title: Effect of diet-induced weight loss on muscle strength in adults with overweight or obesity - a systematic review and meta-analysis of clinical trials.
abstract: We conducted a systematic review and meta-analysis to identify how diet-induced weight loss in adults with overweight or obesity impacts on muscle strength. Twenty-seven publications, including 33 interventions, most of which were 8-24 weeks in duration, were included. Meta-analysis of seven interventions measuring knee extensor strength by isokinetic dynamometry in 108 participants found a significant decrease following diet-induced weight loss (-9.0 [95% confidence interval: -13.8, -4.1] N/m, P < 0.001), representing a 7.5% decrease from baseline values. Meta-analysis of handgrip strength from 10 interventions in 231 participants showed a non-significant decrease (-1.7 [-3.6, 0.1] kg, P = 0.070), with significant heterogeneity (I(2)  = 83.9%, P < 0.001). This heterogeneity may have been due to diet type, because there was a significant decrease in handgrip strength in seven interventions in 169 participants involving moderate energy restriction (-2.4 [-4.8, -0.0] kg, P = 0.046), representing a 4.6% decrease from baseline values, but not in three interventions in 62 participants involving very-low-energy diet (-0.4 [-2.0, 1.2] kg, P = 0.610). Because of variability in methodology and muscles tested, no other data could be meta-analyzed, and qualitative assessment of the remaining interventions revealed mixed results. Despite varying methodologies, diets and small sample sizes, these findings suggest a potential adverse effect of diet-induced weight loss on muscle strength. While these findings should not act as a deterrent against weight loss, due to the known health benefits of losing excess weight, they call for strategies to combat strength loss - such as weight training and other exercises - during diet-induced weight loss. © 2016 World Obesity.
authors.affiliation: The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Zibellini
authors.affiliation: The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia.
authors.forename: R V
authors.initials: RV
authors.lastname: Seimon
authors.affiliation: The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia.
authors.forename: C M Y
authors.initials: CM
authors.lastname: Lee
authors.affiliation: The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia.
authors.forename: A A
authors.initials: AA
authors.lastname: Gibson
authors.affiliation: The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia.
authors.forename: M S H
authors.initials: MS
authors.lastname: Hsu
authors.affiliation: The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Sainsbury
mesh_terms: D050154:Adiposity; D031204:Caloric Restriction; D004038:Diet, Reducing; D018737:Hand Strength; D006801:Humans; D009765:Obesity / Q000178:diet therapy*; D050177:Overweight / Q000178:diet therapy*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D015431:Weight Loss
keywords: diet (reducing); energy restriction; muscle dynamometry; obesity; very-low-energy diet; weight loss