Anxiety can send the human body into fight or flight mode, which enables a person to manage perceived threat. During fight or flight mode, various changes occur to the gastrointestinal system, as digestion becomes suppressed, elimination is quickened, and the stomach stops breaking down food. These responses are helpful if a person is truly in jeopardy, but can become problematic when the stress response is employed too frequently. When a person is experiencing prolonged anxiety, stomach and digestive issues can arise, including changes in appetite. Some people may experience an increase in hunger and cravings and will engage in binge eating behaviors. Other people may experience a decrease in appetite, although this is usually less common.
Loss of appetite is a symptom of stress and is never a presenting problem. Feelings of worry can distract a person from feeling hunger and bodily sensations can prompt nausea or stomach upset. Physical responses can also interfere with a person’s ability to correctly assess when they are hungry. A lack of appetite can be fleeting, can vary in intensity, and can change throughout the day.
It is hypothesized that a combination of factors causes a loss of appetite in relation to anxiety. Cortisol, stomach acid, hormones, neurotransmitters, and emotional factors are all deemed to be contributors to loss of appetite.
During heightened moments of anxiety, some individuals lose their appetite due to elevated levels of cortisol, the body’s stress hormone. Increased cortisol can boost the production of stomach acids, which speeds up digestion and creates a sensation of fullness. This sensation halts signals to the brain that initiate hunger. Increased acid production can also result in the formation of stomach ulcers.
Several hormones and neurotransmitters in the brain are correlated with emotion and hunger. Individuals with anxiety often have irregular levels of the neurotransmitter serotonin. Serotonin impacts feelings of fullness and controls the intensity of anxiety. If serotonin levels are unbalanced, anxiety and appetite can become irregular. Hormones and neurotransmitters can impact communication with the brain, as the brain may be alerted that the body does not need to eat when in fact it does.
Emotional factors can play an important role in a person’s loss of appetite. Eating may not be the main focus when a person is worried about other things. If a person ignores the brain’s hunger messages, the body may eventually stop transmitting them.
Appetite loss can have a negative impact on the body and on a person’s functioning. A lack of appetite can deprive the body of important nutrients, thus harmfully impacting a person’s energy levels, sleep patterns, heart rate, metabolism, and immune system. Fatigue and lack of energy can result if a person does not ingest the appropriate amounts of vitamins and minerals. These symptoms can put the body at a disadvantage in coping with stress and reducing anxiety.
A person experiencing a lack of appetite in response to anxiety can utilize behavioral interventions to increase food intake. A person can set an alarm to go off during mealtimes as a reminder to eat. An individual can also eat several small meals per day instead of ingesting larger meals.
While the fight or flight mode is necessary during moments of danger, it can be debilitating if employed too frequently in response to anxiety and stress. The stress response causes changes to a person’s digestive system, which impacts a person’s appetite. A decrease in appetite is believed to be caused by a variety of factors. Appetite loss can have an overall negative impact on the body and on a person’s level of anxiety. Behavioral interventions can assist a person to monitor their food intake during times of stress.