Effects of breakfast and caffeine on performance and mood in the late morning and after lunch.
The aim of the present study was to examine the effects of breakfast and caffeine on performance, mood and cardiovascular functioning in the late morning and after lunch. Forty-eight subjects were tested at 07.45 and subjects then assigned to one of the four conditions formed by combining caffeine and breakfast conditions. Subjects in the caffeine condition were given a dose of 4 mg/kg, the caffeine manipulation being double blind. At 11.15 subjects were given another coffee (subjects remained in the same caffeine condition) and had lunch at 12.30. Performance was examined prior to lunch (11.30) and after lunch (14.00). Effects of breakfast on recognition memory (lower false alarm rate) and logical reasoning (reduced accuracy) were found in the late morning but not after lunch. However, a semantic processing task was performed more slowly by the breakfast group after lunch. Caffeine improved performance on a sustained attention task, the logical reasoning task and semantic memory task. Subjects given caffeine also reported greater alertness and feelings of well-being, whereas the effects of breakfast on mood changed from the late morning to early afternoon. Few interactions between breakfast and caffeine conditions were obtained.
Smith
A P
AP
Health Psychology Research Unit, School of Psychology, University of Wales College of Cardiff, UK.
Kendrick
A M
AM
Maben
A L
AL
D000328:Adult; D000339:Affect / Q000187:drug effects*; D001143:Arousal / Q000187:drug effects*; D001288:Attention / Q000187:drug effects*; D002110:Caffeine / Q000494:pharmacology*; D002940:Circadian Rhythm / Q000187:drug effects*; D004311:Double-Blind Method; D005247:Feeding Behavior / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000187:drug effects*; D010555:Personality Inventory; D011340:Problem Solving / Q000187:drug effects; D012153:Retention, Psychology / Q000187:drug effects; D012737:Sex Factors; D014706:Verbal Learning / Q000187:drug effects
D002110:Caffeine