Research Supporting Low-Carbohydrate Elimination Diets

Researchers have demonstrated sufficient benefits to a low carbohydrate or ketogenic diet in the treatment of metabolic diseases that the American Diabetes Association, in its Standards of Medical Care, acknowledged that low-carbohydrate ketogenic diets are a viable nutrition therapy for type 2 diabetes. They stated “In addition, research indicates that low-carbohydrate eating plans may result in improved glycemia and have the potential to reduce antihyperglycemic medications for individuals with type 2 diabetes.” There are multiple other research studies supporting this guideline. We will share additional supportive research below.

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The ADA has also acknowledged that a low or very-low carbohydrate diet has not been shown to increase cardiovascular disease risk factors.

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Very low-carbohydrate ketogenic diets, which Revero nutrition therapy is based on, have been shown in an analysis of 42 published studies to improve type 2 diabetes markers compared to nine other types of diets. Findings of this analysis showed that the ketogenic diet intervention resulted in reduced HbA1C, as well as body weight reduction in overweight patients and improvements in blood lipid levels.

Long-term low-carb, ketogenic diets have been shown to result in reduced body weight, BMI, as well as also reducing triglycerides, blood glucose levels, and LDL cholesterol in obese patients. Compared to low-fat diets for obesity, the low-carb, ketogenic diet not only results in greater weight loss, but also in a larger reduction in blood triglyceride levels and a larger increase in HDL cholesterol.

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There are several mechanisms that have been identified as responsible for this finding. Carbohydrates have been shown to reduce HDL cholesterol while elevating triglyceride levels. This occurs because insulin promotes energy storage, often by increasing fat storage in adipocytes. Carbohydrates are converted into triglycerides, then sent to fat cells for storage. As a low-carb, ketogenic diet results in fewer triglycerides formed, and lower insulin levels, the diet helps the body switch modes from lipogenesis to lipolysis. This results in increased rates of fat oxidation, which facilitate weight loss.

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One additional factor that contributes to weight loss occurs because low-carb, ketogenic diets suppress the hunger hormone, ghrelin. This ability of a low-carbohydrate high-fat diet to produce satiety at a reduced energy intake is a contributor to the overall anti-obesity effect of the low-carb, ketogenic diet.

For a portion of the patient population, low-density lipoprotein (LDL) levels will rise, and yet cardiovascular risk will be lower. This is possible because LDL levels comprise a total of different particle sizes, from small dense LDL particles to large buoyant LDL particles. Research evaluating the body of evidence has concluded that small, dense LDL particles are a major, independent risk factor for cardiovascular disease. These small LDL particles continued to define cardiovascular risk even in patients with “normal” LDL levels as well as those undergoing statin therapy. Research has indicated that large buoyant LDL particles do not contribute to cardiovascular disease risk.

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Analysis of 38 randomized trials in a published review concluded that carbohydrate restricted diets reduce the abundance of small dense LDL particles while increasing the level of non-atherogenic large buoyant LDL particles. Sometimes the net effect is an increase in total LDL, though with a lower cardiovascular risk due to the predominance of large particle LDL.

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Besides, irrespective of LDL cholesterol, type 2 diabetes is one of the biggest risk factors for cardiovascular disease (CVD), and improving diabetes control by lowering HbA1C with a low carbohydrate diet will likely help improve CVD risk. Also, obesity, high triglycerides, and hypertension, which are all known independent risk factors for CVD, also have been shown to improve on a low carbohydrate diet, effectively lowering CVD risk (See table above)

Elimination diets involve systematically eliminating foods or food ingredients that are suspected of triggering a harmful response. This strategy is often used to help control inflammatory or autoimmune conditions. In some cases those foods can later be slowly reintroduced, but sometimes they must be eliminated for life.

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An example of one step in an elimination diet would be a low-FODMAP diet. FODMAP is an acronym for Fermentable Oligosaccharides, Disaccharides Monosaccharides And Polyols. Low FODMAP diets have been found to reduce the symptoms of inflammatory bowel disease.

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Another example of an elimination diet is the Autoimmune Protocol Diet (AIP) which involves the elimination of grains, legumes, nightshades, dairy, eggs, coffee, alcohol, nuts/seeds, refined sugars, oils, NSAIDS, and all food additives. This diet has been found to alter the expression of intestinal RNA, modulating immune response to food in patients with autoimmune ulcerative colitis.

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The elimination of gluten is also a form of elimination diet. While primarily used as an intervention for celiac disease or non-celiac gluten sensitivity, elimination of gluten also has shown to be helpful with Hashimoto’s thyroiditis. Non-celiac gluten sensitivity (NCGS) has been demonstrated with anti-gliadin antibodies (gliadin is a peptide that gluten breaks down into), with a significant correlation to autoimmune thyroiditis.

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Paleolithic, or Paleo diets, which seek to mimic the dietary profiles of human ancestors, have also been used as a form of elimination diet. One application of Paleo diets is for the autoimmune conditions Hashimoto’s thyroiditis and Graves' disease.

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There are also many other food reactions that can be identified via elimination diets, including reactions to carrageenan or food dyes.

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These elimination diet strategies can easily be incorporated into a low-carbohydrate diet, providing a way to determine if the condition responds to the elimination strategy.