Excerpt
from Fantastic Voyage: The Science Behind Radical Life Extension
by Ray Kurzweil, Ph.D., and Terry Grossman, M.D.
SOME TIPS FOR HEALTHY -- AND PERMANENT -- WEIGHT LOSS
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.
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, pastas, and breads.
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.
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.
Eat fiber. Consume at least 25 grams per day, including at least 10 grams of insoluble fiber.
Don't switch foods radically. While you are losing weight, we strongly recommend against 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.
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.
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.
Don't rush weight reduction. One of the most important issues in weight loss is recidivism. Most people who lose weight end up gaining it back. Preliminary research on the ghrelin hormone, which is secreted in the stomach, may explain part of this troublesome problem. Ghrelin stimulates appetite at the same time that it slows down metabolism. Both of these effects contribute to increased fat storage. Levels of this hormone spike before each meal and drop after you're full. People given injections of ghrelin become extremely hungry, and studies show they eat much more when unlimited food is available, such as at a buffet.
A recent study at the University of Washington showed that ghrelin levels increase substantially after a period of rapid weight loss. Dr. David E. Cummings, the lead scientist on the study, thinks this was an evolutionary adaptation to encourage the body to regain the lost fat as protection from possible future famine. This genetic program no longer applies to our modern situation. Research is currently under way to develop medications that block ghrelin and its stimulation of appetite and storage of body fat.
Slow, gradual weight loss does not appear to cause the same spike in ghrelin levels, however. This is another important reason to approach your ideal weight gradually. Setting your daily caloric level to match your target weight's maintenance level is the best way to lose weight once and to keep it off.
Get exercise. Physical activity is very important for burning calories, lowering your "set point" (the weight your body gravitates toward), and increasing your metabolic level (rate of burning calories), even while you are not exercising. We recommend burning at least 300 calories daily through exercise.
Raise your metabolic rate. A primary factor in determining your metabolic rate -- the rate at which you burn calories -- is the number of mitochondria in cells. Mitochondria are tiny energy factories that fuel every cell. The more you have, the more energy you will burn, which will keep you leaner. Unfortunately, we cannot simply take a mitochondria supplement. However, fat cells have very few mitochondria because fat cells store energy rather than burn it, whereas muscle cells have many because they need energy to perform their job. So as you build muscle cells from a regular exercise program, you increase your mitochondria, thereby permanently raising your metabolic rate, even when you are not exercising.
Copyright © 2005 Ray Kurzweil and Terry Grossman, M.D.