Your ideal weight depends on more than just your age. Your gender and height also play a role in determining a healthy size. Measurements such as body mass index and body composition analysis that aren't specific to your age help you ensure you've got a healthy ratio of lean mass to fat, too. Even if your weight is "ideal" for your height, you might carry too much body fat, which still puts you at risk for diseases associated with obesity.
Height and Gender Determine Ideal Weight
You can't determine your ideal weight according to age alone. A healthy weight truly depends on your height and gender, regardless of how old you are. Taller people naturally weigh more than petite folks. And, men usually weigh more than women of the same height because they have a greater amount of muscle, which is denser than fat. Keep both factors in mind when considering your weight.
For example, a healthy weight for a person standing 4 feet 10 inches tall is 91 to 118 pounds, while a 6-foot-3-inch person can be healthy at any weight between 152 and 199 pounds. These ranges account for different body shapes and age-related changes in fat and muscle ratios.
BMI is Based on Height and Weight
Your body mass index, or BMI, helps you determine if you're carrying too much fat for your height. BMI isn't age-specific but uses a computation that relates your height to your weight. You can use an online calculator to determine your BMI, or calculate it yourself using this formula:
BMI = weight in pounds / (height in inches x height in inches) x 703.
Note that age doesn't play a role in the formula.
A healthy BMI is between 18.5 and 24.9. Underweight people have a BMI below 18.5, and overweight people are above 25. A BMI of 30 or greater is classified as obese. BMI isn't perfect as it can measure muscular people as being overly fat and miss an abundance of fat in sedentary and older adults. But, for the average 35-year-old, BMI is a starting place to evaluate your weight.
Waist Size as a Measure of Fatness
Regardless of your age and total weight, a large waist size puts you at a higher risk of disease. A man whose belly measures greater than 40 inches around or a woman whose belly is 35 inches around carry too much visceral, or belly, fat. This type of fat is particularly inflammatory and can increase your risk of chronic conditions, including cardiovascular disease, type-2 diabetes and some cancers.
To measure your waist, use a flexible tape measure and encircle your natural waist -- that's usually just above the hipbones for men and slightly above the belly button for women. Breathe out just before recording the measurement.
Body Fat Measures
More precise ways to measure your body fat include body fat scales and calipers. The most accurate and in-depth measures, such as DEXA scans or hydrostatic weighing, require special equipment and trained specialists. Understanding how much body fat you carry gives you a good picture as to whether your body is optimally healthy. A man with more than 20 percent fat and a woman with more than 30 percent fat are at a higher risk of disease associated with obesity. No matter your age, these body fat levels indicate a high possibility of poor health.
For optimal health, a man should aim for a fit level of body fat between 14 and 17 percent and a woman between 21 and 24 percent, according to the American Council on Exercise.