The present research is intended to offer an early contribution toward exploring the question of motivational undermining in the context of the Make Better Choices trial a study testing intensive lifestyle interventions designed to promote health changes in diet and activity using performance-contingent financial incentives (in addition to coaching and support from mobile technology). Based on the self-determination theory, we hypothesized (H1) that self-reported financial motivation (i.e., motivation derived from performance-contingent financial incentives offered for eating healthy and being physically active) would be negatively related to maintenance of both health behavior change and weight loss (after performance-contingent financial incentives were removed). We further predicted (H2) that financial motivation would be unrelated to initiation of either health behavior change or weight loss.