Background and objectives: Our aim was to evaluate the acute effect of switching low-carbohydrate diet (LCD) to high-carbohydrate diet (HCD) on glycemic parameters in healthy women.
Methods and study design: Twen-ty-two women (age 21.7±4.0 years; HbA1c 5.3±0.3 %, mean±SD) wore flash glucose monitoring system and consumed test meals for 3 days from Day 4 to 6. Participants consumed identical HCD meals except LCD dinner on Day 5. The energy ratio of carbohydrate, fat, and protein were 64%, 21%, and 15% for HCD and 47%, 35%, and 18% for Day 5 with LCD dinner (19%, 59%, and 22%).
Results: The incremental glucose peak (IGP, both p<0.001) and incremental area under the curve for glucose (IAUC, both p<0.001) 3h of LCD dinner were all sig-nificantly lower than those of HCD dinner on Day 4 and 6. However, after consuming LCD dinner on Day 5, IGP breakfast (2.33±0.15 vs 1.71±0.15 mmo/L, p<0.01), IGP lunch (3.31±0.25 vs 2.54±0.18 mol/L, p<0.01), IAUC 3h of breakfast (210±18 vs 136±14 mmol/L×min, p<0.001), mean blood glucose (5.72±0.11 vs 5.40±0.11 mmol/L, p<0.01), and standard deviation (1.11±0.06 vs 0.88±0.04 mmol/L, p<0.01) on Day 6 were all signifi-cantly higher than those of corresponding meals before LCD dinner on Day 4, in spite of consuming all identical HCD meals. The glycemic parameters returned to the levels before consuming LCD on Day 7.
Conclusions: Consuming LCD only once is enough to cause 24-h higher postprandial blood glucose concentration in subse-quent consumption of HCD in healthy women.