I want to discuss about stress, food addiction and obesity rate. Stress experiences for humans are generally described as emotional/psychological (employment issues, interpersonal conflicts, death of a loved ones, fear of COVID-19) or physiological (sickness, drug withdrawal, food scarcity) and they are generally very challenging. Acute stress is associated with adaptive responses while chronic stress weakens adaptive mechanisms and may lead to disease susceptibility or exacerbate mood disorders such as depression, anxiety, and PTSD. Stress is big disruptor of homeostasis including eating behavior. Human studies have shown that food intake during stressful periods is quite variable – ~40% increase, ~40% decrease and 20% have not change in eating behaviors.1-2
During acute stress, appetite is suppressed through an intricate mechanism of adaptive responses. First, the sympathetic system is activated with the release of adrenaline and noradrenaline by the adrenal gland. Next, the HPA axis is activated with the hypothalamus release of corticotropin-releasing factor (CRF) which will stimulate the pituitary to secrete adrenocorticotropic hormone (ACTH). Then ACTH act as trigger for the adrenal cortex to release glucocorticoids (GC). This mechanism of response to acute stress will mobilize all the body resources to the muscles, heart and brain as and adaptive fight-or-flight response for survival. Competing events such eating, digestion, and reproduction stopped. GCs are important for the regulation of eating behavior molecules such as CRF, neuropeptide Y (NPY), proopiomelanocortin (POMC), and agouti-related peptide. Once the stress triggers are removed, negative feedback from GC will signal the pituitary and hypothalamus to stop releasing ACTH and CRH. This feedback regulation from hypothalamus to adrenal cortex is critical for a healthy stress response and regulation between energy balance and food intake. Chronic stress will impair the HPA axis regulation and may lead to impaired glucose metabolism, promote insulin resistance, stimulate appetite and fat storage by influencing hypothalamic neuropetides.1
In addition, constant activation of body’s stress response mechanisms interferes with the reward/motivation brain’s pathways leading to wanting palatable/comforting food without metabolic need that lead to obesity. Food addiction is frequently overlooked because the addictive properties of processed foods is the only aspect considered for many clinicians. Stress management of patients is very important in any treatment consideration for obesity.1
- Yau YHC, Potenza MN. Stress and Eating Behaviors. Minerva endocrinologica. 2013;38(3):255-267.
- Sominsky L, Spencer SJ. Eating behavior and stress: a pathway to obesity. Frontiers in Psychology. 2014;5:434. doi:10.3389/fpsyg.2014.00434.