Reanalysis of “A longitudinal study of meat reduction over time in the UK”

Abstract

Bryant et al.’s longitudinal study investigated causes of meat and animal product reduction. While their study design had important strengths, the analysis had significant problems that preclude interpreting the estimates as causal effects or even as meaningful associations. Our reanalysis of this study resolves the statistical issues by using standard causal inference methods for longitudinal studies. Our findings sometimes corroborated those of Bryant et al., but at other times diverged. In contrast to Bryant et al.’s findings, our analyses indicate that increased motivation to reduce meat consumption is associated with lower actual consumption of animal products. This result diverges from Bryant et al.’s surprising finding that motivation to decrease consumption was associated with increased rather than decreased animal product consumption. Additionally, our results suggest that consuming plant-based alternatives and perhaps also handling raw meat were associated with changes in plant-based dietary behavior and ideation. Several other findings corroborated those in the original analysis. We commend Bryant et al.’s study design and appreciate their exceptional support for our performing this reanalysis.