Eat pasta. It fills you up and has little consequence in whether you eat a lot of it. Same goes for rice. Pasta and rice is also a good combining food, in that you can throw in anything you want with it, with a little sauce, and it just works.
Chicken's a healthy meat to eat in comparison to other meats so if you eat meat with anything, use chicken.
I eat a fair bit, and even though my metabolism is not what it once was i manage to stay relatively thin and healthy because of it. The Italians really know how to eat tastey food that is not bad for you. Providing the original recipe has not been Americanised such as in most pizza recipes (IE deep pan).
Also Bran is good for you. I eat my fair share of Bran (i'm addicted to shreddies and bran flakes, no idea why...). It keeps you full for longer and does good for your bowels. Makes your transit system clean and efficient. You can generally tell how healthily you eat by the condition of your poo (Yes, i'm being serious). The more consistancy it has the healthier it is. Slimey shit = too many mars bars. If you have to wipe your arse more than 3 times then you're not eating well.
But back to recipe's and stuff.
Pasta+veg+sauce. Totally up to you what you include, i generally throw in green/string beans, corn, mushrooms and sometimes carrot, and usually some chicken (which needs to be cooked first, of course). By the time you're 16 you generally know what veg works for you, which is cool. Cause you can eat that, and avoid the offensive piece of veg your mum always throws on the plate. I started enjoying food a lot more when i started cooking for myself.
Rice is an easy one too. I usually boil some rice, leave it over night so it dries (make sure to rince out the starch) and then fry it with some mushrooms, tikka chicken pieces and dry mixed spicey herbs. "Fry ups" give the frying pan and act of frying food a bad name, stir fries are fucking amazing meals. You just gotta watch that you don't put to much oil in the pan. Use some tzetchan (sp) sauce or something to lube the food up.
These sorts of meals take about 5 mins to make, although doing the rice that way requires a little prep work. You could just as easily use basmati since that doesn't mush up with starch as much.
If i'm in a hurry i usually keep some fresh tortellini around. Takes 1 minute to heat up in a pan of simmering water. Throw on some chilli olive oil or low fat spread (so it melts) and you got yourself a full on dish.