What Is Childhood Obesity?

The World Health Organization (WHO) has identified childhood obesity as “one of the most
serious public health challenges of the 21st century.” In 2016, WHO found that globally, the number of overweight children under age 5 topped 41 million, and the number between ages 5 and 19 was 340 million.

In the U.S., the Centers for Disease Control and Prevention (CDC) estimates that 19 percent of 2- to 19-year-old American children have obesity, which is about 14.4 million children—or nearly one in five kids. The CDC also reports that the rate of childhood obesity in this country has more than tripled in the past 30 years.

Fortunately, obesity in children can usually be treated through dietary and lifestyle changes. Such changes are important because children who have obesity are likely to remain obese
into adulthood and are more likely to develop weight-related physical problems like diabetes, high blood pressure, and liver and cardiovascular disease. Obesity can also have devastating psychological effects in children and adults alike, including low confidence, social isolation, and depression.

Obesity in children is determined by comparing their body mass index (BMI) to that of other children of their age and sex. This is different from how obesity is determined in adults, which relies solely on the person’s BMI measurement.) BMI is a measure of weight in relation to height, and is calculated by dividing a person’s weight in kilograms by the square of height in meters. You can also use an online tool like the CDC’s Child & Teen BMI Calculator

BMI-for-Age Growth Chart

A child is considered obese if their BMI is at or above the 95th percentile of the CDC sex-specific BMI-for-age growth charts, shown below.

At the most basic level, children—like adults—develop obesity when they eat more calories than their bodies use, called an “energy imbalance.” This can be caused by a variety of factors, including genetics, hormones, metabolic makeup, and medical factors. When a child develops obesity, it’s often through a complex interaction of these and other factors including diet, lifestyle, and environmental conditions.

In other words, certain genetic characteristics may cause a greater tendency to become obese, but if a child eats healthfully and gets plenty of exercise, the gene won’t express itself and the child can maintain a weight in the normal range.

Here is a closer look at various factors that cause obesity in children or are known to increase a child’s risk of becoming obese.

Behavioral Factors

These might include:

• Eating high-calorie, low-nutrient foods and beverages like fast-food, snack foods, candy, and soda

• Eating too much food

• Spending too much time sitting down watching TV or using a computer, tablet, or phone

• Not getting enough exercise. The Physical Activity Guidelines for Americans recommend that children between the ages of 6 and 17 years get at least an hour of moderate to vigorous exercise every day. Children ages 5 and younger should be physically active throughout most of the day.

Environmental Factors

Environmental contributors to obesity can include:

• Lack of easy access to healthful food choice.

• Regularly being served high-calorie, low nutrient meals.

• Lack of ample opportunity for physical activity.

• Lack of access to safe parks, playgrounds, or other areas for physical activity.

• Few or no friends or family with whom to play and exercise.

• Exposure to targeted marketing that promotes junk and fast foods, video games, and a sedentary lifestyle.

Genetic Factors

A child is at higher risk of becoming obese if they have at least one parent who is obese. (However, if obesity runs in the family, there are many ways for parents to help their child lower their risk.)

Several rare genetic syndromes can cause obesity in children, either by causing constant hunger that results in excessive eating or by affecting the way fat is deposited in the body. These include:

• Prader-Willi syndrome

• Pro-opiomelanocortin deficiency

• Leptin receptor deficiency

• Bardet-Biedl syndrome (BBS)

Psychological Factors

Stress, anxiety, and depression all increase a child's risk of obesity. Some children, like some adults, have learned to overeat in order to soothe or avoid difficult emotions like loneliness,
sadness, stress, and boredom.

Socioeconomic Factors

Numerous studies show that people in lower income communities often lack access to supermarkets with fresh fruit and vegetables, instead inhabiting “food deserts” where they can buy only fast food, packaged food, and highly processed prepared foods. Financial hardship can also impact food purchasing, as fast food and high-calorie food is often cheaper than healthier, fresher, but more expensive fare. People who live in lower income neighborhoods might also lack safe places to exercise or the free time and energy to devote to physical activity. All of this helps explain why the obesity rate is much higher in the lowest-income groups in the U.S. compared to the highest-income groups.

Medications

Several classes of medication can encourage weight gain and thereby contribute to obesity, including:

• Steroids

• Antidepressants

• Diabetes medications, including insulin, sulfonylureas, and thiazolidinediones

• Anti-seizure medications, like carbamazepine and valproate

Medical Conditions

Obesity in children and adults can stem from an underlying medical condition, particularly one affecting the endocrine system. Two examples are hypothyroidism (underactive thyroid), in which the thyroid gland secretes too little thyroid hormone, leading to slow metabolism and weight gain; and Cushing’s syndrome (also called Cushing’s disease), a condition marked
by excessively high levels of cortisol. Cushing’s syndrome causes weight gain in the upper body, face, and between the shoulders and can lead to obesity.

In addition to excessive body weight, typical signs and symptoms of childhood obesity include:

• Shortness of breath

• Fatigue

• Increased sweating

• Sleep apnea and snoring

• Joint pain

• Dislocated hips

• Flat feet and knock knees

• Skin rashes and irritation

• Stretch marks on hips, abdomen, and back (though these can occur in non-obese children as well)

• Acanthosis nigricans, which is dark, velvety skin around the neck and in other areas

• Fat tissue in the breast area (which can be particularly challenging for boys)

• Constipation

• Gastroesophageal reflux (also called acid reflux)

• Early puberty in girls

• Delayed puberty in boys

Childhood obesity can lead to immediate health problems as well as put your child at greater risk of developing medical issues in the future. These are some of the weight-related complications that children with obesity are at increased risk of:

• Asthma

• Type 2 diabetes

• High cholesterol

• Heart disease

• High blood pressure

• Gall stones, fatty liver disease, or kidney disease

• Arthritis

• Reproductive problems like irregular menstruation and hormonal imbalances

• Heartburn, reflux, and other digestive problems

• Sleep disorders like sleep apnea

Additionally, children who are obese have an increased risk of being overweight or obese as adults.

Obesity can have a significant negative effect on a child’s mental health, contributing to problems including:

• Anxiety

• Depression

• Low self-esteem

• Being bullied or socially isolated from peers

• Prejudice from adults in their lives like relatives, teachers, and health care provider

“Weight stigma is one of the most prevalent forms of bullying that kids and adolescents face,” says Rebecca Puhl, PhD, a Professor of Human Development & Family Sciences at the University of Connecticut and Deputy Director of the Rudd Center for Food Policy & Obesity. “Children internalize weight stigma and often feel like they’re at fault for their weight.”

Carrying excess weight can interfere with the social and personal growth that are an important part of childhood development, adds Josh Jonas, LCSW, a licensed psychotherapist and clinical director/co-owner of The Village Institute for Psychotherapy in New York City.

“Part of what childhood is about is learning to be social and to begin mastering things, like how to be with people, sports, extracurriculars,” Jonas says. “If you’re successful at those things, you will be more likely to develop a good sense of self. If you’re carrying excess weight, that can make those things much more difficult, and it can take a toll on developing self-esteem.”

Childhood obesity can be diagnosed when a child’s BMI is at or above the 95th percentile of the CDC sex-specific BMI-for-age growth charts. Being in the 95th percentile means that compared with other children the same age and sex, your child has a higher BMI than 95% of them.

Children grow at different rates, however, so BMI alone can sometimes be misleading. To make a diagnosis, a health care provider will generally take into account other factors such as:

• Any weight-related symptoms or health conditions the child is experiencing

• Family history of obesity

• Activity level

• Dietary habits

• Sleep patterns

• Mental health or psychological conditions

• Physical exam results, including vital signs like heart rate and blood pressure

• Results of lab tests for cholesterol, blood sugar, hormone levels, and thyroid function

Which treatment is best for childhood obesity depends on your child's age, family history, and medical conditions, among other factors. Treatment will almost always include changes in diet and activity level, as well as learning and practicing new coping mechanisms for boredom, anxiety, disappointment, and sadness. In some cases, treatment can also include medications or, less commonly, weight-loss surgery.

Talking with your pediatrician about your child’s diagnosis and treatment options is a good place to start. Here is a detailed look at the main treatment options.

Lifestyle Changes

If your child has been diagnosed with obesity or is overweight, adopting some or all of these measures can help your child reach and maintain a healthy weight. If your child is not currently overweight, the same steps can help prevent obesity over a lifetime. Another benefit: Embracing healthy lifestyle measures as a family will improve not just your child’s health but that of everyone in the household.

1. Make sure your child gets adequate exercise. In addition to burning calories, physical activity strengthens children’s bones and muscles, helps them fall asleep and get good quality rest, and can boost their mood and energy. Experts recommend that children get between 150 and 300 minutes per week of moderately intense physical activity. This can take many forms, from going outside for a hike or game of tag to sliding around the house in your socks to having a dance party in your living room. Some other popular ideas: playing at a playground, playing hide-and-seek, jump-rope, having races on foot or bike, dance or martial arts classes, roller skating/rollerblading, swimming, and biking.

2. Serve healthy foods. Focus on serving your child whole foods like fruits, vegetables, whole grains, seeds, nuts, and lean proteins. Emphasize fresh fruits and vegetables in particular. Cut back on processed and convenience foods like cookies, crackers, fast food, and prepared meals, all of which can be high in sugar, fat, and calories. “Put healthy snack and meal choices in the kitchen or pantry at eye level,” suggests Michelle Sands, ND, a licensed Naturopathic Physician specializing in hormones, metabolism, and epigenetics. “Put anything you want them to eat on a stick – such as fruits, vegetables, kabobs – and accompany them with healthy dips. Get your kids involved in cooking healthy meals and making them feel like they’re part of it.”

3. Limit sweetened beverages. Fruit juice and sodas can be high in calories, low in nutrients, and can fill your child up, making it hard for them to eat the food that will keep them healthy and satisfied between meals. Serve water, seltzer, milk, or diluted fruit juice instead.

4. Limit take out and eating out. Restaurant meals are often high in sodium and fat, which can contribute to obesity and high blood pressure. They are also often served in quantities much bigger than a child needs.

5. Eat together, sitting down, for family meals. Try to avoid the TV, computer, or video games at mealtimes, which can encourage overeating and distract kids from their satiety signals. Model healthful, mindful eating where you focus on and enjoy your food. And try to have everyone in the household eat the same thing. “Don’t give one kid a special [healthy] meal and everyone else has pizza,” Dr. Sands says. “Kids follow their parents’ lead — if they see you on the couch eating ice cream they’ll want to do it too.”

6. Don’t make your child clean their plate. Allow them to eat until full, and then don’t force them to “clean their plate,” which teaches children to override fullness cues. You can save leftovers to serve at a future meal. Remember, children don't need as much food as adults do. Their portion sizes should be smaller, and if they say they’re full, allow them to stop eating.

7. Make sure your child gets enough good quality sleep. Not getting enough sleep can lead to weight gain by increasing levels of ghrelin, the hormone responsible for appetite. Too little sleep can also rob your child of the energy to exercise during the day and encourage cravings for sugary foods for quick energy, Dr. Sands points out. To help your child get a good night’s sleep, serve their last meal at least two hours before bedtime, limit screen time in the evening, dim the lights, and have a consistent nighttime routine.” Consult your child’s health care provider to find out how many hours of sleep per night their age group needs.

8. Teach stress-relieving practices. Stress can cause weight gain by weakening self-control, leading kids (and adults) to soothe themselves through food, and by causing hormonal changes that increase weight gain. Children’s yoga, breathing exercises, meditation, or quiet art projects can help to calm mind and body.

9. Be consistent (but leave room for exceptions). Consistency is key! Daily healthy eating and exercise habits are important for long-term success. However, that doesn’t mean your child can’t enjoy a treat for special occasions or take a few days off from exercise if they’re tired or not feeling well. What you do most of the time is what matters.

10. Limit screen time. Being sedentary with video and computer games, watching TV, texting, and scrolling social media can make it hard to keep weight in check. The WHO recommends that children older than two get no more than two hours of screen time a day, and that children younger than two shouldn’t have any.

11. Practice positive messaging. “As parents, we want to be really careful about what we communicate about weight to children,” Puhl says. “Shift the conversation away from the number on the scale and focus on health, healthy behaviors, and on ways that you as a family can promote a healthy lifestyle.” Avoid being critical of your body in front of your children, which may lead them to develop the same stigma around their body.

Medication

If diet and lifestyle changes aren’t sufficiently addressing or preventing obesity, you can talk to your child’s health care provider about prescription weight loss medications. New treatment guidelines published in January 2023 by the American Academy of Pediatrics (AAP) recommend that physicians offer weight loss medication for children ages 12 and older with obesity, as an adjunct to behavior and lifestyle treatment. Drugs that are now approved for treating obesity in this age group include orlistat (Xenical), liraglutide (Saxenda), semaglutide (Wegovy), and phentermine-topiramate (Qsymia). The guidelines also state that medication may be offered for children ages 8 to 11 with obesity in certain situations.

Surgery

Weight loss surgery (bariatric surgery) is usually reserved for adolescents with severe obesity who have not been able to lose weight through other methods. The 2023 AAP guidelines counsel that teens 13 and older who have a BMI of at least 120% of the 95th percentile for their age and sex be evaluated for bariatric surgery. Types of surgery done to treat severe obesity include gastric bypass, gastric banding, and gastric sleeve (sleeve gastrectomy).

It’s important that parents play a loving and supportive role in the upbringing of all children, but especially if your child is facing stigma or self-confidence issues from being obese. To support your child, try to build up their confidence by praising their successes and skills, and avoid commenting on your child’s body, appearance, or weight.

Puhl suggests, “Try to help your child recognize all their strengths and positive characteristics that have nothing to do with physical appearance. We live in such an appearance-focused society that a lot of kids don’t realize they’re important or of value beyond what they look like. Help kids see that their strengths come from their talents, their contributions to society, their positive relationships. Help the child recognize the positive things their bodies do for them – that they’re vessels of strength and nourishment.”

Also very important: Do not encourage your child to diet, skip meals, or go hungry. Growing children need solid nutrition. Focus on affirmative behaviors rather than deprivation. Provide healthful meals and snacks full of colorful fruits, vegetables, whole grains, lean proteins, and healthy fats. Encourage physical activity by playing with your child outside, or set them up with play dates or activities that are movement-focused, like sports, martial arts, dance, swimming, climbing, or playing on playground equipment.

If you are concerned that your child is might be overweight or obese, make an appointment to consult his or her health care provider. They will consider the factors that go into a diagnosis for obesity and help you determine if your child’s weight gain is healthy or putting their health at risk. In general, children should have annual checkups where their BMI, as well as other markers for health, are checked.

• According to the CDC, overweight or obese children are five times more likely to be overweight or obese as adults.

• Childhood obesity and caregiver’s education level have an inversely proportional relationship. The prevalence of childhood obesity increases as the education level of the child’s head of household decreases.

• If a mother is overweight or eats poorly in pregnancy, her child has a greater chance of being overweight and making unhealthful food choices later on in life.

• The prevalence of childhood obesity differs significantly across racial and ethnic groups: In 2017-2018, according to the CDC, 26% of Hispanic children and 24% of non-Hispanic Black children had obesity, compared with 16% of non-Hispanic White children and 9% of non-Hispanic Asian children.

• The rate of childhood obesity in the United States has more than tripled in the last 30 years.