Muscle maintenance in older adults with obesity during weight loss

Weight loss is in obese elderly a risk factor for muscle wasting and sarcopenia. This study evaluates the effect of a high whey protein supplement with added leucine and vitamin D on muscle mass preservation during a weight loss period of 13 weeks with resistance training in older adults with obesity.

Eighty obese elderly were included in this randomized controlled trial. All participants received a low-calorie diet for 13 weeks (-600 kcal) and a resistance training program 3 x/week. Participants in the intervention group received 10 x/week a high whey protein supplement with added leucine and vitamin D (150 kcal, 21 g protein). Participants in the control group were given a isocalorisch control supplement. The primary outcome was change in muscle mass in arms and legs (DXA). Secondary outcomes were handgrip strength, body composition and physical functioning.

The average age at baseline was (± SD) 63±6 years and the BMI 33±4. During the weight loss program was the protein intake in the intervention group 1.11±0.28 vs. 0.85±0.24 g/kg in the control group. Both the intervention and control group lost weight (-3.4±3.6 vs.-2.8±2.8 kg) and fat mass (-3.2±3.1 vs.-2.5±2.4 kg), without differences between the groups. The change in muscle mass in the arms and legs was different in the two groups (+ 0.4±1.2 vs.-0.5±2.1 kg, p = 0.03). Muscle strength and muscle function improved over time, with no differences between the groups.

A high whey protein supplement with added leucine and vitamin D compared to a control supplement preserves muscle mass during a weight loss period with resistance training in obese elderly. Based on the literature, there seems to be sufficient rationale for recommending a minimum of 1.0-1.2 g/kg high quality protein and possibly even higher than 1.2 g/kg in combination with a (resistance) training program.