In October 2019 researchers from the USA published the results of their study to assess the association between protein intake, strength, and lean body mass in under-active vegetarians. A total of 37 vegetarians were divided into two groups with half being given 18 g/day mung bean protein supplement for a period of 8 weeks, and the remaining individuals acting as a control group. Handgrip and knee flexor and extensor strength were measured at the start of the study and again at week eight. It was noted that the lean body mass at the start of the study was significantly related to the amount of protein consumed daily, and also correlated to grip strength and lower body strength. Twenty-five vegetarians completed the study, 11 in the protein supplementation group and 14 in the control group. Results showed that at week 8, the lean body mass did not differ significantly between the two groups. However, the average percent change for grip, flexor, and extensor strength had increased in the group taking the supplementary vegetarian protein but not in the control group. The researchers concluded that there is a strong association between dietary protein, lean body mass and strength in vegetarians and that supplementary vegetarian protein appears to increase strength in the absence of exercise.
Bartholomae E et al. Mung Bean Protein Supplement Improves Muscular Strength in Healthy, Underactive Vegetarian Adults. Nutrients. 2019 Oct 11;11(10). pii: E2423.