Preserving Healthy Muscle during Weight Loss.

Weight loss is the cornerstone of therapy for people with obesity because it can ameliorate or completely resolve the metabolic risk factors for diabetes, coronary artery disease, and obesity-associated cancers. The potential health benefits of diet-induced weight loss are thought to be compromised by the weight-loss-associated loss of lean body mass, which could increase the risk of sarcopenia (low muscle mass and impaired muscle function). The objective of this review is to provide an overview of what is known about weight-loss-induced muscle loss and its implications for overall physical function (e.g., ability to lift items, walk, and climb stairs). The currently available data in the literature show the following: 1) compared with persons with normal weight, those with obesity have more muscle mass but poor muscle quality; 2) diet-induced weight loss reduces muscle mass without adversely affecting muscle strength; 3) weight loss improves global physical function, most likely because of reduced fat mass; 4) high protein intake helps preserve lean body and muscle mass during weight loss but does not improve muscle strength and could have adverse effects on metabolic function; 5) both endurance- and resistance-type exercise help preserve muscle mass during weight loss, and resistance-type exercise also improves muscle strength. We therefore conclude that weight-loss therapy, including a hypocaloric diet with adequate (but not excessive) protein intake and increased physical activity (particularly resistance-type exercise), should be promoted to maintain muscle mass and improve muscle strength and physical function in persons with obesity.

Cava E ，Yeat NC ，Mittendorfer B 《-》

Sarcopenic obesity in the elderly and strategies for weight management.

Sarcopenia is a multifactorial age-related condition associated with a sedentary lifestyle and protein intakes during weight loss that are inadequate to maintain muscle mass. Sarcopenic obesity in the elderly is associated with a loss of independence and metabolic complications and represents a major public health challenge in individuals over the age of 65 years. It is likely that age-related losses of muscle mass and coincident increases in fat mass could be reduced through regular resistance exercise combined with adequate protein intake to maintain muscle mass. It has been established that increased protein intake will maintain muscle mass during calorie-restricted diets to a greater extent than usual protein intake. Other strategies, including the use of high-protein meal replacements or supplementation with specific ergogenic or branched-chain amino acids, may be beneficial.

Li Z ，Heber D 《-》

Exercise attenuates the weight-loss-induced reduction in muscle mass in frail obese older adults.

Frimel TN ，Sinacore DR ，Villareal DT 《-》

Dietary protein intake in sarcopenic obese older women.

Muscariello E ，Nasti G ，Siervo M ，Di Maro M ，Lapi D ，D'Addio G ，Colantuoni A ... -  《Clinical Interventions in Aging》

Weight Loss Strategies and the Risk of Skeletal Muscle Mass Loss.

McCarthy D ，Berg A 《Nutrients》