Sex keeps me in shape. I don't diet, I eat what I like. I love Mars bars and I smoke and drink. But I love running off in the middle of the day to make love. It really burns up calories.
I am not naturally that thin, so I had to go through everything from using drugs to diet pills to laxatives to fasting. Those were my main ways of controlling my weight.
If you've got a big gut and you start doing sit-ups, you are going to get bigger because you build up the muscle. You've got to get rid of that fat! How do you get rid of fat? By changing your diet.