The Relationship between Black Coffee Consumption and Weight Status

Learning outcome To understand the relationship between the amount of black coffee consumed and Body Mass Index (BMI) in individuals 18 years and older. Background Researchers have debated the relationship between weight status and coffee consumption with conflicting results. Lee, Kim, & Kim (2017) found a positive trend exists between the amount of coffee consumed and BMI. Conversely, Grosso et al. (2015) found an inverse trend between coffee consumption and BMI. Methods Quantitative design was used. A researcher constructed questionnaire was piloted through SNAP Survey at a small Midwestern university receiving 939 complete responses. Three questions were included on the pilot study questionnaire soliciting feedback regarding question wording, ordering, and comprehension. The questionnaire was revised for validity and clarity. The revised questionnaire for the main study was administered through Amazon Mechanical Turk. Fifty-seven complete questionnaires were received. Eighty-four participants from the pilot study who reported only black coffee consumption were included in the main study data analysis. The two samples were combined to increase statistical power (n=141). BMI (kg/m2) was calculated for each participant. Results An ANCOVA was performed to examine the relationship between BMI and black coffee consumption (oz.) per day (scale was 4 oz. to 40 oz.). The results showed no correlation between the two variables, F(1, 138)= 0.65, p \u3c 0.001. Unlike the previous studies, this quantitative study controlled for additives (such as cream, sugar, and milk) as confounding factors so that the relationship between black coffee and weight status were studied solely. Conclusions Amount (ranging from ½ to 5 cups) of black coffee consumed per day was not correlated to BMI in this sample of adults