Some restrictive dietary patterns (paleo, vegan) are linked to more positive psychological health; seems that psychological risk factors seen in weight loss dieters are not due to the restrictive dietary regimen

The psychological characteristics of people consuming vegetarian, vegan, paleo, gluten free and weight loss dietary patterns. R. Norwood, T. Cruwys, V. S. Chachay, J. Sheffield. Obesity Science & Practice, https://doi.org/10.1002/osp4.325

Summary
Objective: Previous research has identified several psychological factors associated with dietary restriction, but has focused almost exclusively on the subcategory of people following a weight loss diet. Little is known about the psychological factors associated with other kinds of restrictive dieting patterns. Furthermore, it remains unclear whether the identified psychological characteristics of dieters (e.g., elevated disordered eating behaviors, poor wellbeing) are a cause of dieting, follow from calorie restriction, or are the result of cognitive restraint.

Methods: This study conducted the first direct comparison of people (N = 393) following five different restrictive dietary patterns (vegetarian, vegan, gluten free, paleo, weight loss) as well as a comparison group who were not following a specific dietary pattern.

Results: The weight loss group had more negative psychological characteristics than all other groups, reporting the highest levels of eating disorder symptoms (M = 1.50), food cravings (M = 69.39), emotional eating (M = 2.97), and negative affect (M = 19.72). By contrast, several of the other restrictive dietary groups showed a number of psychological strengths, relative to the comparison group. This was particularly apparent among the paleo group, who reported the lowest levels of eating disorder symptoms (M = 0.74), food cravings (M = 47.63), emotional eating (M = 2.30), and negative affect (M = 14.81). By contrast, people following vegetarian and gluten free diets were largely the same as the non‐restricted comparison group in their psychological characteristics.

Conclusions: People adhering to different dietary patterns showed stark differences in their psychological characteristics. Indeed, some restrictive dietary patterns (paleo; vegan) were associated with more positive psychological characteristics than seen in an unrestricted comparison group. This suggests that the psychological risk factors seen in weight loss dieters are not attributable to a restrictive dietary regimen per se.