Effect of a high-protein and low-glycaemic index diet during pregnancy in women with overweight or obesity on offspring metabolic health—A randomized controlled trial

Background: Maternal obesity and excessive weight gain during pregnancy are associated with higher birth weight and increased risk of childhood obesity. Objective: This study investigated the effect of a high-protein and low-glycaemic-index (HPLGI) diet during pregnancy on offspring body composition and metabolic health. Methods: We conducted a dietary intervention study in pregnant women with a pre-pregnancy BMI of 28–45 kg/m² who were randomly assigned to an HPLGI diet or a moderate-protein moderate-glycaemic-index (MPMGI) diet. A total of 208 offspring born to these women were followed-up from birth to 5 years of age. Results: No differences were found on BMI z-scores at different ages; however, offspring born to women on the HPLGI diet exhibited 0.43 mmol/L higher glucose levels (p = 0.017) at birth compared with the MPMGI diet. At 3 years of age, HPLGI offspring had 0.09 mmol/L lower levels of HDL-cholesterol (p = 0.018) and 16% higher levels of triglycerides (p = 0.044). At 5 years of age, they had 0.25 mmol/L higher total cholesterol levels (p = 0.027) and 0.27 mmol/L higher LDL-cholesterol levels (p = 0.003) compared with the MPMGI diet. Conclusion: An HPLGI diet during pregnancy may lead to adverse metabolic outcomes in the offspring, necessitating further investigation into long-term health implications.