The ideal weight for a woman of any age depends primarily on her body’s Body Mass Index, suggests the Centers for Disease Control and Prevention. BMI is a screening tool used to calculate the amount of fat an individual has in her body. Along with other factors, including activity level, genetics, hormonal changes and osteoporosis risk, BMI can help you and your doctor determine your ideal body weight at age 65 and beyond.
Body Mass Basics
Your BMI is calculated using the ratio of your current weight to your current height. According to the Center for Menopause, Hormonal Disorders and Women’s Health, women lose up to 5 percent of their bone mass in the first two years after menopause, so women age 65 and over can experience changes in their height over time, which means that BMI will change over time as well. Calculating your BMI based on your current height at regular check-ups or other regular intervals can help you and your doctor keep track of your ideal weight.
Finding Your BMI
Calculate your healthy body weight by measuring your height in inches. Multiply that number by itself, then divide that number into your current body weight. Multiply that result by 703 -- the BMI conversion factor -- to determine your BMI. Alternatively, use an online calculator such as one provided on the website of the National Heart, Lung and Blood Institute. A BMI of 18 or less means you are underweight. A BMI of 18.5 to 24.9 means you are in a normal, or ideal, weight range. A BMI of 25 to 29.9 means you are overweight. BMIs of 30 or greater indicate obesity.
Muscle Versus Fat
Along with calorie consumption and activity, biological changes contribute to weight gain in older adults. People lose muscle cells as they age. As a woman age 65 or older, you may weigh exactly the same as you did when you were 35, but you probably have a smaller percentage of muscle, UCLA researcher and geriatrician Jonathan Wanagat told Pattie Neighmond of NPR in 2010. This accounts for the change in how your body looks. It also means you burn fewer calories overall since muscle burns more calories than fat. Calculating your BMI to determine your ideal body weight at your yearly check-up or on your own can help you control weight fluctuations more easily.
Although consuming fewer calories is part of maintaining a healthy weight at age 65, increasing your daily activity is an important part of the equation. Health.gov recommends at least 30 minutes of moderate-intensity physical activity each day to maintain a healthy body weight. But to prevent weight gain, you may need up to 60 minutes of moderate to vigorous activity most days of the week -- while not consuming more calories. Use your BMI calculations to determine whether or not you are on the right track to maintaining the ideal body weight for your age.