Date of Award

January 2023

Document Type


Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Debbie Humphries

Second Advisor

Leah Ferrucci


Background: The prevalence of obesity in the United States has increased over the last few decades. Reasons for the increases are abundant, but one factor consistently stands out, caloric intake. Cross-sectional data on differences in caloric intake by race/ethnicity and socioeconomic status are common; however, few studies have evaluated the long-term trends in calorie intake by these factors. Methods: We evaluated trends in average calories consumed by adults in the United States by income decile, educational attainment level, and race/ethnicity from 1971 to 2018 using data from the National Health and Nutrition Examination Survey (NHANES), which purposely assessed and recorded samples of the United States population. Dietary recall, income, education level, and race/ethnicity variables were extracted from the data sources. Income data was converted to account for inflation prior to any analysis, caloric intake was the total nutrient intake recorded by surveyors in Kcal and after 2003 saw NHANES record two days of total nutrient intakes, which were averaged for the comparison with prior years. An Interrupted Time Series analysis (ITS) was used to compare the trend lines of average caloric intake by income decile, education attainment, and race/ethnicity. Results: Mean calories consumed increased in all groups over the fifty-year period, except for ‘Hispanic’ which had stable caloric intake over the thirty-year period. Trends in mean caloric intake differed. Those classified as having a High School education had the slowest increase in slope compared to other groups. Interactions between the subgroups contained a variety of significant and not statistically significant values. Conclusion: To address the concerning trend of increased caloric intake over the past fifty years, interventions must target upstream areas of influence to bring about change at the societal level.


This thesis is restricted to Yale network users only. It will be made publicly available on 05/10/2024