Diabetes mellitus is escalating globally and it is predicted that 200 million individuals worldwide will have diabetes by 2010 and 300 million by 2025. However, there is compelling evidence from many studies that for subjects with impaired fasting glucose or impaired glucose tolerance the presentation of type 2 diabetes can be delayed by lifestyle modification. The aim of the present review is to present a summary of lifestyle modification interventions that have included a dietary component in their overall diabetes prevention programme. Medline, allied health literature and diabetes journals were searched for peer-reviewed literature using the terms ‘diet*’ and ‘diabetes’ and ‘intervention’. Inclusion criteria were: peer-reviewed studies from 1975 to 2008; a sample of at least fifty subjects; a healthy eating and/or physical activity component; prevention of diabetes as a primary goal. Generally, the participants were in a high-risk category for the development of diabetes. Outcomes were evaluated at two points in time (pre- and post-intervention) in terms of knowledge, behaviour change and clinical improvement, which included weight, blood pressure, BMI, body fat, waist circumference, waist:hip ratio and physiological and/or biochemical measures. Findings indicate that the most successful interventions combine individual dietary counselling with an activity component. Further factors predicting success are weight loss achieved, duration and intensity of the intervention and dietary compliance.