The Down Low on Low-Carb Diets

How to avoid the pitfalls and side effects of a low-carb weight loss plan

By Colette Bouchez
WebMD Weight Loss Clinic - Feature

Reviewed By Brunilda Nazario

You've cleaned out those pantry closets, gone food shopping, and made the commitment. It's official: you're on a low-carb diet!

But while the road to a slimmer new you may be paved with high-protein foods, if you're like most low-carbers it's likely you've also encountered a few potholes along the way.

"Any time you make a fundamental change in your diet your body is going to react -- and when it does you are bound to experience certain symptoms or problems," says Stephen Sondike, MD, director of the Nutrition, Exercise, and Weight Management Program (NEW) at Children's Hospital of Wisconsin.

When that change involves reducing carbs, he says, among the most common problems is constipation.

"One of the primary places where you are going to see metabolic changes on any kind of diet is in your gastrointestinal tract -- and that can include a change in bowel habits often experienced as constipation," says Sondike, who is also credited with conducting the first published, randomized clinical trial on low-carb diets. The reason, Sondike tells WebMD, is that most folks get whatever fiber they consume from high-carb foods such as bread and pasta. Cut those foods out, and your fiber intake can drop dramatically, while the risk of constipation rises.

"However, if you really follow a low-carb diet correctly, you will be replacing those starchy foods with low-carb, high-fiber vegetables -- which should help counter the constipation by providing as much, if not more fiber, than you had before," says Sondike.