Associations between Diet Quality and Allostatic Load in US Adults: Findings from the National Health and Nutrition Examination Survey, 2015-2018

Abstract

Background: Allostatic load (AL), the concept of cumulative biological risk from chronic stressful exposures, may provide a framework with which to examine the links between diet, physiological stress, and disease.

Objective: This study examined the associations between diet quality and AL.

Design: This cross-sectional study was conducted using the 2015 through 2018 cycles of the National Health and Nutrition Examination Survey. Dietary intake was assessed using two 24-hour diet recalls. Diet quality was measured using the Healthy Eating Index 2015. AL was measured by a composite score of nine biochemical markers, with three or more dysregulated values signaling elevated AL. All markers were collected during a physical examination.

Participants and setting: This study was conducted in a nationally representative population of 5,343 US adults aged 19 years or older who had no prior diagnosis of diabetes (except gestational diabetes), cancer (except skin cancer), or cardiovascular disease; were not pregnant; and had complete dietary intake and AL biomarker data.

Main outcome measures: The outcome was odds of elevated AL.

Statistical analyses performed: Accounting for the complex survey design of the National Health and Nutrition Examination Survey, multivariable logistic regression was used to examine the associations between Healthy Eating Index 2015 score and elevated AL, adjusting for sociodemographic variables.

Results: A significant inverse association between AL and diet quality was observed among adults aged 31 years and older but not among those aged 19 to 30 years. Among adults aged 31 years and older, those in higher quintiles of Healthy Eating Index 2015 score had significantly lower odds of elevated AL compared with the lowest quintile (P for trend < 0.05).

Conclusions: These results suggest that, in adults older than age 30 years, consuming a more healthful diet is inversely associated with AL.

Keywords: allostatic load; cumulative biological risk; diet patterns; diet quality; healthy eating index.