The study is thought to be the first of its kind in the UK to look specifically at people of Indian and Pakistani origin, who are up to three times more likely to develop the condition than the general population.
The report found that increasing their levels of physical activity and improving their diet gave them a better chance of losing enough weight to lower their risk of developing type-2 diabetes.
The three-year trial monitored 171 people of Indian and Pakistani background living in Scotland who were already at high risk of diabetes as shown by blood tests done at the start of the trial.
Participants were given detailed advice by dieticians and offered culturally appropriate resources to help them manage their weight through diet and exercise.
Professor Raj Bhopal, from the Centre for Population Health Sciences at the University of Edinburgh, and lead author of the study, said: "These differing approaches show us that a more family-centred strategy, with culturally tailored lifestyle advice, can produce significant benefits to people's health through weight loss."
Participants lost weight and there were indications that they were less likely to become diabetic by the end of the trial.
The trial, led by scientists at the University of Edinburgh, is published in the journal Lancet Diabetes and Endocrinology.
It comes after Diabetes UK Scotland warned the country was in the grip of an epidemic of the condition, with more than 11,000 new cases recorded in a year.