Measurement of coffee and caffeine intake: Implications for epidemiologic research

Coffee intake and risk of incident diabetes in Puerto Rican men: results from the Puerto Rico Heart Health Program

“…Results of one methodological study suggest that coffee intake can be measured reliably using dietary recalls (24) , while another suggests that an individual's coffee intake may vary by day of the week (25) . Because of the prospective study design, it is likely that any misclassification of coffee intake would be non-differential and thus would tend to bias results towards the null.…”

Intake of caffeine and other methylxanthines during pregnancy and risk for adverse effects in pregnant women and their foetuses

“…The five other studies that have specifically reported on gender differences in coffee consumption have all observed a slightly higher coffee consumption among males than among females Gilbert, 1984;Scheiber et al, 1988;Solvoll et al, 1989;Johansson and Solvoll, 1999). The Norwegian data are shown in Table 21.…”

“…It should be pointed out that a negative correlation between caffeine intake from chocolate and caffeine intake from coffee has been observed in an American investigation (Scheiber et al, 1988). Coffee drinkers, who already have a relatively high caffeine intake from coffee, had the lowest intake of caffeine from chocolate.…”

“…Coffee drinkers, who already have a relatively high caffeine intake from coffee, had the lowest intake of caffeine from chocolate. The daily caffeine intake from chocolate among current coffee drinkers was 0.9 mg, whereas it was 1.1 mg among former drinkers, and 1.5 mg among those who never drank coffee (Scheiber et al 1988). …”

“…In another American study, 78.2 % of the surveyed population was identified to be consumers of caffeinated coffee. Within this population, 16.4 % consumed decaffeinated coffee (Scheiber et al, 1988). Habits of drinking social beverages change over time.…”