Macro partitioning
In adults with prediabetes, a high-carbohydrate (50% energy) diet reduces fasting glucose more effectively than a reduced-carbohydrate (35% energy) diet when both are calorie-restricted, despite similar weight loss.
If you have prediabetes, you do not need to severely restrict carbohydrates to improve your fasting blood sugar. A diet providing about 50% of your calories from carbohydrates, focusing on high-fiber foods like whole grains and vegetables, can lower fasting glucose better than a lower-carb diet, provided you are in a calorie deficit. Focus on the quality of carbs (fiber) rather than just cutting them out.
Although the HC group showed greater improvements in fasting glucose, (−8.0 mg/dL; 95% CI: −15.29, −0.67 mg/dL), changes in A1c, fasting insulin, and quantitative insulin sensitivity check index were not different between HC and RC.
Why this rating
Randomized controlled trial with clear statistical significance for the specific outcome, though not powered for secondary interactions.
Source
Adaptive dietary and exercise strategies for weight loss in Adults with Prediabetes Trial (ADAPT): a sequential multiple assignment randomized trial
Katie M. Ellison et al. · American Journal of Clinical Nutrition · 2025
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