Food and Stress-How Does Diet Affect Stress?
Stress is well known to trigger changes in eating behaviors, often increasing appetite for unhealthy “comfort” foods like those high in sugar and fat.212 One reason may be that stress alters levels of appetite-regulating hormones, ghrelin and leptin, producing more hunger signaling.213 Although not everyone eats more in response to stress (about 40% of individuals eat more, 40% eat less, and 20% eat the same number of calories when under stress), a stress-induced rise in preference for high-sugar foods has been consistently observed and may be partly due to a dampening effect of sugar on the stress response.214-217 Compounding the problem, stress appears to increase susceptibility to diet-related metabolic disturbances like abdominal obesity and insulin resistance.218
Countering stress-related appetite changes and food cravings is challenging; however, eating a healthy diet may be even more important during times of stress. Healthy eating habits can help ensure adequate intake of vitamins, minerals, protein, complex carbohydrates, anti-inflammatory fats, fiber, and phytochemicals needed to combat the negative health effects of chronic stress and interrupt the cycle of stress and stress-related behaviors.219,220
Eat More Fruits and Vegetables
Increasing fruit and vegetable intake can help combat stress. A study in young adults showed that increasing fruit and vegetable intake by two servings per day for two weeks resulted in enhanced psychological well-being, vitality, flourishing, and motivation.221 A Mediterranean-style diet, which emphasizes olive oil, whole grains, fruits, vegetables, fish, and nuts and seeds, may improve the stress response and has been associated with better regulation of HPA axis activity. This dietary pattern may also mitigate the effects of stress by reducing systemic inflammation and the risk of many chronic health problems.222-224
Eat Breakfast Regularly
Eating breakfast may help build stress resilience. Compared to breakfast skipping, habitual breakfast eating was associated with lower levels of perceived stress, better cognitive function, and fewer job injuries and accidents in a study that included more than 800 nurses.225 In another study in 65 female participants, habitual breakfast skippers had blunted diurnal cortisol variation, increased overall cortisol output, and higher blood pressure compared with habitual breakfast eaters, suggesting a morning meal may be important for maintaining normal circadian regulation of the HPA axis.226
Minimize Caffeine and Alcohol Intake
Caffeine may seem attractive to those affected by stress-related fatigue, but its effects may aggravate symptoms such as anxiety and poor sleep in susceptible people.227,228 Caffeine stimulates the sympathetic nervous system, and in this way may activate the stress response.229 Even with daily consumption, its intake can raise cortisol levels and has been found to increase the cortisol response to mental stress230,231 and prolong the effects of physical stress on heart rate and blood pressure.232 In one study, habitual coffee drinking was associated with greater increases in heart rate and vascular inflammation in response to mental stress.233 On the other hand, drinking coffee appears to promote healthy metabolism and may protect against type 2 diabetes, liver cancer, and cognitive decline.234 While sensitive individuals may fare better eliminating caffeine during times of stress, moderate intake may be reasonable for others.227
Alcohol is often used as a relaxant during times of stress235,236; however, excessive intake raises cortisol levels and long-term use leads to dysregulated HPA axis signaling and disrupts the normal function of the stress response.237-239 Individuals experiencing stress-related insomnia frequently turn to alcohol as a form of self-medication, but because alcohol erodes sleep quality and quantity, it may actually exacerbate sleep difficulties.240 In addition, because people experiencing intense life stress or with a history of early life stress are more vulnerable to developing problematic drinking habits,239,241 it is especially important to avoid stress-related alcohol use.