Normal BMI hides nutritional gaps in alcohol use disorder

By Vijay Kumar MalesuReviewed by Benedette Cuffari, M.Sc.Feb 4 2026

A sweeping review shows that while calorie intake and BMI often appear normal in people with alcohol use disorder, poor diet quality, hidden deficiencies, and flawed assessment tools may be undermining recovery and long-term health.

Study: Dietary intake, quality, and assessment tools in individuals with problematic alcohol use: a scoping review and meta-analysis. Image Credit: Ingrid Balabanova / Shutterstock.com

In a recent study published in the Translational Psychiatry, researchers compare dietary intake, diet quality, and dietary assessment methods among individuals with alcohol use disorder (AUD) and related problematic alcohol use.

The critical role of nutrition in AUD

Nutrition plays an important role in proper functioning of the brain and immune system, and in recovery from chronic diseases. However, its role has not been widely studied in relation to AUD progression, treatment responses, and recovery outcomes.

Excessive alcohol intake interferes with appropriate nutrient consumption and absorption, impairs metabolism, and increases the excretion of essential nutrients, all of which increase the risk of malnutrition. Many patients with AUD are diagnosed with comorbid liver, cardiovascular, and metabolic diseases, with these symptoms often worsened by nutrient malabsorption and metabolic dysfunction.

Medical nutrition therapy, which involves the development of a personalized diet and lifestyle plan based on specific medical conditions and symptoms, has the potential to support health improvements in AUD patients. Due to the limitations associated with conventional methods used to assess diet quality and behavior, the relationship between nutritional status, dietary behaviors, and AUD and how these factors interact with each other to impact patient outcomes remains insufficiently characterized.

A multi-database review of diet in AUD

The researchers performed a comprehensive search on databases like PubMed/MEDLINE, Scopus, and Web of Science using combinations of keywords and Medical Subject Headings (MeSH) related to alcohol use, diet, nutrition, and dietary assessment. 

Studies were included in the analysis if they provided quantitative dietary data of adults diagnosed with AUD or alcohol-related disorders, as defined in the Diagnostic and Statistical Manual of Mental Disorders. Both active drinking and abstinent phases were included.

Title and abstract screening, followed by full-text review and structured data extraction, were performed by multiple reviewers. Dietary intake data were aligned with studies and separated on the basis of drinking status.

Alchohol calories dominate intake, but without replacing food

A total of 41 studies published between 1968 and 2022 across 16 countries were included in the analysis, which comprised 2,727 individuals with AUD. Most of the study participants were men between the ages of 38 and 54 with an average body mass index (BMI) value of 24.4 kg/m².

Individuals during the active drinking phase consumed an average of 2,900 kcal/day, of which over 1,500 kcal was from alcohol alone, which is equivalent to about 15 standard drinks. Despite the high caloric intake attributed to alcohol among active drinkers, abstinent drinkers, largely assessed in inpatient or residential treatment settings, reported an average daily energy intake of 2,384 kcal/day, suggesting that alcohol calories are consumed in addition to food and non-alcoholic beverage intake during periods of active drinking.

Carbohydrates provided a smaller proportion of total energy as compared to the general United States population, while protein and fat intake were generally comparable to population reference values. Total protein intake was generally sufficient to meet the Recommended Dietary Allowance. 

Using the Healthy Eating Index 2015, one study found that individuals in inpatient treatment consumed diets of slightly higher quality than the general U.S. population, which may be due to structured meal environments. Comparatively, another study using the Nova classification system reported higher consumption of ultra-processed foods during active drinking, a pattern associated in broader literature with poorer metabolic and mental health outcomes.

Dietary fiber intake was infrequently reported and highly variable, as fiber consumption during active drinking was mixed across studies, with some reporting levels below recommendations. In contrast, fiber intake during abstinence was higher in a single inpatient study, likely reflecting structured dietary provision. Fiber is critical for maintaining optimal gastrointestinal health, regulating blood glucose levels, and supporting cardiovascular health. Thus, it is crucial for future studies to clarify daily fiber intake among individuals with AUD and determine the potential health benefits of increasing the consumption of fiber-rich foods in this patient population.

Diet history interviews were the most common dietary tool used in studies, followed by 24-hour dietary recalls and food records. Importantly, none of these assessment tools have been validated for use in individuals with AUD, which increases the potential for recall bias.

Normal BMI masks nutritional deficiencies

The study findings demonstrate that weighted averages of reported intake suggest many individuals diagnosed with AUD have caloric intake, macronutrient distribution, and BMI values that fall within typical population ranges. However, these findings coexist with a high prevalence of micronutrient deficiencies and substantial methodological limitations, including underreporting, impaired nutrient absorption, and metabolic disruption related to chronic alcohol exposure.

Importantly, standard dietary guidelines have been developed for the general U.S. population and, as a result, may not be adequate for AUD patients, thus emphasizing the need to develop AUD-specific nutritional guidance and reference intakes.

Poor diet quality can exacerbate inflammation, cognitive dysfunction, and comorbid conditions often present in people with AUD, while improved nutritional intake, particularly diets rich in fiber, micronutrients, and balanced macronutrients, may support physiological healing, psychological well-being, and recovery.