Does SIBO Cause Weight Gain? – Everything You Need To Know
Your gut microbiota — the community of bacteria that live in your intestines — plays a key role in digestion, metabolism, and immunity. In fact, an imbalance in gut bacteria may actually lead to weight gain.
So, does SIBO actually cause weight gain? The short answer is: possibly. The long answer is a bit more complicated.
There are a few different ways that SIBO could theoretically lead to weight gain. But first, it’s important to understand what we mean by weight gain.
Weight Gain Vs. Fat Gain
When most people think about their weight, they focus on the number on the scale. However, this number doesn’t give the whole story.
You’ve probably heard people say they want to “lose weight,” when what they really mean is that they want to lose fat.
Your weight is your overall body mass and says nothing about your body’s composition (the ratio of muscle to fat in your body).
Fat is stored in adipose tissue which is found all over the body. It cushions and insulates organs, and helps to store energy. When someone gains fat, it means that the size of fat cells in their body has increased.
Gaining weight simply means that the person has gained more mass overall, which could be due to muscle gain, water retention, or fat gain.
For our purposes here, while we may refer to weight gain, we are actually examining whether SIBO causes you to gain fat, not weight.
So how can SIBO lead to fat gain?
Let’s dive in.
How Can SIBO Lead to Weight Gain?
1. Nutrient Malabsorption
First of all, when you have SIBO, you may be more likely to suffer from nutrient malabsorption. This means that your body cannot absorb all the nutrients from the food you eat, and this can lead to weight loss.
However, in some cases, people with nutrient malabsorption actually gain weight because they compensate for the lack of nutrients by eating more food. Their body’s hunger signals tell them to eat more to bring more nutrients into their body, causing them to increase their overall calorie consumption.
2. Gut Bacteria Imbalances
How? Dysbiosis can cause inflammation (more on that below). However, it can also lead to changes in metabolism and the way that the body stores fat. 
3. Gut Inflammation
Finally, SIBO can cause inflammation in the gut which can lead to weight gain. Inflammation can damage the gut lining, making it less efficient at absorbing nutrients . It can also lead to changes in your hormones that regulate appetite, leading to increased hunger and cravings.
4. Bloating and Abdominal Distension
It’s important to remember that SIBO is often associated with bloating and abdominal distension which can give the illusion of weight gain. While your stomach may be pushed out, you have not actually gained body fat.
Plus, if you are retaining water, it actually can increase your weight. However, this is temporary and does not mean you are gaining fat.
Gaining Weight (or Fat) Isn’t A Bad Thing
We as a society are conditioned to fear gaining weight. We’re bombarded with messages telling us that being thin will make us happier and healthier. As a result, we often strive for a body weight that is lower than our natural happy weight – at the expense of our health.
But actually, gaining fat is not a bad thing. Our bodies evolved to store energy in the form of fat, and this helps us to survive when food is scarce.
Our bodies need fat to stay healthy and function properly. Fat is an important part of our bodies, providing insulation and energy storage. It helps to protect our organs and absorb essential vitamins and minerals.
Body fat percentage is not the ultimate determinant of health. There are many factors that are meaningful in determining overall health.
Take the focus away from fat gain and instead, focus on making choices that make you feel good.
Choose nutritious foods that support your gut health. And remember, that doesn’t mean you can never enjoy unhealthy treats that make you feel comforted and good. Restriction leads to poor mental health which impacts your ability to care for your physical health.
- Finding ways to move your body that feel fun and enjoyable.
- Taking care of your mental and spiritual health.
- Prioritizing sleep and pursuing creative hobbies.
All of these things will support your overall health and will support you in finding peace with your body and food.
Remember, stressing out about weight gain is worse for you than the actual weight gain! It’s perfectly normal and healthy for our bodies to change over time. There are no ‘bad’ bodies or shapes your body is meant to be.
So, while SIBO doesn’t necessarily cause weight gain, it can be a contributing factor in some cases. If you are concerned about weight gain, it is important to talk to your doctor or dietitian to find out if SIBO is a contributing factor. If it is, there are treatments that can help to improve gut health and relieve symptoms.
Do you have experience with weight gain and SIBO? Let us know!
Written by Stephanie Moore
Stephanie is a professional freelance writer who is a ‘SIBO survivor’ herself with broad experience writing in the health field. She is a regular writer for SIBO Survivor and calls Berlin, Germany home.