Trials have proved successful and the retailer now plans to roll out the scheme which takes groups of doctors around stores with a registered dietitian and a Sainsbury food advisor.
Overweight patients will also get the chance to tour stores,
Company nutritionist Gill Fine said: "It's completely unique. We're trying to look at innovative ways to address the issue of health and obesity. An important part of this is keeping health practitioners up to date with what's going on."
GPs and dieters can learn about the right amount of fruit and veg to eat, how to understand labels, cooking methods and terms like lower fat' in a store setting.