To measure the prevalence of CHO restriction, weight loss and ketone production in GDM women referred to Fiona Stanley Hospital Diabetes in Pregnancy (DIP) clinic for insulin initiation; to elucidate the reasons women restrict CHO and lose weight; to characterise the women who choose to restrict their CHO intake; and to measure the effectiveness of dietetic consultations in eliciting behaviour change that improves CHO intake and halts weight loss.
All women referred to DIP clinic over a two month period were assessed for weight, BMI, diet history to establish current CHO intake, reason for CHO restriction if applicable, and non-fasting blood ketones. Individualised medical nutrition therapy was provided at this time.
Of 102 women eligible for inclusion, 57% were restricting CHO intake below recommended levels, 38% had recent weight loss, 15% had non-fasting ketones of ≥0.3mmol/L.
The main reason given for consuming inadequate CHO was to avoid insulin therapy (66%). After one dietetic intervention 95% of women who were initially restricting CHO improved their intake.
The average pre-pregnancy BMI of women restricting CHO was 31kg/m2 versus 28kg/m2 in the non-restricting group. Nearly half (48%) of women restricting CHO had weight loss or inadequate weight gain. Non-fasting ketones of ≥0.6mmol/L were recorded in 7% of CHO restrictors compared with 2% of women consuming adequate CHO.
Of the women who lost weight, 70% were restricting CHO versus 48% of women who did not lose weight. After one Dietetic consultation 74% improved their weight status.
Carbohydrate restriction and weight loss are prevalent in GDM women referred for insulin initiation.
Women who restrict carbohydrate intake below recommended levels are more likely to lose weight and show evidence of ketonaemia.
Women who restrict CHO tend to have a higher pre-pregnancy BMI.
The most common reason for women to restrict their CHO intake is to avoid insulin therapy.
MNT is very effective in improving CHO intake and avoiding weight loss.