Specific Carbohydrate Diet (SCD) by Sue Kira

by sue

Specific Carbohydrate Diet (SCD)

by Sue Kira, Naturopath & Clinical Nutritionist

About the Specific Carbohydrate Diet

Benefits of a Specific Carbohydrate Diet

Suitable foods to include in the SCD

Foods and ingredients to avoid while on the SCD

Tips for the specific carbohydrate diet

Case study: Specific Carbohydrate Diet to the rescue with IBD

About the Specific Carbohydrate Diet (SCD)

The Specific Carbohydrate Diet (SCD) is a way of eating that is free of grains, starches, unprocessed foods, and sugar.

The diet removes many foods that are difficult to digest and potentially toxic for a sensitive body.

The principles of the diet were laid down by Dr Sidney Valentine Haas who treated Celiacs and other IBD (Inflammatory Bowel Disease) patients in the 1950s. One of his patients was Elaine Gottschall’s then 5yr old daughter who was very sick with ulcerative colitis. Dr Haas helped Elaine’s daughter achieve lasting remission through diet.

Elaine Gottschall then dedicated her life to researching the diet and the gut connection. She coined the name the Specific Carbohydrate Diet (SCD) and released the science and the how to’s in her life’s work, ‘Breaking the Vicious Cycle, Intestinal health through diet’.

The diet guidelines are based on the reality that everyone does not have a digestive system that can optimally digest complex carbohydrates and other products like sugar.

The main principle of the diet says carbohydrates are classified by their chemical structure, being a monosaccharide, disaccharide, or polysaccharide. With the Specific Carbohydrate Diet (SCD), only monosaccharide types of carbohydrates can be eaten because the other two require an extra digestive workload to break down the chemical bonds into a monosaccharide carbohydrate.

Any food that is not properly digested has the potential to cause bacterial and yeast overgrowth. See the SIBO Diet (small intestine bacterial overgrowth).

Undigested carbohydrates feed bacteria and yeast in the intestinal tract. This can start a chain reaction of excess toxins and acids excreted by the bacteria etc. which causes irritation and damage to the cells lining the small intestine, leading to food malabsorption which will only make matters worse.

The SCD is an all-natural way to break this cycle of bacteria and yeast overgrowth by eliminating the food sources they feed on. By working to restore the friendly gut bacteria to normal levels, the intestinal tract can repair itself.

Although an SCD lifestyle can feel restrictive and cuts out many foods that people enjoy eating, it can be very supportive to people with compromised digestive systems, including Crohn’s disease, ulcerative colitis, irritable bowel syndrome and SIBO.

Even if you suffer from ongoing symptoms like constipation or painful bloating, you can find relief by eliminating the troublesome carbs and only eating the carbs that are the easiest to digest, such as vegetables. This will help to lower risk of fermentation in the gut, gas accumulation and gut permeability (aka leaky gut).

By removing the more ‘complex carbohydrates’ from the diet, such as lactose (milk sugar from dairy products), sucrose (sugar contains glucose and fructose), and many synthetic ingredients, your digestive processes will improve, toxins will be reduced and overall health will get better as the inflammation in your intestines subsides.

What starts the bacterial imbalance in the gut?

Bacterial overgrowth in the small intestines can be triggered by:

  • antibiotics, medications, vaccination reactions and oral contraceptives
  • reduced stomach acidity (which can be caused by medications, aging, overuse of antacids, lack of chewing, poor production of stomach acids, TMJ issues)
  • a weakened immune system (caused by conditions such as malnutrition, infections and chronic stress which increases gut permeability)
  • a poor diet high in inflammatory and processed foods, like sugar, poor quality fats, and foods low in key nutrients
  • environmental and lifestyle factors (low nutrient fast foods, cigarette smoking, alcohol use, stress, poor sanitation, and hygiene)
  • infectious microbes, Lyme’s disease, Ross River, Glandular fever etc
  • genetic susceptibility and conditions that affect the gut during the first few years of life, such as not being breast-fed, C- section delivery, poor diet, antibiotics

How the specific carbohydrate diet works

Many digestive disorders stem from an overgrowth or imbalance of intestinal microbial bacteria. In other words, there are too many harmful types of bacteria, yeast and fungus residing within the gut where most (around 80%) of the immune system is located. We actually have more bacterial DNA in our body than human DNA, which is quite extraordinary.

The organisms in our gut feed and thrive off the food we put into our bodies. Eat the wrong types of food, and harmful bacteria proliferate. Eat the right foods and beneficial bacteria prosper, which are important for immune function, hormonal balance, and even weight control.

The goal of this diet is to allow the good bacteria to flourish while reducing the ‘baddies’, thereby improving the bacterial ratio.

Many of the bacteria in our gut consume certain carbohydrates that are not digested fully, which creates waste products and toxins through the process of fermentation. These gases and toxins include lactic acid, acetic acid, methane, carbon dioxide and hydrogen, which can make you feel bloated and gassy, feed up the bad bugs, and damage and irritate the gut lining leading to increased permeability (leaky gut).

Microbes migrate to the small intestine and stomach when they become over-populated and create SIBO (small intestinal bacterial overgrowth) leaving behind toxic by-products that cause further problems. This can create bacterial DNA mutations, an increase or decrease in stomach acidity, nutrient deficiencies, and increased inflammation anywhere in the body, from the brain to the skin. Many dietary plans to treat SIBO are similar to the SCD diet.

Who is the ‘specific carbohydrate diet’ suitable for?

The SCD is mostly recommended for people with GI (Gastrointestinal) disorders, such as:

  • Irritable bowel syndrome (IBS)
  • Food allergies like celiac disease or lactose intolerance
  • Diverticulitis
  • Ulcerative colitis
  • Crohn’s disease
  • Cystic fibrosis
  • Constipation
  • Diarrhea
  • Bloating/gas
  • Fatigue after eating carbs
  • FODMAPs sensitivity

Also, people taking medications that interfere with how they digest certain carbohydrates can also find relief. It has even been suggested that a Specific Carbohydrate Diet can help those with learning disabilities such as autism.

The SCD is like the GAPS Diet plan created by Dr Natasha Campbell-McBride, who based her diet plan on the SCD, with the same goal to eliminate certain types of carbs that are known to deteriorate gut permeability and inflammation.

Food elimination throughout the GAPS diet is done in stages, and the GAPS diet food list includes many of those used in an SCD, such as most vegetables, fish, healthy fats and oils, grass-fed meat and sprouted nuts, seeds and legumes.

Benefits of a Specific Carbohydrate Diet

Healthy digestive system
The SCD has been shown to help some of the more difficult digestive system disorders, such as ulcerative colitis and Crohn’s disease. Crohn’s disease is characterized by chronic intestinal inflammation and studies show that dietary changes play an important role in the management of digestive symptoms for those with Crohn’s disease.

Other research found SCD diets provided symptomatic and clinical improvement for most people, and complete remission for some patients with ulcerative colitis after using the SCD for 3 to 6 months.

The overgrowth of bacteria in the small intestine can cause increased gas and acid production through fermentation from foods that don’t digest well. This can accumulate toxic waste, create discomfort, and reduce the ability to absorb nutrients. Symptoms can include constipation, gas, bloating, diarrhea, and changes in appetite.

Removing the foods that ferment the most can eliminate the source of the problem and allow the gut to heal.

Healthy nutrient absorption
The harmful toxic by-products caused by fermentation affect enzymes produced in the digestive tract that are needed to metabolize food and absorb their available nutrients.

The small intestine normally produces a protective mucus coating, however if there are too many bad bacteria present, the coating becomes thicker, which is called a ‘Biofilm’ that further inhibits normal digestive processes and absorption of nutrients.

The bad bacteria are trapped by the biofilm to protect the lining of the intestine. But by doing so, it also protects the bad bacteria from attack by the immune system, which means the bacteria can further increase and thrive.

A Specific Carbohydrate Diet reduces fermentation which allows food nutrients to be more easily absorbed by the gut.

Lower inflammation
Along the lining of the mucosal layer within the gastro-intestinal tract are tiny micro-villi, which provide a greater surface area to absorb nutrients. But microvilli can get damaged by fermenting carbohydrates, which then reduce the absorption of nutrients, particularly folate and B12. The longer this goes on, the more the damage to the villi.

Consequently, the barrier created by the microvilli breaks down, leading to more gut permeability (leaky gut) which allows particles to enter the bloodstream, where they should not be, which signals to the immune system that something is wrong.

Research suggests that reversing this process with the SCD ,body-wide inflammation can be reduced or eliminated.

An SCD may protect your brain
The brain is also impacted by inflammation and bacterial fermentation. Gastro Intestinal (GI) dysfunction is commonly seen in individuals with Autism Spectrum Disorder (ASD) and the role of the gut bacteria in ASD is still being researched.

Some evidence shows that lactic acid produced during bacterial fermentation within the gut can affect brain function and behaviour. It can also create a ‘foggy head’ feeling.

An SCD reduces inflammation and fermentation, and consequently may protect the brain.

Suitable foods to include in the SCD

The Specific Carbohydrate Diet is designed to break the cycle of bacterial and yeast overgrowth by eliminating what they feed on. By supporting the body to restore the beneficial friendly bacteria to normal levels, the digestive system can start to repair any damage by itself.

Given the right conditions the gut lining can repair itself in as little as 30 days.

Grass fed, pasture raised meats and poultry, preferably organic – chicken, turkey, beef, pork, wild game, lamb. Free range eggs. Wild-caught fresh fish

Preferably organic or spray free. Asparagus, beetroots, broccoli, Brussels sprouts, cabbage, cauliflower, carrots, celery, cucumbers, eggplant, garlic, kale, lettuce, mushrooms, onions, peas, peppers, pumpkin, spinach, squash, string beans, tomatoes, and watercress

Low-sugar fruits that are preferably organic or spray free include apples, ripe bananas, avocados, all types of berries, dates, coconut, grapes, grapefruit, kiwi fruit, kumquats, lemons & limes, mangoes, melons, nectarines, oranges, papayas, peaches, pears, pineapples, prunes, raisins, rhubarb, tangerines

Preferably organic or spray free, best ‘activated’, which means they have been soaked overnight and then can be dried in an oven or dehydrator. Almonds, pecans, Brazil nuts, hazelnuts, walnuts, cashews, chestnuts (no additives including no salt). Nuts can be used as flour to make SDC cakes etc.

Spices and condiments
Preferably organic, spray free and fresh. Most non pre-mixed spices are allowed, but screen for anti-caking agents and make sure there is nothing else, except herbs or spices in the pack. Condiments like mustard and vinegar are ok too.

Healthy fats
Include coconut oil and olive oil as well as coconut flesh, shredded, desiccated and coconut flour (additive free only)

Homemade coconut probiotic yogurt
Ferment for at least 24 hours. The reason for homemade is because most commercial yoghurts contain additives (even natural ones like the prebiotic fibres can be an issue)

Unsweetened, unprocessed drinks. Weak tea or coffee (can use nut milks in coffee and teas), water, mineral water, soda water, herbal teas, nut milks to drink (nice with some spices such as cinnamon, fresh dates), cacao powder with nut milks and sweetened with honey, fresh coconut milk or water


Foods and ingredients to avoid while on the SCD

Cereal grains
Grains and grain-based products, including wheat (all types), corn, barley, oats, rye, rice, buckwheat, soy, spelt, amaranth, millet, triticale, bulgur, spelt, and products made with grain flours. Quinoa (some can handle quinoa ok, however it is best to avoid until the symptoms have gone).

Processed meats and cured, smoked food. Ham, bacon, processed sausages, lunch meats, bratwurst, turkey dogs, hot dogs, frankfurts.

Any canned veggies which normally include sugars, processing aids or preservative chemicals. Avoid any vegetables that are not included on the ‘suitable list’ above.

Canned and most fruit juices are not allowed due to the common addition of sweeteners, preservatives, and processing aids. Avoid any fruits that are not included on the ‘suitable list’ above. 

Most beans and legumes – chickpeas, bean sprouts, soybeans, mung beans, fava beans and garbanzo beans. Some people have been able to tolerate legumes after three months on the diet, provided they don’t react to them. But first they must be soaked for 10–12 hours to activate prior to cooking and the water discarded.

Use organic or spray free – peanuts, white beans, navy beans, lentils, split peas, lima beans, kidney beans and black beans first when challenging reintroduction of legumes.

All dairy including milk, cheeses, cheese spreads, yogurts, ice cream etc from any animal should be avoided.

Starches and starchy vegetables like potatoes, sweet potatoes, yams, parsnips, arrowroot, parsnip, corn starch, tapioca, wheat starch, rice flour or any flour not from suitable grains for at least three months.

Refined oils and fats
Vegetable oils such as margarine, canola oil, safflower oil and mayonnaise (except some home-made varieties).

Spices and condiments
Curry powders and most onion and garlic powders are filled with anti-caking agents. Avoid condiments such as ketchup/tomato sauce, mustard with sugar, balsamic vinegar.

Instant coffee, commercial juices (unless just fresh cold pressed and all natural with no additives), dairy milk, soft drinks, beer, all alcohol, sweetened drinks.

Many types of sugars, such as lactose, sucrose, beet sugar, high-fructose corn syrup, fructose, molasses, maltose, and any processed added sugars. Also cane and coconut sugar, agave syrup, maple syrup, any artificial sweeteners, isomaltose, and fructooligosaccharides.

Sweets and most packaged snacks
Candy, chocolate, cookies, anything containing the above sugars, potato chips etc

Seaweed products
Seaweed, algae, agar-agar and carrageenan

Tips for the Specific Carbohydrate Diet

  • Plan to cook more at home which makes it easiest to control ingredients
  • Invest in some good kitchen gadgets and appliances, especially a yogurt-making kit and perhaps a crock-pot or slow cooker to easily cook meat/veggies
  • Get to know the list of excluded ingredients and check labels when shopping. Sugar can ‘hide’ under many disguised names!
  • In place of grain flours, use other flours such as almond or coconut flour to make breads, cookies, sauces, etc
  • Cooked foods are usually easier to digest, especially with soups and stews. Make double batches and freeze them for later
  • Look for wild, pasture-raised, grass-fed meat products online which you can purchase in bulk to save money if you have the freezer space, plus use the bones to make healing bone broth afterward
  • For the first three months, avoid all legumes, but you can then try to introduce them (soaked and sprouted first) to test your tolerance
  • Because the SCD is quite a restrictive diet, you may want to talk to your practitioner about taking supplements, because by removing whole food groups from your diet you increase the risk for nutrient deficiencies. Try to eat a variety of foods to get the widest nutrient intake you can.


Before you commence your diet, see your medical or health care professional for qualified guidance about what foods and supplements are best for your body. While on the diet do not stop any medications or supplements previously prescribed unless advised otherwise by your medical or health care professional.

During the early stages of a new diet, you may experience symptoms such as fatigue, headaches, or body aches, which may occur because your body is detoxifying. However, if you are unsure about a symptom at any time, check immediately with your medical or health care professional.

Case study: Specific Carbohydrate Diet to the rescue with IBD

Client name and identifying information changed

When Robert first came to me, he had been suffering from and diagnosed with Ulcerative Colitis, which meant that he had ulcerations in his intestines. His bowel was constantly trying to clear the imbalance by giving him terrible diarrhea that was so bad he bled each time he went to the toilet.

He was already on medication and things had settled quite a bit, but he still needed more help as he was getting terrible tummy cramps and nausea most days, with the occasional bout of diarrhea. His fatigue was so bad that he reverted to working part-time from home so he could easily run to the toilet when needed. Fortunately he worked for himself.

The reason he had an inflammatory bowel disease had not been investigated, so we ran bowel tests which showed that he had an infection of an overgrowth of unfriendly bacteria and very low levels of good bacteria. He also had leaky gut (intestinal permeability) and loads of inflammation markers even though he was on high doses of anti-inflammatory drugs.

He took the test results to his doctor and was promptly put onto drugs to kill off the bad bacteria. We started Robert on some good bacteria (probiotics) along with The Specific Carbohydrate Diet so we didn’t feed the bad guys.

The Specific Carbohydrate Diet is for serious gut conditions. It’s grain free and eliminates most carbs, with only specific carbs allowed that require minimal digestion.

Unfortunately, Robert reacted badly to the antibiotics and had to stop taking them before they had a chance to help. He also reacted to the herbs and nutrients I prescribed. His intestines were far too sensitive at that point, so it was left to the diet to do the job.

Robert was highly motivated as he felt awful most days, so he strictly followed the diet. He became more aware of his body and how different foods felt, and he even dropped a couple of foods on the allowed list that he felt aggravated him.

Robert’s symptoms settled quickly in a couple of weeks and he was excited. Once a lot of inflammation settled, he could tolerate the herbs and extra nutrients much better, such as extra zinc and B12 to help heal his gut. He didn’t want to try the antibiotics again but felt the herbs and nutrients were fine for his body and he felt stronger and more energetic each day.

He followed the diet for several months and then asked his doctor if he could go off his medication. His doctor thought it might be a potentially bad idea but was willing for Robert to gradually decrease his dose and see if there were any flare-ups of symptoms. Robert gradually cut back his dose in small increments and had no problems.

After 12 months on the diet, Robert was off all meds and had started to re-introduce some of the foods he had previously eliminated, which went well.

Some foods such as dairy products, gluten, refined anything, sugar and nuts and most legumes did not suit his body and upset him. But everything else, including all his favourite vegetables and fruits were fine. Gluten free flours were also ok, provided they weren’t made from nuts. (Nuts were a specific problem for Robert, even though many are fine with nuts on the Specific Carbohydrate Diet).

While we would say he was in remission, Robert called it a ‘cure’.


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