Breakfast should be a combination of a complex carbohydrate and protein (the protein will slow down the digestion of the carbohydrate) e.g., egg on toast, an omelette with wholemeal bread, sardines on toast or porridge made with milk (no sweetening). If you can work some vegetables in there, that's even better: some mixed peppers with the omelette, half an avocado with lemon or lime juice, some tomatoes or mushrooms, perhaps. That will give your digestion more fibre to work with and your body more nutrients to use.
Your other main meals should each consist of around 4-6 oz of protein (lean meat, poultry, vegetable protein or oily fish for preference), a complex carbohydrate (e.g., potatoes, wholemeal pasta, brown rice) and a large serving of green vegetables. When you look at your plate roughly one quarter of it should be comprised of protein, one quarter carbohydrate and the rest should be your green vegetables (cooked or raw salad).
Snacks can be whatever you like as long as they are whole food and eaten in moderation: pieces of fresh fruit (not dried because of the disproportionate sugar content) nuts (no more than a couple of ounces per day as they have a LOT of calories) a handful of seeds, some slices of cold meat etc.
Eating this way should allow your body to deal with food more effectively and enable it to send the right messages to your brain regarding how and when to fuel it.
David Bowie, owner of Healthy Fit Life, is a mobile personal trainer and sports massage therapist working in the Farnham and Camberley area.