Obesity and Overweight: What You Should Know

More people are overweight today than ever before. In fact, almost 70 percent of Americans aged 20 and older are overweight. And of those, about one third are considered obese. Unfortunately, the problem has become much more common in children, too. Surprisingly, 17 percent of children aged 6-19 are obese, and 10 percent of children aged 2-5.

What is the difference between being overweight and being obese?

Being overweight or obese are both terms for having more body fat than what is considered healthy. Both are used to identify people who are at risk for health problems from having too much body fat. However, the term "obese" generally means a much higher amount of body fat than "overweight."

Everyone needs some body fat for energy, heat insulation, and other body functions. But having too much can lead to serious health problems. The more body fat you have, the greater your risk for diabetes, kidney disease, heart disease, and other problems.

How do I know if I'm overweight or obese?

The most common way is to figure out your body mass index (BMI). BMI is a quick and simple way to help identify people who are overweight or obese. It allows you to compare your weight to what is considered "normal" for an adult with your same height.

How is BMI calculated?

In adults:

  • BMI is calculated from your height and weight. To find your BMI, multiply your weight in pounds by 704.5. Then, divide the result by your height in inches and divide that result by your height in inches a second time.
    • A BMI between 25 and 29.9 is considered overweight
    • A BMI of 30 or more is considered obese
  • It is important to note, however, that BMI estimates body fat. It does not directly measure body fat. As a result, some people with muscular builds, such as athletes, may have a BMI that identifies them as being overweight even though they do not have excess body fat.

In children and teens:

  • To find your child or teen's BMI, ask your healthcare provider.
  • BMI for children and teens is calculated differently than it is for adults. This is because children are still growing, and boys and girls mature at different rates. The child or teenager's height and weight is compared against growth charts that take age and sex into account. The result shows how a child or teenager's BMI-for-age percentile compares with other boys and girls of the same age.
    • The 85th to less than 95th percentile is considered overweight
    • The 95th percentile or greater is considered obese

Does it matter where the excess weight is located?

Yes. If your excess weight is mostly around your middle (apple shape), you are more likely to develop health problems than if the weight is around your hips (pear shape). The greater your waist size, the greater your health risk. To learn more, ask your healthcare provider to measure your waist.

What kinds of health problems can develop from being overweight or obese?

Being overweight or obese can cause serious health problems, including:

  • Diabetes
  • High blood pressure
  • Heart disease
  • High cholesterol
  • Stroke
  • Certain types of cancer
  • Gallbladder disease
  • Arthritis
  • Breathing problems
  • Kidney disease and kidney failure

Can being overweight or obese increase my risk for kidney disease?

Yes. If you are overweight or obese, you have a greater chance of developing diabetes or high blood pressure, which are the leading causes of kidney disease and kidney failure.

What causes overweight and obesity?

People become overweight or obese from eating more calories than they burn up. Some things that may lead to this imbalance include:

  • Poor diet / Poor food choices
  • Lack of exercise
  • An inactive lifestyle (spending a lot of time watching television, playing video games, working on a computer, working late hours at the office, driving rather than walking)
  • A family history of being overweight or obese. Children whose parents eat high-calorie foods and are inactive tend to learn these same habits. Genes also play a role. They affect how much fat we store, and where it is stored.
  • Oversized or "supersized" food portions
  • Negative emotions like boredom, sadness, or anger, which may influence eating habits.

Can I improve my health by losing excess weight?

Yes. Experts agree that even a modest weight loss can help prevent or control many health problems, including diabetes, heart disease, and high blood pressure. The closer you are to a normal weight, the greater the health benefit.

What should I do if I am overweight or obese?

Speak to your doctor about a weight loss program that is right for you. New research shows that a weight loss program should include three components to be successful — diet, exercise, and behavior modification. Your program may include:

  • Diet. A steady weight loss of about one pound a week is the safest way to lose weight. Your doctor can refer you to a registered dietitian if you need help in planning your diet.
  • Regular exercise such as brisk walking, running, swimming, biking, dancing. The amount of exercise needed to lose weight is different for everyone. Talk to your healthcare professional before you begin any new exercise program.
  • Behavior modification techniques such as:
    • Keep a food diary of everything you eat.
    • Shop from a list and do not shop when you're hungry.
    • Take a different route if you usually pass by a tempting fast food place.

If you have been unable to lose weight or keep if off with diet, exercise, and behavior changes:

  • Weight-loss medications might be recommended for you.
  • Gastrointestinal surgery is sometimes recommended for people with severe obesity.

What if I have more questions?

  • Speak to your healthcare provider.
  • Ask for a referral to a registered dietitian if you need help in planning your meals.
  • Call the National Kidney Foundation's toll-free number 1-800-622-9010 and ask for publications on diet and exercise.

If you would like more information, please contact us.

©2014 National Kidney Foundation. All rights reserved. This material does not constitute medical advice. It is intended for informational purposes only. Please consult a physician for specific treatment recommendations.