Chronic stress and obesity: A new view of “comfort food”

Abstract

The effects of adrenal corticosteroids on subsequent adrenocorticotropin secretion are complex. Acutely (within hours), glucocorticoids (GCs) directly inhibit further activity in the hypothalamopituitary-adrenal axis, but the chronic actions (across days) of these steroids on brain are directly excitatory. Chronically high concentrations of GCs act in three ways that are functionally congruent. (i) GCs increase the expression of corticotropin-releasing factor (CRF) mRNA in the central nucleus of the amygdala, a critical node in the emotional brain. CRF enables recruitment of a chronic stress-response network. (ii) GCs increase the salience of pleasurable or compulsive activities (ingesting sucrose, fat, and drugs, or wheel-running). This motivates ingestion of ''comfort food.'' (iii) GCs act systemically to increase abdominal fat depots. This allows an increased signal of abdominal energy stores to inhibit catecholamines in the brainstem and CRF expression in hypothalamic neurons regulating adrenocorticotropin. Chronic stress, together with high GC concentrations, usually decreases body weight gain in rats; by contrast, in stressed or depressed humans chronic stress induces either increased comfort food intake and body weight gain or decreased intake and body weight loss. Comfort food ingestion that produces abdominal obesity, decreases CRF mRNA in the hypothalamus of rats. Depressed people who overeat have decreased cerebrospinal CRF, catecholamine concentrations, and hypothalamo-pituitary-adrenal activity. We propose that people eat comfort food in an attempt to reduce the activity in the chronic stress-response network with its attendant anxiety. These mechanisms, determined in rats, may explain some of the epidemic of obesity occurring in our society.corticotropin-releasing factor ͉ glucocorticoids ͉ high fat ͉ sucrose ͉ motivation O ur understanding of regulation of function in the hypothalamo-pituitary-adrenal (HPA) axis has changed profoundly in the last decades. The discovery of functions of the distributed cell groups of corticotropin-releasing factor (CRF) neurons, the motor neurons for activation of the pituitary and adrenal, as well as the tight interrelationships between calories, body weight, energy stores, and the HPA axis have occasioned revisions in our thinking. The upshot is a new working model, the output of which is modifiable through manipulation of caloric input (Fig. 1). The long-term consequences of such output modification in chronically stressed individuals may include deleterious weight gain, abdominal obesity, type II diabetes, increased cardiovascular morbidity, and mortality. We arrived at this model through interpretation of the results from studies on manipulation of energy balance, central CRF, and the effects of acute and chronic stress and glucocorticoid (GC) treatment in intact and adrenalectomized rats. GC Effects on HPA Function: Acute and ChronicCanonical GC-feedback inhibition of subsequent adrenocorticotropin (ACTH) secretion is easily demonstrated acutely, within the fi...

The role of the posterior medial bed nucleus of the stria terminalis in modulating hypothalamic–pituitary–adrenocortical axis responsiveness to acute and chronic stress

“…Possible regulators of chronic stress adaptation include regions such as the locus coeruleus, which exhibits enhanced norepinephrine sympathetic capacity following chronic stress (Pardon et al, 2003;Ziegler et al, 1999), and the posterior paraventricular thalamus, which appears to be responsible for chronic stress habituation of the HPA axis (Bhatnagar et al, 2000). In addition, there are data to support the existence of a general, CRH-driven network that can modulate responsiveness to repeated stimuli (Dallman et al, 2003).…”

A systematic review and meta-analysis on the effects of yoga on weight-related outcomes

“…Beyond exercise, yoga can also encompass yogic dietary advice; as well as relaxation, meditation, breath control and positive thinking. Thus, yoga has been shown to effectively decrease chronic depression (Cramer et al, 2013c) and stress (Chong et al, 2011); which might in turn reduce emotional overeating and resulting overweight (Dallman et al, 2003). This way, yoga interventions target both, physical and emotional maintaining factors of obesity.…”

Duration of U.S. stay and body mass index among Latino and Asian immigrants: A test of theoretical pathways

“…The physical impact of stressors may reflect coping patterns, the physiological accumulation of psychosocial stressors (i.e., 'wear and tear' on the body), or the indirect consequences of regularly confronting barriers to health-promoting factors, such as appropriate employment or adequate medical care (Williams et al, 2010). Stress is associated with obesity (Dallman et al, 2003), with at least one of the mechanisms being chronic inflammation in the body (Fuligni et al, 2009;Robles et al, 2005).…”