Why the Whole30 Diet Is Giving You, Um, Some Bowel Problems

If you've been following diet trends over the past few months, you've probably heard about Whole30, a 30-day plan that includes lots of whole foods and no sugar, alcohol, carbs, dairy, soy, or legumes. You might've even tried it — and if you have, you might've found yourself experiencing some unpleasant digestive side effects. The Whole30 forum has been filling with threads like "diarrhea issues" and "intense gas and diarrhea." But is it Whole30 that's causing these issues, or are the people experiencing them just not following the diet properly?

The point of the Whole30 plan is to feed our bodies the things we evolved to digest and get rid of cravings that aren't doing us favors, says registered dietitian Katrina A. Trisko, MS, RDN, CDN. After eating mostly vegetables, fruits, animal proteins, and healthy fats, your body's signals will become more in line with what it actually needs.

There can also be some less desirable effects, though, says Trisko. You might experience headaches, bloating, stomachaches, sugar cravings, and — yes — diarrhea. This is likely the result of all the fiber you're taking in through fruits and vegetables, and it's especially likely to happen if you didn't eat a lot of fiber before. It doesn't mean anything's wrong, though, and it usually subsides over time.

However, the diet's side effects will depend on what specific foods you eat, says nutrition coach Adrienne Daly. Vegetables with FODMAPs, like onions, garlic, broccoli, and cauliflower, can ferment in the colon, causing gas and diarrhea. So if Whole30's giving you bowel problems, try eliminating these and seeing if the issue goes away.

Overall, don't take diarrhea as a sign that the diet's unhealthy. "Eating a whole-food diet based heavily on vegetable, meats, and healthy fat options has absolutely zero drawbacks," Daly said. "Don't give up. There are tons of veggie options that are tummy compatible."

Still, the Whole30 diet is very restrictive and not sustainable for many people, Trisko says, and it can be triggering if you have a history of disordered eating. It may be more realistic to consume more whole fruits, vegetables, lean proteins, and healthy fats and less sugar and alcohol without completely giving up anything.