Aims
To describe change in self‐reported diet and plasma vitamin C, and to examine associations between change in diet and cardiovascular disease risk factors and modelled 10‐year cardiovascular disease risk in the year following diagnosis of Type 2 diabetes.

Methods
Eight hundred and sixty‐seven individuals with screen‐detected diabetes underwent assessment of self‐reported diet, plasma vitamin C, cardiovascular disease risk factors and modelled cardiovascular disease risk at baseline and 1 year (n = 736) in the ADDITION‐Cambridge trial. Multivariable linear regression was used to quantify the association between change in diet and cardiovascular disease risk at 1 year, adjusting for change in physical activity and cardio‐protective medication.

Results
Participants reported significant reductions in energy, fat and sodium intake, and increases in fruit, vegetable and fibre intake over 1 year. The reduction in energy was equivalent to an average‐sized chocolate bar; the increase in fruit was equal to one plum per day. There was a small increase in plasma vitamin C levels. Increases in fruit intake and plasma vitamin C were associated with small reductions in anthropometric and metabolic risk factors. Increased vegetable intake was associated with an increase in BMI and waist circumference. Reductions in fat, energy and sodium intake were associated with reduction in HbA1c, waist circumference and total cholesterol/modelled cardiovascular disease risk, respectively.

Conclusions
Improvements in dietary behaviour in this screen‐detected population were associated with small reductions in cardiovascular disease risk, independently of change in cardio‐protective medication and physical activity. Dietary change may have a role to play in the reduction of cardiovascular disease risk following diagnosis of diabetes.