The Bottom Line: The danger in misusing laxatives to lose weight

SINGAPORE – Feeling bloated and constipated because of festive feasting? Perhaps you are thinking of looking for an over-the-counter laxative to help relieve the discomfort.

While they declined to provide figures, some retailers say sales of laxatives spike during festive periods.

Health and beauty chain Watsons sees demand increase in the months of March, June, September and December – during holidays and festivities – which a spokesman attributes to “changes in diet and daily routine that may lead to constipation”.

A spokesman for FairPrice Group, which runs the Unity chain of pharmacies, says sales remain stable in 2024, with no spikes. But health supplements retailer Nature’s Farm says its sales of “probiotics and detox products” – which include laxatives – go up after major holidays such as Christmas and Chinese New Year.

Digestive woes account for much of these sales, but doctors have also seen patients who take laxatives in the hope of preventing weight gain, or to lose weight.

Advertisements and reviews for some products containing laxatives, seen by The Straits Times on Instagram, contain phrases such as “I pooped so much backed up fat (after consuming the product)”, suggesting that laxatives can help with weight loss.

Global demand for laxatives is also increasing, in part because of interest in the weight-loss potential of such products, according to market research company Market Research Future.

The firm, which is headquartered in the US and India, projects that the size of the laxatives market will grow from US$7.3 billion (S$9.8 billion) in 2024 to US$12.4 billion by 2032.

The “increasing prevalence of eating disorders will fuel industry growth”, states the company’s market research report, issued in December.

Overuse or misuse of laxatives can lead to health problems, doctors warn, and laxatives are not a permanent or healthy way to lose weight.

How laxatives work

Dr Emily Ho, senior consultant at Singapore General Hospital’s department of endocrinology, says laxatives help to make bowel movements easier and are recommended for people with occasional or short-term constipation.

Laxatives may act to stimulate contractions of the intestinal wall and move stool along to the rectum, or coat and soften stools to make their passage easier. Some laxatives absorb liquid and form a bulk that stimulates the bowel.

“Many laxatives work by drawing water from body tissues into the large intestine to soften the stools and act as a stimulant,” adds Dr Ho. “When this stool is expelled, the body loses the water that is directed into the intestines. Losing water in this manner may result in temporary weight loss.”

She cautions that the weight returns when the body rehydrates. Not allowing the body to rehydrate can have adverse effects.

Dr Ng Tay Meng has similar words of caution. “Using laxatives for weight loss is not recommended and can be harmful,” says the gastroenterologist, who practises at private medical group Asian Healthcare Specialists.

“First, laxatives can cause dehydration and electrolyte imbalances, which can adversely affect the heart and kidney functions. Second, regular use of laxatives can lead to dependence, making it harder to have normal bowel movements without them. Third, laxatives can irritate the digestive tract, causing cramps, bloating and diarrhoea.”

Dependence on laxatives can also lead to mental health problems such as eating disorders, adds Dr Ng. “Please remember that laxatives are never meant to be used for weight loss. They’re not a magic solution.”

Misunderstandings fuel demand for laxatives

Dr Shen Xiao You, associate consultant with SingHealth Polyclinics, says: “Some may misuse laxatives under the misconception that laxatives support weight loss by expelling food and calories from the body before they are absorbed.”

“This is not true as laxatives act on the large intestine, while most foods are digested and absorbed before reaching the large intestine,” adds Dr Shen, who is also deputy clinical lead for the gastroenterology workgroup at the polyclinics.

Dr Ng says that laxatives help to eliminate undigested food, water and electrolytes, but not fat. “There is a misconception that laxatives can help to poop or flush out fats from the body. This is not true because laxatives do not prevent fat absorption, which occurs in the small intestine.”

Yet such misunderstandings about laxatives and weight loss fuel demand for the product, as the Market Research Future analysis found.

Some ads and reviews for health supplement brand Happy Mammoth on Instagram, which ST saw in November, contained claims that its Complete Belly Reset product, which has a laxative effect, could help users poop out “backed up fat”.

ST has e-mailed the US-registered Australian brand for clarification. The claims no longer appear on its Instagram page.

Nature’s Farm has a laxative product, Detox Bomb, which is currently marketed under the weight management section of the chain’s website.

In response to queries, a spokesperson for Nature’s Farm says via its public relations agency: “Based on our expertise and experience in the supplements and wellness industry, we can confirm that laxatives are not directly associated with weight management. They do not burn fat, boost metabolism or block carbohydrate absorption, and should therefore not be considered a solution for weight loss.”

However, adds the spokesperson, people on a weight-loss regimen might have constipation because of changes in their diet and physical activity.

“Constipation can temporarily affect weight loss by slowing digestion and causing fluctuations in weight. Chronic constipation may even contribute to a slower metabolism, potentially hindering weight-loss efforts.”

Watch out for hidden laxatives

Many of Dr Ng’s patients have consumed laxatives unknowingly, as they are regular users of weight-loss teas and slimming products that contain such ingredients.

They may develop irritable bowel syndrome, with symptoms such as flatulence, cramps and a bloated abdomen. Prolonged laxative use is revealed as the likely cause of these symptoms when a colonoscopy shows discolouration of the intestinal wall because of deposits of pigment from the laxative. The discolouration itself is harmless and reversible.

Natural or plant-based laxatives may be found in such slimming teas. Dr Tan Wei Jie, a general physician at private practice DTAP Clinic @ Orchard, has several patients who consume weight-loss teas containing laxatives.

He says that senna, a laxative, is a common ingredient in weight-loss teas. “It is important to seek your healthcare provider’s advice before consuming these teas, as some of them may contain extra ingredients that might potentially harm your body when taken over an extended period of time.”

He tells his patients that there is no concrete scientific evidence to show that slimming teas are effective in helping people to lose weight. “Additionally, I would inform them of the potential adverse side effects when consuming these teas and encourage them to find alternative methods to lose weight, such as exercising regularly and eating healthy.”

Caffeine is another common laxative ingredient. Dr Shen says: “Caffeine found in coffee and tea can stimulate movement of the large colon and potentially reduce constipation risk. Excessive caffeine use, however, may lead to palpitations, shaking and an upset stomach. In rare cases, it may also lead to heart problems, hallucinations or seizures.”

How to avoid weight gain during the festive season

Dr Kyle Tan, founder of private practice Novi Health, specialises in weight management and preventive medicine. He says that using laxatives might temporarily adjust the numbers on the scale, but will not lead to fat loss.

Seventy per cent of fat loss comes from one’s diet, he says. You need to be in a calorie deficit – eat less than what you burn throughout the day – and to eat whole foods that are nutrient dense and have volume.

Avoid ultra-processed food and those rich in sugar, which can give you insulin spikes.

Exercise, getting enough sleep and lowering your stress level can also help with weight management.

During the festive season, it might help to plan ahead. Eat smaller meals for breakfast and lunch if dinner will be a feast. Try not to snack mindlessly.

“Don’t deprive yourself, but also eat healthier options,” says Dr Tan.

“It is important to recognise that you may overeat at certain times,” he adds. “You shouldn’t beat yourself up. Be aware and mindful of what you can do the next day – for example, eating less.”

The Bottom Line: Laxatives can lead to loss of water and electrolytes, but not fat. Overuse or misuse of laxatives can adversely affect your health. Consult your doctor or a registered dietitian for weight-loss advice.