Financial incentive for diet recall accuracy does not affect reported energy intake or number of underreporters in a sample of overweight females.

Underreporting of energy intake in diet recalls is common, especially among obese individuals. Incentives have been used to ameliorate the problem, but are typically provided without efficacy assessment. The present study sought to determine whether financial incentives decrease underreporting in diet recalls. Three groups were used to assess incentive timing effects in this parallel group crossover study. One group received a $50 bonus for accurate diet recalls on the first two of four recalls. Accuracy was purportedly verified by salivary analysis. Another group received the $50 bonus for the last two recalls. A third group received no incentive. Mean energy intake during the first two visits was compared to mean energy intake during the last two visits to assess differences resulting from the incentive. Underreporters were identified using a Goldberg cutoff and energy intake <76% of estimated energy expenditure. Energy intake did not differ within or between groups at any time, and the number of underreporters was not associated with group at any time. Overall, the incentive was ineffective in this small, homogeneous sample. Future studies should assess different forms of incentives, other study populations, and the probability of incentives causing undereating.