Weight-Focused Physical Activity Is Associated with Poorer Eating Motivation Quality and Lower Intuitive Eating in Women

Background

Evidence suggests that physical activity may be related to improved eating regulation, helping people self-regulate their eating in a healthier way. Yet the positive associations between physical activity and eating-related behaviors appear to depend on the goals pursued by individuals when they engage in physical activity.

Objective

This study investigated differences in eating motivations (informed by Self-Determination Theory) and intuitive eating between women who did physical activity to lose weight (PA-Wt) vs for non-weight goals (PA-NWt), and explores whether eating motivations mediate associations between weight-focused physical activity and intuitive eating.

Design/participants

A sample of 1,435 physically active women (40 to 50 years) participated in a nationally representative survey conducted in 2009 in New Zealand. Women were asked whether they did physical activity predominantly to lose weight and were dichotomized into PA-Wt and PA-NWt groups.

Main outcome measures

Questions assessing eating in response to hunger and satiety cues (intuitive eating) and eating-related motivations were completed by participants.

Statistical analyses

Analyses of covariance, t tests, correlations, and mediation analyses were conducted to test the study hypotheses.

Results

PA-Wt participants reported lower levels of intuitive eating than did PA-NWt (0.26<Cohen’s effect size d<2.38; all, P<0.001), and higher levels of both autonomous (0.16<d< 0.41; P<0.010) and controlled eating motivations (introjected: d=0.60, P<0.001; external: d=0.24; P<0.001). Associations between PA-Wt and intuitive eating were mediated by introjected motivation (effect ratios=0.18 to 0.29), and less prominently by intrinsic and integrated motivation.

Conclusions

Whether women are active to lose weight or for other reasons seems important when it comes to regulating their eating: weight-focused physical activity appears to be linked to higher eating motivation (ie, quantity), while the presence of poorer-quality motivation (ie, introjected motivation) is related to a less intuitive eating style.