Factors That Can Affect Ingestive Behaviour: Psychological or Hedonic Factors

Continuing with citations from my article in Obesity Reviews on an aeteological framework for assessing obesity, we now turn to the some of the factors that can affect ingestive behaviour:

Psychological or Hedonic Factors

In contrast to hyperphagia resulting from physical hunger, over‐eating for emotional reward or as a coping strategy is regulated by the hedonic system and has little to do with the body’s real or perceived need for calories. The range of psychological or emotional factors that can initiate and influence eating encompass virtually the entire range of emotional responses including stress, frustration, loneliness, anxiety, anger, disgust, fear, grief, joy, relief, all of which can significantly alter dietary restraint or promote disinhibition. Typically, hedonic hyperphagia is associated with the selection and consumption of highly palatable energy‐dense ‘comfort’ foods, although homeostatic hyperphagia also tends to be associated with the preferential consumption of palatable foods.

In addition to simple ‘emotional’ over‐eating, specific psychiatric conditions that affect food intake or can pose important barriers to maintaining a healthy diet must be considered. Increased appetite is a feature of atypical depression and can be interpreted as ‘self‐medicating’ with food – particularly in cases where these foods affect the serotonergic and reward systems to improve mood. Binge eating, night eating and other abnormal eating behaviours must also be seen in the context of underlying emotional or psychological processes that are distinct from homeostatic ingestive behaviour. Other mental health conditions that can significantly affect eating include attention deficit disorders, post‐traumatic stress syndrome, sleep disorders, chronic pain, anxiety disorders, addictions, seasonal affective disorder and cognitive disorders. Particularly sleep deprivation has been associated with increased appetite and ingestion of highly palatable snacks as well as increased risk for diabetes. Patients with obesity resulting from emotional eating or hedonic hyperphagia are most likely to benefit more from psychological and/or psychiatric interventions rather than simply from dietary counselling.

Commentary: Although for didactic and practical purposes I find it helpful to distinguish between what I have referred to as “homeostatic” vs. “hedonic” hyperphagia, it is important to note that at a physiological level, the distinction between the “homeostatic” and “hedonic” pathways is not as clear cut as is often assumed. In fact, there is close and complex cross talk between these pathways. For example, hunger, a feature of the “homeostatic” pathway, is also a powerful activator of the “hedonic” pathway, thus leading to seeking out and consumption of caloric-dense foods. On the other hand, “hedonic” drivers to eat can override satiety and lead to eating even when not hungry. This, physiology, however, does not take away from the fact that in clinical evaluation, trying to distinguish between homeostatic and hedonistic is often helpful in determining the appropriate treatment path.

@DrSharma
Edmonton, AB