(P15-005-24) The Effect of Walnut Butter Product and Nutrition Education on Body Composition and Endothelial Health in Overweight Adolescents

Objectives: The purpose of this study was to examine if the combination of regular consumption of a walnut-based spread and nutrition education in comparison to nutrition education alone would improve fat to muscle mass ratio and have beneficial effects on cardiovascular health by improving endothelial function in adolescents with overweight or obesity.

Methods: A total of 55 adolescents between the ages of 13 and 17 years who met the study criteria were recruited and consented to participate in this study. Participants were randomized into either the control (n=31) or treatment (n=24) group. Participants in the treatment group consumed 2.5 tablespoons (45 grams) of walnut spread product for 120 days. All participants received nutrition education at baseline and midpoint visits. Dual energy x-ray absorptiometry (DEXA) was performed on all participants at baseline and final visit to evaluate body composition. Endothelial vasodilator function was assessed using EndoPAT at baseline and final visits, for all participants.

Results: These findings are preliminary and the intervention is ongoing. After the four-week intervention, both groups showed increased lean mass from baseline to final visit. The control group experienced a decrease in fat mass percent, fat mass, and visceral adipose tissue fat in comparison to the treatment group. Reactive Hyperemia Index (RHI) results indicate that the control group also had some improvement in endothelial function compared to the treatment group.

Conclusions: Several factors may have influenced these unexpected results. Although the study is still ongoing, there have been more participants who have completed the study that were assigned to the control group. It is possible that the participants in the control group had greater adherence to individualized nutrition and fitness goals set during nutrition education. Compliance with walnut butter consumption in the treatment group was also subject to self-reporting. Inflammatory markers, which will be evaluated when all participants have completed all visits and the study concludes, may show more beneficial impact of the walnut spread in the diet. A longer study duration, and stricter monitoring on walnut butter consumption, may more favorably influence body composition and RHI values in this population.

Funding Sources: California Walnut Commission