The effect of pre‐pregnancy lifestyle counselling on food intakes and association between food intakes and gestational diabetes in high‐risk women: results from a randomised controlled trial

BACKGROUND: Healthy diets before and during pregnancy have been suggested to reduce the risk of gestational diabetes (GDM). Several lifestyle intervention studies for pregnant women have reported dietary improvements after counselling. However, evidence concerning the effect of counselling initiated before pregnancy on diets is limited. METHODS: This randomised controlled study explored whether pre‐pregnancy lifestyle counselling influenced food intakes, as well as whether changes in food intakes were associated with GDM. The participants comprised 75 women with prior GDM and/or a body mass index ≥ 30 kg m–². Women were randomised into a control or an intervention group, and their food intakes were followed from pre‐pregnancy to early pregnancy using a food frequency questionnaire. The control and intervention groups were combined to assess the association between changes in food intakes and GDM. The diagnosis of GDM was based on a 75‐g oral glucose tolerance test conducted in the first and second trimester of pregnancy. RESULTS: Pre‐pregnancy lifestyle counselling showed no major overall effect on food intakes. The intake of low‐fat cheese increased significantly in women who did not develop GDM compared to women who did after adjusting for potential confounders (P = 0.028). This association was not observed for regular‐fat cheese. CONCLUSIONS: The findings obtained in the present study suggest that an increased intake of low‐fat but not regular‐fat cheese between pre‐pregnancy and early pregnancy is associated with a lower risk of GDM in high‐risk women.