Daily Patterns and Factors including Gender, Race and Occupation Associated with Caffeine Intake Among US Adults: NHANES 2007–2012
Authors: Lieberman Harris R , Agarwal Sanjiv , Fulgoni Victor L 
Published: November 2023

Caffeine is the most widely consumed stimulant in the world and is found in coffee, tea, cocoa, soft drinks and energy drinks. Data from National Health and Nutrition Examination Survey (NHANES) 2007–2012 (adults age 19+ years, n = 16,173) were used to estimate individual usual caffeine intake from all caffeine containing foods and beverages using the National Cancer Institute method. Mean adult caffeine intake was 179.1 ± 5.3 mg/d (202.7 ± 7.4 mg/d for males and 156.5 ± 4.4 mg/d for females); 71% was consumed before noon (40% between 6 to 9 AM) and 26% was consumed in the afternoon and evening hours (between 12 to 9 PM). Thirty‐eight percent of total caffeine was consumed during breakfast, 10% during lunch, 9% during dinner and 43% at times not associated with any meal. We used regression analyses to characterize factors [gender, ethnicity, physical activity (PA, using Global Physical Activity Questionnaire), poverty‐income ratio, smoking status, alcohol and energy intake] associated with caffeine intake. Caffeine intake was significantly associated with ethnicity (P < 0.0001), with non‐Hispanic Blacks and Hispanics consuming less caffeine (−58% and −31% respectively) than non‐Hispanic Whites. Intake was positively associated with age (1.3 mg/d more caffeine per year of age, P < 0.0001) but not gender (P = 0.6645), and was positively associated with poverty income ratio (13.0 mg/d more caffeine intake among adults with higher incomes compared to adults with lower incomes, P = 0.0023), alcohol intake (14.9 mg/d more caffeine among adults with more‐than‐median alcohol intake compared to adults with less‐than‐median alcohol intake, P < 0.0001), smoking (60.0 mg/d more caffeine intake among current smokers compared to non‐smokers, P < 0.0001) and total calorie intake (4.1 mg/d more caffeine per 100 kcal greater intake, P < 0.0001). Caffeine intake was not associated with total PA at work (P = 0.1717) or time spent walking (P = 0.1880) but inversely associated with recreational PA among adults with above‐the‐median recreational PA compared to those with below‐the‐median recreational score (P = 0.0007), and sleep duration (19.4 mg/d less caffeine among adults sleeping more than 7 hr/d compared to adults sleeping less than 6 hr per day, P = 0.0008). Working in industries such as utilities, construction, manufacturing, finance/insurance, management/administrative/waste services, education services, health care/social assistance, and public administration was associated with consuming more caffeine (29–82 mg/d more caffeine, P < 0.01) compared to working in real estate (data were only available from NHANES 2007–2010). In conclusion, caffeine intake among adults is moderate; it is consumed mainly in the morning hours, and is influenced by demographic, lifestyle and occupational factors. Views expressed here are those of the authors and do not reflect official policy of the US Army, Department of Defense, or US Government.Support or Funding InformationDoD/MRMC