Mental health and eating behaviours: a bi-directional relation.

BACKGROUND: Variations in mental health may contribute to or impair healthy eating. The relation between eating and mental health is bi-directional: one's mood or psychological state can affect what and how much one eats, and eating affects one's mood and psychological well-being. Thus, if we want to promote and develop strategies to encourage healthy eating, it is important to understand the connections between mental health and healthy eating.
METHODS: To contribute to this understanding, we examine the research on individual differences in how people respond to food, as well as mood, and emotional, social and collective influences on what and how much is eaten; we then examine the implications of these connections for mental health, with a focus on adolescents and adults. Looking at the relation between eating and mental health from the other direction, we review research investigating whether the amount that one eats or particular foods one ingests can make one feel good or bad about oneself.
CONCLUSIONS: Overeating and undereating have complex effects, sometimes contributing to improved feelings of well-being and at other times leaving the individual feeling guilty, deprived, depressed and anxious. We attempt to identify both what we know and the gaps in our knowledge.