Aging and Chronic Disease
To determine the effect of beef consumption as a part of the DASH diet on measures of anthropometric and muscle health in adults 65 and older.
Methods : Twenty-eight older adults were randomly assigned to consume either 3 oz. (n=14) or 6 oz. (n=14) of fresh, lean beef as a part of the DASH diet for 12-wks. Anthropometrics and muscle strength were measured at wks 0, 3, 6, 9, and 12 throughout the study. The seven-day cyclical DASH menu contained fresh lean beef. Other red meats, poultry and seafood were excluded. Breakfast, lunch and dinner were provided every day for 12-wks and all food items were purchased, prepared and weighed to the nearest gram by the research staff. The portions of beef were evenly distributed throughout each meal provided every day.
Results : Changes in body composition and muscle strength were observed during the 12-wk study regardless of beef intake. Significant time effects were detected for: body weight (P< 0.001); BMI (P< 0.001); waist circumference (P< 0.001); hip circumference (P< 0.001); %body fat (P< 0.001); absolute fat mass (P< 0.001); systolic blood pressure (P< 0.001); and diastolic blood pressure (P< 0.001) such that a decrease was observed over the 12-wk intervention. Time effects were detected for sit-to-stand (P< 0.001) such that an increase was observed over the 12-wk intervention. Body weight decreased (P = 0.001) by 6.7% from baseline (90kg) to study-end (84kg); BMI decreased (P< 0.001) from baseline (31.2) to study-end (29.4); waist circumference decreased (P< 0.001) from baseline (98.1cm) to study-end (94.4cm); %body fat decreased (P< 0.001) from baseline (36.1%) to study-end (34.2%); absolute fat mass decreased (P< 0.001) from baseline (33.1kg) to study-end (29.4kg); systolic blood pressure decreased (P< 0.001) from baseline (134mmHg) to study-end (118mmHg). Handgrip strength and REE were well-maintained (P >0.05) despite the weight loss. Of the obese participants, 33% were overweight and 29% of the overweight participants were normal weight by study-end.
Conclusions : The results of this highly-controlled dietary intervention study indicate that daily consumption of high-quality protein as a part of the DASH diet positively influences body composition and muscle strength in older adults. These results also suggest that beef can be included in healthy dietary patterns.
Funding Sources : South Dakota Beef Industry Council