Cognitive evaluations of water, urges to drink, and fluid intake in patients with kidney stones.

Increasing fluid intake is a core recommendation for reducing risk of kidney stone recurrence. Thirst is often insufficient to motivate the volume of intake recommended to reduce risk, so this study examined cognitive and affective processes that support fluid intake (water and flavored beverages). Patients (N=230) with a history of kidney stones identified from medical records were recruited to complete an online survey. Participants who associated unflavored water with favorable bodily consequences and positive hedonic experiences were likely to have stronger non-thirst-related urges to drink unflavored water, and those who associated unflavored water with negative hedonic experiences were likely to have stronger non-thirst-related urges to drink flavored drinks. Non-thirst-related urges to drink unflavored water were positively associated with water intake volume, but non-thirst-related urges to drink flavored drinks were negatively associated with water intake volume. These findings establish the importance of affective processing as a target for promoting fluid intake in cases where thirst is not sufficient.