The Specific Carbohydrate Diet: a century-old gut diet that couldn't beat the Mediterranean.

No grains, no potatoes, no rice, no sugar except honey. The Specific Carbohydrate Diet has a loyal following among people with Crohn's and colitis. The best trial so far found a far easier diet worked just as well.

The short version

What it is: Only "simple" carbohydrates allowed: fruit, honey, most vegetables. All grains, starches, most dairy and many legumes are out.
Good for: Some people with inflammatory bowel disease feel better on it, under medical care.
Bad at: Beating easier diets. Staying on it. Getting enough calcium and vitamin D.
Evidence: Weak. One good trial, and it found no edge.
Our take: A medical diet for your gastroenterologist and dietitian to decide on. Not a weight-loss plan.

What the Specific Carbohydrate Diet actually is

The specific carbohydrate diet (SCD) is a gut diet with a long history. A US doctor, Sidney Haas, used it for children with coeliac disease and published on hundreds of cases in the 1950s.¹ Then the science moved on: Dutch researchers including Willem Dicke showed, in the early 1950s, that wheat was the real trigger in coeliac disease, and the gluten-free diet took over.²

The SCD came back through biochemist Elaine Gottschall and her book Breaking the Vicious Cycle. Today it's mostly used by people with Crohn's disease and ulcerative colitis, the two main kinds of inflammatory bowel disease (IBD).

The rules are long and very specific. The official list says only single-sugar carbohydrates are allowed, and bans all grains, potatoes and rice, both white and sweet potatoes, and fluid milk.³ Honey is the only sweetener on the list apart from saccharin. Yes, a sweetener. On our never list. We'll get to that.

How it works in your body

The idea: starches and double sugars (like table sugar and lactose) aren't fully digested in an inflamed gut. The leftovers feed gut bacteria, the bacteria make gas and irritants, the gut gets more inflamed, digestion gets worse. That's the "vicious cycle". Take away everything except single sugars and the cycle is supposed to break.

It's a neat theory. Nobody has proven it works that way. Studies did find the gut microbiome shifts when people change diet, but it shifted on every diet tested, not just the SCD.⁴

What you eat, what you don't

This follows the official legal/illegal list.³ Many foods only come back after months without symptoms. Your dietitian sets the pace.

Eat

Meat, fish, seafood, eggs
Most vegetables (carrots, courgette, spinach, beans in the pod)
Most fruit, bananas only when fully ripe
Homemade yoghurt fermented for 24 hours
Cheese aged 30 days or more, like Parmesan or cheddar
Lentils, split peas, navy beans, prepared the SCD way
Nuts as nut flour or nut butter, once diarrhoea has settled
Butter, olive oil, coconut

Forget it

All grains: bread, rice, noodles, oats, quinoa, buckwheat
Potatoes and sweet potatoes
Milk, buttermilk, most shop-bought yoghurt
Chickpeas, soy, tofu, soy sauce
Sugar, maple syrup, chocolate, cocoa
Seaweed and food with gums or emulsifiers
Processed food, almost all of it

Singapore readers: that's no rice, no noodles, no kaya toast, no tau huay. DACH readers: no Brot, no Knödel, no Kartoffeln. It's a big change.

Alcohol on the Specific Carbohydrate Diet

The official list allows some spirits and bans most other drinks.³ Allowed on the list doesn't mean good for an inflamed gut. Ask your team first.

On the legal list

Gin, vodka, Scotch whisky, bourbon
Homemade mead made only with honey and yeast

Illegal on SCD

Beer
Brandy, sherry
Liqueurs
Anything mixed with juice, cola, tonic or "diet" mixers (sweeteners are on our never list)

50 Club: not on a prescribed diet. Ask your doctor or dietitian what's safe for you. The general rules are in our alcohol guide.

What it's good for, with proof

Lots of people say it helps

In an online survey of 417 people with IBD who used the SCD, 4% said they were in remission before starting, 33% after two months, and 42% at six and twelve months.⁵ That's self-reported, from people recruited through SCD websites and support groups. People it didn't help were less likely to answer. Useful as a signal, not as proof.

Small trials in children with Crohn's

In a randomised pilot, 18 children with mild to moderate Crohn's were put on the SCD, a modified SCD, or a whole-foods diet. Ten finished, and all ten were in clinical remission at 12 weeks.⁴ Every diet seemed to help. With so few children, nobody can say which one is better.

A bigger series of single-patient trials in 54 children compared the SCD with a looser version. 44% dropped out, often because it didn't work or because of side effects. On average, the two diets performed about the same, and neither reliably improved symptoms or inflammation. Some individual children did benefit.⁶

The uncomfortable truth

"The SCD beats normal healthy eating for Crohn's." It didn't, in the one proper head-to-head trial. In DINE-CD, 194 adults with mild to moderate Crohn's disease were randomised to the SCD or a Mediterranean diet. After six weeks, symptomatic remission was 46.5% on SCD and 43.5% on Mediterranean, no real difference. Inflammation markers didn't separate either.⁷

The researchers' conclusion: because the Mediterranean diet is easier to follow and has other health benefits, it may be the better choice for most people with mild to moderate Crohn's.⁷ Same result, a lot less misery. That's not "the SCD is useless". It's "the hard version earned no medal".

And the Cochrane review of diets for IBD as a whole says the effects of diet on Crohn's and colitis are still uncertain.⁸

The risks

Vitamin D and calcium. In a small study of children on the SCD, every single one ate less vitamin D than recommended, and three out of four days fell short on calcium.⁹ No milk and no fortified cereals will do that. Ask for blood tests.
Weight loss you don't want. No bread, rice or potatoes makes it hard to eat enough, especially for growing kids and people who are already thin from IBD.
Avoidant eating. 17% of people with IBD in one clinic screened at risk of avoidant restrictive food intake disorder (ARFID), and they were much more likely to be at risk of malnutrition.¹⁰ A long list of illegal foods can make that worse.
Skipping proper treatment. Untreated inflammation in Crohn's and colitis damages the gut. The diet is something you might add, with your team, never a swap for medication.
Saccharin and honey. The list allows saccharin, which is on our never list, and honey, which is still sugar.³ Neither is a free pass.

Allergies: watch the staples

The SCD leans on foods that are major allergens. If you're allergic, your dietitian has to swap them, not just drop them.

SCD staple	Allergen (EU list of 14)¹¹	Swap
24-hour yoghurt, aged cheese, butter	Milk	Coconut, olive oil; calcium needs a plan
Eggs, egg-based baking	Eggs	Fish, meat
Almond flour, nut butters	Tree nuts	Coconut flour (on the legal list)
Natural peanut butter	Peanuts	Sunflower seed butter, if your team agrees
Salmon, sardines, white fish	Fish	Poultry, meat, eggs
Prawns, crab, mussels	Crustaceans, molluscs	Fish, chicken
Soups and stews with celery	Celery	Carrot, courgette, herbs

Don't do the Specific Carbohydrate Diet if you…

have gut symptoms but no diagnosis yet: see a doctor first
are underweight or losing weight
have ever had an eating disorder
are pregnant or breastfeeding
are a child or teen, unless a paediatric IBD team runs it
want to use it instead of your medication

Healthen me asks about all of these and gives you a different plan if any apply.

How we use the Specific Carbohydrate Diet in your plan

We don't. The SCD is a medical diet, and whether it's right for you is a call for your gastroenterologist and a dietitian who knows IBD.

Healthen me asks about Crohn's, colitis and other gut conditions. If you say yes, we tell you to talk to your doctor before you change how you eat, and we don't build SCD meals. Our plan includes foods the SCD bans, like brown rice, oats and chickpeas, so it isn't a substitute.

What the plan can do: leave out foods you tell us you don't tolerate, keep our never list (no added sugar, no sweeteners, so no saccharin either), and lean on the same Mediterranean-style foods that held their own against the SCD in the big trial. Fasting and Rebel Day only if your doctor agrees.

This article is general information, not medical advice. If you have a medical condition or take medication, talk to your doctor before changing how you eat.

Sources

Haas SV, Haas MP. The treatment of celiac disease with the specific carbohydrate diet; report on 191 additional cases. American Journal of Gastroenterology 1955;23:344–360. pubmed.ncbi.nlm.nih.gov/14361377
van Berge-Henegouwen GP, Mulder CJ. Pioneer in the gluten free diet: Willem-Karel Dicke 1905–1962, over 50 years of gluten free diet. Gut 1993;34(11):1473–1475. doi.org/10.1136/gut.34.11.1473
Breaking the Vicious Cycle. The Legal / Illegal list (based on Gottschall E, Breaking the Vicious Cycle: Intestinal Health Through Diet), August 2022. breakingtheviciouscycle.info/legal/illegal-list-pdf
Suskind DL, Lee D, Kim YM et al. The Specific Carbohydrate Diet and diet modification as induction therapy for pediatric Crohn's disease: a randomized diet controlled trial. Nutrients 2020;12:3749. doi.org/10.3390/nu12123749
Suskind DL, Wahbeh G, Cohen SA et al. Patients perceive clinical benefit with the Specific Carbohydrate Diet for inflammatory bowel disease. Digestive Diseases and Sciences 2016;61:3255–3260. doi.org/10.1007/s10620-016-4307-y
Kaplan HC, Opipari-Arrigan L, Yang J et al. Personalized research on diet in ulcerative colitis and Crohn's disease: a series of N-of-1 diet trials. American Journal of Gastroenterology 2022;117:902–917. doi.org/10.14309/ajg.0000000000001800
Lewis JD, Sandler RS, Brotherton C et al. A randomized trial comparing the Specific Carbohydrate Diet to a Mediterranean diet in adults with Crohn's disease. Gastroenterology 2021;161(3):837–852.e9. doi.org/10.1053/j.gastro.2021.05.047
Limketkai BN, Iheozor-Ejiofor Z, Gjuladin-Hellon T et al. Dietary interventions for induction and maintenance of remission in inflammatory bowel disease. Cochrane Database of Systematic Reviews 2019;2:CD012839. doi.org/10.1002/14651858.CD012839.pub2
Braly K, Williamson N, Shaffer ML et al. Nutritional adequacy of the Specific Carbohydrate Diet in pediatric inflammatory bowel disease. Journal of Pediatric Gastroenterology and Nutrition 2017;65:533–538. doi.org/10.1097/MPG.0000000000001613
Yelencich E, Truong E, Widaman AM et al. Avoidant restrictive food intake disorder prevalent among patients with inflammatory bowel disease. Clinical Gastroenterology and Hepatology 2022;20:1282–1289.e1. doi.org/10.1016/j.cgh.2021.08.009
Regulation (EU) No 1169/2011 on food information to consumers, Annex II (the 14 allergens). eur-lex.europa.eu/eli/reg/2011/1169/oj

Keep reading

The GAPS diet
A two-year gut diet of broth, fermented food and animal fat, sold as a treatment for autism and much more. No trials, real raw milk risks, and a sane version worth keeping.
Low FODMAP
The best-studied diet for IBS, and a test rather than a lifestyle. Cut fermentable carbs for a few weeks, bring them back one by one, and do it with a dietitian.
The Autoimmune Protocol (AIP)
Six weeks without grains, legumes, dairy, eggs, nuts, nightshades and coffee, then a slow reintroduction. Some people with autoimmune disease feel better. The proof is tiny, so do it with your doctor.

See all diets, sorted and explained