(P01-24-26) Functional Performance in Response to a Dietary Guidelines for Americans Diet in Older Adults: Results From a Randomized-Controlled Crossover Diet Intervention

Objectives: To compare changes in functional capacity in response to a Dietary Guidelines for Americans-style (DGA) diet containing beef and vegetable protein.

Methods: This was a 16-wk randomized-controlled, crossover trial investigating the impact of a DGA-style diet with 7-oz of beef and 7-oz of vegetable protein (i.e. Impossible Beef^TM and Beyond Beef^TM) on functional performance in older adults. Participants were randomized to beef-DGA or veg-protein-DGA for 8 wks. After 2-wks, participants who consumed beef-DGA crossed over to veg-protein-DGA for 8 weeks and participants who consumed veg-protein-DGA crossed over to beef-DGA for 8 wks. 6-minute walking (6MW), sit-to-stand (STS), and hand grip (HG) tests were performed 6 times throughout the 16-week intervention.

Results: 24 participants aged 67 years completed the intervention. In response, laps (p=0.012) and total distance was significantly higher with 6MW at wk 4 with beef-DGA (p=0.041), however this was not maintained at wk 8 (laps, p=0.837; total distance, p=0.737). A significant treatment × wk interaction was observed (p = 0.020) in heart rate recovery in response to 6MW. At wk 8, heart rate recovery was greater in response to veg-protein-DGA compared to beef-DGA (p=0.004). Heart rate recovery declined from baseline-to-wk 8 with beef-DGA (p=0.016). For STS, a sequence effect was observed (p = 0.026), indicating differences according to treatment order and potential carryover effects inherent in the crossover design. When examining treatments within the first intervention period, STS was greater at wk 8 in response to veg-protein-DGA compared to beef-DGA (p=0.028). Within the veg-protein-DGA diet, STS increased significantly from baseline-to-wk 8 (p=0.028). HG was lower in response to beef-DGA compared to veg-protein-DGA at wk 4 (p=0.016). This difference, however, was not maintained at wk 8 (p = 0.250).

Conclusions: These data suggest that vegetable protein as a part of a DGA-style diet may result in better heart rate recovery and lower body strength. Albeit we previously reported better maintenance of lean mass and resting metabolic rate with beef intake, thus both protein types may be ideal for older adults.

Funding Sources: Beef Checkoff