Daily Patterns of Caffeine Intake and the Association of Intake with Multiple Sociodemographic and Lifestyle Factors in US Adults Based on the NHANES 2007–2012 Surveys

Abstract

Background Caffeine increases alertness when consumed in single servings of various products including coffee, tea, soft drinks, and energy drinks. Although not a nutrient, caffeine is consumed by 90% of the adult population in the United States.Objective This study examined the daily pattern of caffeine intake and its relationship to multiple demographic variables.Methods Data from the National Health and Nutrition Examination Survey (NHANES) 2007e2012 (adults aged 19þ years; n¼16,173) were used to determine the time of day at which caffeine is consumed and demographic factors associated with intake. Regression analyses characterized factors associated with caffeine intake including sex, age, ethnicity, education, smoking status, physical activity, employment status, total work hours, alcohol, and energy intake.Results Mean adult per capita caffeine intake was 169AE4 mg/d (meanAEstandard error).Most caffeine (70%) was consumed before noon, often at breakfast, and intake decreased progressively over the day, with little consumed after 9:00 PM. Intake was associated with age, ethnicity, smoking status, total calorie intake, and work hours (P<0.01) but not physical activity, economic status, education level, or employment status. Variables with the largest associations with intake were, respectively, ethnicity and age. Non-Hispanic black individuals consumed the smallest amounts (80AE2 mg/d), non-Hispanic white individuals consumed the greatest amounts (194AE3 mg/d), and Asian individuals (126AE7 mg/d) and Hispanic individuals consumed intermediate amounts (127AE3 mg/d). Middle-aged individuals (aged 50 to 54 years) consumed more caffeine (211AE6 mg/d) than younger (107AE4 mg/d, aged 20 to 24 years) and older individuals (153AE4 mg/d, aged 75 to 79 years).Conclusion Most caffeine is consumed in the morning, when alertness is lowest, and very little in the evening before sleep. Ethnicity and age were the variables most strongly associated with intake; work hours, occupation, energy and alcohol intake, and smoking were also associated with intake. Because caffeine increases alertness, it is not surprising that its pattern of consumption and factors associated with its intake vary from those of most other food constituents.

Caffeine Consumption in Switzerland: Results from the First National Nutrition Survey MenuCH

“…Short-term effects of caffeine on health are well documented: stimulation of the central nervous system [2,4], increased metabolism [4], acute elevation of blood pressure [2,[4][5][6], and diuresis [4]. Caffeine is particularly known and sought for its effects on alertness [7] and cognitive performance [7]. However, in some individuals, it can have a negative impact on sleep in a dose-dependent manner if consumed late in the day [2,7,8].…”

“…Caffeine is particularly known and sought for its effects on alertness [7] and cognitive performance [7]. However, in some individuals, it can have a negative impact on sleep in a dose-dependent manner if consumed late in the day [2,7,8]. Longer-term effects of caffeine intake on health are more debated.…”

The impact of daily caffeine intake on nighttime sleep: signs of overnight withdrawal?

“…[10][11][12][13][14] Moreover, sleep intensity, which is usually strongest at the beginning of the night, 33 was particularly disrupted during the first sleep cycle, as indexed in reduced SWS and SWA. 10 However, caffeine intake in the evening, particularly after 9 pm is rare, 5 presumably to avoid impairment of subsequent sleep. 3 Up to date it remained fairly unclear whether caffeine intake in the morning and afternoon still bears the potential to disrupt nighttime sleep.…”

“…Caffeine is the most popular psychoactive substance in the world, 1 consumed daily by around 80% of the population. 2 While caffeine is frequently used to counteract sleepiness and boost performance, 3 its consumption is commonly avoided in the evening 4,5 to prevent adverse consequences on nocturnal sleep. 3 The sleep disrupting effects of caffeine are mainly attributed to its influence on the homeostatic component of sleep-wake regulation.…”

“…10 However, evening caffeine intake only accounts for approximately 10-20% of the total daily caffeine intake in regular consumers. 4,5 It needs to be elucidated whether habitual caffeine intake restricted to the morning and afternoon hours similarly affects nighttime sleep.…”