Obesity and Digestion- What’s the Connection?

Written by: Whitney Hussain

Updated: December 9th, 2024

Obesity is a chronic disease that can be a risk factor for other medical conditions including various digestive health disorders.The prevalence of obesity in Canada is on the rise with an increase from 21% of adult Canadians in 2003 compared to 30% in 2022.

If you’re living with obesity, what are ways you can support your gut health in a practical way? Learn more about simple nutrition and lifestyle solutions you can focus on that can help!

Obesity and Digestive Disorders

Obesity is a chronic disease where there is an excessive accumulation of fat deposits in the body. Obesity could have impacts on someone’s digestive symptoms by:

Increasing abdominal pressure which could cause acid reflux
Changes in bowel motility or how quickly food passes through the digestive tract
Increase in pro-inflammatory proteins that could impact risk of inflammatory bowel disease
Changes in the gut microbiome depending on foods consumed

Obesity is a complex disease that can feel difficult to navigate but there are lifestyle management tips outside of weight loss than can support your symptoms.

Obesity and Esophageal Disease

Esophageal diseases are conditions that effect your esophagus, or the tube that passes food from your mouth to your stomach.

GERD

GERD (or gastroesophageal reflux disease) is where stomach contents move into the esophagus or our mouth. GERD symptoms are usually heartburn or even vomiting of food. Obesity can increase pressure in our abdomen causing the relaxation of muscles that block food from our stomach from entering our esophagus (the esophageal sphincter).

Practical Tips for GERD:

Work with a Dietitian to determine if there are possible trigger foods that may worsen your symptoms like high fat foods, carbonated beverages or citrus foods
Aim for a 2-3 hour interval between your last meal and sleep
Slow down at meals instead of eating quickly

Barrett’s Esophagus

Barrett’s esophagus is a change to tissue structure in your esophagus. The acid from your stomach entering your esophagus when you have GERD can cause tissue lining damage. Obesity related GERD may increase risk for Barrett’s esophagus making management of GERD important for disease prevention.

Esophageal Cancer

Esophageal cancer is cancer in the esophagus. The higher risk of GERD amongst those with obesity may increase risk of esophageal cancer due to prolonged damage of the esophagus. Esophageal cancer can cause many forms of malnutrition related to pain and swallowing difficulties or blockages in the esophagus making it difficult to eat.

Practical Tips for Esophageal Diseases:

Work with your doctor and care team to manage your GERD to prevent other esophageal diseases like Barrett’s esophagus or esophageal cancer.

Obesity and the Gallbladder

The gall bladder is an organ that stores and releases bile. Bile is an important fluid made by the liver to help digest and break down fat we consume.

A common gall bladder disease is gall stones, also called cholelithiasis. These gall stones are small, hard crystals that develop in the gall bladder. If these stones are large, they can cause symptoms of gall bladder pain called biliary colic due to the blockage of cystic ducts (the tube that carries bile from the gall bladder).

Gallstone disease can occur in both those who do or do not have obesity. Excess body weight is linked to increased cholesterol metabolism. One reason for this is obesity may impact insulin resistance or increase insulin levels. This increase in insulin can cause large amounts of cholesterol secretion by the liver, leading to more cholesterol-dense bile and subsequently production of gall stones.

Practical Tips for Gallstones:

Increased intakes of fruits and vegetables
Ensure you meet your energy needs since a very low-calorie diet can increase risk of gallstones
Opting for unsaturated fats more often in your diet

Obesity and the Intestine

The intestines include both the small and large intestine. It’s a very important part of our digestive system since it is where the nutrients we eat are absorbed and used by our body like macronutrients, vitamins, minerals and water.

Irritable Bowel Syndrome

Irritable bowel syndrome is a disorder impacting the intestines due to how food passes through the bowels or how our brain interprets signals from the digestive tract. Common symptoms are abdominal pain and varied bowel patterns including frequency and types of bowel movements (constipation, diarrhea or a mix of both).

There are limited research findings around the association of IBS and obesity but some individuals do report continued symptoms even if other factors are corrected. Symptoms are often IBS-M with mixed symptoms of both constipation and diarrhea. Some potential reasons for IBS in obesity could be (but may not limited to just those with obesity):

Dietary choices including higher fat, lower fibre diets or poorly absorbed carbohydrates. Food options may be limited because of IBS symptoms.
Reduction in activity levels
Larger body weight increasing severity of digestive symptoms
BMI may be inversely correlated with transit time in the colon
Stress and mental health conditions (anxiety, depression, fatigue) impacting gut motility

Practical Tips for IBS:

Working with a Dietitian to help determine foods trigger and adding nutrient dense foods back into your meals

Crohn’s Disease

Crohn’s disease is an inflammatory bowel disease (IBD) that can occur at any part of the digestive tract. It is estimated that 15-40% of those with IBD also have obesity. Crohn’s disease symptoms include:

Abdominal pain
Loose stools
Reduced appetite
Sores anywhere between the mouth and anus.

Obesity can encourage a low-grade inflammatory environment in the body due to visceral adiposity (abdominal fat) releasing signals that affect the function of the intestinal barrier. Impaired gut barrier function can be a feature in obesity, which allows bacteria to move into parts of the bowels it normally is not found. There is some evidence to show that obesity may have protective factors for Crohn’s disease.

Obesity may influence a patient’s response to drug therapy. Obesity can affect how a drug works by altering how the drug is absorbed, metabolized and cleared from the body. For Crohn’s disease and IBD surgery, obesity may increase time in surgery or post operative complications (infections and wound complications).

There is no one special Crohn’s disease diet but it can feel difficult to tolerate certain foods due to your digestive symptoms.

Ulcerative Colitis

Ulcerative colitis is an inflammatory bowel disease of the large intestine, specifically the colon. Many connections relating obesity to ulcerative colitis are like that in Crohn’s disease.

The evidence is mixed for outcomes with those with obesity and ulcerative colitis. Some studies show that obesity may increase of hospitalization and surgery for those with ulcerative colitis, but other findings note reduction of risk for complications.

Practical Tips for Inflammatory Bowel Disease:

Working with a Dietitian is helpful to determine which foods are best for you and meeting your nutritional needs while managing symptoms.
Ensure you are continuing any prescribed medications by your Gastroenterologist to reduce disease activity and keep you in remission.
Incorporate movement and exercise into your daily routine to lower risk of active IBD disease and help with your stress management.

Obesity and The Pancreas

The pancreas is an organ responsible for producing enzymes to digest food. It also produces two hormones (insulin and glucagon) that help with blood sugar management. Pancreatitis is when the pancreas gets inflamed and damaged.

There are two types: acute and chronic pancreatitis. Common symptoms of pancreatitis are abdominal pains, fever, foul smell stools (due to fat malabsorption) and possible weight loss. Some causes of pancreatitis are gall stones, heavy alcohol consumption, and smoking.

Obesity is a risk factor of acute pancreatitis due to the higher incidence of related diseases like:

Gallstones causing blockages in pancreatic ducts
High triglycerides impairing blood flow to the organ tissue

For those with pancreatitis, obesity may worsen symptoms and outcomes due to the visceral fat in or around the pancreas.

Practical Tips for Pancreatitis:

Reducing alcohol intakes and smoking cessation program can be useful for pancreatitis prevention.

Obesity and the Liver

The liver is an important organ with many responsibilities like regulating your body’s supply of energy, hormones and cholesterol, produces bile and helps metabolize and remove toxins.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common liver disease in North America. It is characterized by an accumulation of fat in the liver, with those that do not have a history of large alcohol consumption. It is a common cause of other chronic liver diseases like non-alcoholic steatohepatitis (NASH) due to its inflammatory progression.

The most common cause of MASLD in Canada is obesity. Excess body fat, especially an increase in visceral fat around the abdomen, is linked to MASLD. Some reasons include:

Excess fat in obesity may be stored in the liver
Possible increase in inflammatory proteins that are derived from adipose (fat) tissues
Higher risk of metabolic syndrome in those with obesity which is associated with MASLD

Other causes are sedentary lifestyles and eating larger amounts of refined carbohydrates and high fat foods.

Practical Tips for Liver Disease:

Incorporate physical activity you enjoy into your weekly routine
Work with a Dietitian to add nutrient dense foods into your diet and supporting healthy weight management

Obesity and Other Chronic Health Conditions

Obesity is a risk factor for various chronic health conditions. Obesity Canada breaks these conditions into 4 categories:

Mechanical health including sleep apnea, GERD and osteoarthritis
Mental health including depression, anxiety and low self esteem
Monetary health including influences on education, cost of living and cost of weight management programs
Metabolic health including hypertension, high cholesterol and type 2 diabetes.

Obesity and Diabetes

Diabetes is a condition where the body does not produce enough insulin or is unable to properly use the insulin it makes. Insulin is a hormone that helps our bodies regulate blood sugars. There are various forms of diabetes including:

Type 1: An autoimmune disease where the body is unable to make its own insulin
Type 2: The body is unable to properly use the insulin produced or cannot produce enough. About 90% of people with diabetes have type 2 diabetes.
Gestational: A temporary form of diabetes occurring during pregnancy

It is estimated that 80-90% of individuals with type 2 diabetes are overweight or have obesity. Obesity, its related abdominal fat distribution and liver/muscle triglyceride content can cause both insulin resistance and dysfunction of cells that make insulin.

Practical Tips for Diabetes:

Diabetes Canada has many practical resources to support managing your diabetes in inclusive and positive ways

Key take-aways:

Obesity is a complex chronic disease that can have direct and indirect impacts on our digestive health conditions
There are many dietary and lifestyle factors we can control to support our health including food and beverage choices and exercise and movement.
It’s important to work with your care practitioners (including Family Doctor, Nurse Practitioner, Pharmacist and Dietitian) to receive the best customized care for you!

Conclusion: 

Positive health outcomes can come in a variety of shapes and sizes. Weight loss is a common recommendation for those with diabetes, but this can feel difficult due to resources and access to healthy food choices, stress, managing many chronic health conditions and having the supports around you to encourage your health journey.

Fortunately, there are many lifestyle changes we can positively action on that is more than the number on the scale. This article provides many of those tools to get you started!

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