How to promote weight loss in obese older adults while avoiding loss of muscle mass – this was the aim of research carried out recently by scientists from the Nestlé Research Center (NRC).
Obesity is a growing problem among the older population. Reducing calorie intake is one solution, but this approach also leads to loss of muscle mass. This in turn can hinder the rate of further weight loss, and is associated with reduced strength and functional capacity, and increased risk of disability and mortality.
Twenty obese men around the age of 65 were recruited for a four-week study. This research demonstrates that a reduced-calorie diet does indeed reduce the rate of muscle protein synthesis, confirming that weight loss can also lead to muscle loss. However, the study also demonstrates, for the first time, that a balanced protein intake throughout the day increases muscle protein synthesis when compared to a skewed protein distribution. This beneficial effect is further enhanced when combined with resistance training.
This research remains to be confirmed in long-term studies. The daily optimal amount of protein required to maximally stimulate muscle protein synthesis in older adults also remains to be established. Nevertheless, these preliminary findings provide compelling conclusions which could be used in the design of guidelines for older adults, a population at-risk of muscle mass loss.
Murphy C.H, Churchward-Venne T.A, Mitchell C.J, Kolar N.M., Kassis A., Karagounis L.G., Burke L.M., Hawley J.A. and Phillips S.M., Hypoenergetic diet-induced reductions in myofibrillar protein synthesis are restored with resistance training and balanced daily protein ingestion in older men. American Journal of Physiology 2015.