Genetic inheritance may link ADHD and obesity. Other underlying factors, such as sleep and eating patterns, may also play a role.

Decades of research have shown a strong link between obesity and attention deficit hyperactivity disorder (ADHD) in children and adults.

A 2019 study suggests that about 70% of adults and 40% of children with ADHD have overweight or obesity than those without ADHD.

While it’s unclear whether people with ADHD have obesity because of ADHD or vice versa, certain factors may contribute to both.

A complex mix of genetics and behavior — such as eating habits, exercise, and sleep patterns — underlies the ADHD and higher BMI connection.

The Centers for Disease Control and Prevention (CDC) defines obesity as:

Genetic, environmental, and behavioral patterns seem to play a role in connecting ADHD to a higher BMI.

Genetic and environmental factors

A 2019 narrative review suggests that genetic alterations associated with ADHD may lead to environmental factors resulting in obesity. The review also found that a similar neural substrate may underlie genetic risks for ADHD and a higher BMI.

But researchers note that more research is needed on genetic pathways between ADHD and obesity, including possible differences between the sexes.

A 2020 review examining more than 780,000 mother-child pairs concluded that the children of mothers with overweight before pregnancy might have an increased chance of obesity and ADHD.

Researchers suggested that similar genetic pathways for both conditions and environmental factors, such as dietary habits, likely play a role.

Behavioral factors

Unhealthy eating habits and exercise patterns may be more frequent with ADHD.

This may include behaviors such as:

  • skipping breakfast
  • late-night snacking
  • binge eating (without realizing it)
  • missing exercise classes or practice due to time management challenges

In a 2019 study, 105 patients with obesity were categorized and examined for diagnoses of childhood or adulthood ADHD, addiction to food, binge eating, and sleep apnea.

Childhood and adult ADHD diagnoses were connected to food addiction and binge eating. No correlation between sleep apnea and ADHD was found.

If you live with ADHD, you may have greater reward responses or dopamine activation associated with food. This biological factor may lead to overeating.

Excessive daytime sleepiness

Sleep disturbances are common in folks with ADHD. Researchers estimate that about 75% of children and adults with ADHD have sleep problems.

One type that people with ADHD may have is excessive daytime sleepiness. This often features in people with ADHD and obesity, which might strengthen the link between them.

While not much is known about how ADHD connects to sleep disturbances, a 2017 study found that adults and children with ADHD and sleep problems report more severe ADHD symptoms.

Excessive daytime sleepiness is often a symptom of sleep apnea, which is common in people with obesity. A 2017 study noted that 3% to 7% of men and 2% to 5% of women with obstructive sleep apnea have obesity.

Conversely, people with obstructive sleep apnea are more likely to have obesity.

Inflammation

The narrative review suggests that inflammation may link ADHD symptoms and obesity. It suggests that inflammation impacts executive functions — such as attention, organization, and planning — and is a characteristic of obesity.

A 2021 review supports that inflammation contributes to obesity and is the link to obesity-related conditions such as type 2 diabetes.

But longitudinal studies are needed to further examine the connection.

ADHD and childhood obesity

Children with ADHD have a higher chance of obesity or overweight than those without.

A 2022 study using information from the 1993 Pelotol (Brazil) birth cohort concluded that ADHD in childhood (age 11) might predict higher BMIs in adulthood (age 22).

Childhood ADHD symptoms may predict a poor diet quality in children, but a poor diet doesn’t seem to cause childhood ADHD, according to a 2019 study.

ADHD medication and weight changes

In a 2022 study, nearly 81% of more than 22,000 children with ADHD within the same healthcare system experienced changes in BMI after they started taking ADHD medication.

The researchers found that:

Researchers suggest that future studies might look at effects over a time period longer than 3 years and across races, ethnic groups, and ADHD subtypes.

A 2015 review found a significant association between obesity and ADHD. It reported that about 70% of adults and 40% of children with ADHD had obesity compared to those without ADHD.

Researchers also found a correlation between ADHD and being overweight — defined in this study as having a BMI greater than or equal to 25 in adults and greater than or a BMI equal to the 85th percentile in children.

Correlations among ADHD subtype, sex, race and ethnicity, and BMI

A 2019 study measured the connection between ADHD type, sex, race and ethnicity, and BMI.

The study looked at a national survey with more than 13,000 people ages 12 to 34 with ADHD and compared the results with those who didn’t have ADHD.

Based on self-reporting, the following conclusions were noted:

  • Among those with ADHD inattentive type, European females had higher BMIs.
  • ADHD of the primarily hyperactive-impulsive type was associated with higher BMIs among European males and females.
  • ADHD of the combined type correlated with higher BMIs for Hispanic American females.
  • No ADHD and BMI associations were found for African American males or females or Hispanic American males.

Researchers suggest that the study could not account for these differences. Future studies might consider how sociocultural or genetic differences affect the relationship between ADHD subtype and obesity.

If you have ADHD and are concerned about your BMI, there are strategies you can try lower it.

Consider these tips:

  • Set realistic and specific goals. If you want to start an exercise routine, instead of trying to work out for 45 minutes to an hour each day, try to walk for 20 to 30 minutes each day. The American Heart Association (AHA) recommends getting at least 150 minutes each week of moderate-intensity exercise. Starting slow can help buildup your endurance, and then you can increase your exercise over time.
  • Plan your meals. People with ADHD often have trouble staying focused and on task. You might begin a project and forget to eat until you’re overly hungry. This may make you more likely to grab the first thing you can eat, without consideration of calories or fat content. Consider setting aside a time each day to eat. Planning your meals and having them ready to grab can also be helpful.
  • Choose healthier options. Focusing on nutrition rather than calorie cutting (particularly for children) might help manage your BMI. Try to avoid processed and sugary foods that increase hyperactivity and weight. Consider including more fruits, vegetables, lean meats, and fish.
  • Practice good sleep hygiene. Getting quality sleep each night can help rejuvenate your body and improve your mood. It might also help you resist the urge to reach for those sugary snacks to stay alert.
  • Medication adjustment. If your ADHD medication lists weight gain as a possible side effect, consider talking with a healthcare or mental health professional about adjusting your dose or switching types of medications. They will work with you on what’s best for you and your symptoms.

Does ADHD cause obesity?

No. While research shows a strong association between obesity and ADHD, there’s no evidence that obesity can lead to ADHD or vice versa.

Why are obesity and ADHD often linked?

There’s no direct cause for obesity and ADHD, but contributing factors may include genetics, reward response sensitivity, and different eating and sleep patterns.

Is the connection between ADHD and obesity more likely in children or adults?

The link between obesity and ADHD is stronger in adults but can also be seen in children.

What can you do?

Increasing exercise, improving nutrition, and establishing quality sleep patterns may help with ADHD and high body mass index (BMI).

If you have ADHD and obesity or are overweight, you’re not alone. Research has linked obesity with ADHD for several years.

If you’re concerned and want to lower your BMI, consider a few strategies such as setting weekly or daily goals that are realistic and specific, planning your meals ahead of time, and getting enough sleep.

An accountability partner might also help you sustain your desired habits over time.

It might also help to talk with others who have similar experiences. Unsure where to start? You can check out Psych Central’s page on ADHD resources for help with finding support groups and more.