I'm certainly no nutritionist, but I can tell you what worked for me. It may not be the fastest solution, but by all my research, and just knowing how I felt while I was doing it, it's def. the best I ever did for myself.
Chuckystud seems to have some good advice; I never even thought about the testing of testosterone and thyroid levels. But as far as trimming down strictly from a diet perspective, there were a couple of things that I had to do for myself:
1.) Change my mindset. I couldn't think of it as a diet. I had to think of it as a way of life. Oddly enough, this was by far the hardest thing for me to do. When I went grocery shopping (someting else I had to force myself to start doing), I had to do so with the understanding that I wasn't there for a quick 10lbs. I was there shopping for the rest of my life.
2.) Once I got #1 out of the way, I took inventory of what I liked, and I started researching (on sites like Bodybuilding.com, Health sites, and others) what properties of food were good for what I wanted. Fortunately - and this could very well be different for everyone - I'm NOT a picky eater; I like all sorts of foods, and I was able to assemble quite a rapatoir of yummy, healthy foods to eat! Cheeses, yogurt, lean meats (lean red meat, chicken, fish), green veggies, fruits (fuji apples, in particular), and on, and on. I also invested in a good protien suppliment, "good" here referring to the most protein in a serving with the least cholesterol and carbs.
3.) Once I had that list of "Good Foods" down, I went shopping, procured them all, and - this was hugely important for me - cleaned out my refridgerator at home, and kept an identical stash of foods in the fridge/at my desk at work. I basically made it SO convenient for me to eat healthily, that the temptation to go eat out for lunch one day, or go out for dinner, simply didn't exist. This may not work for you; everyone's different. It's just how I did it.
4.) The final part of this process involved the times at which I ate, and eating as it immediately preceded or succeded a workout. Addressing the former, I basically started eating 6x a day. It looked something like this:
7-7:30AM - Breakfast: Bowl of high protein/high fiber cereal (Kashi makes some; very yummy!) w/ skim milk, an apple, and a small piece of cheese with juice of your choice (with as little sugar as possible).
9:30-10AM - Snack: Handful of almonds, maybe a cup of yogurt; something small, just to tide you until lunch. No more than a "handful" of whatever it is.
12-1PM - Lunch: Usually a sandwich, either peanut butter & low-sugar jam (JIF is my fave pb! Mmmm!
) on whole grain bread OR a roast beef & turkey (Oscar Mayer's Deli-cuts are AWESOME) w/ provolone or mild cheddar cheese, sometimes yogurt or an apple if I hadn't had one previously, and a cup of milk. If it was cold out, I'd have some of the low-sodium nukeable soup cups (1 serving) w/ my sandwich to warm the bones!
3-3:30PM Snack: Usually another handful of almonds, and very often this was the time of day where I had my cup of yogurt. I moved it around to other time slots to vary things a bit, but this was usually it, just enough to keep me going until dinner.
6-7:30PM Dinner: I never really had an established plan for dinner. It got to the point that eating like this meant I was never really particularly hungry by the time evening rolled around. The only real advice I can give is to try to eat before 9pm, keep the serving small and lean, and complete with veggies and/or real rice (not instant; the good stuff).
Addressing the point about eating around workouts, about half an hour before going to the gym, I'd make a peanut butter sandwich and a cup of milk. Drink the milk, and eat only half of the peanut butter sandwich. Sometiems I'd compliment with a banana, too, just cuz I love them, and the boost of potassium they give you supposedly helps prevent cramps. *shrug* I'd go do my thing, obviously drinking lots of water as I went, and whe I got back, I'd eat the other half of the sandwich, and down a protien shake.
Some of you guys are probably lauging at this. LOL But I'll be the first to admit that I'm no pro. This is just what worked. I was 240lbs in October of 2006, and 185lbs the following June. I did a lot of cardio during this time period, too, and I would try to find other foods that I liked to sub in; unsalted sunflower seeds, green salads w/ vinegarette dressings. And, honestly, every now and again, you HAVE to let yourself splurge. You just can't go too far with it. Usually my "splurge" waso ne of those giant Marie Calendar's chicken pot pies. Mmmmmmmm :} But you have to reward yourself, or it just gets laborious. But once you do this enough, you'll find it becomes more of a way of life than a diet.
I hope this helps you lose that midsection. I'm still working on mine, though with work and school schedules, and a boyfriend that likes his guys bigger (sigh), it's been hard to keep my eating where it should be. But I'm still going, and now that the holidays are over, and gym schedules are normalized, I'll be well on my way again very soon!
Best of luck!