The Specific Carbohydrate Diet (SCD) is a grain-free, low-sugar regimen that eliminates complex carbohydrates (disaccharides and polysaccharides) to address gastrointestinal issues. Developed by Dr. Sidney V. Haas and popularized by Elaine Gottschall, the diet's core principle is that undigested carbohydrates can feed harmful gut bacteria, leading to inflammation and damage to the intestinal lining. Following the diet strictly is key, which means a thorough understanding of all forbidden or “illegal” foods is essential. The illegal foods are those containing long-chain carbohydrates that require more complex digestive enzymes to break down, which may be lacking in those with digestive disorders.
The Breakdown of Illegal Foods on SCD
To navigate the SCD successfully, one must become a vigilant label reader and understand the different categories of forbidden foods. The list of illegal items includes a wide range of common staples, from grains to processed snacks.
Grains and All Starchy Tubers
This is one of the most significant exclusions on the SCD. All cereal grains and their derivatives are off-limits because they contain polysaccharides, which are too complex for compromised digestive systems. The list of prohibited grains includes:
- Wheat, including wheat germ, spelt, and kamut
- Barley
- Oats
- Corn
- Rice (all types, including brown and wild)
- Quinoa
- Millet
- Amaranth
- Buckwheat
- Triticale
Furthermore, all products made from these grains, such as pasta, bread, crackers, and cereal, are illegal. In addition to grains, all starchy tubers like potatoes, sweet potatoes, turnips, and parsnips are forbidden because of their complex carbohydrate structure. Arrowroot and tapioca starches are also illegal.
Sugars and Sweeteners
The SCD permits only monosaccharide sugars, which are single sugar molecules that are easily absorbed. This means most common sweeteners are forbidden. The main illegal sweeteners are:
- Sucrose (table sugar)
- Maple syrup
- Molasses
- Processed fructose (including high-fructose corn syrup)
- Artificial sweeteners (e.g., sucralose, aspartame, acesulfame-K)
- Sugar alcohols (e.g., xylitol, sorbitol)
Honey is the only sweetener that is legal on the diet, as it consists of easily digestible glucose and fructose.
Dairy Products
Most commercial dairy products are off-limits due to their high lactose content, a disaccharide sugar. SCD guidelines make specific allowances for lactose-free, properly fermented dairy items. Illegal dairy includes:
- Fluid milk (cow, goat, or sheep)
- Store-bought yogurt (which may contain additives or unfermented lactose)
- Ice cream
- Sour cream
- Soft cheeses (e.g., cream cheese, ricotta, cottage cheese, feta)
Only very specific, aged cheeses (like sharp cheddar, dry curd cottage cheese, Swiss) and homemade yogurt that has been fermented for at least 24 hours are permitted.
Processed Foods and Additives
The SCD strongly emphasizes whole, unprocessed foods. This means that a vast array of common, store-bought products are illegal. These include:
- Canned vegetables with added sugar or starch
- Processed meats with additives (e.g., hot dogs, some sausages)
- Certain condiments and sauces (e.g., ketchup, commercial mayonnaise, balsamic vinegar)
- Bouillon cubes
- Many spice mixes
- Candies, chocolates, and most sweets
Labels must be checked carefully for hidden ingredients like starches, preservatives, and sugars. For example, some nuts are roasted with a starch coating, making them illegal.
Certain Legumes
While some legumes like lentils, split peas, and dried navy beans are permitted, many are forbidden, especially during the initial phases of the diet. Illegal legumes include:
- Chickpeas (garbanzo beans)
- Soybeans
- Black beans (unless symptoms have fully subsided)
- Fava beans
- Lima beans
Legal vs. Illegal Foods on the SCD
| Category | Legal Foods (Allowed) | Illegal Foods (Not Allowed) |
|---|---|---|
| Grains/Starches | Nut flours (almond, pecan), coconut flour | Wheat, rice, oats, corn, barley, quinoa, potatoes, sweet potatoes, starches (tapioca, arrowroot) |
| Sugars/Sweeteners | Honey, saccharine (sometimes) | Sucrose, maple syrup, molasses, corn syrup, artificial sweeteners, sugar alcohols |
| Dairy | Aged hard cheeses (cheddar, Swiss), dry curd cottage cheese, homemade 24-hour yogurt | Fluid milk, store-bought yogurt, ice cream, cream, soft cheeses, buttermilk |
| Legumes | Dried navy beans, lentils, peas, unroasted cashews (after initial phase) | Chickpeas, soybeans, black beans (initially), fava beans |
| Meat/Proteins | Fresh, unprocessed meats (beef, poultry, fish), eggs | Processed meats with additives, canned meats |
| Fruits | Most fresh fruits, unsweetened frozen fruit, specific unsweetened juices (apple cider, grape juice diluted) | Canned fruits with added sugar, fruit juices with added sugar/concentrate |
| Vegetables | Most non-starchy vegetables (carrots, spinach, broccoli), winter/summer squashes | Starchy vegetables (potatoes, sweet potatoes), canned vegetables with additives |
The Critical Role of Reading Labels
Following the SCD necessitates meticulous label reading to identify hidden illegal ingredients. Many processed foods contain added starches, sugars, or preservatives that are not immediately obvious. For example, cured meats might use sugar, and some fruit juices are from concentrate with added sweeteners. The presence of terms like "modified food starch," "dextrose," or various thickeners can render a product illegal. Always purchase fresh, whole foods whenever possible and prepare meals at home to maintain full control over ingredients. The foundational text, Breaking the Vicious Cycle, provides a definitive legal/illegal list that should be the ultimate reference for anyone on the diet.
Conclusion
Knowing what is illegal on the SCD diet is the most important part of successfully implementing this healing protocol. The diet’s strict elimination of complex carbohydrates found in grains, starches, most dairy, processed foods, and certain legumes is designed to reduce gut inflammation and restore a healthy balance of intestinal flora. While the list of restrictions is extensive, focusing on the abundance of fresh, whole, and unprocessed foods—such as meats, fruits, vegetables, and specific fermented dairy—allows for a nutrient-dense and satisfying diet. Always consult with a healthcare professional or registered dietitian before starting a restrictive diet like the SCD to ensure it is appropriate for your specific health needs and to mitigate the risk of nutritional deficiencies.
