The Rise of Obesity in the US: Recognizing Gastrointestinal and Hepatic Comorbidities


Obesity rates in the US have skyrocketed, and so has the prevalence of several comorbid gastrointestinal and hepatic diseases - not all patients know their risks or have the financial means to take preventative measures.

The obesity epidemic in the US is at an all-time high, sounding the alarm on a new low for nutritional health. During this period of digestive distress, comorbid gastrointestinal and hepatic diseases have run rampant among patients with elevated body mass index (BMI).

The World Health Organization defines obesity as abnormal or excessive fat accumulation presenting a risk to health, measured as a BMI over 30 kg/m2.1 According to the 2017–March 2020 National Health and Nutrition Examination Survey, 41.9% of adults in the US have obesity, more than a 10% increase from 1999–2000.2

Obesity is a systemic issue and as a result, affects multiple organ systems. Being considered overweight or obese increases the risk of a wide spectrum of benign digestive diseases such as gastroesophageal reflux disease, Barrett's esophagus, erosive esophagitis, nonalcoholic fatty liver disease, gallstones, and pancreatitis. Digestive organ cancers such as cholangiocarcinoma, hepatocellular carcinoma, pancreatic cancer, colorectal cancer, and esophageal cancer are also more prevalent among those with obesity.3

As costly as obesity can be to one’s health, its economic impact can be just as severe. The estimated annual medical cost of obesity in the United States was nearly $173 billion in 2019. Medical costs for adults with obesity were $1,861 higher than medical costs for people with healthy weight.2

The framework surrounding obesity prevention is clear and well-established: replace high-calorie foods with healthier alternatives, incorporate more physical activity, get adequate sleep. Preventing obesity also means attenuating the impact of a long list of diseases and conditions it puts people at a greater risk for, yet rates of obesity and its known comorbidities are on the rise.4

Unprevented, Underrecognized

The growing prevalence of obesity, as well as gastrointestinal and hepatic comorbidities, may be due to a lack of preventative care or education, with one study finding two-thirds of adults experience recurrent digestive symptoms like gas, bloating, and abdominal pain, but few seek care from their doctor.5 Insufficient access to healthcare poses a significant barrier for many, with one-third of Americans lacking access to primary care services and 40% of US adults reporting delaying care because of the associated financial costs.6

“Most of these patients haven't been seeing their primary care physician regularly, so no one is there to advise them that they’re overweight, their BMI is increasing, they need to make these changes and take care of themselves,” said Adelina Hung, MD, clinical assistant professor at Rosalind Franklin University of Medicine and Science and gastroenterologist at Sinai Health System Chicago, in an interview with HCPLive. “So when most of them come to me, they're already very advanced. Having less access to medical care from the very beginning for prevention, that also leads to obesity in the population that I see.”

In a 2022 study published in Lancet Diabetes and Endocrinology, obesity was associated with 21 nonoverlapping cardiometabolic, digestive, respiratory, neurological, musculoskeletal, and infectious diseases. Compared with healthy weight, the confounder-adjusted hazard ratio (HR) for obesity was 2.83 (95% confidence interval [CI], 2.74–2.93) for developing at least 1 obesity-related disease, 5.17 (95% CI, 4.84–5.53) for 2 diseases, and 12.39 (95% CI, 9.26–16.58) for complex multimorbidity.7

Obesity is also associated with a greater risk of gastrointestinal cancers, with one study reporting overweight BMI in early adulthood (HR, 1.23; 95% CI, 1.10-1.37) and overweight BMI in middle adulthood (HR, 1.23; 95% CI, 1.13-1.34) and later adulthood (HR, 1.21; 95% CI, 1.10-1.32) as well as obese BMI in middle adulthood (HR, 1.55; 95% CI, 1.38-1.75) and later adulthood (HR, 1.39; 95% CI, 1.25-1.54) were associated with an increased risk of colorectal cancer.8

Poor diet and obesity are believed to cause chronic gastrointestinal diseases like inflammatory bowel disease, often referred to as IBD, with both conditions rapidly increasing and reaching greater proportions of comorbidity than seen in the past.9 The risk of developing gastroesophageal reflux disease also increases with weight and is especially prevalent among those with obesity.10

Weight reduction improves metabolic syndrome and insulin resistance and subsequently may reduce the risk of obesity-related benign diseases. Although the exact role diet plays in gastrointestinal disease is not completely understood, food and controlled nutrition are believed to play a large role in preventing and modulating symptoms.11

“I tell my patients I don't want to scare them, but also, I'm treating them like my family member and telling them they need to hear this and need to be aware of this so they can take action for it,” said Roberto Simons-Linares, MD, director of bariatric endoscopy at Cleveland Clinic, in an interview with HCPLive.

Inadequate Diet and Exercise

Weight gain and loss are primarily the result of total calories consumed versus total calories used, making diet a key component of obesity prevention.12

Widely considered to be a major contributor to the growing rate of obesity in the US, the standard American diet is low in fruits and vegetables while incorporating large portions of foods high in fat, sodium, and calories. By avoiding certain foods popular in the American diet and replacing them with healthier options, obesity and its long-term complications can be significantly reduced.13

“Part of my education to my patients regarding nutrition is eating the healthy fat, high fiber things that actually reduce the amount of carbohydrates that gets absorbed so quickly and stored as fat in our body. You stay full longer, get enough protein, and avoid the processed foods, especially since they have lots of bad fats and high sugar intake with them,” said Bincy Abraham, MD, MS, director of the Fondren Inflammatory Bowel Disease Program at the Underwood Center for Digestive Disorders at Houston Methodist Hospital, in an interview with HCPLive.

“Treatment of obesity is multifaceted because obesity is complex and has multiple factors as well. So it can't really be solely managed and just one approach, and I really think treatment should be looked at through a long term management, multidisciplinary lens. And nutrition is a big part of that,” added Bailey Flora, MS, RDN, LD, clinical outpatient dietitian at Cleveland Clinic.

However, as important as diet and nutrition are for weight management, they aren’t the only factors at play when it comes to obesity. Other lifestyle choices make a difference, too.

The US Centers for Disease Control and Prevention recommends adults get 150 minutes of moderate-intensity physical activity each week and 2 days a week of muscle-strengthening activities. As many as 80% of adults in the US don’t meet these criteria. Even people who are physically active can still gain weight if they consume more calories than they use, so a healthy lifestyle for obesity prevention must include both physical activity and being conscious of nutrition.12

“I try to gently coach my patients and say ‘Hey, some of these issues may be driven by diet and exercise or inactivity, and while I don't want you to be going out there and running a marathon or changing your diet entirely, let's just do one small step at a time.’ I never want to make a huge change, because I think that loses some buy-in from patients,” explained Chamil Codipilly, MD, senior associate consultant in the division of gastroenterology and hepatology at Mayo Clinic, in an interview with HCPLive.

Financial Barriers

Economically, some of the known preventative measures for obesity aren’t accessible to everyone. Despite the robust knowledge surrounding obesity and how to effectively prevent and manage it, people continue to fall victim to it at accelerating rates.

“We know that healthy food can be expensive. So even if you tell patients to eat healthy and buy things like quinoa or brown rice, those are things that they are sometimes not able to afford. Things like junk food and fast food, can be much cheaper, and much more affordable to them,” explained Hung.

One study of neighborhood food prices of packaged goods sold in large chain supermarkets across the US found healthier foods cost nearly twice as much as unhealthier foods per serving on average (mean healthy-to-unhealthy ratio, 1.97; standard deviation [SD], 0.14).14

“I think it's also really important for health care providers, providers, nutrition professionals, to really be talking with patients and educating them on how you can prepare healthy options on a budget,” Flora said.

Treating obesity can be even more costly than preventing it. Between 2001 and 2015, obesity-related medical expenditures rose nearly 30%. Direct and indirect medical costs attributable to obesity reached $1.4 trillion in 2014 and are predicted to rise as more patients continue to develop obesity and seek treatment.15

“Even though we have all of these potential treatments for obesity, the medication, the endoscopic treatment, the surgical treatment, not everything is covered by insurance. I wish I could offer more options to my patients, but they usually aren’t covered,” Hung said. “With each patient, we have to realize that even though we have all of these potential interventions, we might not be able to offer them to patients.”


  1. World Health Organization. Obesity. Health topics. Accessed October 6, 2023.
  2. Centers for Disease Control and Prevention. Adult Obesity Facts. Data and Statistics. May 17, 2022. Accessed October 6, 2023.
  3. Nam SY. Obesity-Related Digestive Diseases and Their Pathophysiology. Gut Liver. 2017;11(3):323-334. doi:10.5009/gnl15557
  4. Johns Hopkins Medicine. Obesity Prevention. Health. Accessed October 6, 2023.
  5. MDVIP. Two-Thirds of Americans Are Living With Gut Issues, Unaware of the Health Consequences. Press Room. May 24, 2023. Accessed October 6, 2023.
  6. PBS. Why more Americans are putting off going to the doctor. March 25, 2023. Accessed October 6, 2023.
  7. Kivimaki M, Strandberg T, Pentti J, et al. Body-mass index and risk of obesity-related complex multimorbidity: an observational multicohort study. Lancet Diabetes Endocrinol 2022; 10: 253–63. S2213-8587(22)00033-X
  8. Loomans-Kropp HA, Umar A. Analysis of Body Mass Index in Early and Middle Adulthood and Estimated Risk of Gastrointestinal Cancer. JAMA Netw Open. 2023;6(5):e2310002. doi:10.1001/jamanetworkopen.2023.10002
  9. Kim JH, Oh CM, Yoo JH. Obesity and novel management of inflammatory bowel disease. World J Gastroenterol. 2023;29(12):1779-1794. doi:10.3748/wjg.v29.i12.1779
  10. UChicago Medicine. GERD and Obesity. Accessed October 6, 2023.
  11. Corsello A, Pugliese D, Gasbarrini A, Armuzzi A. Diet and Nutrients in Gastrointestinal Chronic Diseases. Nutrients. 2020;12(9):2693. doi:10.3390/nu12092693
  12. Centers for Disease Control and Prevention. Finding a Balance of Food and Activity. Healthy Weight, Nutrition, and Physical Activity. Accessed October 6, 2023.
  13. Rakhra V, Galappaththy SL, Bulchandani S, Cabandugama PK. Obesity and the Western Diet: How We Got Here. Mo Med. 2020;117(6):536-538.
  14. Kern DM, Auchincloss AH, Stehr MF, et al. Neighborhood Prices of Healthier and Unhealthier Foods and Associations with Diet Quality: Evidence from the Multi-Ethnic Study of Atherosclerosis. Int J Environ Res Public Health. 2017;14(11):1394. doi:10.3390/ijerph14111394
  15. Strategies to Overcome and Prevent Obesity Alliance. Cost of Obesity. Fast Facts. Accessed October 6, 2023.
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