Determining Your Body Mass Index Your BMI gives a fairly accurate assessment of how much of your body is composed of fat. What's Your Healthy Weight? In today's society, there's much confusion over what constitutes a healthy weight. Here are some ways to find out where you stand on the weight issue. Metabolism's Weighty Role To stay at the same weight you were when you were younger, you just need to keep doing what you've always done—and maybe a bit more. Obesity Treatment Overview Whatever treatment plan a person follows, losing weight slowly will be more effective and healthy over the long term.