What Is the Specific Carbohydrate Diet?

Kendall Conrad thought she could lay her infant daughter's health issues to rest. Since undergoing ear tube surgery at 11 months old, the baby no longer had the constant ear infections that plagued her first months of life. Problem solved.

But then, another emerged. Likely due to how Conrad's daughter's gut was affected by the six courses of antibiotics she received for her ear infections prior to surgery, "she just stopped being able to digest," remembers Conrad, an accessories designer living in Montecito, California. "Everything started to go through her." The illness peaked during a family vacation in Mexico when the 1-year-old landed in the hospital with salmonella. "I was like, 'Enough of this,'" Conrad says. "What's going on with her belly?"

Answering that question took about two years. It also took multiple visits to allergists, pediatricians and other clinicians at top hospitals and plenty of best guesses but no firm diagnoses. "They didn't have any solutions," Conrad says.

[See: 10 Concerns Parents Have About Their Kids' Health.]

When her daughter was 2-and-a-half years old, Conrad took a nutritionist's advice to read a book called "Breaking the Vicious Cycle: Intestinal Health Through Diet." She couldn't put it down. "I literally read it all night long," Conrad remembers. "I read all these testimonials just like what my daughter had, and it made all the sense in the world."

The book, which was first published in 1994 by now-deceased biochemist Elaine Gottschall, whose daughter had severe ulcerative colitis, outlines the Specific Carbohydrate Diet. The eating plan eliminates all disaccharides and polysaccharides -- or carbohydrates with more than one molecule structure, including all grains, sugar and even some vegetables -- in an effort to treat various digestive conditions. By limiting carbohydrates to those with a single molecule structure, which are easily digestible, followers aim to starve the gut's "bad" bacteria to establish the harmony that's key to treating many digestive conditions related to an overgrowth of bad bacteria, according to the book.

For Conrad, the SCD was at least worth a shot. "I ultimately did what the book said, and it started working the very first day," she remembers. "It was just enlightenment -- I found an answer; this is the answer."

Limited Evidence

The Specific Carbohydrate Diet is not a "diet" in the sense that it's marketed for average Joes seeking fast weight loss. Rather, it's a rigid eating plan developed by a gastroenterologist in the 1950s as a way to manage celiac disease, although that condition has since been proven treatable with the less-restrictive gluten-free diet. Following the SCD means adhering to a strict list of "legal" and "illegal" foods. "No food should be ingested that contains carbohydrates, other than those found in fruits, honey, properly prepared yogurt, and those vegetables and nuts listed," according to the Breaking the Vicious Cycle website. Staples of the diet then become fresh or frozen meats, certain cheeses and yogurts, eggs and some fruits and vegetables, making it paleo-esque in many ways.

"All [such diets] have a healthy point, which is we should be using pure food and avoiding processed foods and poorer-quality sugars and starches," says Dr. Sheila Crowe, a clinical professor of medicine at The University of California--San Diego and president-elect of the American Gastroenterological Association. "We should not be eating as much junk food as most people do."

[See: How to Make Healthful Dietary Changes Last a Lifetime.]

But because following the SCD requires diligence; skills, time and tools for cooking and label-reading; and often social sacrifices since dining out can be near impossible; it's usually a last resort among parents looking for solutions to their children's gastrointestinal disorders and, increasingly, among parents of children with autism. "SCD has a cult following with specific populations of people," like those with Crohn's disease, small intestinal bacterial overgrowth (known as SIBO) and irritable bowel syndrome, says Niki Strealy, a registered dietitian in Portland, Oregon, who specializes in digestive health. "Breaking the Vicious Cycle" also advertises the diet as an eating plan for ulcerative colitis, diverticulitis, celiac disease, cyctic fibrosis and chronic diarrhea. "These people have really attached themselves to SCD as being the end-all, be-all."

Whether it actually is remains to be seen. Strealy, for one, worries about any eating plans that forbid certain foods, since that mentality could lead to disordered eating behaviors. And, unlike some medications and the low FODMAP diet, a similar eating pattern that limits certain types of carbohydrates and has shown to improve symptoms of irritable bowel syndrome and other digestive disorders, there's little solid research on the SCD, experts say. "The concept would be that ... we aren't designed as humans to have all of these processed foods and we should be eating more like a caveman," Crowe says. "The problem becomes: Is there data to support these people?"

So far, it's minimal. In one recent study, for instance, researchers found that pediatric patients with either Crohn's disease or ulcerative colitis seemed to improve while following the SCD, but the study was small and retrospective and the results were not meant to be applied to people with severe forms of Crohn's disease. "I'd say it's not a good enough trial that I would recommend my child or my neighbor's child or anybody's child to go on this diet," Crowe says.

[See: U.S. News' 38 Best Diets Overall.]

Another 2015 study in the Journal of the Academy of Nutrition and Dietetics surveyed 50 people in remission from inflammatory bowel disease who followed the SCD. More than 90 percent of them reported the diet effectively controlled symptoms and prevented a recurrence, but the authors note that the participants -- all people who found, followed and stuck to the SCD for some time -- aren't necessarily reflective of all IBD patients. Still, digestive health experts look forward to more research on the diet since it has helped some people. "Some people are keeping their disease in remission," Strealy says, "and I think that's why it's exciting."

Proceed With Caution

Conrad's daughter is one of those people. After three years mending her daughter's gut by feeding her only SCD-compliant foods, Conrad slowly integrated "illegal" foods, such as brown rice and quinoa, back into her meals. Today, at age 16, her daughter is healthy and "eats anything," although some people find they must adhere to at least some aspects of the plan longer to keep their symptoms at bay. "She's totally cured," says Conrad, whose cookbook "Eat Well, Feel Well: More Than 150 Delicious Specific Carbohydrate Diet Compliant Recipes," came out in 2006.

But as with any restrictive diet, Conrad and medical experts recommend consulting a physician, registered nutritionist or both before diving in. Particularly in the case of SCD, which is often used on children, medical guidance is critical to ensure they're not cheated out of healthy growth and development. "Like any diet," Crowe says, "make sure it's nutritious and adequate to sustain a healthy life."