How to Change BMI

BMI, or body mass index, is a measure of height-weight proportion commonly used by doctors to determine whether a person is underweight, healthy weight or overweight. The Centers for Disease Control and Prevention defines a person with a BMI below 18.5 as underweight, 18.5-24.9 as normal weight, 25.0-29.9 as overweight, and 30.0 and above as obese. You can change your BMI by gaining or losing weight.

Step 1

Determine your BMI to see whether you are underweight or overweight. Divide your weight in kilograms by your height in meters squared. If your BMI is under 18.5 you are underweight and you should try to raise your BMI. If your BMI is at least 25.0, you are overweight and you should try to lower your BMI. If your BMI is between 18.5 and 24.9 you are a healthy weight and you should try to stay within that range.

Step 2

Adjust your caloric intake. If you need to raise your BMI, you should consume more calories; if you need to lower your BMI, you should consume fewer calories. Practice portion control and include low-calorie foods like fresh fruits and vegetables to cut calories, or include healthy calorie-dense foods like avocado, rice and cheese to raise your caloric intake. Be sure to eat at least 1,200 calories each day to avoid stunting your metabolism.

Step 3

Adjust your exercise routine. If you're trying to lose weight, increase the frequency and length of your workout sessions and focus on calorie-blasting activities like running or kickboxing. If you need to gain weight, try a weight-lifting routine to add lean muscle. Find activities you enjoy to keep your workout routine interesting, and commit to a schedule to keep yourself accountable.

Step 4

Be patient. Changing your weight is a slow process, and gaining or losing weight too quickly is unhealthy and dangerous. Aim to lose or gain one to two pounds per week, and don't be frustrated if it takes some time to see results.