Would any of you guys like to comment on the following article. Any criticisms of it?
Amer J of Clin Nutrition, Vol. 76, No. 3, 511-517, Sept 2002
Effect of protein source on resistive-training-induced changes in body composition and muscle size in older men
Mark D Haub, Amanda M Wells, Mark A Tarnopolsky & Wayne W Campbell
Background: Aging is associated with reductions in muscle mass and strength, but nutrition and exercise interventions can delay this progression and enhance the quality of life.
Objective: We examined whether the predominant source of protein consumed by older men influenced measures of muscle size and strength, body composition, resting energy expenditure, and skeletal muscle creatine concentrations in response to 12 wk of resistive training.
Design: After consuming a lactoovovegetarian (LOV) diet for 2 wk, 21 men aged 65 ?? 5 y were randomly assigned to either consume a beef-containing (BC) diet (n = 10) or to continue the LOV diet (n = 11) throughout resistive training. The BC diet included 0.6 g protein per kg per day from beef and the LOV diet included 0.6 g protein per kg per day from textured vegetable protein (soy) sources. The remaining protein in the diets came from self-selected LOV sources.
Results: The mean total protein intake for both groups ranged from 1.03 to 1.17 g ??per kg per day during the intervention. Men in both groups had improvements (14???38%) in maximal dynamic strength of all the muscle groups trained, with no significant difference between groups. With resistive training, cross-sectional muscle area of the vastus lateralis increased in both groups (4.2 ?? 3.0% and 6.0 ?? 2.6% for the LOV and BC groups, respectively) with no significant difference between groups. Body composition, resting energy expenditure, and concentrations of muscle creatine, phosphocreatine, and total creatine did not differ significantly between groups or change over time.
These data suggest that increases in muscle strength and size were not influenced by the predominant source of protein consumed by older men with adequate total protein intake.