EFFECTS OF CARBOHYDRATE AND PROTEIN MEALS ON CARDIOVASCULAR LEVELS AND REACTIVITY

This study examined the effects of standard laboratory stressors on ca rdiovascular measures before and after the consumption of a modest mea l. A mental arithmetic task and a reaction time task were administered before and 2 h after a carbohydrate or a protein meal. A noncaloric p lacebo meal and a fasting condition were included as control treatment s. The caloric meals, in particular the carbohydrate meal, induced an increase in cardiac output, ventricular contractility, and systolic bl ood pressure. Total peripheral resistance and diastolic blood pressure dropped. Although postprandial adjustments were substantial, stress r eactivity patterns generally were not perturbed by the meals. Only hea rt rate reactivity was stronger after eating the carbohydrate meal. It is concluded that subjects' meal consumption prior to their participa tion in a psychophysiological experiment needs to be taken into accoun t.