Obesity and Mental Illness: Can one lead to the other?

By: Cassidy Shumway, LWDI Intern 

It is commonly understood that obesity and mental health are correlated to each other. In fact, it  is almost hard to acknowledge one of these topics without eventually addressing the other. We  know that there is some sort of connection, the question that remains is: what is it

In order to set the stage for the rest of this post, consider these two questions:

• Can obesity lead to developing a mental disorder? 

• Can a mental illness increase a person’s risk for developing obesity? 

Let’s start at the beginning: 

It is no secret that obesity is increasing not only within the United States, but worldwide as well.  According to the Center for Disease Control and Prevention (CDC), data from a National Health  and Nutritional Examination Survey found that in the United States between the years of 2017- 2018, the prevalence of obesity in adults was 42.4% which is more than a third of the population (1).  

CDC: Estimates for adults aged 20 and over were age adjusted by the direct method to the 2000  U.S. Census population using the age groups 20–39, 40–59, and 60 and over (1). 

This is a public health concern because: 

1. Obesity raises the risk for most chronic conditions 

2. Obesity can lead to poor mental health

3. Obesity can increase your risk for mortality (2).  

What is obesity? 

Obesity is a complex, multifactorial disease that is typically defined as excess body weight for  height. Body Mass Index (BMI) is the most widely used criteria for determining obesity and is  classified by a BMI of 30 kg/m2 or greater (2).  

Mental Health 

In addition, not only is obesity rapidly increasing, but mental health illnesses  as well. According to the American Psychiatric Association, one in five U.S. adults live with a mental illness which is roughly 51.5 million people.  A mental illness is a health condition that results in changes to an  individual’s emotions, thinking, or behavior and they are often associated with distress and result in an individual having difficulty functioning normally in  social, work, or family situations (3).  

Common mental illnesses include: 

• Depression 

• Anxiety 

• Bipolar disorder 

• Eating disorders 

• Personality disorders 

• Psychotic disorders 

• PTSD disorders. 

Nearly one in five U.S. adults experience some form of mental illness.

Individuals who are obese have an increased risk of developing some sort of neuropsychiatric  disorder such as depression and anxiety and individuals that have neuropsychiatric conditions  may exhibit features that can lead to the development of obesity (4).  

Let’s dig in and look into those questions from the beginning a little further: 

Can obesity lead to developing a mental disorder? Short answer: Possibly 

Individuals who are obese have a higher chance of developing some sort of  neuropsychiatric disorder such as depression and anxiety than non-obese people.  Unfortunately, because of high social expectations, beauty standards, and media, an individual with obesity can negatively influence a person’s self-image with a self depreciating perception. Ultimately, this can make an individual vulnerable lead to  depressive symptoms.  

Research Says: 

• A systematic review in 2017 was conducted which indicated that depressed adolescents  had a 70% higher risk for being obese and another study showed that older women with  obesity had a 38% increased risk for developing depression (5). 

• In 2019, a study was conducted to understand obesity in college aged women. This study  found that: 

o Obese women had significantly lower body image, self-esteem, and high  depressive symptoms than non-obese women. 

o The obese women who reported depressive symptoms reporting more eating  problems, and poorer body image (6).  

• A meta-analysis conducted in 2018 ultimately showed that individuals with central  obesity had a 38% increase of having depression than non-obese individuals (7).  

Within society, it has been established that there are many negative weight-related issues  prevalent in society today including (6): 

Because of this, individuals might look for ways to restrict their diets in an effort to lose weight.  Ultimately, that behavior has the potential to exacerbate depression and put obese individuals at  an increased risk for developing a mood disorder (7).  

Can a mental illness increase a person’s risk for developing obesity? Short answer: Possibly 

For the most part, it is common knowledge that obesity can increase an individual’s chance of  developing mental health disorders and maybe it is common knowledge because we are all aware  of the weight bias, discrimination, and stigmatization that exists in society as a whole, within the  media, but is also apparent on a normal basis in our day to day lives (4). How often do we think  about how mental illness can increase a person’s risk for developing obesity? 

Research Says: 

• Depressive symptoms can lead to an unhealthy lifestyle including being sedentary and  poor eating habits. 

o In college students, it was found that depressive symptoms lead to the  consumptions of sweets, cookies, snacks, and fast food. 

• Food preferences may change during states of stress of depression. 

• High carbohydrate food can temporarily life a person’s mood. 

o Leads to the consumption of pleasant tasting foods (usually those that are high in  fat and sugar) which activate the brains opioid system. 

o Carbohydrate consumption may increase serotonin production in the brain. • Mood disorders can cause sleep abnormalities and sleep impairment is associated with an  increase in the hormone ghrelin (hunger hormone) and decreases the hormone leptin  (inhibits hunger). 

• A high fat diet that can come from having depressive symptoms can potentially lead to  hypothalamic inflammation in the brain which ultimately compromises the regulation of  satiety and can promote weight gain.  

• Antidepressants and mood stabilizers that are prescribed in the treatment of mental health  disorders have been found to be associated with weight gain (4).  


Within the past couple of decades, studies are being conducted and evidence is being  accumulated that shows that there is an association between mental health disorders and obesity.  However, more specific studies are needed as there still a lot of unknowns and unanswered  questions. However, the evidence and literature that is currently available is significant and may be impactful by leading efforts towards further research and to the development of better  therapeutic strategies for these conditions. 


1. Products – Data Briefs – Number 360 – February 2020. Centers for Disease Control and  Prevention. https://www.cdc.gov/nchs/products/databriefs/db360.htm. Published  February27, 2020. Accessed November 25, 2020.  

2. Hruby A, Hu FB. The Epidemiology of Obesity: A Big Picture. Pharmaco Economics.2015;33(7):673-689.  

3. What Is Mental Illness? https://www.psychiatry.org/patients-families/what-is-mental-illness.  Accessed November 25, 2020.  

4. Martins LB, Monteze NM, Calarge C, Ferreira AV, Teiziera AL. Pathways linking obesity  to neuropsychiatric disorders. Nutrition. 2019;66: 16-21.  

5. Rajan TM, Menon V. Psychiatric disorders and obesity: A review of association studies. J Postgrad Med. 2017;63(3): 182-190. 

6. Sarigiani PA, Olsavsky AL, Camarena PM, Sullivan SM. Obesity and depressive symptoms  in college women: analysis of body image experiences and comparison to non-obese  women. International Journal of Adolescence and Youth. 2019;25(1): 765-779. 7. Mulugeta A, Zhou A, Power C, Hypponen E. Obesity and depressive symptoms in mid-life:  a population-based cohort study. BMC Psychiatry. 2018;18: 1-10.

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