Obesity Reviews

Samocha‐Bonet, D.; Dixit, V. D.; Kahn, C. R.; Leibel, R. L.; Lin, X.; Nieuwdorp, M.; Pietiläinen, K. H.; Rabasa‐Lhoret, R.; Roden, M.; Scherer, P. E.; Klein, S.; Ravussin, E.

doi: 10.1111/obr.12199pmid: 25059108

Obesity is closely associated with cardiovascular diseases and type 2 diabetes, but some obese individuals, despite having excessive body fat, exhibit metabolic health that is comparable with that of lean individuals. The ‘healthy obese’ phenotype was described in the 1980s, but major advancements in its characterization were only made in the past five years. During this time, several new mechanisms that may be involved in health preservation in obesity were proposed through the use of transgenic animal models, use of sophisticated imaging techniques and in vivo measurements of insulin sensitivity. However, the main obstacle in advancing our understanding of the metabolically healthy obese phenotype and its related long‐term health risks is the lack of a standardized definition. Here, we summarize the proceedings of the 13th Stock Conference of the International Association of the Study of Obesity. We describe the current research and highlight the unanswered questions and gaps in the field. Better understanding of metabolic health in obesity will assist in therapeutic decision‐making and help identify therapeutic targets to improve metabolic health in obesity.

Wang, F.; Zhang, L.; Zhang, Y.; Zhang, B.; He, Y.; Xie, S.; Li, M.; Miao, X.; Chan, E. Y. Y.; Tang, J. L.; Wong, M. C. S.; Li, Z.; Yu, I. T. S.; Tse, L. A.

doi: 10.1111/obr.12194

Baillot, A.; Audet, M.; Baillargeon, J. P.; Dionne, I. J.; Valiquette, L.; Rosa‐Fortin, M. M.; Abou Chakra, C. N.; Comeau, É.; Langlois, M. F.

doi: 10.1111/obr.12171pmid: 24712685

The objective of this systematic review was to appraise current knowledge on the impact of physical activity (PA) and physical fitness (PF) on the health of class II and III obese subjects and bariatric surgery (BS) patients. All original studies were searched using four databases (Medline®, Scopus®, CINAHL and Sportdiscus). Two independent investigators selected studies assessing the impact of PA or PF on specific health outcomes (anthropometric parameters, body composition, cardiometabolic risk factors, PF, wellness) in adults with a body mass index ≥35 kg m−2 or in BS patients. Conclusions were drawn based on a rating system of evidence. From 3,170 papers identified, 40 papers met the inclusion criteria. The vast majority of studies were recently carried out with a predominance of women. Less than one‐third of these studies were experimental and only three of them were of high quality. Each study reported at least one beneficial effect of PA or PF. However, a lack of high‐quality studies and heterogeneity in designs prevented us from finding high levels of evidence. In conclusion, although results support the importance of PA and PF to improve the health of this population, higher‐quality trials are required to strengthen evidence‐based recommendations.

Rouhani, M. H.; Salehi‐Abargouei, A.; Surkan, P. J.; Azadbakht, L.

doi: 10.1111/obr.12172pmid: 24815945

A body of literature exists regarding the association of red and processed meats with obesity; however, the nature and extent of this relation has not been clearly established. The aim of this study is to conduct a systematic review and meta‐analysis of the relationship between red and processed meat intake and obesity. We searched multiple electronic databases for observational studies on the relationship between red and processed meat intake and obesity published until July 2013. Odds ratios (ORs) and means for obesity‐related indices and for variables that may contribute to heterogeneity were calculated. A systematic review and a meta‐analysis were conducted with 21 and 18 studies, respectively (n = 1,135,661). The meta‐analysis (n = 113,477) showed that consumption of higher quantities of red and processed meats was a risk factor for obesity (OR: 1.37; 95% CI: 1.14–1.64). Pooled mean body mass index (BMI) and waist circumference (WC) trends showed that in comparison to those in the lowest ntile, subjects in the highest ntile of red and processed meat consumption had higher BMI (mean difference: 1.37; 95% CI: 0.90–1.84 for red meat; mean difference: 1.32; 95% CI: 0.64–2.00 for processed meat) and WC (mean difference: 2.79; 95% CI: 1.86–3.70 for red meat; mean difference: 2.77; 95% CI: 1.87–2.66 for processed meat). The current analysis revealed that red and processed meat intake is directly associated with risk of obesity, and higher BMI and WC. However, the heterogeneity among studies is significant. These findings suggest a decrease in red and processed meat intake.

Reeves, M. M.; Terranova, C. O.; Eakin, E. G.; Demark‐Wahnefried, W.

doi: 10.1111/obr.12190pmid: 24891269

Obesity has been associated with poor health outcomes in breast cancer survivors. Thus, weight loss is recommended for overweight and obese survivors. We systematically reviewed studies (published up to July 2013) that evaluated behaviourally based, weight loss interventions in women with breast cancer exclusively. Completed randomized trials, single‐arm trials and ongoing trials were reviewed. Within‐group and between‐group differences for weight loss were extracted, as was data on secondary outcomes, i.e. clinical biomarkers, patient‐reported outcomes, adverse events. Ten completed randomized trials, four single‐arm trials and five ongoing trials were identified. Statistically significant within‐group weight loss was observed over periods of 2 to 18 months in 13 of the 14 trials, with six randomized and two single‐arm trials observing mean weight loss ≥5%. Clinical biomarkers, psychosocial and patient‐reported outcomes were measured in a small number of studies. No serious adverse events were reported. Only two trials assessed maintenance of intervention effects after the end‐of‐intervention and none reported on cost‐effectiveness. The studies included in this review suggest that weight loss is feasible to achieve and is safe in women following treatment for breast cancer. Future studies should assess (and be powered for) a range of biomarker and patient‐reported outcomes, and be designed to inform translation into practice.

Hemmingsson, E.

doi: 10.1111/obr.12197pmid: 24931366

The lack of significant treatment and prevention progress highlights the need for a more expanded strategy. Given the robust association between socioeconomic factors and obesity, combined with new insights into how socioeconomic disadvantage affects both behaviour and biology, a new causal model is proposed. The model posits that psychological and emotional distress is a fundamental link between socioeconomic disadvantage and weight gain. At particular risk are children growing up in a disharmonious family environment, mainly caused by parental socioeconomic disadvantage, where they are exposed to parental frustrations, relationship discord, a lack of support and cohesion, negative belief systems, unmet emotional needs and general insecurity. Without adequate resilience, such experiences increase the risk of psychological and emotional distress, including low self‐esteem and self‐worth, negative emotions, negative self‐belief, powerlessness, depression, anxiety, insecurity and a heightened sensitivity to stress. These inner disturbances eventually cause a psycho‐emotional overload, triggering a cascade of weight gain‐inducing effects including maladaptive coping strategies such as eating to suppress negative emotions, chronic stress, appetite up‐regulation, low‐grade inflammation and possibly reduced basal metabolism. Over time, this causes obesity, circular causality and further weight gain. Tackling these proposed root causes of weight gain could potentially improve both treatment and prevention outcomes.