Definition of Obesity
Obesity is an excess of body fat that frequently results in a significant damage of health. Obesity results when the size or number of fat cells in a person’s body increases. A normal-sized person has between 30 and 35 billion fat cells. When a person gains weight, these fat cells first increase in size and later in number. One pound of body fat represents about 3500 calories.
When a person starts losing weight, the cells decrease in size but not in number. This is part of the reason that once you gain a significant amount of weight, it is more difficult to lose it.Studies that have been published in 1998 seem to found out that fat cells can be destroyed. A decrease in fat cell number may occur if a lower body weight is maintained for a prolonged period of time and in combination with some medications.
Each fat cell weighs a very small amount (about 0.4 to 0.6 micrograms). However, the weight of billions and billions of fat cells adds up significantly. Obviously, it is not very practical to count and measure the number of fat cells in a person’s body, so science has come up with easier methods to determine if a person is obese.
The most commonly used method involves tables of desirable weights by height. Life insurance companies have developed these over the years by determining people’s average heights and weights.
However, a better method that more closely correlates with body fat and the metabolic complications of obesity is the Body Mass Index (“BMI”).
Causes of Obesity
Obesity results when there is an imbalance between energy intake and energy expenditure. In other words, you consume more calories than you expend in your daily activities. Weight gained during certain critical periods, that is difficult to treat and to reduce, are the following:
1) between 12 and 18 months of age
2) between 12 and 16 years of age
3) adulthood (when a person gains in excess of 60% of the ideal body weight)
4) for women during pregnancy
During these periods, an excessive amount of weight gain causes an increased number of fat cells. Once a fat cell is formed, you generally cannot get rid of it.