Positive Mental Health and Meat Consumption: A Systematic and Meta-Analytic Review

In this systematic and meta-analytic review, we examined the current evidence on positive psychological variables between individuals who consumed meat and individuals who abstained from meat consumption. After systematically searching five online databases for primary research on positive psychological outcomes in meat consumers and meat abstainers, 19 studies with 94,204 participants (nmeat consumers = 82,449, nmeat abstainers = 9,964) met the inclusion/exclusion criteria. The primary outcomes were self-esteem, satisfaction with life, and positive mental health. The secondary outcomes were positive affect, psychological well-being, vigor, optimism, happiness, and meaning in life. Individuals who consumed meat had greater positive mental health (g = 0.21, 95% CI [0.08, 0.31], p = .001) than meat abstainers. No significant differences were found between the groups on self-esteem (g = 0.19, 95% CI [-0.01, 0.38], p = .06) and satisfaction with life (g = 0.02, 95% CI [-0.04, 0.07], p = .57). The majority of studies examining the secondary outcomes showed no group differences. The evidence was limited, requiring more studies to determine the role of study quality in diet-health relations. Study designs precluded inference of causal and temporal relations. With respect to clinical practice, our findings add to the current controversial diet-health debate.