(P23-006-23) Impact of a Higher (Egg) Protein Weight Loss Intervention on Physical Function and Glucose Handling in Older Adults with Obesity and Prediabetes

Objectives: Treatment for obesity-associated disease in older adults seeks to reduce body fat without adverse effects on lean mass and physical function. While higher protein intake may protect muscle, its impact on glucose handling is not fully known, especially in those with prediabetes. This randomized controlled trial assessed the impact of a higher protein (egg) obesity-reduction diet on weight reduction, physical function, and glucose handling in older adults with prediabetes (sampled to include equal numbers of Black and White participants).

Methods: Older (≥60 yrs) adults with obesity (BMI≥30 kg/m²) and prediabetes were randomized to either a higher Protein hypocaloric diet (≥30g high quality protein/meal; primarily from eggs; 1.2 g/kg/d) or an RDA-level (0.8 g/kg/d protein) Control hypocaloric diet. Groups met weekly for weight measurement and support during the 4-month trial; egg white powder for smoothies and boiled eggs were provided to the Protein participants. Measurements at baseline and 4 months included Short Physical Performance Battery, 6-minute walk, 8 foot up and go, and handgrip strength; blood levels of glucose and hemoglobin A1_C were also determined.

Results: Of 74 participants randomized, 58 (n=27 Control, n=31 Protein) completed the 4-month trial. The completers were age 68.4±5.1 years, 84.5% female, and 52% Black. Both groups reduced (p < 0.001) body weight: losses were 5.5±3.7 and 5.7±3.7 % body weight in Control and Protein, respectively, with no group difference. Results for the 8 foot up and go showed improvement (no group difference). Black race was associated with lower physical performance for some tests but there was no effect of race on intervention responses. Glucose handling improved in both groups; there was a significant overall decrease in fasting blood glucose levels (p < 0.05), with a mean decrease of 3.5 mg/dL. Hemoglobin A1_C levels also decreased (p < 0.001) between baseline and endpoint.

Conclusions: Study findings support the use of eggs in a high-protein dietary intervention to reduce obesity and improve glucose handling in Black and White older adults with prediabetes, relative to an RDA-protein-level Control weight loss regimen. We found egg protein useful for increasing protein intake during obesity reduction in terms of both feasibility and benefit.

Funding Sources: Egg Nutrition Center and National Institute on Aging