A Primer on Weight
It's easy to blame your thyroid for the fact that you've recently put on some pounds. But in reality, many factors influence your body weight, and your thyroid is only one of them — albeit an important one. Other factors that influence your body weight include:
Genetics. Your genes affect your appetite, your BMR, and your distribution of body fat. They may also influence your susceptibility to becoming overweight.
Hormones. The body makes many hormones that regulate weight, mostly to ensure it doesn't go down. For primitive man, the problem was not enough food, so most hormones evolved to prevent weight loss.
Diet. The types of food you eat and the amount you ingest have a direct effect on your weight.
Exercise. The more physical activity you do, the less likely you are to gain weight.
Body composition. Muscle naturally burns more calories than fat.
Age. As you get older, your metabolism slows, so that you can't eat the same amount you did when you were younger without gaining weight.
People in the process of gaining weight are basically taking in more calories than they're expending. The process of becoming overweight or obese is often a slow, insidious one that you may not realize is happening until you try to squeeze into a pair of old jeans or you go shopping and realize you've jumped up a size.
Being overweight is a serious problem in the United States. Approximately two-thirds of the population is now overweight, with a third of those people being obese. This excess weight puts them at significantly higher risk for diseases such as diabetes, cancer, heart disease, and premature death.
But how do you know for sure if you really are overweight? Snug jeans or a bigger dress size are one measurement, but a more scientific method is to calculate your body mass index (BMI). BMI doesn't measure body fat, but it does tell you how your body weight relates to your height. For adults over the age of twenty, the formula is your weight in pounds divided by your height in inches squared (multiplied by itself), times 703. So if you are five foot seven and weigh 130 pounds, you have a BMI of 20.4. Here's what the number reveals:
BMIs under 18.5 are considered underweight.
BMIs between 18.5 and 24.9 are considered normal.
BMIs between 25.0 and 29.9 are considered overweight.
BMIs above 30.0 are considered obese.
Essential
For a quick calculation of your body mass index (BMI), visit the Centers for Disease Control and Prevention Web site at
The bottom line on weight management is simple: to lose weight, you need to expend more calories than you take in. To gain weight, you need to ingest more calories than you burn. Unfortunately, for many people, actually losing weight — and keeping it off — is an incredible challenge. The odds are stacked against most people, who must battle against hormones that prevent us from losing weight, a lifetime of ingrained habits, and lifestyles that discourage activity.
