Diet >>>>>>>> exercise, unless you are working out like an athlete. You'll see loses eventually though if you go from sedentary to exercising a good amount.
I mean, if you really feel like you can't get your calories under control, if you exercise it won't hurt you (well talk to your doctor, it actually could depending on how much and how hard you do it. You need to take your physical state into consideration.) I would try to eat healthier.
I'm 26 and I'm already borderline high cholesterol and blood pressure (within normal values, but at the top end). I know I'd have diabetes within a few years, at least, if I don't correct my eating habits. I did well for a while, and am back on the wagon, but its tough.
I'd recommend you at least make some attempt to eat healthier. Even if its just cutting one thing out of your diet (I know I developed a weakness for making cheesesteaks when I went off my diet) I'd make them maybe 4 times a week. Usually one weekday and once on the weekend just make two sandwiches. Thats just one thing, I have a few more vices I'm saying goodbye to, too =P But it was a process. I stopped one thing at a time till I got back to my diet (not a conscious effort, money got tight =P).
When I say diet, I really just mean eating what I should. If my friends are going out to eat, I'll go with them. I make good choices, considering my situation, but I don't starve myself.
Sorry if this post is rambling. My tooth was killing me, and I need to sleep so I had myself a little drink. That was 2 parts gin, 2 parts rum, and some ice. I think I put some cranberry juice in there somewhere.
I just got really scared, health-wise, recently. I was reading up on all the problems I could look forward to based on my blood work and my history. Even though I've lost over 40 lbs in the last 2 years, I'm still in bad trouble.
So yea, anyway, look into what you are eating. Just start small. In a few months you'll be healthier and the effort will be minimal if you take small steps.
Force yourself to eat fruits and vegetables for three days straight, and nothing else. Then eat a sensible diet.
Thats waht worked for me originally. Previously my idea of diet was not putting whipped cream and hot fudge on my gallon of ben and jerrys.
Or at least, not extra helpings of it.