Genomics and Obesity: We Need Both Population and Individualized Approaches in the Prevention and Management of Obesity

January 29, 2018 by Muin J, Khoury, Office of Public Health Genomics, Centers for Disease Control and Prevention, Atlanta, Georgia
a person standing on a scale and a crowd of people with DNA overlayed

a person standing on a scale and a crowd of people with DNA overlayed

Obesity is a serious, global public health problem that has increased markedly in the last few decades. As of 2016, 795 million people were estimated to have been affected . Obesity is associated with leading causes of death worldwide—such as diabetes, cardiovascular disease, and cancer—making the search for effective weight management strategies a global priority.

Obesity results from energy imbalance that occurs when a person consumes more calories than their body burns. Risk factors for obesity range from individual factors, such as behavior and genetics, to environmental and societal factors, such as food environment, education and skills, and food promotion and marketing.

Consistently following a healthy diet may lessen genetic susceptibility to weight gain

A recent prospective cohort study with 8828 female (Nurses’ Health Study) and 5218 male (Health Professionals Follow-up Study) participants showed the importance of genetic and environmental factors in obesity. The authors calculated an obesity genetic risk score (GRS) based on 77 variants associated with body mass index. They examined dietary patterns using validated dietary instruments and conducted five repeated measurements of changes in body weight and body mass index. Two decades of follow-up showed that the genetic association with their body mass index was significantly lessened when each group maintained a heathy diet. The authors suggested that consistently following a healthy diet may lessen genetic-associated weight gain. The beneficial effect of improved diet on weight was particularly striking among individuals with a high genetic risk for obesity. These findings are also consistent with previous studies showing that products, such as sugar-heavy drinks and fried food, can worsen the effects of genetic associations on increased body mass index.

Overall, this and other studies illustrate the importance of healthy diet in preventing weight gain, especially in people at greatest risk. They also support the importance of guidelines that promote adherence to healthy diet. Furthermore, they also help to address the misconception that people with genetic susceptibility to obesity do not benefit from weight management. Finally, the findings reinforce the importance of policy approaches to healthy food environments and systems.

Fighting the obesity epidemic requires multiple approaches

Even in obesity-conducive environments, not everyone will develop obesity. How people respond to these obesity-favorable environments may be related to psychological, social, and economic factors (to name a few) as well as genetic variations. Other proposed factors include interactions with the gut microbiome , and as well as early life exposures associated with epigenetic changes.

There are a few single gene disorders associated with severe, childhood-onset obesity. People with rare mutations of genes in the leptin-signaling pathway (e.g., complete deficiencies of leptin or its receptor) have a very high likelihood of developing obesity. For those people, tailored interventions have begun to pay dividends. For people with leptin deficiency, treatment with leptin leads to sustained improvement in adiposity. With additional insight into genes regulating body weight, more targeted treatments may be on the horizon.

Nevertheless, most people with obesity do not have a single gene causation. It is unlikely that a single approach can stop the problem of obesity; instead, fighting the obesity epidemic requires multiple fronts. CDC continues to emphasize population-level approaches to the problem, including the involvement of state and local organizations, business and community leaders, and school, childcare, and healthcare professionals. Partnerships are key to create environments that foster healthy lifestyles. Check out the CDC obesity website for ways state and local organizations can create a supportive environment to promote healthy living behaviors that prevent obesity.

The Journal of the American Medical Association recently revisited old approaches and reimagined new solutions to obesity in a recent obesity-themed issue . Ultimately, the use of individualized and population level interventions are needed, and not merely the search for ”obesity genes.”[PDF 153 KB] Identifying additional genetic, metabolic, behavioral, and environmental factors that make people susceptible to obesity and better clarifying the differences that affect the success of obesity treatment, could lead to newer precision approaches to obesity prevention and treatment.

For additional information on genomics and obesity, please visit our updated web page. Also, search our public health genomics knowledge base for the latest scientific information, guidelines, and tools on the impact of genomics on obesity.

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January 29, 2018 by Muin J, Khoury, Office of Public Health Genomics, Centers for Disease Control and Prevention, Atlanta, Georgia