It may be the start of an ed, but as people have already said, it depends on the mental side of things. eating just one meal a day is really unhealthy, and will not do you any good at all. try eating fruit and veg, and meat such as chicken.
try something like this:
breakfast - cereal (i usually go for special k or fitness), or a fruit smoothie, or fresh fruit and natural yoghurt.
midmorning - piece of fruit
lunch - roast veg. wrap or a salad with chicken, bacon or fish, with a low cal dressing.
midafternoon - piece of fruit.
dinner - veg stir fry, you can add chicken if you like or roast veg pasta, or fishcakes with salad, or corn on the cob with boiled baby potatoes and veg or salad or a jaket potato filled with anything you like with some salad or veg, or any sort of fish with veg and potatoes.
early evening - cereal bar.
i find these meals are good because they fill you up, but they are healthy as well, so youre getting pretty much all the things that you need.