Healthy eating in daily life: the role of relative autonomous motivation when it is difficult

Most people try to eat healthy, but the temptation of unhealthy foods (among other factors) can make it difficult. Despite these difficulties, some people still achieve their healthy eating goals. Following self-determination theory (SDT; Ryan & Deci, 2000), we propose that relative autonomous motivation (RAM) can foster people’s effort in pursuing health goals. In two daily diary studies, we tested the hypothesis that RAM predicts attainment of healthy eating goals, especially when it is difficult. In Study 1, we focused on difficulties associated with trying to eat certain foods while avoiding others, whereas in Study 2, we focused on difficulties associated with the availability of unhealthy and healthy foods. Multilevel analyses provided some support our hypothesis, and highlighted the role of RAM for eating (vs. skipping) lunch and packing a lunch–two approach-based healthy eating strategies. We discuss these findings in relation to SDT and propose directions for future research on within-person changes in motivation and other sources of difficulty. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11031-022-09960-3.