Objective

We previously identified distinct muscle and liver insulin resistance (IR) metabotypes in middle-aged and older adults. The PERSON study showed that a low-fat, high-protein, high-fiber diet benefits the muscle IR group, while a high-monounsaturated fatty acid diet benefits the liver IR group. We also developed the MetaboHealth score, reflecting risks of mortality, frailty, and cognitive decline. This study aimed to examine whether MetaboHealth interacts with IR metabotypes to influence (i) cardiometabolic health and (ii) body composition outcomes in the PERSON study, informing precision nutrition strategies.

Methods

In total, 242 adults aged 40-75 with IR were randomized to follow an isocaloric low-fat, high-protein, high-fiber or high-monounsaturated fatty acid diet for 12 weeks. Of these, 184 with complete data were grouped into MetaboHealth tertiles (higher = poorer health). Outcomes included a 7-point oral glucose tolerance test and DXA-based body composition. Linear mixed models assessed four-way interactions.

Results

No interaction was observed for cardiometabolic outcomes. Significant interactions were found for android, gynoid, total fat percentage, and fat mass index. In the healthiest tertile, matched diets led to greater fat loss. In the poorest tertile, both diets were similarly effective. MetaboHealth remained unchanged.

Conclusions

Combining metabotype with MetaboHealth may enhance personalized dietary strategies for fat loss in insulin-resistant adults.

© 2026 The Author(s). Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society.