Helen J Moore

Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review.

Abstract Objective To review systematically the evidence for an effect of long chain and shorter chain omega 3 fatty acids on total mortality, cardiovascular events, and cancer. Data sources Electronic databases searched to February 2002; authors contacted and bibliographies of randomised controlled trials (RCTs) checked to locate studies. Review methods Review of RCTs of omega 3 intake for 3 6 months in adults (with or without risk factors for cardiovascular disease) with data on a relevant outcome. Cohort studies that estimated omega 3 intake and related this to clinical outcome during at least 6 months were also included. Application of inclusion criteria, data extraction, and quality assessments were performed independently in duplicate. Results Of 15 159 titles and abstracts assessed, 48 RCTs (36 913 participants) and 41 cohort studies were analysed. The trial results were inconsistent. The pooled estimate showed no strong evidence of reduced risk of total mortality (relative risk 0.87, 95% confidence interval 0.73 to 1.03) or combined cardiovascular events (0.95, 0.82 to 1.12) in participants taking additional omega 3 fats. The few studies at low risk of bias were more consistent, but they showed no effect of omega 3 on total mortality (0.98, 0.70 to 1.36) or cardiovascular events (1.09, 0.87 to 1.37). When data from the subgroup of studies of long chain omega 3 fats were analysed separately, total mortality (0.86, 0.70 to 1.04; 138 events) and cardiovascular events (0.93, 0.79 to 1.11) were not clearly reduced. Neither RCTs nor cohort studies suggested increased risk of cancer with a higher intake of omega 3 (trials: 1.07, 0.88 to 1.30; cohort studies: 1.02, 0.87 to 1.19), but clinically important harm could not be excluded. Conclusion Long chain and shorter chain omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer.

Effect of reducing total fat intake on body weight: systematic review and meta-analysis of randomised controlled trials and cohort studies

Objective To investigate the relation between total fat intake and body weight in adults and children. Design Systematic review and meta-analysis of randomised controlled trials and cohort studies. Data sources Medline, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials to June 2010. Inclusion criteria Randomised controlled trials and cohort studies of adults or children that compared lower versus usual total fat intake and assessed the effects on measures of body fatness (body weight, body mass index, or waist circumference) after at least six months (randomised controlled trials) or one year (in cohorts). Randomised controlled trials with any intention to reduce weight in participants or confounded by additional medical or lifestyle interventions were excluded. Data extraction Data were extracted and validity was assessed independently and in duplicate. Random effects meta-analyses, subgroups, sensitivity analyses, and metaregression were done. Results 33 randomised controlled trials (73 589 participants) and 10 cohort studies were included, all from developed countries. Meta-analysis of data from the trials suggested that diets lower in total fat were associated with lower relative body weight (by 1.6 kg, 95% confidence interval −2.0 to −1.2 kg, I2=75%, 57 735 participants). Lower weight gain in the low fat arm compared with the control arm was consistent across trials, but the size of the effect varied. Metaregression suggested that greater reduction in total fat intake and lower baseline fat intake were associated with greater relative weight loss, explaining most of the heterogeneity. The significant effect of a low fat diet on weight was not lost in sensitivity analyses (including removing trials that expended greater time and attention on low fat groups). Lower total fat intake also led to lower body mass index (−0.51 kg/m2, 95% confidence interval −0.76 to −0.26, nine trials, I2=77%) and waist circumference (by 0.3 cm, 95% confidence interval −0.58 to −0.02, 15 671 women, one trial). There was no suggestion of negative effects on other cardiovascular risk factors (lipid levels or blood pressure). GRADE assessment suggested high quality evidence for the relation between total fat intake and body weight in adults. Only one randomised controlled trial and three cohort studies were found in children and young people, but these confirmed a positive relation between total fat intake and weight gain. Conclusions There is high quality, consistent evidence that reduction of total fat intake has been achieved in large numbers of both healthy and at risk trial participants over many years. Lower total fat intake leads to small but statistically significant and clinically meaningful, sustained reductions in body weight in adults in studies with baseline fat intakes of 28-43% of energy intake and durations from six months to over eight years. Evidence supports a similar effect in children and young people.

Systematic review of long-term lifestyle interventions to prevent weight gain and morbidity in adults

The aim of this article is to determine the effectiveness of long‐term lifestyle interventions for the prevention of weight gain and morbidity in adults. Prevention of weight gain is important in adults who are of normal weight, overweight and obese. A systematic review of controlled trials of lifestyle interventions in adults with a body mass index of less than 35 kg m−2 with at least 2 years of follow‐up was carried out. Eleven of 39 comparisons produced significant improvement in weight between groups at 2 years or longer with mean difference weight change ranging from −0.5 to −11.5 kg. Effective interventions included a 600 kcal/day deficit diet deficit/low‐fat diet (with and without meal replacements), low‐calorie diet, Weight Watchers diet, low‐fat non‐reducing diet, diet with behaviour therapy, diet with exercise, diet with exercise and behaviour therapy. Adding meal replacements to a low‐fat diet (with and without exercise and behaviour therapy) produced significant improvement in weight. Head‐to‐head interventions failed to show significant effect on weight with the exception of a Mediterranean diet with behaviour therapy compared with low‐fat diet. Diet with exercise and/or behaviour therapy demonstrated significant reduction in hypertension and improvement in risk of metabolic syndrome and diabetes compared with no treatment control. Lifestyle interventions demonstrated significant improvement in weight, reduction in hypertension and reduction in risk of type 2 diabetes and the metabolic syndrome.

European energy balance research to prevent excessive weight gain among youth (ENERGY) project: Design and methodology of the ENERGY cross-sectional survey

BackgroundObesity treatment is by large ineffective long term, and more emphasis on the prevention of excessive weight gain in childhood and adolescence is warranted. To inform energy balance related behaviour (EBRB) change interventions, insight in the potential personal, family and school environmental correlates of these behaviours is needed. Studies on such multilevel correlates of EBRB among schoolchildren in Europe are lacking. The ENERGY survey aims to (1) provide up-to-date prevalence rates of measured overweight, obesity, self-reported engagement in EBRBs, and objective accelerometer-based assessment of physical activity and sedentary behaviour and blood-sample biomarkers of metabolic function in countries in different regions of Europe, (2) to identify personal, family and school environmental correlates of these EBRBs. This paper describes the design, methodology and protocol of the survey.Method/DesignA school-based cross-sectional survey was carried out in 2010 in seven different European countries; Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia, and Spain. The survey included measurements of anthropometrics, child, parent and school-staff questionnaires, and school observations to measure and assess outcomes (i.e. height, weight, and waist circumference), EBRBs and potential personal, family and school environmental correlates of these behaviours including the social-cultural, physical, political, and economic environmental factors. In addition, a selection of countries conducted accelerometer measurements to objectively assess physical activity and sedentary behaviour, and collected blood samples to assess several biomarkers of metabolic function.DiscussionThe ENERGY survey is a comprehensive cross-sectional study measuring anthropometrics and biomarkers as well as assessing a range of EBRBs and their potential correlates at the personal, family and school level, among 10-12 year old children in seven European countries. This study will result in a unique dataset, enabling cross country comparisons in overweight, obesity, risk behaviours for these conditions as well as the correlates of engagement in these risk behaviours.

Evidence-based recommendations for the development of obesity prevention programs targeted at preschool children

The ToyBox intervention was developed using an evidence‐based approach, using the findings of four reviews. These reviews included three critical and narrative reviews of educational strategies and psychological approaches explaining young childrens acquisition and formation of energy‐balance related behaviours, and the management of these behaviours, and also a systematic review of behavioural models underpinning school‐based interventions in preschool and school settings for the prevention of obesity in children aged 4–6 years.

The development and evaluation of a novel computer program to assess previous-day dietary and physical activity behaviours in school children: The Synchronised Nutrition and Activity Program TM (SNAP TM )

Self-report recall questionnaires used to measure physical activity and dietary intake in children can be labour intensive and monotonous and tend to focus on either dietary intake or physical activity. The web-based software, Synchronised Nutrition and Activity Program TM (SNAP TM ), was developed to produce a novel, simple, quick and engaging method of assessing energy balance-related behaviours at a population level, combining principles from new and existing 24 h recall methodologies, set within a user-friendly interface. Dietary intake was measured using counts for twenty-one food groups and physical activity levels were measured in min of moderate to vigorous physical activity (MVPA). A combination of the mean difference between methods, type II regression and non-parametric limits of agreement techniques were used to examine the accuracy and precision of SNAP TM . Method comparison analyses demonstrated a good agreement for both dietary intake and physical activity behaviours. For dietary variables, accuracy of SNAP TM (mean difference) was within ^ 1 count for the majority of food groups. The proportion of the sample with between-method agreement within ^1 count ranged from 0·40 to 0·99. For min of MVPA, there was no substantial fixed or proportional bias, and a mean difference between methods (SNAP TM – accelerometry) of 29 min. SNAP TM provides a quick, accurate, low-burden, cost-effective and engaging method of assessing energy balance behaviours at a population level. Tools such as SNAP TM , which exploit the popularity, privacy and engagement of the computer interface, and linkages with other datasets, could make a substantial contribution to future public health monitoring and research.

A narrative review of psychological and educational strategies applied to young children's eating behaviours aimed at reducing obesity risk

Strategies to reduce risk of obesity by influencing preschool childrens eating behaviour are reviewed. The studies are placed in the context of relevant psychological processes, including inherited and acquired preferences, and behavioural traits, such as food neophobia, ‘enjoyment of food’ and ‘satiety responsiveness’. These are important influences on how children respond to feeding practices, as well as predictors of obesity risk. Nevertheless, in young children, food environment and experience are especially important for establishing eating habits and food preferences. Providing information to parents, or to children, on healthy feeding is insufficient. Acceptance of healthy foods can be encouraged by five to ten repeated tastes. Recent evidence suggests rewarding healthy eating can be successful, even for verbal praise alone, but that palatable foods should not be used as rewards for eating. Intake of healthier foods can be promoted by increasing portion size, especially in the beginning of the meal. Parental strategies of pressuring to eat and restriction do not appear to be causally linked to obesity, but are instead primarily responses to childrens eating tendencies and weight. Moderate rather than frequent restriction may improve healthy eating in children. Actively positive social modelling by adults and peers can be effective in encouraging healthier eating.

Critical narrative review to identify educational strategies promoting physical activity in preschool

The aim of this narrative review is critically to evaluate educational strategies promoting physical activity that are used in the preschool setting in the context of obesity prevention programmes. Literature search was conducted between April and August 2010 in English and German databases (PubMED, PsychINFO, PSYNDEX, ERIC, FIS Bildung). Outcomes considered were time and intensity of physical activity, motor skills or measures of body composition. A total of 19 studies were included. Ten studies added physical activity lessons into their curriculum, one study provided more time for free play, eight studies focused on the social and play environment. Studies reporting positive outcomes implemented physical activity sessions that lasted at least 30 min d−1. Several studies showed that children are most active in the first 10–15 min. The existence or installation of playground markings or fixed play equipment had no effect, whereas the presence or addition of portable play equipment was positively correlated with moderate‐to‐vigorous physical activity. Teacher training may be a key element for successful interventions. To overcome time constraints, a suggested solution is to integrate physical activity into daily routines and other areas of the preschool curriculum.

A systematic review of the effectiveness of individual, community and societal level interventions at reducing socioeconomic inequalities in obesity amongst children

BackgroundTackling childhood obesity is one of the major contemporary public health policy challenges and vital in terms of addressing socioeconomic health inequalities.We aimed to systematically review studies of the effectiveness of interventions (individual, community and societal) operating via different approaches (targeted or universal) in reducing socio-economic inequalities in obesity-related outcomes amongst children.MethodsNine electronic databases were searched from start date to October 2012 along with website and grey literature searches. The review examined the best available international evidence from interventions that aimed to prevent obesity, treat obesity, or improve obesity-related behaviours (diet and/or physical activity) amongst children (aged 0-18 years) in any setting and country, so long as they provided relevant information and analysis on both socioeconomic status and obesity-related outcomes. Data extraction and quality appraisal were conducted using established mechanisms and narrative synthesis was conducted.ResultsWe located 23 studies that provided the ‘best available’ (strongest methodologically) international evidence. At the individual level (n = 4), there was indicative evidence that screen time reduction and mentoring health promotion interventions could be effective in reducing inequalities in obesity. For the community level interventions (n = 17), evidence was inconclusive - with some studies suggesting that school-based health promotion activities and community-based group-based programmes were effective in reducing obesity - others not. Societal level evaluations were few (n = 1). However, there was no evidence to suggest that any of these intervention types increase inequalities and several studies found that interventions could at least prevent the widening of inequalities in obesity. The majority of studies were from America and were of 6-12 year old children.ConclusionsThe review has found only limited evidence although some individual and community based interventions may be effective in reducing socio-economic inequalities in obesity-related outcomes amongst children but further research is required, particularly of more complex, societal level interventions and amongst adolescents.

A systematic review of the effectiveness of individual, community and societal level interventions at reducing socioeconomic inequalities in obesity amongst adults.

Background:Socioeconomic inequalities in obesity are well established in high-income countries. There is a lack of evidence of the types of intervention that are effective in reducing these inequalities among adults.Objectives:To systematically review studies of the effectiveness of individual, community and societal interventions in reducing socio-economic inequalities in obesity among adults.Methods:Nine electronic databases were searched from start date to October 2012 along with website and grey literature searches. The review examined the best available international evidence (both experimental and observational) of interventions at an individual, community and societal level that might reduce inequalities in obesity among adults (aged 18 years or over) in any setting and country. Studies were included if they reported a body fatness-related outcome and if they included a measure of socio-economic status. Data extraction and quality appraisal were conducted using established mechanisms and narrative synthesis was conducted.Results:The ‘best available’ international evidence was provided by 20 studies. At the individual level, there was evidence of the effectiveness of primary care delivered tailored weight loss programmes among deprived groups. Community based behavioural weight loss interventions and community diet clubs (including workplace ones) also had some evidence of effectiveness—at least in the short term. Societal level evaluations were few, low quality and inconclusive. Further, there was little evidence of long term effectiveness, and few studies of men or outside the USA. However, there was no evidence to suggest that interventions increase inequalities.Conclusions:The best available international evidence suggests that some individual and community-based interventions may be effective in reducing socio-economic inequalities in obesity among adults in the short term. Further research is required particularly of more complex, multi-faceted and societal-level interventions.