Being at a healthy weight means neither weighing too much nor too little. While it may be obvious when your weight is not at the level where it should be, it is not always obvious exactly what a healthy weight for you should be. There are a few methods for determining your optimum weight. One method involves using a simple formula that estimates your ideal weight using your height:

• For women: add 100 pounds of body weight for the first 5 feet of height then add 5 pounds for each additional inch of height. Example: a 5’ 6” woman should weigh about 130 lbs.
• For men: add 106 pounds of body weight for the first 5 feet of height then add 6 pounds for each additional inch of height. Example: a 5’ 10” man should weigh about 166 lbs.
• To account for differences in body type, people with a small body frame should subtract 10% from the weight they calculated. Example: a 5’ 6” woman with a small frame should weigh about 130 - 13 = 117 lbs. For a large frame, 10% should be added. Example a 5’ 10” man with a large frame should weigh about 166 + 17 = 183 lbs.

Body mass index (BMI)

Another way to estimate a healthy weight range is by calculating your body mass index or BMI. The BMI is an indirect measure of the portion of your body that is made up of fat. This is the measure most often used to determine your risk of diseases related to excess weight such as type 2 diabetes and heart disease.

Your BMI takes into account your height and weight; higher numbers mean you carry more fat. If your BMI is above 25 but below 30, you are considered “overweight.” If your BMI is between 30 and 39 you are considered “obese,” while a BMI of 40 or above is considered extremely or “morbidly obese.” Notice that the terms “overweight” and “obese” are not synonyms; medically, they refer to distinct categories of excess weight.

The formulas for calculating BMI are:

• BMI = (weight in pounds/height in inches2) x 703
  -or-
• BMI = weight in kilograms/height in meters2

Here is how to measure and calculate your BMI (using pounds and inches):

• Weigh yourself on your bathroom scale.
• Measure your height in inches using a yardstick or tape measure.
• Take your height in inches and square the number (i.e. multiply the number of inches by the same number of inches).
• Divide your weight in pounds by the answer from above (your height in inches squared).
• Multiply that answer by 703. The answer is your BMI.

Alternatively, if you know your height and weight, you can determine your BMI using a BMI table such as the one found on the National Institute of Diabetes and Digestive and Kidney Diseases Weight-control Information Network: http://win.niddk.nih.gov/statistics/index.htm#table

Body fat measurements

Body fat measurements are used to estimate the percentage of your body weight made up by fat. A registered dietitian or exercise physiologist can help you calculate your body fat.

For women, the recommended amount of body fat is 20 - 21%, while the average American woman has approximately 22 - 25% body fat. A woman with 30% body fat or more is considered obese.

For men, the recommended amount of body fat is 13 - 17% while the average American man has approximately 17 - 19% body fat. A man with 25% body fat or higher is considered obese.

Body shape

While it is never healthy to carry too much excess weight, where you carry the weight on you can have implications for your health.

There are two main types of body shape called “apples” and “pears” based on the parts of the body where people tend to store excess fat. Apple-shaped people have central body fat in the abdomen, mainly around the stomach and chest. Pear-shaped people store excess body fat below the waist in the hips, thighs, and buttocks. Research studies have demonstrated that having an apple shape increases the risk of developing type 2 diabetes, heart disease, and high blood pressure. For unknown reasons, central body fat is more resistant to the actions of insulin and so increases the risk for type 2 diabetes.

To determine if you are an apple or a pear, you can stand in front of a full-length mirror and decide where the majority of your excess weight is stored. You can also use a tape measure to measure your waist just above the hipbone while you exhale (don’t suck in your stomach). The risks of an apple shape increase for women whose waist is more than 35 inches and for men whose waist is more than 40 inches.

The most accurate way to determine your body shape is to calculate your waist-to-hip ratio, or WHR. To get your WHR, measure your waist at the smallest part and your hips at the widest part and then divide your waist measurement by your hip measurement. A healthy WHR for women is 0.80 or below and for men is 1.0 or below.