What is the difference between BMI and body fat percentage?

  • 2 Minutes Read
Brenda Braslow
Brenda Braslow, MS, RDN, LDN, CDCES - Registered Dietitian Nutritionist and Certified Diabetes Care and Education Specialist (CDCES)

So, what is the difference between BMI and body fat percentage? Weighing yourself regularly, tracking your body measurements, and noticing how your clothes fit are good ways to tell if your weight is headed in the right direction. Learn more about how BMI and body fat percentage reveal even more about your health than you thought.

The difference between BMI and body fat percentage

Breaking down the difference between BMI and body fat percentage

When you log your weight into MyNetDiary, our program automatically calculates your BMI (Body Mass Index) to guide you toward a healthy body mass ratio. In general, according to a BMI chart, a BMI under 20 indicates being underweight and anything over 25 indicates being overweight.

BMI is a calculation of your weight relative to your height. The BMI is a rough indicator of body fat, but it is not the same as having your actual body fat percentage measured. BMI is a calculation that does not consider frame size, body composition, or even sex. Clearly, every body differs, so your BMI may not completely and accurately indicate your real body fat percentage.

So why care about body fat percentages at all? Well, you certainly don't have to. The BMI is there to guide you toward a healthy weight. BMI is quick and easy to calculate, and doctors and trainers commonly use it to reference weight classifications. However, knowing your body fat percentage may show that your weight loss is primarily fat loss, or that you are building muscle.

Too little and too much body fat can be risky for health

Your body needs some fat. There's no way around that. It relies on fat for insulation, energy storage, producing hormones, and other metabolic functions. Those who have too little body fat risk their health just like those who carry too much of it. If a woman dips too low in body fat, for instance, she can stop menstruating and experience thinning hair or loss.

Like your BMI, your body fat percentage can also place you into specific health and fitness categories. According to the American Council on Exercise, athletic females range from 14 to 20 percent body fat (again, not BMI); athletic men range from 6 to 13 percent. Fit women are between 21 and 24 percent body fat, and fit males are 14 to 17 percent. Average women are 25 to 31 percent; average men are 18 to 24 percent. And obese women are over 32 percent body fat, while men are over 25 percent

The highest health risk occurs when excess body fat is around your waist, especially near your internal organs (also called "visceral fat"). Having excess visceral fat is associated with an increased risk of type 2 diabetes, cardiovascular disease, high blood pressure, and dementia.

How to measure your body fat percentage

The different ways to measure body fat can be easy and cheap or more expensive, requiring specialized equipment and technicians.

Ways to get your body fat percentage tested

Remember, tracking diet and exercise with MyNetDiary can help you decrease your calorie intake while increasing activity-a proven combination that can help you lose weight. If you have high results for BMI and body fat, losing weight will help you reduce those numbers and make a difference in your health.

Original contributions by Ryan Newhouse - health writer, MyNetDiary

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Weight Loss->Body composition
Feb 26, 2021
Disclaimer: The information provided here does not constitute medical advice. If you are seeking medical advice, please visit your healthcare provider or medical professional.

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