various times of day with total daily and macronutrient intakes. The intakes of 388 male and 621 female free-living individuals reported in 7 d diet diaries were reanalysed. The intakes of twenty-four different types of foods and seven different drinks occurring during the morning (04.00-10.29 hours), afternoon (10.30-16.59 hours) and evening (17.00-02.00 hours) were identified and related to overall daily intakes. Dairy foods, ice cream, beef, other meats, potatoes, pastry, nuts, chips and snacks, condiments, alcohol and soda were significantly associated with higher total intake over the day, while fruit, soup, breakfast cereal, pasta, pizza, water, coffee/tea and diet soda were either not associated or were associated with lower overall intake. Dietary energy density appeared to mediate the associations between particular foods and beverages and overall energy intake. This suggests that eating low-density foods in the morning and avoiding high-density foods at night might aid in reducing overall intake and may be useful in dietary interventions for overweight and obesity.

Four-week pedometer-determined activity patterns in normal-weight, overweight and obese adults

OBJECTIVE

To assess pedometer-determined ambulatory activity in normal-weight, overweight and obese UK adults.

METHODS

Eighty-six normal-weight (BMI <25 kg/m(2)) (age=34+/-12.1 years), 91 overweight (BMI 25-29.9 kg/m(2)) (age=40.6+/-13.6 years) and 75 obese (BMI >or= 30 kg/m(2)) (age=41.2+/-12.4 years) participants, from the East Midlands, provided 4 weeks of continuous pedometer-determined activity data, during the winter in 2006. Activity levels and patterns were assessed for all three groups.

RESULTS

The normal-weight group had a significantly higher mean step count (10247 steps/day) than the overweight (9095 steps/day) and obese (8102 steps/day) participants (p<0.05). No differences in step counts were observed between the overweight and obese groups. A consistent reduction in activity was observed on Sundays in all groups, with this reduction being two-fold greater in the overweight and obese groups (approximately 2000 steps/day) when compared with the normal-weight group (approximately 1000 steps/day).

CONCLUSIONS

With the increasing prevalence of obesity in the UK, changes in the activity levels of those at risk are needed. The issuing of pedometers to overweight and obese individuals, with the instruction to increase their ambulatory activity on all days of the week, with particular emphasis on Sunday activity, could be a good starting point in tackling the problem of obesity in the UK.

The time of day and the proportions of macronutrients eaten are related to total daily food intake

Intake in the morning is particularly satiating and associated with lower total amounts ingested for the day while intake at night is associated with greater overall daily intake. But, the influence of carbohydrates, fats or proteins ingested at various times of the day is unknown. The intakes of 375 male and 492 female free-living individuals that were acquired with 7 d diet-diary reports were reanalysed. The intakes of carbohydrates, fats and proteins, and the density of intake occurring during three 6 h periods (06.00 to 11.59 hours (morning), 12.00 to 17.59 hours (afternoon) and 18.00 to 23.59 hours (evening)) were identified and related to overall daily and meal intakes. Energy density of intake during all periods was found to be positively related to overall intake. When the proportion of daily carbohydrate ingested in the morning was high, less total food energy and carbohydrate were ingested over the entire day. When the proportion of daily fat ingested in the morning was high, less total food energy and carbohydrate and fat were ingested over the entire day. When the proportion of daily protein ingested in the morning was high, less protein was ingested over the entire day. Conversely, when intake was relatively high in the evening of either total food energy, carbohydrate or fat, then overall daily energy intakes tended to be higher. The results suggest that the morning intake association with reduced total intake is macronutrient specific, with morning carbohydrate, fat and protein intake associated with reduced daily carbohydrate, fat and protein intake, respectively.

Low-energy reporting and duration of recording period

Three-day, rather than 7-day, food records are frequently used because mis-reporting of food intake is believed to increase with recording period. Data from the National Diet and Nutrition Survey of adults were used to explore trends in reported energy intake (REI) with day of recording and to compare average REIs from Thursday to Saturday and from Sunday to Tuesday to the complete 7-day record. Although REIs decreased from days 2 to 7, this was by a quantitatively insignificant 49 kJ per day (P=0.026) and well within the measurement error of recorded food intakes. Furthermore, REIs were lowest on the first recording day. The 3- and 7-day averages were similar (mean difference 0.039 (s.d.+/-1.0) MJ (NS), range -3.3 to +4.2 MJ). However, the difference was greater for those reporting higher than average energy intakes because of higher REIs on weekend days. Food intake reporting periods of longer than 3 days and ideally 7 days are preferable.

Monitoring weight daily blocks the freshman weight gain: a model for combating the epidemic of obesity

BACKGROUND

The Tissue Monitoring System (TMS) is an algorithm that estimates changes in body tissue from a series of daily weight measures. It is intended to provide people with a feedback of changes in their tissue weight so they may have a basis for estimating how much they would have to change their intake or expenditure to maintain their weight at a prescribed level. We tested the effectiveness of the TMS to prevent freshmen from gaining weight during their first semester in college.

METHODS

In two similar but independent studies (Fall 2002, 2003), female freshmen college students were given analog bathroom scales and instructed to weigh themselves each morning immediately after rising from bed, then e-mail their weight to our staff. After 7 days, a linear function was performed on the most recent 7 days of the weight-day function for each participant. In the first study, the slope of this function was e-mailed back to the participants. In the second study, the difference between last point and the original weight was determined, using linear regression techniques, converted to calories, and the information was e-mailed back to the participants. Control participants in both studies were weighed at the beginning and the end of the semester.

RESULTS

The untreated controls gained 3.1+/-0.51 kg and 2.0+/-0.65 kg, respectively (P<0.01 for both studies), whereas weight gain of the experimental groups was 0.1+/-0.99 kg and -0.82+/-0.56 kg, values that were not significantly different than zero.

CONCLUSIONS

The TMS appears to be an effective technique to help female college freshmen resist gaining weight in an environment that is conducive to weight gain. These results suggest that the TMS may be a useful method to help curb the slow increase in the prevalence of overweight and obesity that is characteristic of all industrialized societies.

The temporal pattern of the contribution of fat to energy and of food groups to fat at various eating locations: implications for developing food-based dietary guidelines

Objectives

To examine the temporal pattern of the number of eating occasions that occurred at home, at work and outside the home, and to examine the contribution of fat to energy and the contribution of 26 food groups to fat at home and outside the home.

Design and setting

Food intake data were collected using a 7-day food diary from a random sample of 18–64-year-old adults from the Republic of Ireland (n= 958). Respondents recorded the day, time and location of every eating occasion.

Results

The number of eating occasions was constant across the days of the week for meals consumed at home, whereas the number of eating occasions increased at weekends for meals outside the home. The contribution of fat to energy approximated the 35% recommendation at home from Monday to Friday, but increased above this on Saturday and Sunday. The contribution of fat to energy outside the home was always above the recommendation. The food groups that contributed most to fat were similar at home and outside the home. These included butter and full-fat spreads, fresh meat, meat products, meat dishes, biscuits, cakes and pastries, whole milk, and chips and processed potatoes.

Conclusion

The contribution of fat to energy was above the recommendations when eating outside the home, regardless of day of the week. A number of food groups have been identified that contributed most to fat intake outside the home and these might be targeted in developing public health nutrition strategies to reduce fat intake.

Detailed analysis of binges in obese women with binge eating disorder: Comparisons using multiple methods of data collection

OBJECTIVE

This study compares multiple methods of assessing food intake in obese women with binge eating disorder (BED).

METHOD

Twelve women meeting BED criteria completed six random 24-hour dietary recalls, engaged in a laboratory binge eating episode, and completed the EDE interview.

RESULTS

There was not a significant difference in total or macronutrient intake when binge eating episodes were assessed via the recall and laboratory methods. However, within-individual correlations were low for the size of different binge eating episodes collected by the two methods. Significantly more calories were consumed during objective than during subjective binges, and significant differences in macronutrient composition were observed. Meal patterning data collected by the EDE and the recalls were comparable.

CONCLUSION

The findings suggest only moderate agreement between the methods that were examined. Future investigations with larger sample sizes are needed to examine the relationship among these different methods of assessing food intake.

Four-week pedometer-determined activity patterns in normal weight and overweight UK adults

OBJECTIVE

To assess pedometer-determined physical activity levels and activity patterns in a sample of free-living normal weight and overweight UK adults.

DESIGN

Pedometer-based 4-week observational study.

PARTICIPANTS

One hundred and twenty-two healthy participants, recruited from two regions in the UK, classified as normal weight (33 females and 26 males) or overweight (31 females and 32 males), in the age range of 18 to 65 years, completed the study.

MEASUREMENTS

Daily step counts were measured using a Yamax SW-200 pedometer, and were then recorded in an activity log. Comparisons were made between activity patterns occurring over different days of the week for the normal weight and overweight groups. Measurements of height, weight and percentage body fat, by bioelectrical impedance, were taken pre- and post-study.

RESULTS

A consistent reduction in activity was observed on a Sunday in the overweight group, and mean daily step counts accumulated on Sundays were significantly lower, by an average of 2221 steps/day, when compared with all other days of the week (all P<0.001). In comparison, no day-of-the-week effect was observed in the normal weight group. Mean step counts reported on each day of the week did not differ significantly between the two groups, with the exception of Sunday when the overweight group reported significantly fewer steps than the normal weight participants (8093 versus 10 538, P<0.001).

CONCLUSIONS

Activity levels dropped dramatically in the sample of overweight adults on a Sunday. Simple instructions to at-risk individuals, to increase their general activity levels on a Sunday, via general practitioners and public health messages could prove to be a subtle, but effective, strategy to tackle obesity.

Ritmos circadianos de consumo alimentar nos lanches e refeições de adultos: aplicação do semanário alimentar

OBJETIVO: Este estudo descreve o perfil alimentar de indivíduos saudáveis, em seu ambiente natural, a partir da análise da ingestão de energia e macronutrientes nos lanches e refeições e sua distribuição circadiana. MÉTODOS: Dezessete voluntários, professores e funcionários técnico-administrativos de uma instituição de ensino de Florianópolis com idade média de 46,71 (±2,2) anos, e índice de massa corporal médio de 24,93 (±0,9) kg/m² registraram, durante sete dias consecutivos, o tipo e a quantidade de alimentos e bebidas consumidos, especificando o modo de preparo, o tipo de evento alimentar (refeição ou lanche), a hora do dia e o dia da semana. RESULTADOS: Realizaram-se, em média, 2,7 refeições e 3,2 lanches diariamente. Os lanches e as refeições mostraram diferenças entre si, tanto em relação à proporção de macronutrientes quanto ao valor energético total. As refeições forneceram cerca de três vezes mais calorias que os lanches e foram compostas, predominantemente, por proteínas e lipídios, enquanto nos lanches predominaram os carboidratos. A hora do dia também mostrou exercer influência no consumo. CONCLUSÃO: No período das 12h às 15h59min, o consumo foi significativamente maior que nos demais momentos do dia, mas não se observou um aumento significativo do consumo energético total nos dias do fim de semana.

Diurnal and weekly rhythms of health-related variables in home recordings for two months

Several telecare systems for long-term monitoring of the well-being of patients at home have been developed as an aid in healthcare and to reduce hospitalization costs. Most of the systems have been designed to measure only one or two variables. Because well-being is a combination of both psychological and physiological wellness, there is a need to monitor several psychophysiological variables simultaneously in out-of-hospital conditions for a long period. To understand better the variability of patients' wellness-related variables in long-term recordings, the knowledge of the normal variation in health-related variables in healthy people is necessary. In our study, 14 healthy working middle-aged men were studied daily for 24 h and periods of 50 to 79 days. The variables measured were beat-to-beat heart rate, motor activity, blood pressure, body weight, and temperature. At night respiratory frequency, time of movements, amount of quiet sleep, and ballistocardiographic respiratory variation were also measured. Heart rate variability in the waking period was calculated later (standard deviation of the 5 min average of the successive normal to normal beat to beat intervals). Daily self-reported well-being, activities, and consumption of alcohol were monitored by keeping a behavioral diary. After normalizing the physiological data, the diurnal and weekly variability was calculated for each variable. In several variables the most notable diurnal and weekly variability was found between working time and free time. In conclusion, diurnal and weekly rhythms in several wellness-related physiological and psychological variables were identified, depending on working and free-time in healthy middle-aged men.

Effect of ambience on food intake and food choice

Eating takes place in a context of environmental stimuli known as ambience. Various external factors such as social and physical surroundings, including the presence of other people and sound, temperature, smell, color, time, and distraction affect food intake and food choice. Food variables such as the temperature, smell, and color of the food also influence food intake and choice differently. However, the influence of ambience on nutritional health is not fully understood. This review summarizes the research on ambient influences on food intake and food choice. The literature suggests that there are major influences of ambience on eating behavior and that the magnitude of the effect of ambience may be underestimated. Changes in intake can be detected with different levels of the number of people present, food accessibility, eating locations, food color, ambient temperatures and lighting, and temperature of foods, smell of food, time of consumption, and ambient sounds. It is suggested that the manipulation of these ambient factors as a whole or individually may be used therapeutically to alter food intake and that more attention needs to be paid to ambience in nutrition-related research.