If you’ve ever been constipated and then finally found relief, you too know the hallelujah glory that an overdue poop can bring. You don’t just feel better…you feel lighter, thinner even, without that rock sitting in your abdomen. Which might explain why people still consider taking laxatives for weight loss.
“It’s an age-old myth that never seems to go away,” says Neilanjan Nandi, M.D., a gastroenterologist at Drexel Medicine. “Laxatives are a terrible idea for weight loss. They’re neither effective nor safe.”
Here’s the dealio: If you think of your body in simple terms, you eat food, then digest it, then secrete it (a.k.a. poop it out). When you take a laxative, all you are doing is lubricating the stool and stimulating your intestines to urgently clear it. “You might think you’re losing weight because of how much lighter you feel, but you’re not burning calories or removing fat, so any ‘weight loss’ is temporary and not real,” Dr. Nandi says.
When you pop a laxative, what you’re really losing is a lot of water, a little stool, and—sorry—zero fat. “Removing water from your body makes you look immediately slimmer, because there’s less fluid under your skin,” he adds. “But that puts you on the fast track for dehydration and an electrolyte imbalance.” Those two things can cause a cycle of problems, like headaches, low blood pressure, and fatigue, to the point of hospitalization.
Not to mention, hydration is key to legit weight loss. In short, your body needs ample water for your cells, heart, and muscles to function properly. Since weight loss occurs when calories in < calories out—an equation that’s best achieved via exercise—you want to set yourself up for the best workouts possible.
What’s more, while taking laxatives for weight loss may seem like an easy way to speed up your metabolism (more poop must mean a faster engine, right?), you’re actually not affecting your metabolism at all. “By the time food has formed into stool, the calories and fat that was in it has already been stored in the body,” Dr. Nandi says.
In fact, taking laxatives for weight loss can actually create the opposite effect. By taking laxatives regularly, you essentially teach the muscles of your intestines and colon to shut off, since they get used to having an outside source do their job. The result: paradoxical constipation (the name says it all). “Your body basically stops trying to remove stool on its own, and you’re stuck with constipation that can be extremely difficult to reverse,” explains Dr. Nandi. (Oh, sh*t…)
So…laxatives for weight loss is a no, but is there ever a good time to take a laxative? Sure—but in very specific (read: not vain!) instances.
“If you suddenly don’t have a bowel movement for a week when you’re used to having multiple movements per week or day, take a couple of stool softeners,” says Dr. Nandi. (Stool softeners, such as Miralax, are less extreme versions of laxatives. They’re less likely to cause the, er, explosiveness that full-blown laxatives might spike.) If you’re still not seeing progress after two weeks, it’s time to see a doc.
And remember, no instant “skinny” feeling is worth risking your overall health. If you want to lose weight, stick to the tried and true basics: eat clean, exercise regularly, and for everyone’s sake, drink lots and lots of water.