Carbohydrate malabsorption in anorexia nervosa: a systematic review

J Eat Disord. 2022 Dec 6;10(1):189. doi: 10.1186/s40337-022-00713-8.

Abstract

Objectives: Anorexia nervosa (AN) is an eating disorder accompanied by a low body mass index and (self-) restricted food intake. Nutritional limitations can cause complaints of the digestive system, because of a disturbed absorption of food components. The absorption of carbohydrates may be seriously affected and reduced to a minimum. On this basis, a possible connection between AN, and the prevalence of gastrointestinal symptoms due to malabsorption was examined.

Methods: For the systematic literature research with the aim of a better understanding of the topic the databases PubMed, Web of Science, Cochrane Library, Livivo and Google Scholar were used.

Results: After the manual selection process of 2215 retrieved studies, 89 full texts were read and according to the predetermined eligibility criteria, finally 2 studies on the monosaccharide fructose and disaccharide lactose were included in this review.

Conclusion: Malabsorption is often observed in patients with AN. It may contribute to the gastrointestinal complaints reported by patients and hamper body weight regain. Among others, mucosal atrophy and duodenal transporter dysfunction are discussed as main reasons. In the future more studies on carbohydrate malabsorption related to low body weight as observed in AN are warranted and may be conducted rather in an outpatient setting.

Keywords: Anorexia nervosa; Carbohydrate malabsorption; Fructose malabsorption; Lactose intolerance.

Plain language summary

People with anorexia nervosa (AN) may experience a preference for foods containing fewer calories but more carbohydrates, e.g. fruits and vegetables. The consequences of this food restriction and selection may include malabsorption of sugars such as fructose and lactose, the mechanism of which is incompletely understood. This may contribute to symptoms similar to those seen in people with lactose intolerance, e.g. bloating, and make it harder for people to eat recommended foods. This paper presents a comprehensive literature search for research on this topic. However, only two studies were identified which highlights that further investigation is needed to explore this clinically relevant field.

Publication types

  • Review