TM. Wolever, K. Miller and T. Banh (2025). Equivalent Glycemic Load and Insulinemic Responses Elicited by Low-Carbohydrate Foods: A Randomized Trial in Healthy Adults. Current developments in nutrition, 9(12), 107594. https://doi.org/10.1016/j.cdnut.2025.107594

PubMed 41439105

[Abstract]
BACKGROUND: The information on the Nutrition Facts Label may overestimate the available-carbohydrate (avCHO) content and glycemic impact of some low-carbohydrate foods containing novel carbohydrates.

OBJECTIVES: The primary objective was to test the hypothesis that the glycemic impact of low-carbohydrate foods, quantified as equivalent-glycemic-load (EGL), measures their avCHO content accurately and precisely (within ±1g). The secondary objectives were to measure the glycemic and insulinemic responses elicited by 7 low-carbohydrate foods.

METHODS: Healthy overnight-fasted adults (n = 25) consumed 20.8 g or 5.2 g avCHO from white bread (WB20.8, WB5.2, respectively), or 1 of 7 test-products in random order; each subject tested WB20.8 twice. Plasma-glucose responses were measured in all subjects with serum-insulin measured in 10. For each subject, 20.8 × T/W was calculated [T = incremental area under the glucose curve (iAUC) after the test-food, W = mean iAUC after WB20.8]; the mean of the resulting values (excluding outliers) was the test-food EGL.

RESULTS: The expected EGL of WB5.2 was 5.2 g and the measured value was 4.0 g (95% margin of error = 0.6 g). On the basis of the food-label, the test-products contained 3-12 g avCHO (total-carbohydrate minus dietary-fiber). However, because 5 of the test-products contained allulose, which is not included in dietary-fiber and not quantified on the food-label, their content of netCHO (avCHO minus allulose) ranged from 3 to 6 g; even so, their EGL values varied from just 0.6 to 2.4 g. The mean insulin responses elicited by the test-products were positively related to their protein content, but none differed significantly from that elicited by WB5.2.

CONCLUSIONS: The results support the hypothesis that the EGL measure is accurate and precise to within ∼±1 g. The EGLs of the 7 test-products were 20%-90% less than expected from their food-labels. The test-products elicited small insulin responses that were positively related to their protein content.This trial was registered at clinicaltrials.gov as NCT05870891 (https://clinicaltrials.gov/study/NCT05870891).