Background: The prevalence of Gestational Diabetes Mellitus (GDM) has increased in South West Sydney from 15.3% in 2013 to 21.5% in 2017. While diet is a cornerstone of GDM management, little has been reported on pre-GDM dietary intake. Improved understanding of the dietary intakes of women prior to treatment would allow Medical Nutrition Therapy (MNT) to be targeted to common nutrition issues, particularly in a region with high cultural diversity.
Aim: To evaluate the diet quality, percentage of energy from nutrient-dense core versus energy-dense, nutrient-poor, non-core food groups and intakes of micronutrients in women newly diagnosed with GDM.
Method: Dietary intake pre-GDM was assessed using the Australian Eating Survey (AES), a validated food frequency questionnaire. The AES was self-administered before attending group dietary education at a diabetes outpatient clinic in a tertiary hospital in New South Wales. Diet quality was evaluated using the Australian Recommended Food Score (ARFS) which assesses variety within core food groups. Nutrient intakes were compared to Estimated Average Requirements (EARs).
Results: 50 women completed the survey; mean (SD) age = 30.9 (4.7) years, pre-pregnancy BMI = 28.9 (9.0) kg/m2 and 24.6 (6.5) weeks gestation. A variety of cultural backgrounds were represented with 69% born overseas and 9.6% requiring an interpreter. The mean (SD) total ARFS was 31.7 (±11.4) points (maximum 73) with mean (SD)/maximum points ARFS sub-scale scores for vegetables 10.1 (5.4)/21, fruit 6.3 (2.8)/12, meat 2.8 (1.7)/7, meat alternatives 2.4 (1.3)/6, bread and cereals 5.2 (2.1)/13 and dairy products 3.7(2.5)/11. The % energy from core foods was 64.2 ±12.5%, whereas non-core foods contributed 35.8 ±12.5% energy. Mean iron and folate intakes were below EARs.
Conclusions: Women with GDM have low dietary variety of nutrient-dense foods, with a high percentage of energy derived from energy-dense, nutrient-poor foods, along with inadequate intakes of iron and folate. These dietary intake patterns are suboptimal in terms of achieving optimal diet-related health outcomes and require attention within MNT for GDM.