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Obesity (Poster Session)

(P20-072-25) Impact of a 12-Week Hypocaloric Weight Loss Diet With Mixed Tree Nuts vs. Pretzels on Trimethylamine-N-Oxide (TMAO) Levels in Overweight Adults

Sunday, June 1, 2025
12:45 PM - 1:45 PM ET
Location: Poster Board D-59

    Presenting Author(s)

  • JY

    Jieping Yang, PhD

    Associate project scientist
    University of California, Los Angeles
    Los Angeles, California, United States

    • Co-Author(s)

  • OL

    Onkei Lei

    University of Macau, China (People's Republic)

  • Zhaoping Li, PhD, MD (she/her/hers)

    Professor
    University of California, Los Angeles
    Los Angeles, California, United States

Disclosure(s):
Jieping Yang, PhD: No relevant financial relationship(s) with ineligible companies to disclose.


Objectives: Trimethylamine N-oxide (TMAO), a gut microbiome metabolite linked to cardiovascular health, can be influenced by dietary factors like choline intake and diet quality. This study compared the effects of mixed tree nuts (MTNs) and pretzels, as part of a 12-week hypocaloric weight loss diet, on TMAO levels and identified dietary predictors.

Methods: Plasma samples from 95 overweight individuals consuming either 1.5 oz. of mixed tree nuts (MTNs, n=56)) or isocaloric pretzels (n=39) daily for 12 weeks were analyzed. Nutritional data were collected at baseline and week 12 with ASA24 dietary recall. TMAO levels were determined and analyzed using linear mixed-effects models, adjusting for covariates. Paired t-tests compared baseline and week 12 TMAO and weight. Multiple linear regression identified baseline predictors of TMAO.

Results: Baseline demographics, anthropometric measures, HEI scores, and dietary choline intake were similar between the MTNs and pretzels groups. A significant positive association was observed between baseline dietary choline intake and plasma TMAO levels (p = 0.012). The 12-week hypocaloric diet led to significant weight reduction with no difference between groups (MTN: -3.47 lbs vs. Pretzels -4.25 lbs; p = 0.18). Plasma TMAO levels decreased significantly in both groups with no difference between them (MTNs: -0.34 vs. Pretzels: -0.37; p = 0.43). HEI scores and dietary choline intake remained unchanged, with no significant time-intervention interaction. Participants with low baseline HEI scores (≤53.72) had a more pronounced reduction in TMAO levels in the MTN group compared to the pretzels group (MTN: -0.54 vs. Pretzel: -0.23; p = 0.045) over 12 weeks, despite similar weight loss. This difference was not observed in participants with higher HEI scores.

Conclusions: The 12-week hypocaloric diet reduced body weight and plasma TMAO levels similarly in both MTNs and Pretzels groups. Participants with lower dietary quality saw a greater reduction in TMAO levels in the MTN group, suggesting MTNs may better modulate TMAO levels, especially for those with poorer baseline diets.

Funding Sources: Center for Human Nutrition and International Tree Nut Council Nutrition Research and Education Foundation.