Determine your basal metabolic rate (metabolism at rest). You can find an online calculator, or you can use the following formulas, depending on your gender: Women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)[1] X Research source Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in year)[1] X Research source Calculate your total daily calorie needs using a formula known as the Harris-Benedict equation. Once you have calculated your BMR, you can estimate your total calorie needs for different levels of activity. Decreasing your metabolism means you are "turning down" your body's internal furnaces, which lowers your calorie requirements. Use your BMR to make the following calculations. If you: Are inactive or exercise rarely: Calories to stay the same weight = BMR x 1.2[1] X Research source Exercise lightly 1 to 3 days per week: Calories to stay the same weight = BMR x 1.375[1] X Research source Exercise moderately for 3 to 5 days per week: Calories to stay the same weight = BMR x 1.55[1] X Research source Exercise actively for 6 to 7 days per week: Calories to stay the same weight = BMR x 1.725[1] X

Research source Exercise intensely every day: Calories to stay the same weight = BMR x 1.9[1] X Research source Understand that "slow metabolisms" aren't necessarily responsible for weight gain. If you want to gain weight, go here for a discussion of how to do so in a healthy way. Doctors generally agree that other factors are more responsible for weight gain or weight loss than your metabolism.[2] X Research source These factors include: How many calories you consume daily. How much and how intensely you exercise. Your genetics and family history. The medications you may be taking. Other unhealthy habits such as not getting enough sleep. Understand that slowing your metabolism might not be the healthiest way to gain weight. Slowing your metabolism can involve some pretty unpleasant things: skipping meals, eating few calories, etc. Proper, medically-sound weight gain often involves: Increasing caloric intake. Eating more calories than your body burns in a day. Addressing any underlying medical issue that might be causing you to lose weight, e.g. thyroid issues, diabetes, anorexia nervosa. Skip meals. If you want to decrease your metabolic rate, start skipping meals. This is not a

healthy way to lower your metabolism, but it's effective. Skipping meals causes the body to think that it might have to start preparing for famine, causing it to lower its metabolism in an effort to save energy.[3] X Research source Eat fewer calories. When you give your body fewer calories, it compensates by lowering your overall metabolic rate.[3] X Research source And it makes sense: with fewer overall calories to work with, your body can't expect to use the same amount of energy that it can when it's getting more calories. Note: When you give your body fewer calories, it might start burning muscles or body tissue in order to compensate for the lack of calories it's getting. If you are already skinny, this isn't a good method for weight gain. Take naps. Every time you sleep, your metabolic rate dips and then remains suppressed for a period after you awaken.[4] X Research source [5] X Research source Replace simple carbohydrates (sugar) with complex carbohydrates (starch and fiber) when possible. Studies show that sugars and fruit are digested and absorbed more rapidly than complex carbohydrates, such as bread, producing a rollercoaster of blood sugar with high peaks and low

troughs.[6] X Research source It has also been shown[7] X Research source that the total carbohydrate oxidation over a six-hour period is lower with complex carbohydrates (bread and maize starch) than with sugars.[6] X Research source Sucrose (table sugar) also contains fructose, while complex carbohydrates are made up exclusively of glucose units. Fructose consumption results in greater thermogenesis (calorie burning) than glucose consumption.[8] X Research source Choose high-fiber foods such as grains (especially whole grains) and vegetables. High-fiber meals have been shown to reduce thermogenesis (calorie burning) for six hours after eating.[9] X Research source Include nuts and seeds in the diet. Of all the foods you can eat, nuts and seeds, which contain almost no moisture and provide healthful unsaturated fats, have the highest caloric density, packing in the most calories per ounce. Polyunsaturated fats, such as those in nuts, have been shown to be oxidized more slowly than monounsaturated fats.[10] X Research source Nuts and seeds are also rich in the amino acid arginine. Arginine is used by the body to make nitric oxide, a gas that has been shown to reduce the metabolic

rate.[11] X Trustworthy Source PubMed Central Journal archive from the U.S. National Institutes of Health Go to source [12] X Research source [13] X Trustworthy Source PubMed Central Journal archive from the U.S. National Institutes of Health Go to source Dress warmly. Heat loss is a major energy drain, so dress warmly to slow down your metabolism. When you are cold, your body increases the levels of uncoupling protein in your cells. Uncoupling proteins interfere with ATP production, resulting in heat instead of useful energy from the food that you eat. Levels of thyroid hormone also rise in this situation. This may serve to initiate the production of uncoupling proteins. Thyroid hormone is "the most significant regulator of basal metabolic rate"[14] X Research source representing about one-half of the BMR.[15] X Research source Huddle with other people if you have company. Move to the warmest area you can find, or build a shelter if you are outdoors. Lie still. Everything that you do burns calories. Even small things like picking up sticks or skipping rocks. After you have been exercising for a while, your metabolism remains elevated for a period of time, even when you are

resting.[16] X Research source [17] X Trustworthy Source PubMed Central Journal archive from the U.S. National Institutes of Health Go to source Every mile that you walk burns 100 calories, and that does not account for the increase in metabolism produced by exercise. Try to sleep if possible. Do not drink cold water or eat snow. Your body will expend energy to warm up the water.[18] X Research source This is energy that you could be saving for a more life-critical task, such as hunting for food for surveying for escape routes.