People who go to see their GP because they are overweight could be prescribed a tour of a supermarket.

UK supermarket chain Sainsbury's has launched an initiative in collaboration with the National Health Service to show overweight patients the fatty foods they should avoid and the healthier alternatives they should eat instead, reports BBC News Online.

The guided tour will point out low-fat versions of popular foods, such as ready-meals, as well as focusing on cheaper products such as tinned fruit and frozen vegetables.

Obesity Forum chairman Dr Ian Campbell told BBC Radio 4's Today programme many of his patients were determined to lose weight but found it "very difficult" to find healthy foods in shops.

City University food policy expert Professor Tim Lang agreed that the NHS lacks the resources to fund the sort of dietary advice that patients need but added that supermarkets should sell less fat and tackle the social causes of obesity.

Patsy Calton, Liberal Democrat health spokesperson, welcomed the move.

"The public and health service providers need to be aware of the dangers of eating unhealthy foods. This scheme is an imaginative contribution to that," she was quoted as saying by BBC News Online.

"All of us can enjoy fatty foods occasionally. But we need to remember that we are storing up long-term health problems if we eat fatty foods all the time.

"Promoting good public health must be a higher priority for the government. Ministers must examine how we can promote an effective preventive health agenda. That means not just advice, but also promoting exercise and healthier lifestyles."