What is Gluten?
Gluten is a protein commonly found in grain products such as breads, pastas and cereals. It consists of two proteins called glutenin and gliadin. Gluten enhances the structure, texture, chewiness and palatability of foods
Celiac disease and non-celiac disease gluten sensitivity are two diagnoses requiring a gluten free diet. About 1% of the population has celiac disease. In this condition, gluten causes damage to the small intestine leading to symptoms such as abdominal pain, bloating and abnormal bowel movements.¹ Non-celiac gluten sensitivity is present in 0.5 - 3% of the population and is defined as the presence of GI signs and symptoms related to intake of gluten containing food.¹
However, recently the gluten free diet has become popular for its suspected health and weight loss benefits. Between the years of 2013 and 2015 there has been a 67% increase in individuals who consume gluten free diets.² As of 2015, 25% of Americans reported adhering to a gluten free diet despite the small percentages of people who actually require the gluten free diet ( celiac disease and gluten/wheat sensitivities).² A survey conducted in 2016 demonstrated that 64% of Americans believed the gluten free diet was healthier.³ This demonstrates how widely accepted these beliefs are in the public eye. Furthermore, one study investigated consumers' perception of foods with a gluten free label.⁴ Overall, findings supported that consumers believed that a gluten free food product had less calories, was less processed and was more healthful.⁴
Is Gluten Healthier?
Despite the perceived health benefits of the gluten free diet, the composition of gluten free foods is suboptimal in comparison to its gluten containing counterparts. One study analyzed the nutrient profiles of 58 gluten free foods and their gluten containing counterparts.⁵ Findings proved that folate, iron were lower in gluten free foods in comparison to gluten containing foods.⁵ Both of these nutrients are required to maintain normal body function. Moreover, of the 58 gluten free foods, there were only three cold cereals that were fortified with folic acid. Folic acid is an incredibly important nutrient for women of child bearing age as it is vital in preventing neural tube defects in offspring during pregnancy.⁶
Another study investigated the nutritional value of several gluten free foods and their gluten containing counterparts. It was found that gluten free bread and pastas had a third less protein and contained twice as much fat, mainly saturated fat.⁷ Pasta’s also had higher salt content and lower fiber content in the gluten free foods in comparison to the gluten containing foods.⁷ However, it should be mentioned that both of these studies only analyzed 58 and 206 food products, respectively. This is a limitation of both of these studies.
Does Gluten Aid in Weight loss?
The gluten-free diet will not magically lead to weight loss. Due to the restrictive nature of this diet, it is possible for some people to experience initial weight loss. But it doesn’t have to do with a gluten free being healthier or enhancing metabolism.
One study investigated weight changes in children diagnosed with celiac disease who had to switch to a gluten free diet. This study found that after being placed on a gluten free diet, the number of overweight children nearly doubled.⁸
Increased weight during a gluten free diet may be related to increased calorie consumption, the desire to decrease gluten free carbohydrate food sources in exchange for food products higher in fat and protein, decreased fiber intake as well as increased consumption of high calorie sweets.⁸
However, this research study has limitations. These children were diagnosed with celiac disease; therefore, the results are not generalizable to individuals who are on the gluten free diet for health benefits and not a diagnosis. Furthermore, this study was conducted on children who have more of a preference towards sweet foods. Nonetheless, this is a study that suggests that certain factors of the gluten free diet may lead to weight gain rather than weight loss.
Bottom Line:
As of right now, evidence does not support claims that gluten free diet leads to weight loss. However, evidence does suggest that a gluten free diet may be lacking in some key nutrients. Furthermore, increased calories, decreased palatability, and decreased dietary fiber content of gluten free food may lead to weight gain.
Written by Helayne Speroni on behalf of Supriya Lal.
Resources:
Leonard MM, Sapone A, Catassi C, Fasano A. Celiac disease and nonceliac gluten sensitivity a review. JAMA. 2017;318(7):647-656
Bulka C, Davis M, Karagus M, Halibut A, Argos M. The unintended consequences of the gluten free diet. Epidemiology. 2017;28(3):pe24-e25
U.S. Gluten-free Foods Market- Statistics & Facts. Statista website. https://www.statista.com/topics/2067/gluten-free-foods-market/ Published October 2020, Accessed October 2020
Prada M, Godinho C, Rodrigues DL, Lopes C, Carrido MV. The impact of a gluten-free claim on the perceived healthfulness, calories, level of processing and expected taste of food products. Food Qual Prefer. 2019;73:284-287 https://doi.org/10.1016/j.foodqual.2018.10.013
Thompson T. Folate, iron and dietary fiber contents of the gluten free diet. J Am Diet Assoc. 2000;100(11):1389-96 doi: 10.1016/S0002-8223(00)00386-2.
Gazzino R, Marrocco W, Pio D’Ingianna A et al. Folic acid supplementation in Italian women during pregnancy: a cross-sectional study conducted in general practice. Nutr. 2020;79-80:1-6
Miranda J, Lasa A, Bustamante MA, Churruca I, Simon E. Nutritional differences between a gluten-free diet and diet containing equivalent products with gluten. Plant Foods Hum Nutr. 2014;69(2):182-187
Valetta E, Fornaro M, Cipolli M,Conte S, Bissolo F, Danchielli C. Celiac disease and obesity: need for nutritional follow up after diagnosis.Eur J Clin Nutr. 2010;64:137-1372