The following is an excerpt from Fantastic Voyage by Ray Kurzweil and Terry Grossman, M.D. Your weight reflects your total calorie consumption, how much you exercise, and your metabolic rate, but the composition of the food you eat is also important.

Here are some tips...

1. Reduce carbs. We have found that it's almost impossible to lose weight and keep it off without eating substantially fewer carbohydrates, particularly those with a high glycemic load (GL). As we discussed in "Carbohydrates and the Glycemic Load," consumption of high-GL carbohydrates leads to a desire for more carbohydrates. Eating a low-carbohydrate, low-GL diet will help you control your appetite and decrease cravings. You'll feel full sooner, you'll find it far easier to stop eating once you're satisfied, and you'll find yourself less hungry between meals. If you are trying to lose weight, we recommend you keep total carbohydrates under one-sixth of your calories and eliminate all high-GL carbohydrates such as sugary foods
2. Reduce fats. Reducing fat in the diet aids weight loss because high-fat foods are more calorically dense -- 9 calories per gram versus 4 for carbohydrates and protein.
3. Go for veggies. Emphasize foods that are low in caloric density (that is, low in calories but high in weight). The ideal category: low-starch vegetables, which have a low glycemic index and are rich in valuable nutrients of all kinds, high in fiber, and filling.
4. Eat fiber. Consume at least 25 grams per day, including at least 10 grams of insoluble fiber.
5. Don't switch foods radically. While you are losing weight, we strongly recommend diets that involve eating in a significantly different way from how you intend to eat when not "dieting." People count the days until they are released from this type of gastronomic prison. They do not associate the benefit of weight loss with learning proper eating habits -- changing tastes, desires, and attitudes -- but rather with the artificial eating patterns that they are anxious to leave.
6. Make health, not weight loss, your goal. If you set a healthy lifestyle as your goal, you are more likely to succeed in both improving your health and attaining permanent weight loss. Don't be too anxious to drop pounds right away. Enjoying the experience is crucial. You want to associate the experience of reaching a healthy weight with that of healthy eating. It may take a few months longer, but it will ensure that you'll never have to lose weight again.
7. Don’t get discouraged. A major reason people get discouraged and drop out of weight-loss programs is weight plateaus. Gained muscle mass and blood-vessel expansion due to exercise may temporarily halt weight loss or cause a small gain, but these are actually very desirable phenomena. Since muscle weighs more than fat, you can lose body fat and inches without dropping pounds if you are building muscles at the same time. Changes in medication, menstruation, constipation, water retention, and other factors may also cause weight loss to slow down or even reverse. Remember that your goal is to lose body fat. None of these factors causes an increase in body fat, so do not be discouraged by minor shifts of weight in the wrong direction. Be patient.