How accurate is self-reported dietary energy intake?

Area of Science:

• Nutritional Science
• Human Physiology
• Dietary Assessment

Background:

• Self-reported dietary intake is a cornerstone of nutritional science.
• The accuracy of self-reported intake remains poorly understood.
• The doubly-labeled water method offers a validated reference for energy expenditure.

Purpose of the Study:

• To evaluate the accuracy of self-reported energy intake.
• To compare self-reported intake with objective energy expenditure measurements.
• To identify patterns and extent of inaccuracy in dietary self-reports.

Main Methods:

• Utilized the doubly-labeled water method to measure total energy expenditure.
• Compared energy expenditure data with self-reported energy intake data from nine studies.
• Analyzed discrepancies between reported intake and measured expenditure.

Main Results:

• Significant inaccuracies were documented in self-reported energy intake across multiple studies.
• Self-reported intakes were consistently lower than measured energy expenditure, indicating underestimation.
• The degree of underreporting was found to correlate positively with actual energy intake levels.

Conclusions:

• Self-reported dietary intake is subject to considerable inaccuracy, often underestimating true energy consumption.
• Individuals may adjust reported intake towards perceived social or dietary norms.
• Further research is needed to refine dietary assessment methods for greater accuracy.