Effects of Snack Intake on Appetite, Affect and Attention

Area of Science:

• Nutrition Science
• Cognitive Psychology
• Human Physiology

Background:

• Afternoon snacking is common, but its impact on appetite, mood, and cognitive performance is not fully understood.
• Previous research has not consistently controlled for factors like deprivation, sensory, hedonic, and expectancy effects in snack studies.

Purpose of the Study:

• To investigate the dose-response relationship between afternoon snack energy content and subsequent appetite, mood, and attention.
• To differentiate the effects of snacks from the impact of a prior meal (lunch) on these variables.

Main Methods:

• A controlled experiment with 30 male volunteers using a dose-response design.
• Participants consumed a standard lunch followed by one of four snacks varying in energy content (124-724 kcal) or no snack.
• Assessed appetite (hunger, fullness), mood, reaction time, and accuracy in a perceptual discrimination task.

Main Results:

• Appetite ratings (hunger, fullness) were significantly influenced by snack energy content.
• Mood and attention task performance showed only weak responses to snack intake.
• Lunch consumption had a more pronounced effect on mood compared to afternoon snacks.
• Larger snacks led to decreased fatigue but only marginally improved reaction time.

Conclusions:

• When controlled for confounding factors, afternoon snack intake has subtle effects on mood and attention.
• The energy content of snacks influences appetite more than cognitive performance or mood.
• Lunch plays a more significant role in modulating mood than afternoon snacks.