You should Memorize this: Your body is only as good as the things you give it.
Eat three full meals a day, with 2-3 snacks. So it works out to a "feeding" every 3 hours or so. Balance, bay-bee (bad impression of Austin Powers). Protein, lots of fruits and veggies, and a little fat (unsaturated). If your balance is out of whack, you're going to be out of whack, too. With practice, you'll find the right balance for you.
Vitamin/Mineral supplement. Why? They help you to use the food you eat more efficiently. They help aid in digestion and assimilation of your food, plus you get an added boost that your diet is lacking.
Energy needs change depending on the activity level, so your menu should, too. That means you don't have to count calories; instead, you'll naturally learn to pay attention to what your body needs from day to day.
Buy foods that can remember where they came from; no processed junk or convenience foods. Hey, give organic foods a once-over, if you haven't already.
READ LABELS. It still surprises me how many of us still don't read the labels. Keep sugars low, about 10% of the carbohydrate grams. E.g., if there's 20 grams of carbohydrates, there should only be 2 grams sugar.
Create a reserve of nutritious foods. Cook your meals on a Sunday to hold you over for a few days. Stock up your refrigerator or cooler at work. Home, too. Buy a box of nutrition bars, like Balance Bars (and the like) to eat when you're extra busy. Keep them in your gym bag, your desk drawer, coat pockets. You won't be so inclined to order in or eat out.
Scrap diet sodas and caffeine. Water is very effective in fighting fatigue. Helps you lose weight, control appetite, enhance fat-burning, and cleans your system. Keep on hand protein powder for a low-calorie energy boost.
Keep your blood sugar in check and quiet sugar cravings by making absolutely sure that you're following principle #2 - especially with protein.
If you do go out to eat, eat only half of what you get. Most restaurants give you twice as much as you need - even if you're working out like a son-of-a-gun. And pitch the bread basket, by the way. Instead, have a salad with dressing on the side.
Keep your energy and metabolism humming by following #2.
Pump iron, first and foremost. Muscle is your most metabolically active tissue, so it makes sense to develop it. Can't do it with 3 lb. dumbbells. Pump iron LIKE YOU MEAN IT. Challenge yourself EVERY workout. 4-6 days a week, no longer than 30-45 minutes per workout.
Try this for aerobic training: switch activities every couple of weeks so your body has to work at re-learning another activity, which burns some extra calories. Swap cycling for the Stairmaster one month, for instance.
Back to #12. The fastest route to muscular development is taxing your muscles to the max. To the very last full repetition of every set of every exercise. When you think you've finished, if you can do more, DO IT. No wusses allowed!
Get out of the "maintain" frame of mind. There is no maintain. That ends up as trouble for most people. If you think that once you reach a certain level of conditioning and you can back off, you're in for a rude awakening. Your body will love it, and will begin to start shutting down. A slow, gradual loss of muscle and metabolism, and a slow, gradual increase of body fat.
Get your Sleep. Muscles aren't built at the gym; they are built when they are given time to rest and recuperate. But they can't do that if you're getting 4-5 hours of sleep a night and stressing out on a daily basis. Not to mention, you must have a sound nutritional plan to help you recover faster between workouts. Shoot for 8 hours/night (I'm working on it, too!).