People who are obese or overweight often complain constipation. Many people wonder if these two are related. The answer is yes and no. I will explain why.
Constipation means less frequent bowel movements associated with bloating and hard stools. In this condition, you may not be able to completely clear the faeces from the rectum. So, if you have chronic constipation, there is more chance of accumulation of faeces in the rectum and bowels.
Technically, it can increase your body weight. For example, if 200 g of stools accumulate each day, you will gain 1kg of weight in 5 days. That is a sudden weight gain.
However, the increase in your body weight is temporary, not permanent. You can’t continue gaining weight like this for a long term. According to the above calculation, you should gain 18 kg of weight in 3 months. Before that happens, your tummy will burst.
To be clear, you may have some short term weight gain due to severe constipation. However, it doesn’t mean that you are getting fatter. This is not a fat accumulation. It is just a faecal weight.
However, constipation and weight gain can coexist. I will explain 3 classical situations.
Number one is underactive thyroid. The thyroid gland secretes a hormone called thyroxine. This thyroid hormone controls many metabolic activities of the body. If you have low levels of thyroid hormone, your metabolic rate will be slow down. You can’t burn enough calories. That makes you gain weight. Constipation is a cardinal symptom of underactive thyroid.
The second situation is you are eating lots of junk food. These unhealthy foods have lots of calories. They are usually loaded with fat or refined sugar. Eating these fast foods will make you put on weight. In addition, these foods don’t normally have enough fibre. So, you will be constipated. Furthermore, the majority of fast food meals comes with a soft drink or coffee. They will make you dehydrated. That will make the constipation even worse.
The third scenario is not enough physical activity. Lack of exercise makes you fat. In addition, it makes your bowels lazy. Slow bowel movements make the stools hard and difficult to pass. If you are a physically active person, there is less chance of getting constipated.
Bottom line:
Constipation can cause weight gain to a small extent. Most of the time, it is an association rather than a causation. So, don’t try to lose weight by taking laxatives.