Table of ContentsView AllTable of ContentsGeneticsInherited ObesityObesity Risk FactorsComorbidities and ObesityWhat to Focus on Now
Table of ContentsView All
View All
Table of Contents
Genetics
Inherited Obesity
Obesity Risk Factors
Comorbidities and Obesity
What to Focus on Now
Genetics can play a role inhaving obesity. Twin studies have found the heritability of obesity to be approximately 40% to 75%. Up to 500 obesity-related genes have been recognized in humans.
Although evidence for a genetic link with obesity is strong, the contribution of genes to obesity is considered small. Environmental factors such as diet and physical activity are believed to be a bigger influence on obesity than genetics alone.
This article will discuss the link between genes and obesity, genes and inheritance, known risk factors, comorbidities, and obesity, and what to focus on.
Alessandro Biascioli / Getty Images
Genes and Obesity: A Genetic Link?
Research shows obesity results from an interaction between environmental and innate biological factors.
The specific genetic influences of obesity are still being studied, but up to 500 specific genes have been linked to obesity. These genes can affect factors such as:
There also appears to be a high rate of heritability with somemeasures of obesity, such as:
Most instances of obesity are considered polygenic obesity, meaning multiple genetic factors are playing a role rather than any single gene alone.
Genetics isn’t considered to cause obesity; rather, they can makesome people more predisposedto it. This means that the genes passed down to them can make some people more likely to gain weight (or have difficulty losing it) than others because of their influence on and interaction with environmental factors, like eating and physical activity patterns.
Does Everyone With Obesity Have a Genetic Link?
Not everyone with a genetic predisposition to obesity will have obesity and not everyone with a strong genetic predisposition to it.
Genes are more likely a strong contributor to your obesity or overweight if most or all of the following apply to you:
People with a strong genetic predisposition to obesity often find it difficult to lose weight or maintain weight loss with what some consider sheer willpower. They often require help from a healthcare provider and may need treatments such asmedicationsor weight loss surgery.
Genetic factors may play less of a role with your obesity or overweight if most or all of the following apply:
Several studies have shown that adopting practices such as being physically active can offset genetic predisposition. One study found that physically active participants had the same BMIs whether they had a genetic predisposition to obesity or not.
Keep in mind that BMI is a dated, flawed measure. It does not take into account factors such as body composition, ethnicity, sex, race, and age, but BMI is still widely used in the medical community as an inexpensive and quick way to analyze a person’s potential health status and outcomes.
Other research has found that those with one of the main gene variants associated with obesity had a higher risk of obesity than those who did not, but that those who carried the gene variant and were active had a 30% lower risk of obesity than those who carried the gene variant and were not active.
Thrifty GenesAbout 85% of people carry so-called thrifty genes. These genes were of great benefit to our ancestors as they helped people conserve energy and store body fat to live off during times when food was scarce. The people with these genes were more likely to survive than those without, meaning these genes became favored genes, making people with them better able to survive and reproduced.Now, food is readily available, people don’t have to expend energy to hunt or harvest it, and those thrifty genes are no longer needed. Unfortunately,geneticevolution moves much slower than our environmental adaptation, so these genes and their instructions to store fat persist even when unnecessary.
Thrifty Genes
About 85% of people carry so-called thrifty genes. These genes were of great benefit to our ancestors as they helped people conserve energy and store body fat to live off during times when food was scarce. The people with these genes were more likely to survive than those without, meaning these genes became favored genes, making people with them better able to survive and reproduced.Now, food is readily available, people don’t have to expend energy to hunt or harvest it, and those thrifty genes are no longer needed. Unfortunately,geneticevolution moves much slower than our environmental adaptation, so these genes and their instructions to store fat persist even when unnecessary.
About 85% of people carry so-called thrifty genes. These genes were of great benefit to our ancestors as they helped people conserve energy and store body fat to live off during times when food was scarce. The people with these genes were more likely to survive than those without, meaning these genes became favored genes, making people with them better able to survive and reproduced.
Now, food is readily available, people don’t have to expend energy to hunt or harvest it, and those thrifty genes are no longer needed. Unfortunately,geneticevolution moves much slower than our environmental adaptation, so these genes and their instructions to store fat persist even when unnecessary.
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High-risk genetic variations in approximately 24 dozen genes are known to cause monogenicobesity.
Monogenic obesity has the following characteristics:
A person who develops severe obesity before the age of 2 years should be considered for screening to look for:
Syndromic ObesitySyndromic obesity is a rare form of obesity that is part of multiple clinical characteristics such as cognitive delay, organ-specific abnormalities, and dysmorphic features.Some examples of syndromic obesity due to chromosomal defects include:Prader-Willi syndromeDown syndromeBardet–Biedl syndromeFragile X syndromeAlstrom syndromeCornelia de Lange syndromeAlbright’s hereditary osteodystrophyWAGR syndrome
Syndromic Obesity
Syndromic obesity is a rare form of obesity that is part of multiple clinical characteristics such as cognitive delay, organ-specific abnormalities, and dysmorphic features.Some examples of syndromic obesity due to chromosomal defects include:Prader-Willi syndromeDown syndromeBardet–Biedl syndromeFragile X syndromeAlstrom syndromeCornelia de Lange syndromeAlbright’s hereditary osteodystrophyWAGR syndrome
Syndromic obesity is a rare form of obesity that is part of multiple clinical characteristics such as cognitive delay, organ-specific abnormalities, and dysmorphic features.
Some examples of syndromic obesity due to chromosomal defects include:
Known Risk Factors Linked to Obesity
In addition to genetics, there are many factors thataffect weight regulation, and can be associated with obesity. Many of these influences are believed to be significant contributors to the recent rise in rates of obesity.
Some ofthese factorsinclude:
What Is and Is Not Controllable With Developing Obesity?We cannot control having a genetic disposition to obesity. Nor can we control our past. We also can’t control every aspect of our environment that influences weight regulation.Manyadults with obesityhave years-long eating, exercise, sleep, stress, and other patterns that have contributed to weight gain, and those can be hard to change.People cangain controlover their lifestyle habits. Developing and sticking to healthy lifestyle practices, such as eating various nutritious foods and getting plenty of exercise, can be difficult, but it is within our control.If you want to make these changes but are having difficulty or don’t know where to start, talk to your healthcare provider or contract a registered dietitian for guidance.
What Is and Is Not Controllable With Developing Obesity?
We cannot control having a genetic disposition to obesity. Nor can we control our past. We also can’t control every aspect of our environment that influences weight regulation.Manyadults with obesityhave years-long eating, exercise, sleep, stress, and other patterns that have contributed to weight gain, and those can be hard to change.People cangain controlover their lifestyle habits. Developing and sticking to healthy lifestyle practices, such as eating various nutritious foods and getting plenty of exercise, can be difficult, but it is within our control.If you want to make these changes but are having difficulty or don’t know where to start, talk to your healthcare provider or contract a registered dietitian for guidance.
We cannot control having a genetic disposition to obesity. Nor can we control our past. We also can’t control every aspect of our environment that influences weight regulation.
Manyadults with obesityhave years-long eating, exercise, sleep, stress, and other patterns that have contributed to weight gain, and those can be hard to change.
People cangain controlover their lifestyle habits. Developing and sticking to healthy lifestyle practices, such as eating various nutritious foods and getting plenty of exercise, can be difficult, but it is within our control.
If you want to make these changes but are having difficulty or don’t know where to start, talk to your healthcare provider or contract a registered dietitian for guidance.
Not everyone with obesity develops significant health problems, but having obesity can increase the risk ofhealth concernssuch as:
Treatment for obesitydoes not focus largely on genetics. Strategies for obesity treatment primarily target environmental, social, and behavioral factors, such as:
Sometimes, lifestyle changes may not be enough to lose weight and keep it off long-term effectively. Forsevere obesity, bariatric surgery with long-term follow-up is the most successful treatment. If you think this surgery may benefit you, talk to your healthcare provider.
A Word From VerywellIf individuals find that they are not achieving their desired weight despite their consistent efforts to maintain a healthy diet and exercise routine, it is recommended to consult a healthcare provider. Underlying medical conditions can hinder weight loss, even when individuals follow a healthy lifestyle.—KARINA TOLENTINO, RD, CHWC, MEDICAL EXPERT BOARD
A Word From Verywell
If individuals find that they are not achieving their desired weight despite their consistent efforts to maintain a healthy diet and exercise routine, it is recommended to consult a healthcare provider. Underlying medical conditions can hinder weight loss, even when individuals follow a healthy lifestyle.—KARINA TOLENTINO, RD, CHWC, MEDICAL EXPERT BOARD
If individuals find that they are not achieving their desired weight despite their consistent efforts to maintain a healthy diet and exercise routine, it is recommended to consult a healthcare provider. Underlying medical conditions can hinder weight loss, even when individuals follow a healthy lifestyle.
—KARINA TOLENTINO, RD, CHWC, MEDICAL EXPERT BOARD
Summary
Obesity has genetic links, but in most cases, individual genes associated with obesity play minor roles in the development of obesity.
Genetics can predispose people to developing obesity. This means they are more likely to gain weight and have more difficulty losing it, but it does not necessarily mean they will develop overweight or obesity.
Obesity is usually the result of an interaction between several factors, including genetics, environment, and behaviors.
Obesity is associated with several comorbidities, includingheart disease, type 2 diabetes, andsleep apnea.
Treatment for obesity focuses on lifestyle and behavior changes, such as healthful eating, physical activity, and good quality sleep. Severe obesity may be most effectively addressed withbariatric surgery.
11 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mahmoud R, Kimonis V, Butler MG.Genetics of obesity in humans: a clinical review. IJMS. 2022;23(19):11005. doi:10.3390/ijms231911005Harvard T.H. Chan School of Health.Genes are not destiny.Loos RJF, Yeo GSH.The genetics of obesity: from discovery to biology. Nat Rev Genet. 2022;23(2):120-133. doi:10.1038/s41576-021-00414-zObesity Medicine Association.Obesity and genetics: What is the connection?Harvard Health.Why people become overweight.Centers For Disease Control and Prevention.Risk Factors for Obesity.University of Utah.Evolution and obesity.Australian Family Physician.Genetics of obesity.MedlinePlus.Causes and risks for obesity in children.National Health Service.Obesity.Heitkamp M, Siegrist M, Molnos S, et al.Obesity genes and weight loss during lifestyle intervention in children with obesity. JAMA Pediatr. 2021;175(1):e205142. doi:org/10.1001/jamapediatrics.2020.5142
11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mahmoud R, Kimonis V, Butler MG.Genetics of obesity in humans: a clinical review. IJMS. 2022;23(19):11005. doi:10.3390/ijms231911005Harvard T.H. Chan School of Health.Genes are not destiny.Loos RJF, Yeo GSH.The genetics of obesity: from discovery to biology. Nat Rev Genet. 2022;23(2):120-133. doi:10.1038/s41576-021-00414-zObesity Medicine Association.Obesity and genetics: What is the connection?Harvard Health.Why people become overweight.Centers For Disease Control and Prevention.Risk Factors for Obesity.University of Utah.Evolution and obesity.Australian Family Physician.Genetics of obesity.MedlinePlus.Causes and risks for obesity in children.National Health Service.Obesity.Heitkamp M, Siegrist M, Molnos S, et al.Obesity genes and weight loss during lifestyle intervention in children with obesity. JAMA Pediatr. 2021;175(1):e205142. doi:org/10.1001/jamapediatrics.2020.5142
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Mahmoud R, Kimonis V, Butler MG.Genetics of obesity in humans: a clinical review. IJMS. 2022;23(19):11005. doi:10.3390/ijms231911005Harvard T.H. Chan School of Health.Genes are not destiny.Loos RJF, Yeo GSH.The genetics of obesity: from discovery to biology. Nat Rev Genet. 2022;23(2):120-133. doi:10.1038/s41576-021-00414-zObesity Medicine Association.Obesity and genetics: What is the connection?Harvard Health.Why people become overweight.Centers For Disease Control and Prevention.Risk Factors for Obesity.University of Utah.Evolution and obesity.Australian Family Physician.Genetics of obesity.MedlinePlus.Causes and risks for obesity in children.National Health Service.Obesity.Heitkamp M, Siegrist M, Molnos S, et al.Obesity genes and weight loss during lifestyle intervention in children with obesity. JAMA Pediatr. 2021;175(1):e205142. doi:org/10.1001/jamapediatrics.2020.5142
Mahmoud R, Kimonis V, Butler MG.Genetics of obesity in humans: a clinical review. IJMS. 2022;23(19):11005. doi:10.3390/ijms231911005
Harvard T.H. Chan School of Health.Genes are not destiny.
Loos RJF, Yeo GSH.The genetics of obesity: from discovery to biology. Nat Rev Genet. 2022;23(2):120-133. doi:10.1038/s41576-021-00414-z
Obesity Medicine Association.Obesity and genetics: What is the connection?
Harvard Health.Why people become overweight.
Centers For Disease Control and Prevention.Risk Factors for Obesity.
University of Utah.Evolution and obesity.
Australian Family Physician.Genetics of obesity.
MedlinePlus.Causes and risks for obesity in children.
National Health Service.Obesity.
Heitkamp M, Siegrist M, Molnos S, et al.Obesity genes and weight loss during lifestyle intervention in children with obesity. JAMA Pediatr. 2021;175(1):e205142. doi:org/10.1001/jamapediatrics.2020.5142
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