The glycemic index (GI) categorizes carbohydrates as “fast” (high-GI) or “slow” (low-GI) based on their impact on blood sugar levels. This review assessed whether dietary GI influences body weight and obesity risk using data from observational studies and meta-analyses of randomized controlled trials (RCTs).
Key Points:
- Data from 43 cohorts involving nearly 2 million adults showed no consistent relationship between dietary GI and BMI.
- In 70% of cohort studies, BMI was either similar or higher in groups consuming lower-GI diets.
- Meta-analyses of RCTs revealed no significant advantage of low-GI diets for weight loss, except in adults with normal glucose tolerance when dietary GI differences exceeded 20 units.
GI appears to have minimal impact on body weight or diet-induced weight loss. Its role in obesity prevention is limited compared to other factors of carbohydrate quality and overall diet.
