Specific Carbohydrate Diet vs. FODMAP Diet

With so many different diets claiming to help relieve digestive symptoms, it can be hard to know which one is right for you. The low FODMAP diet has shown its ability to help relieve people with irritable bowel syndrome and other digestive conditions of symptoms. On the other hand, the Specific Carbohydrate Diet (SCD) also claims to help those with IBS and other digestive conditions but is not quite the same as the low FODMAP diet.

The theory behind the SCD diet is that any undigested food in the gut will be fed on by bacteria and yeast and cause overgrowth of such microbes in the gut. In turn, food absorption and other digestive issues will arise. It has been used to reduce inflammation in those with Crohn’s disease and ulcerative colitis as well as celiac disease.

Let’s explore the differences of these two eating regimens.

What are FODMAPs?

The low FODMAP diet focuses on limiting FODMAPs in the diet. FODMAPs are fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. In simpler terms, the low FODMAP limits foods and drinks that contain compounds such as:

• Lactose, or milk sugar, found in animal milk and milk products.
• Fructose, or fruit sugar as well as processed forms of this sugar like high fructose corn syrup. Also, fruits that are high in fructose like apples, watermelon, cherries, blackberries, pears, and peaches should be avoided on the low FODMAP diet.
• Sugar alcohols like xylitol, mannitol, erythritol, and sorbitol, commonly found in sugar-free processed foods and drinks, as well as sugar-free gum.
• Plant-based foods such as garlic, onion, asparagus, Brussels sprouts, legumes, as well as nuts like cashews and pistachios, and limited amounts of almonds.
• Grains such as wheat and rye.

Typically, those with IBS would strictly follow this diet for two to eight weeks. After that time, foods would slowly be added in to help identify which are the major trigger foods. This process should be supervised by a qualified healthcare practitioner such as a registered dietitian familiar with the low FODMAP diet, to help ensure a safe transition from the elimination diet.

How is the SCD regimen different?

The SCD regimen is very similar to the low FODMAP diet in that it cuts out foods and drinks with lactose and sugar alcohols as well as certain legumes. It also leans towards un-processed meats and canned fruits and vegetables due to additives that could cause symptoms. Again, very similar to what low FODMAP encourages. However, it is a bit stricter than the low FODMAP diet for several reasons.

• It avoids ALL grains.
• It restricts all sugars except for monosaccharides like fructose, glucose, and galactose.
• No starches or tubers such as potatoes, sweet potatoes, yams, parsnips, cornstarch, and tapioca starch are allowed.

Other differences include the fact that fructose, such as that found in certain fruits and honey is allowed on SCD and not low FODMAP. Also, fructans such as onions and garlic, which are no-no’s on low FODMAP , are allowed on SCD.

So, which diet is best?

There is no easy answer to this question. It will all depend on what digestive condition and symptoms you are dealing with. For example, research shows that the low FODMAP diet may be more effective than SCD for those with IBS. On the other hand, SCD may be more fitting for someone with inflammatory bowel disease.

It will be best to talk with your gastroenterologist and healthcare team to find the best solution for your situation. It will also be important to listen to how your body feels when you eat or drink certain things. Keep a food-symptom diary to find out what foods are causing symptoms and plan your meals and snacks from there. Perhaps a combination of the two diets will be best for you, or maybe a modified version of one or the other. The best diet for you ultimately is the one that makes you feel your healthiest and best.

Written by Staci Gulbin, MS, RD a Board-certified dietitian.