Let’s face the truth: It is a lot easier for a man to operate smoothly and vigorously in bed if he is not carrying a 20-pound belt of blubber around his waist. Not only are there health risks to being overweight, but for most women, a lean physique is much more attractive than a chubby one. But even more important than how other people see you is your perception of your body.

Maintaining a healthy body weight encourages self-confidence and promotes a healthy and positive outlook on life. In addition, if you are overweight, you might start thinking of your penis as small because layers of fat obscure so much of it. Remember, the penis comes from under the pubic bone. If there are two or three inches of fat above the pubic bone, your erect penis will need to traverse that distance before it sees the light of day. Excess belly fat creates the illusion of a very short penis, which, in turn, will cause you to think “small” about your penis power.

In general, I have found that men with poor body images have some degree of penis weakness. Men who are comfortable with their bodies and are content with their looks have a higher likelihood for super potency.

You do not necessarily have to emulate the image of a man with a sleek, muscular body, with a gorgeous woman at your side, promoting everything from a deodorant to a pickup truck. Whose self-image could possibly live up to those standards? You need to avoid comparing yourself to other men, especially images of the “perfect” man portrayed in magazines and on the silver screen.

The key to achieving a good body image is a proper diet, regular exercise, and maintenance of a sensible weight. This regimen will, in itself, promote a sense of general well-being and improve your sexuality.

If you are dieting, you know you have to count calories, carbs, and fats. But recent studies have shown that if you really want to keep the weight off, you might want to focus on the glycemic index, a measure of how quickly foods are digested. High-glycemic foods cause a surge in blood sugar, followed by a crash. This biologic reaction releases hormones that stimulate hunger, lower metabolism, and make it difficult to both lose and maintain weight.

In a recently published study in the Journal of the American Medical Association, Dr. David Ludwig compared a low-carbohydrate, low-fat, and low-glycemic diet to see which burned the most calories daily. The low-carbohydrate diet was the best, the low-fat diet was the worst, and the low-glycemic diet burned more calories per day than the low-fat diet. But most importantly, the low-glycemic diet proved easier to stick to over the long term than even the low-carbohydrate diet.

The key to this combination of a low-carbohydrate and a low-glycemic diet is to start eating more fruits and vegetables. When it comes to carbohydrates, choose those with a lower glycemic index: brown rice versus white, whole-grain pasta rather than regular pasta, and steel-cut oats instead of quick-cooking oats. Avoid processed foods like white bread, white rice, breakfast cereals, and crackers, all of which have a high glycemic index.

According to Dr. Ludwig, low-glycemic foods “increase the metabolic rate and decrease hunger, giving us a biological advantage” in losing and maintaining weight. Natural foods—like most vegetables and fruits, nuts, beans, and whole grains—wind their way slowly through the body’s digestive system, using up more energy and burning more calories in the process than high-glycemic foods do.

Dr. Ludwig points out that this study was short and not conclusive. He is working to design a better study that examines diet and weight-loss maintenance over a longer period of time.

I would recommend a moderation in foods containing carbohydrates and fats. I would also emphasize moderate exercise (at least 60–90 minutes every day) as an important part of the equation. This regimen of diet and exercise is guaranteed to improve your sex life, irrespective of age or level of physical fitness.