The American diet causes disease. It is composed of 25 percent animal products and 62 percent processed foods and only 5 percent of calories from fruits and vegetables.

Instead of trying to increase your metabolism with the goal of losing weight, try to slow your metabolism with a low-calorie, high-nutrient diet for a longer, healthier life.

For most teenage runners, the right foods means a varied diet, decreasing the amount of fat found in the typical American diet and replacing those calories with carbohydrates. Avoid saturated fats, such as those found in fried foods, and eat plenty of fresh fruits and vegetables.

For the vast majority of those who are obese - those with a Body Mass Index over 30 - their size is their choice. They choose to take in more calories than they burn. They choose to take in high fat calories over low-fat ones. They choose to fad diet, if they choose to diet at all.

I would have never wanted to write another management book. There are so many of them, and everybody says the same thing about them, and they are all the same - they give the exact same advice. It's like a diet book; they all say eat less calories, exercise more, and every single book has the same conclusion.

I work out every day, and I eat 1,200 calories. Here's the truth - like I've said to everybody, 'Every diet works if you follow the diet.'

When I learned that flour pound for pound has as many calories as sugar, and that when eating pasta you're basically eating cake, I was size 23, and my neck was restricting my breathing, and so I got on a microbiotic diet and got myself an exercise bike.

At my heaviest, I was 5'8" and 175 pounds. I ate well, but in too large quantities, and I rarely made a concerted effort to burn off the extra calories. I'd beat myself up about being overweight, even though I had the tools to be in shape. Then I'd resort to an unhealthy diet to lose the weight that was making me self-conscious.

'Immortals' was very much a martial arts based training program - a lot of body weight stuff, very little in the way of actually lifting heavy weights, and a very, very low calorie diet.

I follow an extremely strict diet counting my calorie intake, keeping in mind a very balanced ratio of proteins, carbs, and fats.

I tried the paleo diet, which is the caveman diet - lots of meat. And I tried the calorie restriction diet: The idea is that if you eat very, very little - if you're on the verge of starvation, you will live a very long time, whether or not you want to, of course.

The problem with the standard American diet, a primary cause of our current obesity epidemic, is the fact that the majority of foods consumed are high in calories and low in micronutrients.

The truth of the matter is if we listened to our bodies and cleared our psychologies, we would inherently know what we need to do to stay healthy, and there wouldn't be a market for diet pills, extreme cleanses, or low-calorie, pre-packaged junk food.

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.

When I'm off the road, and I can really control my diet down to the calorie, I juice seven days a week. Every afternoon, whatever I have at hand, beets, carrots, ginger, whatever. I juice, literally, every single day. And on the road, I try to find fresh juice wherever I can.

The first thing I did was give up sweet tea because I drank so much. I'd start drinking at lunchtime and wouldn't set it down until I went to bed. When you calculate how much empty calories and how much sugar I was consuming, it was staggering. So I haven't had a glass of sweet tea in three years.

Do you know how many calories are in butter and cheese and ice cream? Would you get your dog up in the morning for a cup of coffee and a donut?

I find it almost comforting to count calories, because it makes me conscious of what I'm eating. But on Super Bowl Sunday, I thought, 'Surrender to it. It's nacho time.' Then I ate nothing but Doritos all day.

I never count calories, but I eat so well.

I am constantly working out-circuit training, jumping rope, and stair-stepping, and sticking to 1200 calories a day. It can't be something that you're doing to lose weight, and then once you do, you're done. I do it every day of my life.

Nothing burns more calories than dancing in 5-inch heels... try it!

This is what people don't understand: obesity is a symptom of poverty. It's not a lifestyle choice where people are just eating and not exercising. It's because kids - and this is the problem with school lunch right now - are getting sugar, fat, empty calories - lots of calories - but no nutrition.

Don't compare yourself with someone else's version of happy or thin. Accepting yourself burns the most calories.

Once you have to start counting calories, it takes away from the joy of eating.