Key Points about BMI
- Body mass index (BMI) is a measure of relative size based on the mass and height of an individual.
- BMI is a simple, inexpensive, and noninvasive alternative measure of body fat.
- BMI should be used as a screening tool to identify potential weight problems in individuals.
- Factors such as age, sex, ethnicity and muscle mass are not accounted for in BMI.
- Because BMI does not measure body fat directly, it should not be used as a diagnostic tool.
What is BMI?
BMI is used as a screening tool to indicate whether a person is underweight, overweight, obese, or a healthy weight for their height. If a person’s BMI is out of the healthy BMI range, their health risks may increase significantly.
What do the numbers mean?
- < 18.5: A BMI of less than 18.5 indicates that you are underweight. You may need to put on some weight. Ask your provider for advice.
- 18.5 – 24.9: A BMI of 18.5-24.9 indicates that you are at a healthy weight for your height. By maintaining a healthy weight, you lower your risk of developing serious health problems.
- 25 – 29.9: A BMI of 25-29.9 indicates that you are slightly overweight. You may be advised to lose some weight for health reasons. Talk to your provider for advice.
- > 30: A BMI of over 30 indicates that you are overweight. Your health may be at risk if you do not lose weight. Talk to your provider for advice.
Health Lifestyle Tips
Exercise and get at least 30 minutes of physical activity each day. Some ideas are:
- Go on a walk
- Take the stairs instead of the elevator
- Park farther away and walk
- Go on a bike ride
- Go on a jog
- Go swimming
- Go on a hike
- Play a game of basketball or soccer
Nutrition is an important part of a healthy lifestyle. Some ideas are:
- Eat a health breakfast
- Cut out snacking
- Cut out soda
- Don’t eat 2 hours before bed
- Drink at least 9 cups of water a day
Girls and boys develop differently and have different amounts of body fat at different ages. A child’s age gender, height, and weight are taken into consideration when looking at their BMI. Children are then placed in a percentile based on both age and gender.
Nearly one third of children or teens in the US are overweight or obese. Carrying extra weight as a child or teenager can pose significant health risks, both during childhood and into adulthood.
Maintaining a healthy weight during childhood is especially important for heart health. Research shows that nearly 60% of overweight children aged 5-17 had at least one risk factor for cardiovascular disease and 25% had two or more. Obese children have an 80% chance of staying obese their entire lives.
Heart disease, often caused by high blood pressure or high cholesterol, is not the only health risk of obesity. Childhood obesity may also lead to significant health problems, including:
- Type 2 diabetes
- Sleep apnea
- Psychological stress, including low self-esteem, caused by the social stigma of being obese.
BMI does not tell the whole story. It is very common for kids to gain weight quickly and see their BMI go up during puberty. It is important to talk to your provider if you have questions about whether your child is at his or her ideal weight.
If you are concerned about your child’s weight, encourage them to be active and help them to eat healthy.
- Go on a bike ride
- Play a sport
- Play at the park
- Limit screen time to less than 2 hours a day
- Offer fruits and vegetables as snacks
- Replace soda with water or low-fat milk
- Save “treats” for special occasions
- Cut out fried food
- Give children smaller portions than adults
- Don’t use food as a reward
- Limit fast food