Influences of dietary and intraduodenal lipid on alertness, mood, and sustained concentration.
The effects of intraduodenal and dietary lipid on alertness, mood and performance in a task requiring sustained attention were investigated in two studies. The first experiment compared the effect of duodenal infusion of either 100 g/l Intralipid (8.36 kJ/min) or isotonic saline (9 g NaCl/l) in paired studies carried out on two non-consecutive days on five male volunteers. Two consecutive 3 h infusions, one of lipid, the other saline, were given blind on each day using a crossover design. Analysis of variance indicated that lipid significantly reduced alertness (P < 0.05) and affected the speed and accuracy of performance in a sustained attention task (P < 0.05). A second experiment compared the effects on eight male volunteers of two isoenergetic lunches of similar appearance, taste and protein content but differing fat and carbohydrate (CHO) contents (fat energy:CHO, 64:18 v. 7:76). Alertness was lower (P < 0.05) and responses to stimuli in a sustained attention task were slower after the high-fat meal than after the low-fat meal (P < 0.05). In conclusion, infusion of lipid into the small intestine, and the substitution of fat for carbohydrate while keeping energy and protein constant in a lunch, both cause an enhanced postprandial decline in alertness and concentration. This may be related to the presence of lipid in the small intestine.
Wells
A S
AS
Centre for Human Nutrition, University of Sheffield, Northern General Hospital.
Read
N W
NW
Craig
A
A
D000328:Adult; D000339:Affect / Q000187:drug effects*; D001288:Attention / Q000187:drug effects*; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage*; D004386:Duodenum / Q000378:metabolism*; D004435:Eating; D006801:Humans; D008297:Male; D013647:Task Performance and Analysis; D013997:Time Factors
D004040:Dietary Carbohydrates; D004041:Dietary Fats