A groundbreaking UCLA Health study underscores that diet and exercise alone can’t combat obesity — social stressors and environmental factors play a significant role. This research highlights the need for comprehensive policy reform and personalized care to tackle America’s obesity epidemic.
Obesity is not just a matter of poor diet and lack of exercise. In a compelling new review, researchers at UCLA Health illuminate the profound impact that stress, social struggles and environmental challenges have on the brain-gut microbiome, making it harder for individuals to maintain a healthy weight.
Published in the journal Clinical Gastroenterology and Hepatology, the paper explores how social determinants of health — ranging from income and education to neighborhood conditions and experiences of discrimination — influence obesity.
Approximately 40% of American adults are obese, a condition that incurs about $173 billion in health care costs annually. Alarmingly, a study noted a tripling of obesity-related cancer deaths in the United States from 1999 to 2020.
The research, led by Arpana Church, details how the brain-gut microbiome acts as a critical interface between a person’s environment and their obesity risk. This system produces signaling molecules like appetite hormones and inflammatory markers that affect eating behavior, metabolism and exercise habits.
“Our findings reveal that tackling obesity requires more than focusing on individual choices — it demands recognizing the powerful role that social and environmental forces play in shaping gut health, behavior and long-term health outcomes,” Church, who co-directs the Goodman-Luskin Microbiome Center at UCLA Health, said in a news release. “Reversing the escalating obesity epidemic in America demands a dual approach — personalized, equitable care for individuals and bold, systemic policy reforms that address the root causes.”
Lower socioeconomic status often restricts access to health education and forces reliance on inexpensive, calorie-dense processed foods. In many disadvantaged communities, limited availability of healthy foods, coupled with chronic exposure to stress and structural racism, exacerbates obesity risk.
Social isolation, too, disturbs the brain networks involved in appetite and decision-making, leading to unhealthy eating patterns and weight gain.
These factors go beyond influencing behavior; they cause actual changes in the brain-gut microbiome system. Chronic consumption of unhealthy food alters brain structure, affecting areas that regulate motivation and emotion, while poor diets disrupt gut bacteria composition, fueling inflammation that weakens self-control and reinforces unhealthy eating habits.
Chronic stress, including racism and social isolation, further impacts brain pathways and gut microbes, driving inflammation and weakening self-regulation.
“Neighborhood disadvantage is also linked to reduced gut microbiome diversity and a higher presence of harmful bacteria — factors that further impair metabolism and heighten the risk of obesity and related diseases,” Church added.
The repercussions can begin early, with environmental stressors and social adversity during prenatal and childhood stages setting the stage for lifelong weight struggles.
While systemic policy reforms are necessary to combat the obesity crisis, individuals can take proactive steps to support their health, such as prioritizing nutritious foods, building social connections, and engaging in stress-reducing activities like journaling or spending time in nature, according to Church.
“At the same time, healthcare providers have a vital role to play, not only by screening for current social determinants of health, but also by recognizing how these factors accumulate and evolve over time, which is rarely accounted for in today’s clinical practice,” Church added.
By understanding these multifaceted influences, health care providers can offer personalized treatment plans that address both biological and psychosocial challenges, empowering individuals to take control of their health and promoting long-term well-being, concluded Church.
Source: UCLA Health