title: A systematic review and meta-analysis on the effects of exercise training versus hypocaloric diet: distinct effects on body weight and visceral adipose tissue.
abstract: Exercise training ('exercise') and hypocaloric diet ('diet') are frequently prescribed for weight loss in obesity. Whilst body weight changes are commonly used to evaluate lifestyle interventions, visceral adiposity (VAT) is a more relevant and stronger predictor for morbidity and mortality. A meta-analysis was performed to assess the effects of exercise or diet on VAT (quantified by radiographic imaging). Relevant databases were searched through May 2014. One hundred seventeen studies (n = 4,815) were included. We found that both exercise and diet cause VAT loss (P < 0.0001). When comparing diet versus training, diet caused a larger weight loss (P = 0.04). In contrast, a trend was observed towards a larger VAT decrease in exercise (P = 0.08). Changes in weight and VAT showed a strong correlation after diet (R(2)  = 0.737, P < 0.001), and a modest correlation after exercise (R(2)  = 0.451, P < 0.001). In the absence of weight loss, exercise is related to 6.1% decrease in VAT, whilst diet showed virtually no change (1.1%). In conclusion, both exercise and diet reduce VAT. Despite a larger effect of diet on total body weight loss, exercise tends to have superior effects in reducing VAT. Finally, total body weight loss does not necessarily reflect changes in VAT and may represent a poor marker when evaluating benefits of lifestyle-interventions.
authors.affiliation: Department of Physiology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: R J H M
authors.initials: RJ
authors.lastname: Verheggen
authors.affiliation: Department of Physiology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: M F H
authors.initials: MF
authors.lastname: Maessen
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.|School of Sport Science, Exercise and Health, the University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: D J
authors.initials: DJ
authors.lastname: Green
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: A R M M
authors.initials: AR
authors.lastname: Hermus
authors.affiliation: Department of Physiology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: M T E
authors.initials: MT
authors.lastname: Hopman
authors.affiliation: Department of Physiology, Radboud University Medical Centre, Nijmegen, The Netherlands.|Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.
authors.forename: D H T
authors.initials: DH
authors.lastname: Thijssen
mesh_terms: D050154:Adiposity; D001835:Body Weight; D031204:Caloric Restriction; D004038:Diet, Reducing; D015444:Exercise; D006801:Humans; D009765:Obesity / Q000628:therapy*; D050177:Overweight / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic
keywords: Exercise training; hypocaloric diet; obesity; visceral adipose tissue