Does the cost of a meal influence the portion size effect?

Area of Science:

• Behavioral Economics
• Nutritional Science
• Psychology

Background:

• Portion size significantly influences food intake.
• The impact of meal cost on portion size effects is not well understood.
• Understanding these factors is crucial for public health and dietary interventions.

Purpose of the Study:

• To investigate how the cost of a meal influences the portion size effect on food and energy intake.
• To examine individual differences in satiety responsiveness as a moderator of portion size effects.

Main Methods:

• A controlled crossover study with 79 adults.
• Participants consumed pasta meals varying in portion size (400g vs. 600g) and cost ($8 vs. $16) over 4 weeks.
• Questionnaires assessed satiety responsiveness and other behavioral factors.

Main Results:

• Larger portion sizes significantly increased food intake (18% by weight) and energy intake (20%).
• Meal cost did not significantly affect food intake or alter the portion size effect.
• Satiety responsiveness moderated the portion size effect; larger portions increased intake only in those with lower satiety responsiveness.

Conclusions:

• The portion size effect on food intake in a controlled setting is robust and not influenced by meal cost.
• Individual differences in satiety responsiveness play a critical role in modulating responses to larger portion sizes.
• Findings suggest that interventions targeting satiety responsiveness may be effective in mitigating overconsumption driven by portion size.