Short-term improvements in diet quality in people newly diagnosed with type 2 diabetes are associated with smoking status, physical activity and body mass index: the 3D case series study

BACKGROUND: Dietary intake impacts glycaemic control through its effect on weight and glucose-insulin homeostasis. Early glycaemic control is associated with improved outcomes and reduced mortality for people with type 2 diabetes (T2D). To date, the diet quality of people with T2D has only been studied cross-sectionally. The objective of this paper is to quantify short-term improvements in diet quality and to identify factors associated with improvements after T2D diagnosis among participants in the 3D study. METHODS: This paper presents data from the 3D study of 225 Australian adults, newly diagnosed with T2D. Telephone interviews collected demographic, diet, physical and health data at baseline and 3 months. Diet quality was assessed using the Dietary Approaches to Stop Hypertension (DASH) tool to examine short-term changes in diet quality after diagnosis. Participants were categorised into two groups: those who improved their diet quality by 3 months (increase in DASH score of 3 or more) and those who did not. Factors associated with change in DASH scores were clinically and statistically evaluated. RESULTS: The 3D cohort was comparable to Australian cohorts with diabetes by gender and body mass index (BMI) but differed by age, remoteness and socioeconomic status. Mean (SD) baseline DASH score was 24.4 (4.7), in the midrange of possible scores between 8 and 40. One third of participants improved their DASH score by 3-months. This group had lower diet quality (p < 0.001), lower BMI (p = 0.045), higher physical activity levels (p = 0.028) and were less likely to smoke (p = 0.018) at baseline. CONCLUSIONS: Diet quality changes after diagnosis do not appear to be associated with demographic characteristics but were associated with lifestyle behaviours. Strategies targeted at better supporting smokers, those with low physical activity and higher BMI are required. Future research should investigate how the diet quality changes people make around time of diagnosis are related to long-term health outcomes.