LAUSR

Background To determine the effect of food intake on complete blood count (CBC) results. Method We analyzed the CBC in whole capillary blood specimens collected from 33 adult volunteers into microtubes between 8:00 AM and 11:00 AM. Blood specimens were drawn from patients who had been fasting 12 hours and then 1 and 2 hours after consumption of a light meal containing carbohydrates, protein, and lipids. All measurements were performed using the hematologic analyzer Sysmex XN-1000. Results The red blood cell count, hemoglobin concentration, hematocrit level, and platelet count decreased 2 hours after meal consumption (P = .007, P = .008, P = .003, and P = .03, respectively). The lymphocyte number decreased after the first and second hour following meal consumption (P = .004 and P = .001); the number of neutrophils had increased 1 and 2 hours after food intake (P = .003 and P = .006, respectively). Conclusions Food consumption impacts CBC results. To ensure the consistency, quality, and repeatability of CBC analysis, blood should be drawn from fasting patients.