A. Smith et al., EFFECTS OF FAT-CONTENT, WEIGHT, AND ACCEPTABILITY OF THE MEAL ON POSTLUNCH CHANGES IN MOOD, PERFORMANCE, AND CARDIOVASCULAR FUNCTION, Physiology & behavior, 55(3), 1994, pp. 417-422
This study examined the effects of fat content and meal size on postlu
nch changes in mood, performance, and cardiovascular function. Forty-s
ix subjects (20 males, 26 females) were tested before and after lunch.
Subjects were assigned to one of the following lunch conditions: a) l
ow fat (23 g), large meal (860 g); b) low fat (18 g), small meal (600
g); c) high fat (84 g), large meal (840 g); d) high fat (79 g), small
meal (530 g). The results showed only small effects of fat composition
and meal size, with no cardiovascular effects being observed and no e
vidence of fat content or the weight of the meal influencing performan
ce of logical reasoning or cognitive vigilance tasks. A few effects of
meal type were significant in the mood data, but given the large numb
er of analyses conducted, these could represent chance effects. Result
s from two selective attention tasks showed that subjects given the hi
gh-fat meals responded more slowly but more accurately, which differs
from the effects of carbohydrate, protein, and calorie content reporte
d in earlier papers. Weight of the meal influenced the degree of distr
action from near and far distracters and also the accuracy of response
s to central and peripheral targets. However, both the effects of fat
and meal size were modified by task parameters, and further research i
s required before firm conclusions can be drawn about the functional i
mportance of the influences of nutrient content and meal size on perfo
rmance. The high-fat and large meals were rated as more acceptable tha
n the low-fat and small meals. These differences in acceptability coul
d not, however, account for the changes in performance observed after
consumption of the different meal types.