Ideas about a healthy diet keep changing as new research goes on, but the basics are pretty well known by now. One of the most effective tips is the idea of the eatwell plate. If you visualise a dinner plate, about a third of the food on it should consist of starch based foods such as potatoes, pasta or bread. Another third should consist of fruit and vegetables, and the rest is a mixture of protein - this is usually meat, fish, or certain high protein foods such as tofu and nuts - dairy products or dairy substitutes, and a little fat.

The most important thing is variety. We're advised to eat 5 portions of fruit and vegetables a day, for instance, but it's not so good if you just eat big quantities of one or two vegetables. The idea of the rainbow plate is helpful too - try and get some green, red, yellow and orange on your plate, which will ensure a good mix of fruit and veg types.