Why Do Some IBS Patients Lose Weight?
Irritable bowel syndrome (IBS) is among the most common digestive disorders and has a variety of different symptoms. But can IBS cause people to lose weight?
In this article we explain IBS weight loss, why it might occur, how to prevent it, and when to see a doctor. Here’s everything you need to know.
What is IBS Weight Loss?
Unlike some other digestive disorders, including inflammatory bowel disease and celiac disease, weight loss is not typically a symptom of IBS.
The classic IBS symptoms include:
- Abdominal pain
- Bloating
- Gas
- Irregular bowel habits
- Diarrhea
- Constipation
- Mucus in the stools
- Sensations of incomplete bowel emptying
Although weight loss is not generally considered an IBS symptom, some of the above issues can indirectly cause people to lose weight. Let’s take a closer look.
What IBS Symptoms Cause People to Lose Weight?
People with IBS often experience severe abdominal pain and bloating, especially after eating. This might prompt them to eat smaller amounts or less frequently in order to manage their symptoms. However, doing so can cause a calorie deficit and, therefore, lead to weight loss.
Furthermore, many IBS sufferers have restricted diets. Certain foods can exacerbate IBS symptoms, limiting what they can eat. Some of the most problematic foods include:
- Alcohol
- Caffeine
- Carbonated beverages
- Processed foods
- High-fat foods
- Fried foods
- Dairy products
- Artificial sweeteners
Many of the above are high-calorie foods and drinks. Therefore, cutting them out of the diet could lead to weight loss. The plus side is that most of these trigger foods are unhealthy choices and eliminating them could help to improve a person’s general wellbeing. The problem is finding healthy alternatives to replace them.
Many people with IBS are also sensitive to insoluble fiber and fermentable carbohydrates known as FODMAPs. These are found in many fruits, vegetables, pulses, and whole grains. The long list of IBS trigger foods can make it challenging for people with the condition to know what to eat.
How Likely Are People to Lose Weight From IBS?
It is unclear exactly how many people with IBS also experience weight loss. In fact, there is some research that links the condition to weight gain. The 2015 study claims that people with IBS are likely to have an average or higher-than-average body mass index (BMI).
The authors state that this could be because IBS sufferers have abnormal levels of the hormones that regulate hunger. For example, they seem to have increased levels of ghrelin, the hormone that stimulates the appetite. Meanwhile, their levels of other, appetite-suppressing hormones are reduced.
However, this research is controversial. Another 2011 study found that people with diarrhea-predominant IBS, specifically, were more likely to have a low BMI. It is clear that more research is necessary before we fully understand how IBS affects body weight.
How is Weight Lost From IBS?
Weight loss due to IBS is more likely to be gradual than sudden. It is usually the result of calorie restriction, meaning that it may only become obvious after several weeks or months. Anyone with IBS who loses weight suddenly should see a doctor as it may be due to another issue.
The good news is that IBS weight loss is preventable. The key is for individuals to find out which foods they can tolerate and use these as the basis for their daily diets.
It may be useful to keep a journal for several weeks to learn which foods trigger IBS symptoms and should be excluded. It is also a good idea to count calories or use a fitness app to ensure enough food is being consumed each day.
Many people with IBS find it beneficial to eat four or five small meals throughout the day rather than three large ones. By not eating too much at once, it is possible to minimize symptoms like abdominal pain and bloating. It is essential not to skip meals, as this can contribute to weight loss and malnutrition. There are some high-calorie, IBS-friendly foods to consider eating more of.
Low-FODMAP nuts and seeds:
- Almonds (maximum 10 per day)
- Hazelnuts (maximum 10 per day)
- Brazil nuts
- Macadamia nuts
- Pecans
- Peanuts
- Pine nuts
- Walnuts
- Chia seeds
- Pumpkin seeds
- Sesame seeds
- Sunflower seeds
Low-FODMAP fruits (maximum three portions daily):
- Bananas
- Blueberries
- Raspberries
- Strawberries
- Grapes
- Cantaloupe
- Honeydew melon
- Kiwis
- Oranges
- Pineapple
- Papaya
- Rhubarb
Healthy, high-fat foods:
- Coconut oil
- Extra virgin olive oil
- Olives
- Avocados
Of course, not all of these are suitable for everyone with IBS. Try experimenting with a small amount first to see how individual foods affect your symptoms before increasing gradually.
When to Consult a Doctor About IBS Weight Loss
It is essential to consult a doctor about any unexpected weight loss. While it could be an IBS symptom, it could also indicate another digestive disorder, such as ulcerative colitis, Crohn’s disease, or celiac disease. These conditions have some similar symptoms to IBS, but the treatment is very different. Therefore, getting a correct diagnosis is critical.
Furthermore, weight loss can be a symptom of serious diseases like cancer. See a physician as soon as possible if your weight loss is accompanied by bloody stools or sudden bowel habit changes. This is especially important for anyone aged over 60 or with a family history of ovarian or bowel cancer.