Obesity Reviews

Tate, E. B.; Wood, W.; Liao, Y.; Dunton, G. F.

doi: 10.1111/obr.12262pmid: 25879393

Child obesity continues to be a prevalent public health issue. This meta‐analysis synthesized 17 studies investigating the association between levels of psychological stress experienced by mothers and the body mass index of their children. The overall standardized mean difference effect size was positive and significantly different from zero in cross‐sectional d = 0.20 (k = 14, 95% confidence interval [CI]: 0.06, 0.34) and longitudinal studies d = 0.18 (k = 5, 95% CI: 0.00, 0.351) and had significant heterogeneity in both (cross‐sectional, Q[13] = 193.00, P < 0.001; longitudinal, Q[4] = 29.46, P < 0.001). In longitudinal studies, effect sizes were larger when children also would have experienced the stressor, Q(6) = 4.68, P < 0.05, for toddlers than infants, Q(4) = 5.04, P < 0.05, and in higher quality studies, Q(4) = 14.58, P < 0.05. Results highlight the potential benefits of including a parent stress management component in childhood obesity prevention programmes.

Mayne, S. L.; Auchincloss, A. H.; Michael, Y. L.

doi: 10.1111/obr.12269pmid: 25753170

Policies and changes to the built environment are promising targets for obesity prevention efforts and can be evaluated as ‘natural'‐ or ‘quasi'‐experiments. This systematic review examined the use of natural‐ or quasi‐experiments to evaluate the efficacy of policy and built environment changes on obesity‐related outcomes (body mass index, diet or physical activity). PubMed (Medline) was searched for studies published 2005–2013; 1,175 abstracts and 115 papers were reviewed. Of the 37 studies included, 18 studies evaluated impacts on nutrition/diet, 17 on physical activity and 3 on body mass index. Nutrition‐related studies found greater effects because of bans/restrictions on unhealthy foods, mandates offering healthier foods, and altering purchase/payment rules on foods purchased using low‐income food vouchers compared with other interventions (menu labelling, new supermarkets). Physical activity‐related studies generally found stronger impacts when the intervention involved improvements to active transportation infrastructure, longer follow‐up time or measured process outcomes (e.g. cycling rather than total physical activity), compared with other studies. Only three studies directly assessed body mass index or weight, and only one (installing light‐rail system) observed a significant effect. Studies varied widely in the strength of their design and studies with weaker designs were more likely to report associations in the positive direction.

Hutchesson, M. J.; Rollo, M. E.; Krukowski, R.; Ells, L.; Harvey, J.; Morgan, P. J.; Callister, R.; Plotnikoff, R.; Collins, C. E.

doi: 10.1111/obr.12268pmid: 25753009

A systematic review of randomized controlled trials was conducted to evaluate the effectiveness of eHealth interventions for the prevention and treatment of overweight and obesity in adults. Eight databases were searched for studies published in English from 1995 to 17 September 2014. Eighty‐four studies were included, with 183 intervention arms, of which 76% (n = 139) included an eHealth component. Sixty‐one studies had the primary aim of weight loss, 10 weight loss maintenance, eight weight gain prevention, and five weight loss and maintenance. eHealth interventions were predominantly delivered using the Internet, but also email, text messages, monitoring devices, mobile applications, computer programs, podcasts and personal digital assistants. Forty percent (n = 55) of interventions used more than one type of technology, and 43.2% (n = 60) were delivered solely using eHealth technologies. Meta‐analyses demonstrated significantly greater weight loss (kg) in eHealth weight loss interventions compared with control (MD −2.70 [−3.33,−2.08], P < 0.001) or minimal interventions (MD −1.40 [−1.98,−0.82], P < 0.001), and in eHealth weight loss interventions with extra components or technologies (MD 1.46 [0.80, 2.13], P < 0.001) compared with standard eHealth programmes. The findings support the use of eHealth interventions as a treatment option for obesity, but there is insufficient evidence for the effectiveness of eHealth interventions for weight loss maintenance or weight gain prevention.

AlKhater, S. A.

doi: 10.1111/obr.12271pmid: 25753407

Non‐alcoholic fatty liver disease (NAFLD) is a progressive disease that encompasses a spectrum of liver diseases, ranging from simple steatosis to non‐alcoholic steatohepatitis (NASH). Data related to survival in children are scarce, but these data firmly associate NAFLD with higher risks of hepatic and non‐hepatic morbidities and mortalities compared with the general population. More recently, the association between NAFLD and cardiovascular disease among children has increasingly been recognized. Given that obesity is a major risk factor for the disease, paediatric NAFLD is becoming a global issue, paralleling the dramatic rise in obesity worldwide. NASH, which is more common in obese children, has the potential to advance to liver fibrosis and failure. It is unclear why certain patients undergo such transformation but this susceptibility is likely related to an interaction between a genetically susceptible host and the surrounding environment. Currently, treatment is largely conservative and includes lifestyle modification, attainable through healthy weight reduction via diet and exercise. In this review, current knowledge about NAFLD in children is summarized. This review aims to increase the awareness of the medical community about a hidden public health issue and to identify current gaps in the literature while providing directions for future research.

Rabkin, S. W.; Campbell, H.

doi: 10.1111/obr.12270pmid: 25753297

The objectives were to determine whether epicardial fat (EAT) is subject to modification, and whether various strategies accomplish this end point and the relationship between weight loss and EAT. A systematic review of the literature following meta‐analysis guidelines was conducted using the search strategy ‘epicardial fat’ OR ‘epicardial adipose tissue’ AND ‘diet’ OR ‘exercise’ OR ‘bariatric surgery (BS)’ OR ‘change in body weight’ limited to humans. Eleven articles were identified with 12 intervention approaches of which eight studies showed a statistically significant reduction in EAT. A random‐effects meta‐analysis suggests an overall significant reduction of 1.12 standardized units (95% CI = [−1.71, −0.54], P value < 0.01). While there is a large amount of heterogeneity across study groups, a substantial amount of this variability can be accounted for by considering intervention type and change in body mass index (BMI). These variables were incorporated into a random‐effects meta‐regression model. Using this analysis, significant EAT reduction occurred with diet and BS but not with exercise. BMI reductions correlated significantly with EAT reductions for diet‐based interventions, i.e. for some but not all interventions. In conclusion, EAT, a factor that is significantly associated with coronary artery disease, can be modified. The type of intervention, in addition to the amount of weight loss achieved, is predictive of the amount of EAT reduction.

Bagheri, M.; Speakman, J. R.; Shabbidar, S.; Kazemi, F.; Djafarian, K.

doi: 10.1111/obr.12272pmid: 25753533

The obesity paradox is often attributed to fat acting as a buffer to protect individuals in fragile metabolic states. If this was the case, one would predict that the reverse epidemiology would be apparent across all causes of mortality including that of the particular disease state. We performed a dose‐response meta‐analysis to assess the impact of body mass index (BMI) on all‐cause and stroke‐specific mortality among stroke patients. Data from relevant studies were identified by systematically searching PubMed, OVID and Scopus databases and were analysed using a random‐effects dose‐response model. Eight cohort studies on all‐cause mortality (with 20,807 deaths of 95,651 stroke patients) and nine studies of mortality exclusively because of stroke (with 8,087 deaths of 28,6270 patients) were evaluated in the meta‐analysis. Non‐linear associations of BMI with all‐cause mortality (P < 0.0001) and mortality by stroke (P = 0.05) were observed. Among overweight and obese stroke patients, the risk of all‐cause mortality increased, while the risk of mortality by stroke declined, with an increase in BMI. Increasing BMI had opposite effects on all‐cause mortality and stroke‐specific mortality in stroke patients. Further investigations are needed to examine how mortality by stroke is influenced by a more accurate indicator of obesity than BMI.

Hendrikse, J. J.; Cachia, R. L.; Kothe, E. J.; McPhie, S.; Skouteris, H.; Hayden, M. J.

doi: 10.1111/obr.12265pmid: 25752592

Obesity rates have increased dramatically in recent decades, and it has proven difficult to treat. An attentional bias towards food cues may be implicated in the aetiology of obesity and influence cravings and food consumption. This review systematically investigated whether attentional biases to food cues exist in overweight/obese compared with healthy weight individuals. Electronic database were searched for relevant papers from inception to October 2014. Only studies reporting food‐related attentional bias between either overweight (body mass index [BMI] 25.0–29.9 kg m−2) or obese (BMI ≥ 30) participants and healthy weight participants (BMI 18.5–24.9) were included. The findings of 19 studies were reported in this review. Results of the literature are suggestive of differences in attentional bias, with all but four studies supporting the notion of enhanced reactivity to food stimuli in overweight individuals and individuals with obesity. This support for attentional bias was observed primarily in studies that employed psychophysiological techniques (i.e. electroencephalogram, eye‐tracking and functional magnetic resonance imaging). Despite the heterogeneous methodology within the featured studies, all measures of attentional bias demonstrated altered cue‐reactivity in individuals with obesity. Considering the theorized implications of attentional biases on obesity pathology, researchers are encouraged to replicate flagship studies to strengthen these inferences.