Here is an unusual way of burning calories: making the body use up calories by keeping itself warm.

Imagine a 182-pound man, 5 feet 9 inches tall, with a semiactive profession. During his normal routine he eats and uses up on average about 2,400 calories a day.

Let’s pinpoint exactly how and where he uses these calories:

• 300 calories per day ensure that his vital organs and functions work: the heart, brain, liver, kidneys, and so forth. Very little energy is used for all this, showing how well our organs are energy is used for all this, showing how well our organs are adapted to survive; so we cannot get our bodies to increase energy consumption here.

• 700 calories per day are needed for motor activity and movement. Plainly we have the means of increasing this activity. I realized how vitally important exercise is for losing weight and, even more so, for stabilizing it in the long term. I have therefore made walking one of the sacred tenets of my method. Now, I no longer "recommend” walking—I "prescribe” it as I would for any medicine.

• 1,400 calories per day, the main amount, covers our metabolic requirements, and over half is used to keep our central body temperature at around 98.6 degrees Fahrenheit (37 degrees Celsius), essential for our survival. This then is the area where we can and will increase energy consumption.

To do this we just have to accept the idea that the cold can become a friend and ally of the overweight. Long gone are the days when humans warmed themselves by open fires. We have long since conquered the cold, sparing our bodies the task of keeping us warm by employing a whole range of external protection (central heating, clothes), which nowadays we too often take to extremes. Studies show that the average Westerner is overprotected against the cold, and overweight people, with their layer of fat, even more so. No longer adapted to cope with the cold, when forced to do so our bodies burn up huge amounts of calories just to maintain our vital internal temperature.

The technique I suggest here increases the number of calories you use to keep yourself warm. and consists of a series of simple but highly effective measures that I’ll list below. First, though, you need to know that the human body has to maintain its temperature above 95 degrees Fahrenheit (35 degrees Celsius) to sustain life.

Eat Cold Food As Often As Possible

When you put hot food in your mouth, not only do you absorb its calories, you also absorb the heat in the food, which provides heat that helps maintain your body temperature at 98.6 degrees Fahrenheit (37 degrees Celsius). Your body stops burning its own fuel and uses the heat in the food.

On the other hand, when you eat cold food, your body has to heat it up to body temperature before it can be absorbed into your bloodstream. This operation not only burns calories but also has the added advantage of slowing down digestion and assimilation, thereby delaying the return of your appetite.

Obviously, I am not advising you to eat cold food all the time, but whenever you have the choice between a hot or cold dish, choose the cold one.

Enjoy Cold Drinks

Eating cold food is not always pleasurable. However, having a cold, calorie-free drink is a simple habit to adopt, and can be very effective. When you take 2 quarts of water from your fridge its temperature is 39.2 degrees Fahrenheit (4 degrees Celsius). After you have drunk it, you will then eliminate it in your urine at 98.6 degrees Fahrenheit (37 degrees Celsius). To bring the temperature of this water up from 39.2 degrees Fahrenheit (4 degrees Celsius) to 98.6 degrees Fahrenheit (37 degrees Celsius), your body has to burn 60 calories. Once this becomes a habit, you can burn 22,000 calories a year, equivalent to almost 6 pounds and a godsend for anyone who finds stabilization difficult.

Conversely, a cup of very hot tea, even if you use artificial sweetener, nevertheless gives you a dose of heat that adds a few crafty calories that few people know about.

Slim in the Shower

Try this simple experiment: Take a shower holding a plastic thermometer (a glass one might slip out and break). Let the water run until the thermometer reads 77 degrees Fahrenheit (25 degrees Celsius). What could you compare this temperature to? A pleasant dip in the sea in the summer! If you stay under the shower for 2 minutes, your body has to expend almost 100 calories just to prevent your temperature from going down, the same amount you would use to walk about 2 miles.

This refreshing shower is most effective when the water is applied to the areas of the body where the blood circulating is the warmest: the armpits, groin, neck, and chest, where the large arteries are nearest to the skin’s surface, so most heat will be lost. Avoid getting your hair wet or showering your back at this temperature as it serves no purpose and can be unpleasant. If you are one of those people who are just too sensitive to the cold, you can still lose a few calories by showering those parts of your body that can handle cold temperatures: your thighs, legs, and feet.

Avoid Overheated Environments

In winter an indoor temperature of 77 degrees Fahrenheit (25 degrees Celsius) encourages the tendency to put on weight. For anyone wanting to lose weight, lowering the temperature to 72 anyone wanting to lose weight, lowering the temperature to 72 degrees Fahrenheit (22 degrees Celsius) or lower can make the body burn an extra 100 calories a day, the equivalent of running for 20 minutes.

Do Not Wrap Up So Much

When the cold weather arrives, more often out of habit than necessity you get out all your sweaters and warm underwear. At night, many people put on extra blankets, less out of a real need for warmth than for the pleasure of feeling snug. Make a choice and get rid of at least one of these three protective layers: warm underwear, sweaters, or extra bedcovers. You will burn up 100 calories every day by simply doing this.

Wearing tight or clinging clothes is not recommended. We sweat a little when dressed; this is to refresh the body and to lower body temperature and should be encouraged by wearing clothes as loosely as possible. By adding up all these ways of burning up energy, we can understand the importance of using the cold to help stabilize difficult weights:

Drinking 2 quarts of water at 50°F (10°C) forces your body to burn

60 calories

Sucking 6 flavored ice cubes 60 calories

A 2-minute shower at 77°F (25°C) 100 calories

Lowering the room temperature 5°F (3°C) 100 calories

Going without thermal underwear, a sweater, or extra blanket 100 calories Total 420 calories

Everyone knows from experience just how much it costs to heat a badly insulated house. Our bodies work on the same principle, so we can make use of this and get our bodies to start using up some of those calories they like to hoard.

Cooling your body can be very useful in a tricky third stage, when sometimes something very small can make all the difference and turn things round. Modest but regular calorie usage to tackle the cold can be that little extra that guarantees success.

If you doubt me, test the technique on your own, and you will not need any more convincing.

If you have a less extreme predisposition to gaining weight, this technique is not crucial. However, you can make use of it at risky times such as holidays, celebrations, and parties, or you can select a cooling-down day you are comfortable with.

I would also like to add that confronting the cold can be a useful exercise if you feel a weakness in certain areas of your psychological makeup, or if you have a desire to strengthen your willpower in areas where you already feel strong. Facing up to cold temperatures can also help you face up to weaknesses in your eating habits.

To finish, I would say that heat and comfort soften you up, whereas the cold makes you dynamic, encourages muscular activity, and strengthens the working of the thyroid. I have known many depressed people who began to sing once they started taking a colder shower.