According to research, fasting may affect a person’s mood and mental health. However, studies have reached conflicting conclusions as to whether it worsens or improves depressive symptoms.

Fasting refers to the practice of not eating, or eating extremely little, over a period of time. A person may fast either for religious and cultural reasons or with the aim of managing weight and improving overall health.

Some research has shown that fasting can increase feelings of sadness, suggesting that it may worsen depression symptoms.

However, other studies have shown that fasting may reduce symptoms of depression. Despite this, doctors do not routinely recommend fasting as a treatment for depression.

This article will cover whether fasting may trigger depression, how fasting can affect a person’s mental health, and what possible effects — both positive and negative — fasting may produce.

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Research into the effects of fasting on depression shows mixed results.

A small 2018 study looked at mood changes that occurred after a 72-hour fast in 15 healthy women compared with women of the same age who had not fasted. The researchers found that those who had fasted experienced an increase in sadness, difficulty making decisions, and self-blaming.

The study also used MRI scans to analyze how fasting affected the brain. Researchers noted that there was decreased activity in the same brain receptors that are underactive in people with major depressive disorder (MDD).

Conversely, a 2021 literature review found that there were several neurobiological mechanisms involved during a fast that could improve depressive symptoms.

A larger 2022 study that focused on people with MDD also investigated the use of fasting for depression. It found that fasting led to a reduction in symptoms in people experiencing moderate to severe depression.

Fasting can lead to many changes throughout the body, some of which may affect a person’s mood and mental health.

A 2022 paper notes that short-term fasting has been linked to an increase in depression, anxiety, irritability, and tension. It also stated that some studies found an increase in positive mood after fasting. Participants experienced feelings of pride, reward, and achievement.

These conflicting results suggest that the effects of a fast can vary from person to person.

The researchers developed various theories for why people may react differently to fasting. They include:

  • religious or spiritual beliefs that make fasting a more positive experience
  • the emotional level of self-control required to fast
  • feelings of success after completing a fast
  • a previous fasting experience leading to more positive mood changes

While some research suggests that fasting can bring both physical and mental health benefits, there are also associated risks. Some people may experience increases in:

  • depression
  • anxiety
  • irritability
  • anger
  • tension

During a fast, a person may also experience physical side effects, such as:

Some research suggests that fasting may have a positive impact on a person’s mood.

A 2021 study found that fasting may help reduce anxiety and depression without increasing fatigue. However, more research is needed to confirm these findings.

Some studies show that fasting for religious reasons can have positive effects on a person’s mental health. Many of these have been done on Muslim populations fasting during Ramadan, the ninth month of the Islamic calendar.

A 2018 study of people fasting during Ramadan found that participants reported lower levels of depression, anxiety, and stress after fasting. However, some of these benefits are likely tied to the community and cultural traditions that take place during the month of Ramadan.

Some research also suggests that fasting can also have benefits for a person’s physical health. It may aid in weight loss and reduce cholesterol levels.

A 2019 study suggests that eating more calories early in the day and having regular fasting periods may provide further physiological benefits, such as:

  • higher energy levels
  • better sleep pattern
  • lower inflammation
  • increased autophagy, which is the process of removing damaged cells

However, the authors of the study acknowledge that this pattern of caloric intake and fasting may not be feasible for some people.

A person should speak with a doctor about what they would like to achieve by fasting so they can discuss whether that is the safest and healthiest option for them.

Fasting may affect each person differently, depending on their physical and mental health. For example, if a person has a health condition such as diabetes, they should speak with a doctor about how fasting may affect their condition.

If a person has a history of eating disorders or other mental health conditions, it is best to work with a doctor to understand the associated risks. Fasting may not be a safe choice for them.

Fasting is a practice that involves not eating, or eating significantly less, for a period of time. Research has found that while this can lead to feelings of pride, accomplishment, and overall improvements in mood, it may also lead to an increase in depressive symptoms for some.

The conflicting results in research show that each person’s mood may respond differently to fasting.

A person should speak to a doctor about their interest in fasting and how best to perform it in a safe and healthy way.