Overview

• Fifty-five participants without type 2 diabetes wore continuous glucose monitors and underwent metabolic testing for insulin resistance and beta cell function.
• Post-meal glucose spikes from potatoes and pasta varied with specific metabolic dysfunctions, and the potato-to-grape response ratio emerged as a potential insulin resistance biomarker.
• Rice and grapes triggered elevated blood sugar in nearly all participants, while resistant-starch foods elicited diverse glycemic patterns linked to elevated triglycerides and fatty acids in insulin-resistant subjects.
• Preloading meals with fiber or protein blunted postprandial glucose peaks only in metabolically healthy individuals, with little effect in those showing insulin resistance or beta cell impairment.
• Researchers warn that one-size-fits-all dietary advice may fall short and advocate for personalized carbohydrate recommendations to improve prediabetes and diabetes prevention.