What is really causing the obesity epidemic? A review of reviews in children and adults.

Obesity prevention is a public health priority and intervention strategies have focused primarily on healthy eating and physical activity in children and adults. To date, no review has systematically compiled and synthesised the scientific evidence from published review articles to determine whether there is clear consensus on the causes of obesity. A systematic review of the literature was conducted searching PubMed/Medline for narrative and systematic review articles published between January 1990 and October 2014 that examined the causes of obesity. In total, 12 of 65 articles met the inclusion criteria; 7 reviews focused on adults (1 systematic, 6 narrative) and 5 reviews on children (2 systematic, 3 narrative). The most popular cause of obesity identified in reviews of adult studies was "combined physical activity and diet" (3 of 7 studies), whereas the most popular cause specified in reviews of child studies was deemed "inconclusive" (2 of 5 studies). While a number of reviews have examined the causes of obesity, the methodology and conclusions varied widely, and few were conducted systematically. Currently, no consensus exists across published literature reviews regarding the primary cause of the obesity epidemic, and more research, particularly prospective studies using state-of-the-art measures, is warranted.