Weight Loss /Metabolism

One-third of Americans are currently overweight. Just 15 years ago, only 25 percent were overweight. This is an increase of 32 percent.The average adult weighs 8 pounds more now than 10 years ago.

Society places a lot of pressure on women to stay thin. In the 1950's fashion models weighed 8 percent less than the average woman. Today, models weigh 25 percent less. Natural weight or "ideal" weight can be described as the weight at which your body comfortably stays while eating for appetite and exercising regularly. Primitive folks burned approximately 2900 calories per day hunting and gathering food. Today the average American burns only 1800 calories.

If both of your parents are obese, you have an eighty percent likelihood of becoming obese. If 1 of your parents is obese, there is a 40 percent probability that you would be obese. If both of your parents are lean however, there is only a 15 percent chance that you will weigh more than 20 percent over your ideal weight.

A study on identical twins indicated that genetics played a critical role in what they weighed. Identical twins separated at birth weighed nearly the same after years of living apart.

Another interesting study was done on twins by researcher Claude Bouchard. Results showed similar weight gains among sets of identical twins when they were fed 1000 extra calories daily for 120 days. A fascinating outcome was the wide variance of weight gain between the sets of twins. Some sets gained as little as 8 pounds with the over feeding while others ballooned up as much as 29 pounds. Clearly this demonstrated that genetics played a major role in weight gain.

But this investigation also demonstrated that there are other influences that determine weight. Some people gain more and others less, with the same stimulus.

Your menstrual cycle is a physiological process which consumes calories. In the post ovulatory phase (the two weeks before your menstrual flow begins) your metabolic rate increases about 200-300 calories per day. At menopause the loss of this function could cause a weight gain of approximately 4-6 pounds a year. That is, if you do not make an adjustment in either your energy expenditure or food intake.

Age is another factor. Between the ages of 30 and 70, it is estimated that your fat free mass (muscle) declines by 40 percent. This is thought to be the single most important reason why you store more body fat as you age. The loss of fat free mass and resulting slow down of metabolic rate makes you susceptible to gaining fat. Each pound of lean tissue burns approximately 50 calories a day. A loss of just half a pound of muscle or 25 calories expended daily, could theoretically cause you to gain 2.6 pounds in a year. In 10 years, 26 pounds. In 20 years, 52 pounds. In 30 years, 78 pounds.

The average female has 27 billion fat cells. Obese women may have as many as 75 billion.

There are 3 critical times when you gain fat cells:

1. The last trimester in the womb.

2. The first year of life.

3. During puberty.

When you gain weight you increase the size of your fat cells. When you lose weight, you decrease the size of your fat cells. Normal cell size is .5-.6 micrograms. The upper limit is 1.0 micrograms. When fat cells are full, your body can make new ones. It is also theorized that you can generate additional fat cells during pregnancy. When you lose weight, the fat cells do not disappear, however. Therefore, if your friend has more fat cells than you, she will ultimately be fatter as each of those cells will contain some fat.

Your body is not physiologically designed to lose weight or fat rapidly. One pound of fat supplies the energy to walk nearly 30 miles. Your body uses about 50 percent fat and 50 percent carbohydrate at rest.

During exercise this will change, depending on your intensity. At higher intensities, you use a greater percentage of carbohydrates. At lower intensities, a higher percentage of fat is used.

Alternating high and low intensity exercise has tremendous advantages for weight loss and weight control for women. You should not be concerned with which fuel you are burning at the moment, but rather how many calories you are expending during and after exercise.

Most women store more fat in their hips and thighs. Lower body adipose stores have more alpha receptors which are inhibitors to fat mobilization and therefore do not readily give up their fat. This makes sense biologically, since women accumulate lower body fat primarily to provide energy to carry and feed their babies.

To receive the greatest value from exercise, strive to become as fit as you can so you burn more calories from fat at rest, and utilize more storage fat during exercise.