The relationship between dietary factors and drinking behavior: A meta-analysis of observational studies

The detrimental effects of heavy alcohol use on nutrition status are well documented; however, the relationship between dietary factors and moderate alcohol consumption in the general population is poorly understood. Evidence suggests that alcohol toxicity may be modified by dietary macronutrient composition and nutritional status of the alcoholic. Studies have addressed relationships between alcohol consumption and intake of energy and/or macronutrients. Nonhuman experimental studies indicated manipulation of diet resulted in alteration of alcohol self-administration. Human experimental studies addressing relationships between energy intake, macronutrient profile and alcohol consumption were limited. While relationships between energy and macronutrients and alcohol consumption have been observed in epidemiological studies, no consensus indicates the magnitude, direction, and significance of these relationships. As such, questions arose as to the nature of these relationships in the human population of moderate alcohol consumers. The pertinent questions were (1) is there a significant association between alcohol consumption and energy and macronutrient profile in moderate drinkers? If yes, what is the average effect and for what nutritional categories is an association present, i.e. energy, carbohydrate, protein, fat? (2) what is the direction and consistency of the association across studies? and (3) what predictors of variation exist? A quantitative research synthesis of existing observational studies addressed these questions. The meta-analysis indicated that moderate drinkers consumed more kilocalories including alcohol, KCAL+, and less kilocalories excluding alcohol, KCAL−, relative to abstainers. Carbohydrate intake was decreased by moderate drinkers in both KCAL+ and KCAL−. Protein intake was unchanged in KCAL+ and increased in KCAL−. Fat intake was increased in KCAL+ and decreased in KCAL−. This meta-analysis provided for an enhanced understanding of the association between energy and macronutrient consumption and moderate alcohol consumption.