Fasting and the Effects on Mental Health

The following blog is a research piece that I, Paige, submitted as a part of my Advanced Scientific Nutrition Certificate in 2020.


Fasting is a type of nutritional, life style change where you restrict the hours that you eat, and the hours that you don’t. Often called intermittent fasting, where you have strict hours of when you are fasting. The purpose of fasting is to not suffer or cause stress but originally to guard against impure thoughts and words, due to Fasting being established by religion. The purpose of fasting now has been adjusted to the modern world and can be used for weight loss, weight gain, and general health support to regenerate cells and adapt the body to stress. In this paper I will be looking into the effects of Fasting on a persons mental health, due to personally working with these symptoms and some people deeming it to be more harmful to the mind than beneficial, as it was built for.


The types of different Fasting regimes that you can implement into your lifestyle is; 16-8 method where you eat for 8 hours and fast for the remaining 16. Or the 5/2 method where you eat normally for 5 days of the week and you fast the other two. And there is the 6-1 method similar to the 5-2 method. And the simple 24 hour fast, recommended to do twice per week. Although these are intermittent Fasting commonly talked about, you can integrate fasting to fit your lifestyle. Originally in religion the Fasting is for a month or weeks, where you fast from dawn to dusk. Normally we fast for 8-12 hours when sleeping, regardless.


In terms of addressing Fasting in religions for many years Ramadan Fasting has been used to purify the soul and body.  And just in recent years many studies have looked into evaluating the effects of fasting, not just mentally but physical effects within the body too. Ramadan Fasting is an islamic ritual  important to muslims. It has been reported that people with religious beliefs have a higher level of mental health than others who may not. Having a faith in God can reduce the amount of stress, this can be a conflicting factor when looking into the effects of fasting on mental health in religions. However it cannot be ignored that Ramadan fasting is an impact on self-esteem and mental health with decreases in insignia, anxiety, social impairment and depression when in Ramadan. The reasons behind Ramadan is to encourage people to feel physical and emotional stress to lead to a sense of self love and control.


Firstly, what exactly does Fasting do to the body and brain? Fasting supports the release of a hormone, ghrelin, that tricks your body into thinking you are not hungry. Fasting can help support the body systems to cleanse the body of bacteria, viruses, and dead or deteriorated cells, damaged cells and proteins to improve autophagy. It’s an internal clean to help keep you energised and clear headed. Your body’s cells that regenerate every 120 days, after Fasting will now come through disease-fighting effects to boost the immune system. They will also be strengthened for you to experience less anxiety and depression to feel happier, sleep more and learn faster.


When we enter fasting regime we go through a series of phases, firstly the glycogen stores in the liver are used first to sustain the body’s energy needs. Once this has been used the body switches to using stored fats, this time of switching fuels can vary between 12 - 16 hours for people. In this there is a difference in the way each person may benefit from Fasting. During fasting we go through a self-cleansing process where damaged and dangerous parts of cells are repaired or removed. This is autophagy.


The effects of Fasting on your mood can be where you get ‘hangry’, an anger that comes from a the stomach being empty; it is very possible that your moods will take a shift when fasting. The reasons that we may feel cranky? This is because the blood sugar levels are dropping and your cortisol levels are rising, the stress hormone. This can then make you more anxious and the mere cortisol running through your body can make you feel stressed overall; this can then lead to weight gain as high cortisol can be linked to the storage of fats. However, Fasting can improve the quality of sleep and therefore make it easier for you to handle stress, adjust to it and improve overall tolerance. Simply? The stress caused from Fasting can effectively allow your body to adjust to the stress and improve tolerance to stress too. But there may be a storm before the balance within your nutritional lifestyle.


Fasting has been found to be the quickest way to improve your overall health but there is the need for consistency in finding the right fasting schedule for you. The more that you stick to a fasting schedule, the more that your brain learns when it is actually hungry and when it is not. Overeating can effectively slow your mind and body down due to the overwhelming amount of calories to digest in the body. When we constantly eat or just overeat, we exhaust our digestive systems and effectively exhaust ourselves through the pressure. Due to full digestion taking up to 2 and a half hours from the last solid being swallowed.


It is important to note that fasting with its strict rules can trigger more complications for someone who has eating disorders.  Ignoring the signs of hungry or constantly emptying the stomach is the underling basics to eating disorders, and so fasting has been found to make conditions worsen.  Eating disorders are listed under the DSM as mental health disorders. Introducing this as a diet can cause loss of control and overeating, being apart of binge eating disorder. One study found that 70 percent of the time over 4 weeks was spent having eating-related thoughts, increased fear, and frequency to overeat. The risk of bulimia and binge eating may be increased, and so, understanding a person’s mental relation to food and mentally overall is important.


When Fasting the brain adjusts the neurotransmitting speeds and accessibilities of neutrons and communications within the brain. What this can mean is that by restricting foods it may increase your serotonin level, and may also cause less of the feel good chemical in the brain and cause mental health issues. However, this is a conflict in other studies finding that the serotonin levels can increase in certain areas, importantly in strengthening learning and memory areas. Conflict in data can be down to the mental health sensitivities of the person. It may be interesting to note that taking into account the stress within a persons lifestyle, Homelife and worklife before Fasting.


What affects does fasting have on our memory and learning? During fasting the regulation of growth factors is increased where synaptic plasticity can occur and improve our learning, memory and cognition. A lot of diseases or illnesses related to memory such as dementia is due to poor glucose, insulin resistance and metabolic syndrome; all of which Fasting can support healthy factors of. Fasting can improve the blood glucose control and sensitivity to insulin in supporting cognitive decline.


Fasting has been found to act as an antidepressant by reducing moods and anxiety. This can be due to the fasting reducing inflammation, the support of microbiome in support the gut health and the brain and gut links. As more and more research is coming out to support the evidence that the mind and body are not two seperate entities but are a direct link to each other.


Dopamine is our ‘be happy’ hormone that helps to support positive behaviours within ourselves and give us a better balance in our lives by reducing stress. Studies have shown a link to dopamine health and fasting. Built around the premise of stimulus control. This is where you limit the time you have in a certain activity to provide structure and reduce impulsive behaviour. Using these studies it has been found that by entering Fasting this gives a person back control, reduces impulses and to leads up to a point that people can appreciate their foods more. There is caution around eating behaviours causing distress to some mental health illnesses and lack of food can cause impairment in decision making; giving this reason to the reduced impulse control. In saying this, research has shown that even small fasts of 2 - 3 hours can be enough to stress the body and increase dopamine for better mental health outcomes.


The HPA axis, Hypothalamus, Pituitary and Adrenal activation is important when considering fasting and mental health together. These help with the neurotransmission of serotonin and noradrenaline, which need to be increased in those with depression or similar negative thought patterns and behaviour illnesses. Research has shown that by fasting over 8 days or more can cause activation of the HPA functions and reduce glucose and decrease leptin levels, this is a response to the starvation processes and can be linked to mood disorders. Although it can be shown that leptin level changes when Fasting can induce improvement in depression, this is due to the stress adaptation affect on leptin levels. However, this can be different in the genders as a fast decline can cause depressive like behaviours in men, but with women, some studies show no significance to depression and leptin levels. Overall it is known that high leptin levels can be linked to poor mental health behaviours and illnesses, so in using fasting it can be important to watch the intensity of the fast and stress adaptation tolerance in different individuals.


When working with mental health it is important to understand the person’s behavioural and mood mechanisms in underlying depression conditions. All diet changes and adjustments will have effect on the neurotransmitting in the brain and whether this is positive or negative underlies to the person’s make up. Whether something can be taken for the long term or short term can depend on the person as well. There may be a threshold to what a person can handle and when drastic measures need to be reduced to a more normal state. Such as fasting for days on end to maintaining a 5:2 fasting regime when mood or mental state is reached.


Calorie restriction effects have been studied more and more with the neuroendocrine system and mood conditions, due to the stress response the body takes on. Restrictions can cause neural cellular signalling to increase in improving stress responses and metabolism. Yet, research has proven that fasting and calorie restriction can relieve negative moods and enhance euphoria like feelings. It has also been noted that it can reduce depressive symptoms when sustained for 6 months of more with no negative effects on mood, although no major positive either.


So what is the difference between calorie restriction and fasting - is it the same? Do they have the same effects on mood, or should we focus on one more than the other?


With calorie restriction a person may still be eating their usual; 10 hours of fasting and 14 of eating, just with decreased calorie intake. When a person is utilising their digestive system and eating every couple of hours, there is no significant stress adaptation needed compared to that of Fasting. The digestive system will still be exercised. When Fasting the digestive system stops for a significant period and causing the body and brain to stress adapt and increase tolerance, as well as using extra resources.


In terms of looking at those who fast under religion compared to those who fast outside of religion can have significant different impacts on mental health. Due to the strong positive relationship between region and mental health overall. But results cannot be ignored with Fasting showing improved social abilities and mental health, reduced insomnia and anxiety. Studies that have focused on fasting with religious people and non-religious people, non-religious resulted in no impact on suicidal tendencies but those with religious practises and fasting did.


Through my own case studies working with three participants for a ranges of issues, I found fasting to be effective in all, in terms of reducing symptoms. But it again, like the research and studies discussed, mental health is important to take into consideration. One participant was for inflammation reduction with anxiety and depression, another was to improve type 2 diabetes symptoms, and the last case study was working with through an eating disorder for lack of food.


Through the case study who wanted to reduce inflammation, I found that mentally they began to feel more in control, more energy, but did struggle to motivate self to stick with the fasting regime and move past the hunger side of fasting. This made the case study feel down on self for feeling as though they were failing due to being unable to reach fasting hours set out. It was explained that this was a guideline and the way I work through fasting with a client is to find their threshold, and balance that they can maintain. There was mixed messages and feelings within this client’s mental state, with control given but frustration of feeling as though they were failing which lead to stages of depressive let downs. But the success was in that symptoms of pain was reduced significantly. Going forward, the client and I have found a regime that works with the her lifestyle so that she can maintain reduced inflammation pain and be happy with the Fasting hours set.


When working with a person who has Type Two Diabetes it was important to work alongside a medical professional too. My case study and I had a nurse that she could work with who supported the fasting regime we would put out for her to follow. The plan was adjusted every 3 - 4 weeks. We slowly built up to two 24 hour fasts per week, with 18-6 ratio of fasting on other days. This worked wonders, this client was able to drop 10 kgs, and reduced her blood sugar levels to a normal range. At the same time, this client was experiencing quite difficult lifestyle stresses, but found the fasting to have no positive or negative impact on her mental health processing. But she was feeling more energised and more in control of her diabetes, which had a positive impact on her overall wellbeing.


With the case study that had an eating disorder where they would not eat anything at all for months at a time. When this person came to me they had not eaten for 9 months. When this person was not eating they felt like they could control something and people noticed that they were skinner, and this made them feel pretty. Due to eating disorders impacts wellbeing and being a reflection of behaviours - they are deemed as a mental health disorders. As some research has stated that Fasting can impact mental health positively and negatively, in terms of some cases can lead to disorders such as anorexia or similar illnesses. So using Fasting as a regime with this client was very different and needed to be monitored every day. I used Fasting in reverse for this client. As not eating made her feel like she had control, I gave her hours in which she would eat. We reversed the psychology to be where instead of not eating for some many hours or days or in this case months, she would eat between the hours of 4 -6 pm. And each week when she felt comfortable we would increase this window or intermittent sections of eating hours. Not only did working this way for 12 weeks increase her eating and nutrition, but she no longer had headaches, stomach pain or chronic fatigue.


Would I recommend fasting to help mental health, or recommend it those who struggle with mental health disorders? Honestly, I personally believe that we can learn a lot from religions who fast on a regular basis and learn a better sense of wellbeing within our body’s and our mind’s. Whether this is for everyone and everyone should implement Fasting? No, but I do think that sensible fasting can be very beneficial to individuals, whether or not they have mental health disorders or are sensitive to them. It is in the practise that you are bettering yourself, your wellbeing and learning the functionings of your body that is the important benefit. Yes, there is threshold to each person and not one person can fast the same as another. I think working with a professional to find the right fasting regime for you is important to the success of the fasting and the care of your mental health. Whether your priority is in illness reduction, inflammation reduction or better health - when the outcome is reached it is important to find a balance in sustaining a regime for you; that can become a habit. I would suggest that each person starts with a small fast and slowly lead up to a fasting routine that works with life balance, and the strength in the body’s functioning. Regardless of whether you want to be able to do week long or month long fast, I think this would be the best approach to see how your body reacts under stress. Fasting does have an impact on mental health, but it is also a stress that we can adapt to; whether these affects are negative or positive is all in the approach to Fasting you and your professional have.



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1 comment

  • Stunning article Paigie! Congratulations on taking your incredible learnings/talents/education to another level❤️


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