Determinants of a dietary pattern linked with greater metabolic risk and its tracking during adolescence.

BACKGROUND: Although growing evidence suggests that dietary patterns associated with noncommunicable diseases in adulthood may develop early in life, when these are established, as well as their determinants, remains unclear. METHODS: We examined determinants and tracking of a dietary pattern (DP) associated with metabolic risk and its key food groups among 860 adolescents in the Western Australian Pregnancy (Raine) Cohort study. Food intake was reported using a food frequency questionnaire (FFQ) at 14 and 17 years. Z-scores for an 'energy-dense, high-fat, low-fibre' DP were estimated by applying reduced rank regression at both ages. Tracking was based on the predictive value (PV) of remaining in the DPZ-score or food intake quartile at 14 and 17 years. Early-life exposures included: maternal age; maternal pre-pregnancy body mass index; parent smoking status during pregnancy; and parent socio-economic position (SEP) at 14 and 17 years. Associations between the DPZ-scores, early-life factors and SEP were analysed using regression analysis. RESULTS: Dietary tracking was strongest among boys with high DPZ-scores, high intakes of processed meat, low-fibre bread, crisps and savoury snacks (PV > 1) and the lowest intakes of vegetables, fruit and legumes. Lower maternal education (ß = 0.09, P = 0.002 at 14 years; ß = 0.14, P < 0.001 at 17 years) and lower maternal age at birth (ß = 0.09, P = 0.003 at 14 years; ß = 0.11, P = 0.004 at 17 years) were positively associated with higher DPZ-scores. CONCLUSIONS: An energy-dense, high-fat, low-fibre dietary pattern tracks more strongly among adolescent boys who have high scores for this pattern at 14 years of age. These findings highlight target foods and population subgroups for early interventions aiming to improve dietary behaviours.

Evaluation of the psychometric properties of the main meal quality index when applied in the UK population.

BACKGROUND/OBJECTIVES: The aim of this study was to evaluate the validity and reliability of the Main Meal Quality Index when applied on the UK population. SUBJECTS/METHODS: The indicator was developed to assess meal quality in different populations, and is composed of 10 components: fruit, vegetables (excluding potatoes), ratio of animal protein to total protein, fiber, carbohydrate, total fat, saturated fat, processed meat, sugary beverages and desserts, and energy density, resulting in a score range of 0-100 points. The performance of the indicator was measured using strategies for assessing content validity, construct validity, discriminant validity and reliability, including principal component analysis, linear regression models and Cronbach's alpha. RESULTS: The indicator presented good reliability. CONCLUSIONS: The Main Meal Quality Index has been shown to be valid for use as an instrument to evaluate, monitor and compare the quality of meals consumed by adults in the United Kingdom.

The effects of partial sleep deprivation on energy balance: a systematic review and meta-analysis.

BACKGROUND/OBJECTIVES: It is unknown whether short sleep duration causatively contributes to weight gain. Studies investigating effects of partial sleep deprivation (PSD) on energy balance components report conflicting findings. Our objective was to conduct a systematic review and meta-analysis of human intervention studies assessing the effects of PSD on energy intake (EI) and energy expenditure (EE). SUBJECTS/METHODS: EMBASE, Medline, Cochrane CENTRAL, Web of Science and Scopus were searched. Differences in EI and total EE following PSD compared with a control condition were generated using the inverse variance method with random-effects models. Secondary outcomes included macronutrient distribution and resting metabolic rate. Heterogeneity was quantified with the I2-statistic. RESULTS: Seventeen studies (n=496) were eligible for inclusion in the systematic review, and 11 studies (n=172) provided sufficient data to be included in meta-analyses. EI was significantly increased by 385 kcal (95% confidence interval: 252, 517; P<0.00001) following PSD compared with the control condition. We found no significant change in total EE or resting metabolic rate as a result of PSD. The observed increase in EI was accompanied by significantly higher fat and lower protein intakes, but no effect on carbohydrate intake. CONCLUSIONS: The pooled effects of the studies with extractable data indicated that PSD resulted in increased EI with no effect on EE, leading to a net positive energy balance, which in the long term may contribute to weight gain.

Chrono-nutrition: a review of current evidence from observational studies on global trends in time-of-day of energy intake and its association with obesity.

The importance of the circadian rhythm in regulating human food intake behaviour and metabolism has long been recognised. However, little is known as to how energy intake is distributed over the day in existing populations, and its potential association with obesity. The present review describes global trends in time-of-day of energy intake in the general population based on data from cross-sectional surveys and longitudinal cohorts. Evidence of the association between time-of-day of energy intake and obesity is also summarised. Overall, there were a limited number of cross-sectional surveys and longitudinal cohorts that provided data on time-of-day of energy intake. In the identified studies, a wide variation in time-of-day of energy intake was observed, with patterns of energy distribution varying greatly by country and geographical area. In relation to obesity, eight cross-sectional surveys and two longitudinal cohorts were identified. The association between time-of-day of energy intake and obesity varied widely, with several studies reporting a positive link between evening energy intake and obesity. In conclusion, the current review summarises global trends in time-of-day of energy intake. The large variations across countries and global regions could have important implications to health, emphasising the need to understand the socio-environmental factors guiding such differences in eating patterns. Evidence of the association between time-of-day of energy intake and BMI also varied. Further larger scale collaborations between various countries and regions are needed to sum data from existing surveys and cohorts, and guide our understanding of the role of chrono-nutrition in health.

Indices for the assessment of nutritional quality of meals: a systematic review.

This systematic review aimed to synthesise information on indices developed to evaluate nutritional quality of meals. A strategy for systematic search of the literature was developed using keywords related to assessment of meal quality. Databases searched included ScienceDirect, PubMed, Lilacs, SciELO, Scopus, Cochrane, Embase and Google Scholar. The literature search resulted in seven different meal quality indices. Each article was analysed in order to identify the following items: authors, country, year, study design, population characteristics, type of meal evaluated, dietary assessment method, characteristics evaluated (nutrients or food items), score range, index components, nutritional references, correlations performed, validation and relationship with an outcome (if existing). Two studies developed instruments to assess the quality of breakfast, three analysed lunch, one evaluated dinner and one was applied to all types of meals and snacks. All meal quality indices reviewed were based on the evaluation of presence or absence of food groups and relative contributions of nutrients, according to food-based guidelines or nutrient references, adapting the daily dietary recommendations to one specific meal. Most of the indices included three items as components for meal quality assessment: (I) total fat or some specific type of fat, (II) fruits and vegetables and (III) cereals or whole grains. This systematic review indicates aspects that need further research, particularly the numerous approaches to assessing meals considering different foods and nutrients, and the need for validation studies of meal indices.

The effects of nutritional interventions on recurrence in survivors of colorectal adenomas and cancer: a systematic review of randomised controlled trials.

BACKGROUND/OBJECTIVES: Nutrition and dietary supplementation may modulate outcomes in colorectal cancer (CRC) survivors. However, no recent systematic review has focused on randomised controlled trials (RCTs). The aim of this systematic review was to examine the effects of nutritional RCTs in survivors of colorectal adenomas and cancer. SUBJECTS/METHODS: Medline, Embase, Scopus, Web of Science and the Cochrane Library were searched to identify research between April 2006 and January 2014. The primary outcomes were colorectal adenoma and cancer recurrence. Each included study was assessed for risk of bias. A meta-analysis using a random-effects model was performed, in which two or more RCTs investigated the same dietary intervention. RESULTS: Eight completed RCTs, all in colorectal adenoma survivors, were identified, with four investigating the effect of folic acid. A meta-analysis of the four folic acid RCTs showed no statistically significant effect of folic acid on colorectal adenoma recurrence (relative risks=0.93; 95% confidence interval: 0.69, 1.25). The impact of the remaining completed RCTs, investigating antioxidant supplementation, green tea extract, prebiotic fibre and phytooestrogens/insoluble fibre, could not be reliably estimated because of the limited number and heterogeneity of the interventions. In addition, three heterogeneous ongoing RCTs were identified, investigating green tea (n=1) and eicosapentaenoic acid (n=1) in colorectal adenoma survivors and dietary modifications (n=1) in CRC survivors in remission. CONCLUSIONS: Overall, this systematic review highlights the need for further research, especially in CRC survivors, as we identified no completed and only one ongoing RCT in this population.

Identification of a dietary pattern associated with greater cardiometabolic risk in adolescence.

BACKGROUND AND AIMS: Energy dense, high fat, low fibre diets may contribute to obesity in young people, however their relationships with other cardiometabolic risk factors are unclear. We examined associations between an 'energy-dense, high-fat and low-fibre' dietary pattern (DP) and cardiometabolic risk factors, and the tracking of this DP in adolescence. METHODS AND RESULTS: Data was sourced from participants in the Western Australian Pregnancy (Raine) Cohort Study. At 14 and 17 y, dietary intake, anthropometric and biochemical data were measured and z-scores for an 'energy dense, high fat and low fibre' DP were estimated using reduced rank regression (RRR). Associations between DP z-scores and cardiometabolic risk factors were examined using regression models. Tracking of DP z-scores was assessed using Pearson's correlation coefficient. A 1 SD unit increase in DP z-score between 14 and 17 y was associated with a 20% greater odds of high metabolic risk (95% CI: 1.01, 1.41) and a 0.04 mmol/L higher fasting glucose in boys (95% CI: 0.01, 0.08); a 28% greater odds of a high-waist circumference (95% CI: 1.00, 1.63) in girls. An increase of 3% and 4% was observed for insulin and HOMA (95% CI: 1%, 7%), respectively, in boys and girls, for every 1 SD increase in DP z-score and independently of BMI. The DP showed moderate tracking between 14 and 17 y of age (r = 0.51 for boys, r = 0.45 for girls). CONCLUSION: An 'energy dense, high fat, low fibre' DP is positively associated with cardiometabolic risk factors and tends to persist throughout adolescence.

Trends in food consumption over 30 years: evidence from a British birth cohort.

BACKGROUND/OBJECTIVES: As populations are ageing, more emphasis is placed on healthy ageing. Over the past decades, food consumption patterns and food availability have also changed drastically, and therefore this study aimed to describe these changes in an ageing population. SUBJECTS/METHODS: Food consumption of participants from the Medical Research Council National Survey on Health and Development, a British birth cohort study, was assessed using a 5-day estimated food records at 60-64 years (2006-11), 53 years (1999), 43 years (1989) and 36 years (1982). Only those who recorded ⩾3 days at all four time points were included in the analyses, n=989 (n=438 men and n=551 women); trends were tested using the Friedman test. RESULTS: Consumption of white bread, whole milk, fats and oils, meat and meat products, alcoholic drinks, coffee, sugar, preserves and confectionery decreased (P<0.001), whereas consumption of wholemeal and granary bread, semi-skimmed milk, fish and fruit and vegetables increased (P<0.001) over time. These observed changes in food consumption reflect a healthier diet, for example, replacement of white bread by granary and wholemeal bread, lower consumption of red and processed meats, somewhat higher consumption of fish, higher consumption of vegetables and lower consumption of coffee. This could partly be because of ageing of the cohort or compliance with dietary recommendations, facilitated by greater availability of healthier foods, such as semi-skimmed milk and wholegrain bread, in the UK. CONCLUSIONS: The changes in food consumption in this British birth cohort over the past three decades are encouraging and reflect a healthier diet in the later years.

Dietary patterns derived with multiple methods from food diaries and breast cancer risk in the UK Dietary Cohort Consortium.

BACKGROUND/OBJECTIVES: In spite of several studies relating dietary patterns to breast cancer risk, evidence so far remains inconsistent. This study aimed to investigate associations of dietary patterns derived with three different methods with breast cancer risk. SUBJECTS/METHODS: The Mediterranean Diet Score (MDS), principal components analyses (PCA) and reduced rank regression (RRR) were used to derive dietary patterns in a case-control study of 610 breast cancer cases and 1891 matched controls within four UK cohort studies. Dietary intakes were collected prospectively using 4- to 7-day food diaries and resulting food consumption data were grouped into 42 food groups. Conditional logistic regression models were used to estimate odds ratios (ORs) for associations between pattern scores and breast cancer risk adjusting for relevant covariates. A separate model was fitted for post-menopausal women only. RESULTS: The MDS was not associated with breast cancer risk (OR comparing first tertile with third 1.20 (95% CI 0.92; 1.56)), nor the first PCA-derived dietary pattern, explaining 2.7% of variation of diet and characterized by cheese, crisps and savoury snacks, legumes, nuts and seeds (OR 1.18 (95% CI 0.91; 1.53)). The first RRR-derived pattern, a 'high-alcohol' pattern, was associated with a higher risk of breast cancer (OR 1.27; 95% CI 1.00; 1.62), which was most pronounced in post-menopausal women (OR 1.46 (95% CI 1.08; 1.98)). CONCLUSIONS: A 'high-alcohol' dietary pattern derived with RRR was associated with an increased breast cancer risk; no evidence of associations of other dietary patterns with breast cancer risk was observed in this study.

Irregular consumption of energy intake in meals is associated with a higher cardiometabolic risk in adults of a British birth cohort.

BACKGROUND/OBJECTIVES: A potential risk factor for cardiometabolic diseases is irregular or inconsistent eating, however, research on this topic is scarce. We aimed to study associations between irregular consumption of energy intake in meals and cardiometabolic risk factors. SUBJECT AND METHODS: Dietary intake data were derived from 5-day estimated diet diaries of 1768 participants of the National Survey of Health and Development. Energy intakes during predefined meals (breakfast, lunch, dinner, between meals) and daily totals were analyzed using a score for irregularity based on the deviation from the 5-day mean energy intake. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for having the metabolic syndrome or one of its components. Models were adjusted for sex, physical activity, socioeconomic status, marital status and smoking. RESULTS: Irregularity scores of energy intake ranged from 0-160 and were highest for between meals. An increased risk of the metabolic syndrome was associated with more irregular energy intake during breakfast (OR=1.34 (0.99, 1.81); P trend=0.04) and between meals (OR=1.36 (1.01, 1.85); P trend=0.04). Moreover, increased waist circumference was associated with irregular energy intake during breakfast (OR=1.90 (1.47, 2.45); P trend <0.01), evening meal (OR=1.36 (1.06, 1.75); P trend=0.02) and daily total (OR=1.34 (1.04, 1.72); P trend=0.01). No significant associations were found for the other components of the metabolic syndrome. CONCLUSIONS: Individuals with a more irregular intake of energy, especially during breakfast and between meals, appeared to have an increased cardiometabolic risk.

No effect of fish oil supplementation on serum inflammatory markers and their interrelationships: a randomized controlled trial in healthy, middle-aged individuals.

BACKGROUND: A high intake of n-3 polyunsaturated fatty acids (PUFAs), mainly present in fish, may be associated with decreased inflammation. Previous intervention studies on fish PUFA and inflammatory markers in healthy individuals did not analyze a broad spectrum of inflammatory cytokines, chemokines and cell adhesion molecules, or their interrelationships. Therefore, we determined the effects of fish oil supplementation on 19 serum inflammatory markers and their interrelationships in healthy, middle-aged individuals. METHODS: Individuals (n=77) aged 50-70 years completed a randomized, double-blind placebo-controlled intervention study. Participants received 3.5 g/day fish oil (1.5 g/day total n-3 PUFA) (n=39) or placebo (high oleic sunflower oil) (n=38) for 12 weeks. Serum concentrations of 19 inflammatory markers were determined using a multiplex immunoassay before and after intervention. Changes in concentrations were analyzed using analysis of covariance and differences in patterns in inflammatory markers between the fish oil and placebo group were analyzed by principal component analysis. RESULTS: Fish oil supplementation did not significantly affect serum concentrations of cytokines, chemokines or cell adhesion molecules as compared with placebo. However, there was a trend for all inflammatory markers to increase after fish oil supplementation. PCA did not result in markedly distinctive patterns of inflammatory markers for the fish oil and placebo group. CONCLUSION: In conclusion, this 12-week randomized, double-blind placebo-controlled intervention trial did not show that 1.5 g/day n-3 PUFA significantly affected the serum inflammatory response in healthy individuals, nor did patterns of inflammatory markers. Thus, a healthy middle-aged population may not benefit from fish oil as an anti-inflammatory agent.