A to Z Health Guide

Is Your Child Overweight or Obese? It Could Affect their Kidneys in the Future

kid's lunchMore Americans are overweight today than ever before, but the problem has also become more common in children. About 17% of children and adolescents aged 2-19 are obese, and 10% of children aged 2-5, according to the Centers for Disease Control and Prevention (CDC). More than one third of children and adolescents are overweight or obese.

What is the difference between being overweight and being obese?

Overweight and obese are both terms for having more body fat than what is considered healthy. These terms 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." Another difference between the two terms is that being overweight can result from things other than too much body fat (for example, more muscle mass), however being obese only results from an excess of body fat.

Everyone needs some body fat for energy, heat insulation, and other body functions. However, if more fat and calories are consumed than used up, then gaining too much weight can result. Having too much body fat can lead to serious health problems. The more excess body fat your child has, as they get older, the greater their risk for diabetes, kidney disease, heart disease, and other problems.

How do I know if my child is overweight or obese?

The most common way to find out whether your child is overweight or obese is to figure out your child’s 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 child’s weight to what is considered "normal" for a child of the same age.

How is BMI calculated in children and teens?

In general, BMI is calculated from height and weight. 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

To find your child or teen's BMI, ask your child’s healthcare provider.

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

Children and adolescents who are obese are also at risk of having serious health problems. They are more likely to have high blood pressure or high cholesterol. They are also at higher risk for diabetes (high blood sugar), and are more likely to develop bone and joint problems.

Children who are obese are more likely to be obese as adults. As time goes by and they get older, children and adolescents who are obese have a higher risk for a number of health problems, including not only diabetes and high blood pressure, but also heart and blood vessel disease, certain types of cancer, arthritis, and even kidney disease.

How can being overweight or obese increase my child’s risk for kidney disease?

Some studies have shown that childhood obesity is associated with a higher risk of kidney disease over time. If your child is overweight or obese, as they get older they have a greater chance of developing diabetes or high blood pressure, which are not only risk factors for heart disease, but also the leading causes of kidney disease. As the blood filtering units of your body, your kidneys are prone to problems with blood circulation and blood vessels. High blood pressure and high blood sugar from diabetes can place an additional strain or burden on your kidneys. The kidneys may also have to work harder to meet the higher demand from the excess weight.

What causes overweight and obesity in children?

Basically, similar to adults, children and adolescents become overweight or obese from taking in more calories than they burn off. Their bodies store the extra calories as fat. There are many different reasons, or factors, for children to gain excess weight, which can include the following:

  • Poor diet (soda and other sugary soft drinks, candy, chips and other salty snacks, fast food, processed food, etc.)
  • Oversized portions of unhealthy foods
  • Advertising of less healthy foods
  • Limited access to healthy affordable foods
  • Lack of exercise and an underactive lifestyle (spending too much time watching television, playing video games, being on a computer or smart phone for long periods of time, being in a car rather than walking)
  • Lack of available space near the home for children to play and be active
  • 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
  • Negative emotions like boredom, which may influence eating habits

Not all factors impact children the same way. For example, access to open space and healthy foods may differ between communities. Knowing the factors that can impact a child’s weight and level of activity is an important first step. Once you are aware of these factors, then they can be addressed.

Can I improve my child’s health by losing excess weight?

Yes. Losing excess weight can help prevent or control many health problems, including diabetes and high blood pressure. You should speak to a healthcare professional about age-appropriate weight-loss steps for your child, and discuss any health considerations before beginning any new diet, exercise, or activity. You will also want to avoid too much weight loss in too short of a time. There are many different steps that can help, including the following:

  • Reinforce a healthy diet and good nutrition for your child
  • Serve your family water instead of sugary drinks
  • Limit candy and salty snacks
  • Prepare meals that are the appropriate portion size
  • Make sure your child eats regular meals (breakfast, lunch, and dinner) and healthy snacks
  • Get your child involved in preparing meals
  • Make sure your child gets regular exercise and physical activity each day (also make sure the activities are appropriate for your child’s age and any medical conditions they may have)
  • Limit media time for your children. Media time can include television, smartphones, tablets, and computers
  • Remain positive and supportive. Encourage your child if they are having difficulty staying with a diet or physical activity. Reward your child when they succeed

The key is to focus on overall health, and not just losing weight. That means not only making you’re your child takes in in fewer calories, but that the foods are nutritious, satisfying, and taste good. Just like a healthy diet, exercise and physical activity also need to be fun and things they would want to stay with. There are many ways to incorporate more physical activity into your child’s schedule, such as walking the dog together, walking more instead of being in the car, and getting them more involved in house and yard work. It will also be easier for your child if you have more physical activity as a family. Making sure that you and your family participate in fun activities throughout the year can help everyone maintain healthy habits.

Finally, parents and guardians are the most influential figure in a child’s life. If you have healthy habits, then it makes it easier for your child to learn and maintain healthy habits.

Teaching your child how to eat better and get more physical activity, while they are young, will help them live a healthier lifestyle throughout their life.

The information shared on our websites is information developed solely from internal experts on the subject matter, including medical advisory boards, who have developed guidelines for our patient content. This material does not constitute medical advice. It is intended for informational purposes only. No one associated with the National Kidney Foundation will answer medical questions via e-mail. Please consult a physician for specific treatment recommendations.