Frances C Hillier

The association between diet and physical activity and subsequent excess weight gain and obesity assessed at 5 years of age or older: a systematic review of the epidemiological evidence

Background The geographical or natural conditions of a country affect the manner in which economic growth takes place. Overcoming natural impediments and making use of geographical and natural advantages is the duty of economic experts and researchers. In order to overcome geographical and natural hardships, investments above international norm are needed and, on the contrary, by the optimal use of natural and regional advantages of a given area, less investment is needed for economic growth. In spite of all defeats and victories, ups and downs, the inhabitants of this land have relatively always played a determining role in West Asia and have greatly influenced and being influenced by the neighboring events and nation. The Iranian territory is located inside the desert belt of the Northern Hemisphere and is geographically placed in a belt line, the same as the plains in North Africa, Tibet and Turkistan. The country of Iran is about 1648195 square kilometers. From the total 1648195 square kilometers of the Country nearly 509442 square kilometers are used in agriculture and the rest is uncultivable areas or covered by cities, villages, lakes and roads. From 31% cultivable land in Iran; the two Northern provinces on the Caspian Sea coasts with an area of 5.5% of the overall area of Iran form more than 20% of the cultivable lands. 11 Introduction Obesity arises from a complex interplay between genetic susceptibility and behaviour, primarily relating to dietary habits and physical activity (Foresight, 2007). Evidence for specific behavioural factors that promote or protect against excess weight gain have been usefully reviewed (Wareham, 2007); (Jebb, 2007), and is more limited in children compared with adults (Rennie et al., 2005). A number of behavioural risk factors have been postulated, including TV viewing, diets with a high energy density, and fast foods. Most evidence is derived from cross sectional studies which can frequently produce conflicting results. Prospective studies with accurate measure of diet and physical activity exposures, and outcomes in terms of body fatness, are deemed to provide the more robust evidence on which to base interventions to achieve long-term behavioural change and prevent excess weight gain. The question to be answered by this comprehensive systematic review of the epidemiological evidence was ‘What is the association between food, food groups, nutrition and physical activity and subsequent excess weight gain and obesity in humans?’ Relevant exposures include patterns of diet; breastfeeding; food and drink; food preparation; dietary constituents; physical activity and inactivity; energy intake; energy density of diet; energy expenditure. Outcomes in adulthood and childhood have reported separately. Outcomes of interest included markers of weight gain; overweight; obesity; markers of body composition; markers of distribution of fat. The results of this review will provide evidence of association, but not causes, of subsequent excess weight gain and obesity. There is a degree of uncertainty inherent in epidemiological evidence, given that it is impossible to determine if there are uncontrolled variables, including genetic variations. The well known association between relatively high non caloric sweetner usage and subsequent weight gain is a useful reminder that, whilst an evidence based approach is critical to the process of scientific enquiry, consideration of evidence from other types of studies (mechanistic studies, intervention studies) and understanding the context of the evidence reviewed is essential if we are to provide policy makers, industry, service providers and the public with sensible recommendations.

The contribution of overweight, obesity, and lack of physical activity to exit from paid employment: a meta-analysis

OBJECTIVES The objective of this review was to analyze systematically the association between overweight, obesity, and lack of physical activity (PA) and exit from paid employment through disability pension, unemployment, and early retirement. We also aimed to identify the influence of study population and study design on the magnitude of this association. METHODS We searched PubMed and Embase for English language, longitudinal, quantitative studies that described the relationship between overweight, obesity, or lack of PA and exit from work. A short checklist was used to assess the internal and external validity of the studies. We first estimated the pooled effects using a random effects model and then analyzed the influence of study and population characteristics on associations by stratified meta-analyses. RESULTS In total, 28 out of 1097 publications met the inclusion criteria. Obese [relative risk (RR)=1.53) and, to a lesser extent, overweight (RR=1.16) individuals had an increased likelihood of exit from paid employment through disability pension, but were not at statistically significant increased risk for unemployment or early retirement. Of 17 associations between a lack of PA and disability pension, 8 were statistically significant; this was also the case for 2 of 3 for unemployment. No associations were statistically significant for early retirement. CONCLUSIONS Obesity is a risk factor for exit from paid employment through disability pension. There are also indications that a lack of PA is related to an increased risk of disability pension and unemployment. To protect workers against premature exit from paid employment, long-term interventions to prevent overweight and obesity and promote PA in the working population should be considered for implementation.

Tackling inequalities in obesity: a protocol for a systematic review of the effectiveness of public health interventions at reducing socioeconomic inequalities in obesity amongst children

BackgroundThere is growing evidence of the impact of overweight and obesity on short- and long-term functioning, health and well-being. Internationally, childhood obesity rates continue to rise in some countries (for example, Mexico, India, China and Canada), although there is emerging evidence of a slowing of this increase or a plateauing in some age groups. In most European countries, the United States and Australia, however, socioeconomic inequalities in relation to obesity and risk factors for obesity are widening. Addressing inequalities in obesity, therefore, has a very high profile on the public health and health services agendas. However, there is a lack of accessible policy-ready evidence on what works in terms of interventions to reduce inequalities in obesity.Methods and designThis article describes the protocol for a National Health Service Trust (NHS) National Institute for Health Research-funded systematic review of public health interventions at the individual, community and societal levels which might reduce socioeconomic inequalities in relation to obesity amongst children ages 0 to 18 years. The studies will be selected only if (1) they included a primary outcome that is a proxy for body fatness and (2) examined differential effects with regard to socioeconomic status (education, income, occupation, social class, deprivation and poverty) or the intervention was targeted specifically at disadvantaged groups (for example, children of the unemployed, lone parents, low income and so on) or at people who live in deprived areas. A rigorous and inclusive international literature search will be conducted for randomised and nonrandomised controlled trials, prospective and retrospective cohort studies (with and/or without control groups) and prospective repeat cross-sectional studies (with and/or without control groups). The following electronic databases will be searched: MEDLINE, Embase, CINAHL, PsycINFO, Social Science Citation Index, ASSIA, IBSS, Sociological Abstracts and the NHS Economic Evaluation Database. Database searches will be supplemented with website and grey literature searches. No studies will be excluded on the basis of language, country of origin or publication date. Study inclusion, data extraction and quality appraisal will be conducted by two reviewers. Meta-analysis and narrative synthesis will be conducted. The main analysis will examine the effects of (1) individual, (2) community and (3) societal level public health interventions on socioeconomic inequalities in childhood obesity. Interventions will be characterised by their level of action and their approach to tackling inequalities. Contextual information on how such public health interventions are organised, implemented and delivered will also be examined.DiscussionIn this review, we consider public health strategies which reduce and prevent inequalities in the prevalence of childhood obesity, highlight any gaps in the evidence base and seek to establish how such public health interventions are organised, implemented and delivered.PROSPERO registration number: CRD42011001740

Technology-based dietary assessment: development of the Synchronised Nutrition and Activity Program (SNAP™)

BACKGROUND Accurate, reliable and feasible methods of dietary intake and physical activity assessment are required to improve our understanding of the associations between energy balance-related behaviours and health. METHODS The Synchronised Nutrition and Activity Program (SNAP) was developed to enhance recall in children by integrating new and established methods of dietary intake and physical activity recall. A list of commonly consumed foods (n = 40), drinks (n = 9) and physical activities (n = 29) was used in SNAP. All foods and drinks were analysed by count (i.e., the number of times a particular food was selected), as a proxy indicator of dietary behaviours. All reported physical activities were assigned an intensity code [in metabolic equivalents (METs)] to determine minutes of moderate-vigorous activity (MVPA; ≥3 METs). RESULTS Most participants completed a whole days recall (both dietary intake and physical activities) in less than 25 min. SNAP was compared against 24-h multiple pass questionnaire and accelerometry in 121 children (aged 7-15 years old). For dietary variables, the accuracy of SNAP(™) (mean difference) was within ±1 count for the majority of food groups. The proportion of the sample with a between-method agreement within ±1 count ranged from 0.40 to 0.99. For MVPA, there was no substantial fixed or proportional bias, with a mean difference between methods (SNAP) - accelerometry) of -9 min of MVPA. Qualitatively, participants have indicated that they find SNAP easy and fun to use. CONCLUSIONS SNAP was developed to be a simple, quick and engaging method of assessing energy balance-related behaviours at a group or population level and succeeded because it can collect a whole days recall (dietary intake and physical activities) in less than 25 min to a reasonable and acceptable degree of accuracy.

The development and evaluation of a novel Internet-based computer program to assess previous-day dietary and physical activity behaviours in adults: the Synchronised Nutrition and Activity Program for Adults (SNAPA™).

The Synchronised Nutrition and Activity Program for Adults (SNAPA™) was developed to address the need for accurate, reliable, feasible, inexpensive and low-burden methods for assessing specific dietary and physical activity behaviours in adults. Short-term test-retest reliability of SNAPA™ was assessed in forty-four adults (age 41·4 (SD17·3) years) who completed SNAPA™ twice in 1 day. Concurrent validity against direct dietary observation and combined heart rate and accelerometry was assessed in seventy-seven adults (age 34·4 (SD11·1) years). Test-retest reliability revealed no substantial systematic shifts in mean values of the outcome variables: percentage of food energy from fat (% fat), number of portions of fruit and vegetables (FV) and minutes of moderate-to-vigorous physical activity (MVPA). For lunchtime dietary intake, the mean match rate between food items reported using SNAPA™ and those observed was 81·7%, with a phantom rate of 5·6%. Pearsons correlations between SNAPA™ and the reference methods ranged from 0·27 to 0·56 for % fat, FV portions and minutes of MVPA. For % fat and FV intake, there was no fixed or proportional bias, and mean differences between the methods (SNAPA™ - reference) were 5·1% and 0 portions, respectively. For minutes of MVPA, a fixed bias of - 28 min was revealed when compared with all minutes of MVPA measured by combined heart rate and accelerometry, whereas a proportional bias (slope 1·47) was revealed when compared with minutes carried out in bouts ≥ 10 min. SNAPA™ is a promising tool for measuring specific energy balance behaviours, though further work is required to improve accuracy for physical activity behaviours.