(PO19-12-22) The Effect of a Mediterranean Diet With or Without Calorie Restriction on Cognition, Lifestyle, and Metabolic Health of Obese, Predominately Non-Hispanic Black Older Adults

Objectives: To compare the effect of a Mediterranean Diet with (Med-WL) or without caloric restriction (Med-A) for intentional weight loss (IWL) versus a typical diet control (TDC) on cognition, lifestyle and cardiometabolic health.

Methods: A randomized clinical trial of obese, predominately non-Hispanic black, older adults was conducted between June 2017 and December 2020 at community sites in Chicago, Illinois. Participants (n=185) were randomized (2:2:1) to 1 of 3 groups for 8-months: Med-WL, Med-A, or TDC. The primary outcome was change from baseline to post-intervention in three cognitive composite scores: attention, information & processing; executive function; and learning, memory & recognition. Secondary outcomes included changes in MedDiet adherence, physical activity, body weight, total and regional body fat, blood pressure, fasting blood lipids, glucose, insulin and C-reactive protein (CRP).

Results: Participants were 85.9% female with a mean (SD) age of 66.3 (6.1) years, and retention was similar across arms (85.3% Med-WL, 87.7% Med-A, 94.6% TDC, p = 0.36). The MedDiet interventions did not affect cognitive composite scores. MedDiet adherence improved significantly more in Med-WL (adjusted mean [95% CI] score change, +6.3 [4.9 to 7.6] points) and Med-A (+4.8 [3.4 to 6.2] points) relative to TDC (+0.6 [‑1.3 to 2.4] points, p< 0.05). Weight loss was significantly greater in Med-WL (adjusted mean [95% CI]: ‑4.6 [(‑5.6 to ‑3.5] kg) than in Med-A (‑2.6 [‑3.7 to ‑1.5] kg, p< 0.05) and TDC (‑0.6 [‑2.1 to 0.8] kg, p< 0.05). Reduction in central body fat was significantly greater in the MedDiet arms (adjusted mean change [95% CI], Med-WL: ‑147 [‑235 to ‑59] gm; Med-A: ‑162 [‑248 to ‑76] gm) than in TDC (+91 [‑18 to 200] gm, p< 0.05). For cardiometabolic health, only fasting insulin changed significantly in Med-WL (adjusted mean change [95% CI]: ‑2.2 [­‑3.2 to ‑1.2] uIU/mL) relative to Med-A (‑0.6 [‑1.6 to 0.4] uIU/mL, p< 0.05) and TDC (‑0.5 [‑1.8 to 0.8] uIU/mL, p< 0.05).

Conclusions: An 8-month MedDiet lifestyle intervention with or without caloric restriction for IWL did not produce superior effects on cognitive function compared to a TDC, but it did produce significant effects on diet quality, total body weight and central body fat.

Funding Sources: National Heart, Lung And Blood Institute; National Cancer Institute; National Institute On Minority Health And Health Disparities