10 Medical Reasons Your Child Is Overweight

A child's weight isn't always the result of poor dieting or exercise habits. Genetic and biological causes could also be to blame.

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Leptin resistance

Medical Reasons Your Child Is OverweightMOHD BAHIRI BIN IBRAHIM/ShutterstockWhen a child is overweight, it can be easy to point fingers at parents. But the true causes of weight gain and loss can be pretty subtle—for example, check out how your fat cells work to produce leptin and control weight. In some cases, a lack of daily physical activity, poor nutrition, and over-eating can be the culprit. As Eboni Hollier, MD, a board-certified pediatrician practicing in Houston, Texas, explains, "Less than 5 percent of cases of obesity are thought to be due to genetic syndromes or metabolic abnormalities." But, that doesn't mean they don't exist. Dr. Hollier says that leptin resistance, although especially rare in children, can be to blame. Leptin is a hormone produced in the body's fat cells that tells the brain when you're full and helps balance the calories you burn and fat stored in the body. In some people, the body doesn't regulate leptin correctly, causing leptin resistance. "It is thought that when pathways including leptin (or other parts of the brain involved in this pathway) are disrupted, that obesity may be the result," Hollier says.


Medical Reasons Your Child Is OverweightDaniel Jedzura/ShutterstockAlthough rare in children, hypothyroidism can lead to weight gain. This condition causes the thyroid gland to produce too little of the thyroid hormone, which regulates metabolism, blood pressure, energy levels, and more. According to Maria Maguire, MD, MPP, FAAP, and a board-certified pediatrician with the University of Maryland Community Medical Group-Pediatrics, "usually hypothyroidism by itself only causes mild weight gain, rather than true obesity or severe weight gain." The thyroid may also cause other health problems, like fatigue and depression, that can play a role in obesity.

Your child's medications

Medical Reasons Your Child Is OverweightDaniel Jedzura/ShutterstockIf your child is currently on medication for an illness or disorder and seems to be gaining weight, her medications could be to blame. (Look for these 11 silent signs that medication could be making them sick.) Esther K. Liu, MD, FAAP, and chair of pediatrics for the University of Maryland Baltimore Washington Medical Center, states that "some medications can make you feel hungrier, decrease your metabolism, or increase fluid retention," which can contribute to weight gain. The most notable ones to affect a child's weight are antidepressants, anti-seizure medications, oral steroids, and some antihistamines.

Unhealthy gut

Medical Reasons Your Child Is OverweightMaria Uspenskaya/ShutterstockSure, an unhealthy diet can lead to obesity in children. Consistent grazing on salty or sweet snacks can pack on the pounds even if your child is active. But, what if you try your best to feed your child a healthy diet filled with fruits and vegetables, yet it doesn't seem to make an impact on his weight? According to Walter Gaman, MD, a family practice physician at Healthcare Associates of Texas, an unhealthy gut microbiome could be to blame. "[Recent findings from studies] show that if we don't have enough healthy bacteria in our gut, especially as children, it can lead to obesity and then continue on to diabetes and other health issues," says Dr. Gaman. "The packaged and processed foods, artificial sweeteners and colors, along with the use of antibiotics, all play a role in destroying the good bacteria and causing an overgrowth of the bad bacteria." In some cases, changing your child's diet to include more foods rich in prebiotics or probiotics, like Greek yogurt without additives, can help. But, other underlying issues may also cause an unhealthy gut, like undiagnosed food allergies or lactose intolerance. If your child seems to be experiencing consistent tummy problems, it's best to get him evaluated by your pediatrician. Learn more about how an unhealthy gut affects the body and how to improve it.

Cushing's syndrome

11-Cushing-Medical Reasons Your Child is Overweight_565423735-TaborskyTaborsky/ShutterstockCushing's syndrome causes the body to produce too much cortisol, a hormone that regulates things like blood pressure and blood sugars, and it's triggered by an improperly functioning pituitary gland. According to Dr. Maguire, Cushing's syndrome can slow a child's growth while encouraging fat retention around the waist and belly. Children with the syndrome are at risk for early puberty, diabetes, and high cholesterol and blood pressure. (It's also just one of several medical causes of a slow metabolism.)

Prader-Willi syndrome

Medical Reasons Your Child Is OverweightJiri Hera/ShutterstockPrader-Willi syndrome (PWS) is a rare genetic disorder that can affect children and is associated with behaviors leading to weight gain, like binge eating. According to Nicolette D. Morris, MD and physician director of Pediatric Outpatient Care at the University of Maryland St. Joseph Medical Center, PWS is "the most common syndromic form of obesity." She notes that doctors will look for it in infants up to two years of age who have poor or reduced muscle tone and strength (called hypotonia); if a child between two to six years of age has hypotonia and global developmental delay, PWS may be the cause. When combined with harmful eating habits, the symptoms of PWS—including developmental delays and cognitive impairment—can cause weight gain.

Gestational diabetes

Medical Reasons Your Child Is OverweightBlueBoeing/ShutterstockWomen with gestational diabetes, a pregnancy condition that can cause high blood pressure and difficulty regulating sugar, may have a baby with an increased risk of high birth weight that can carry over to childhood. Expecting mothers should be on the lookout for these potential signs of gestational diabetes. Dr. Maguire notes that babies born to mothers with gestational diabetes may be between 9 and 10 pounds at birth and that "there is higher risk that children of moms with gestational diabetes will also have increased BMI and obesity."

Formula feeding

Medical Reasons Your Child Is OverweightAfrica Studio/ShutterstockAlthough formula fed babies don't always result in overweight or obese children, some medical experts to believe there is a link. According to Dr. Maguire, "one [theory] suggests that breastfed babies have a better ability to control their intake of food, whereas formula fed babies are fed a set amount in the bottle—although the same is true of infants fed breast milk through a bottle." And, the higher protein content in formula may have a link to obesity. Breast milk can better adapt to whatever baby's needs are than formula. One study by German researchers said that 4.5 percent of non-breastfed children in the study were overweight upon entering school, compared to 2.8 percent of children who were breastfed. Did you know that breastfeeding may also reduce anxiety and hyperactivity in children?


Medical Reasons Your Child Is OverweightRuslan Guzov/ShutterstockAccording to Dr. Maguire, depression does not cause obesity, but its devastating effects could play a role in a child's weight gain. Is your child exhibiting any of these danger signs of depression? Maguire says, "Depression is common in the U.S.—the prevalence is about 2 percent in school age children and about 5-8 percent in adolescents. However, the weight gain associated with depression is usually mild." She explains that excessive eating and lack of desire to participate in physical activities, two common side effects, may cause weight gain. However, "the association is often the other way around—obese children may be more likely to have depression."

Asthma and allergies

Medical Reasons Your Child Is Overweightbubutu/ShutterstockAsthma and allergies don't directly cause obesity in children, but they may indirectly affect a child's weight. "Children with asthma and allergic rhinitis have difficulty breathing which can limit their physical tolerance for exercise," says Dr. Liu. And, oral steroids and antihistamines that can help these conditions may also contribute to weight gain. If your child's having difficulty participating in physical activity, talk to your child's doctor about asthma symptoms.

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