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.
9. 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.
10. 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.
