less sugar, simple carbs (non whole wheat), and fats
more protein
if you're lifting, eat plenty still (just of the right stuff) there's no point in making your body struggle to make any gains
if you're not lifting eat maybe 10-20% less calories than you normally do and walk everyday or every other day for half an hour to an hour. First thing in the morning before breakfast is the best time, and then eat right after your walk.
Don't eat any carbs really at all within 4-6 hours of going to bed, dinner should be a piece of chicken or fish or steak and some vegetables (yea they're carbs but you'd have to eat several plate fulls to get the same amount as a couple pieces of bread, and they're complex carbs for the most part)
Eat every 2-4 hours, small meals of about 40% protein, 20% fat, and 40% complex carbs (except at night) and in the morning you can leave out the fat and add some extra carbs, including some simple ones like fruit juice or fruit. Also if you're lifting, eat simple carbs before lifting as well as some after and alot of protein, no or almost no fat.
Never have the mentality of "oh well I skipped this meal so I'll just eat twice as much now" or vice versa "oh well I ate alot for lunch so I'll skip this meal", same with working out
Oh and for weight lifting, do mainly big (multiple muscle) exercises such as bench press, Bent over rows, deadlift, and squats. Your body gains the most from these movements, especially when you're pushing yourself, and you also experience an increase in testosterone from big movements like these (squat I believe is by far the highest), the more extension you get from each movement (bigger range of motion), the more beneficial it will be to your body, so go all the way down.
OH AND DRINK LOTS OF WATER. you'd be surprised how often people mistake thirst pains for hunger pains, and the water is extremely good for your body.
