Imbalances in certain hormones, such as cortisol, thyroid hormones, insulin, and others, can link to childhood obesity. However, factors such as diet and physical activity levels more often lead to obesity in children.

Hormones are chemical messengers that maintain a delicate balance of functions across the body. These functions include how people use energy, store fat, crave food, and grow during childhood.

Illness or injury can sometimes affect hormone balances. Weight gain is a symptom of several hormone issues. This article explains how some hormones can contribute to obesity in children.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Many risk factors linked to childhood obesity relate to a child’s social environment. These factors include access to healthy food and safe places to play and exercise. However, in rare circumstances, hormones may still contribute in several ways.

Current ranges indicate that a child or teen has obesity if their body mass index (BMI) is higher than 95% of others of the same sex in the same age group.

According to the Centers for Disease Control and Prevention (CDC), around 14.7 million children ages 2 to 19 years in the United States had obesity during the period from 2017 to 2020.

Parents or caregivers can talk with a pediatrician about what information BMI may be able to provide about a child’s health.

The flaws of BMI

BMI is a calculation of a person’s body fat based on their height and weight. However, studies suggest it is a poor indicator of a person’s body fat percentage.

It can be misleading because the measure does not account for overall body composition or capture information on the mass of fat in different body sites. The latter relates to both health and social issues.

BMI cutoff points were generated mostly from the white population, but body fat distribution differs by race and ethnicity.

For additional information, talk with your doctor about other body fat assessment methods.

Cortisol

The body releases cortisol in response to stress.

According to a 2023 literature review, there is evidence that stress exposure in childhood and adolescence promotes changes that contribute to the multifactorial development of obesity.

A person’s appetite might increase if their stress system is constantly active and releasing cortisol. High cortisol may also lead to more fat building up around vital organs.

Rarely, ongoing raised cortisol levels in children can lead to Cushing’s syndrome, which may occur due to benign tumors on the adrenal glands. Cushing’s syndrome can contribute to:

Thyroid hormones

The thyroid is a butterfly-shaped gland that produces thyroid hormones, which support growth and development in children and maintain the body’s energy use and organ function.

Hypothyroidism is a condition in which the gland cannot produce enough thyroid hormones.

In children, hypothyroidism can cause slow growth and delayed puberty. Another possible symptom of hypothyroidism is weight gain, although obesity does not often develop due to hypothyroidism alone.

Read more about the symptoms of hypothyroidism.

Sex hormones

As children develop through adolescence, their levels of sex hormones increase, including:

However, some people have low levels of these hormones due to a condition called hypogonadism, a condition where a person produces little to no sex hormones.

According to a 2023 review, studies have identified a link between obesity and low testosterone in males. However, the review does not confirm that low testosterone causes obesity, just that testosterone may be lower in adolescent males with obesity. Obesity may also contribute to lower testosterone levels.

A 2020 study found that low testosterone may have links to increased levels of leptin, a hormone that helps control hunger. The body may become more resistant to leptin, meaning a person’s appetite remains high even though they are full. Increased leptin may also be a contributing factor to low testosterone levels.

However, research has not verified this association as a cause of obesity, and more studies are necessary. Having an imbalances of these hormones do not mean a person will definitely have obesity.

Insulin

Insulin is a hormone that allows blood glucose (sugar) to leave the bloodstream and enter cells for use as energy.

However, if the body does not respond enough to insulin, insulin resistance can develop, which can lead to raised blood glucose levels and increase a person’s risk of type 2 diabetes.

According to a 2024 review, insulin resistance might contribute to obesity development in children, especially when accompanied by excess glucose intake.

A pancreas tumor called an insulinoma may also lead to weight gain by causing low blood sugar and severe, ongoing hunger. This kind of tumor can be a rare cause of obesity in childhood.

Learn more about insulin resistance.

Parathyroid hormones

The parathyroid gland produces hormones that help preserve bone, kidney, and gut health.

According to a 2022 review, an inherited condition called pseudohypoparathyroidism type 1a can cause obesity in the first 2 years of life. The condition means the body does not respond to parathyroid hormones even though the parathyroid gland makes enough.

Androgens

Androgens are a group of sex hormones that play a role in reproductive activity and physical traits that develop during puberty.

Although people sometimes refer to them as “male” hormones, people with female reproductive organs also have androgens. People with polycystic ovary syndrome (PCOS) often have an imbalance of these hormones.

Weight gain is common with PCOS. However, as with other conditions related to sex hormones, it may be that having obesity causes or contributes to PCOS, rather than PCOS causing weight gain. It is also important to note that not everyone with PCOS has obesity.

PCOS symptoms often become clear in the late teens. Symptoms can include:

The hormonal system requires a delicate balance. When levels of one hormone increase, another may decrease. Deficiencies or excesses of different hormones may affect body weight in various ways:

  • Metabolism: Hormones such as thyroid hormone and insulin affect how the body uses energy. If the body uses energy slowly, it stores unused calories from food as fat, increasing body weight.
  • Feeling full: Hormones such as leptin and ghrelin help the body acknowledge that it has consumed enough food. If a hormone imbalance interferes with these levels, a person can experience an increased appetite and may eat more.
  • Fat buildup: Hormones can influence where fat builds up.

Although hormones contribute to obesity in some children, the World Health Organization (WHO) advises that the leading cause of childhood obesity is an energy imbalance between the amount of calories children consume and the amount of calories they expend.

It notes that obesity rates are rising due to a global shift toward consuming more energy-dense foods high in fat and sugars but low in vitamins, minerals, and other healthy micronutrients. At the same time, there has been a trend towards decreased physical activity levels.

Countries and communities with low or middle levels of income often experience what the WHO calls a “double burden” of both undernutrition and obesity due to inadequate access to appropriate nutrition for pregnant people, infants, and children.

Parents or caregivers who have concerns about a child’s rapid weight gain or other common hormonal symptoms such as tiredness, delayed puberty, or slow growth can speak with a doctor.

Many blood tests can help identify levels of certain hormones that may be contributing to obesity.

If a doctor suspects an insulinoma, PCOS, or Cushing’s syndrome, they may request imaging scans to investigate any growth in hormone-producing tissue.

Treatments for childhood hormone conditions linked to obesity depend on the cause. For some conditions, a person may be able to supplement hormone levels by taking oral medications or receiving injections.

Other cases may require surgery to remove a tumor or repair an injury.

Some conditions, such as hypothyroidism, require lifelong supplementation.

Following a diet plan and engaging in physical activity as regularly as possible might support weight management during or after treatment.

Find tips that may help with eating a balanced diet.

Nutrition resources

For more science-backed resources on nutrition, visit our dedicated hub.

Several hormonal imbalances have links to obesity in children. For example, excess cortisol can lead to weight gain through increased appetite. A deficiency in thyroid hormone can reduce the speed of a child’s metabolism.

Imbalances in sex hormones, insulin, or parathyroid hormone can also lead to increased body weight. Generally, hormone imbalances lead to obesity by causing a person to experience a slower metabolism, increased appetite, and fat buildup.

Supplementation or surgery may be necessary to treat underlying hormonal conditions. However, a balanced diet and regular exercise are vital for body weight management as children develop.