Half should be salad or fresh vegetables. The remaining half should be half protein, such as fish, chicken, eggs, beans or tofu, and the other half slow-releasing carbohydrate such as wholewheat bread, pasta or brown rice.

A chicken sandwich with wholemeal bread and loads of salad would hit the mark. Alternatively, egg and cress, but ideally you want double the cress contained in a standard sandwich. A bean and rice salad with some vegetables would be great for a vegetarian. Or, if you' re on the road, try a small tub of hummus (chickpea spread), a raw carrot and half a dozen oatcakes.

Don' t drink a fuzy drink. Either have water (still or naturally carbonated), apple juice or best of all an Optio, which is a blend of fruit juices with optimal amounts of nutrients. These are available in supermarkets.