In today’s developed world food is all around us, available at every corner it seems. We are told so many contradictory things – from eating three square meals a day (possibly with snacks in between) or six small meals a day, and that eating meals in these particular ways will impose different effects on our body. So where does fasting come into play? Well, let’s start with what happens when we eat.
Following a meal, our insulin levels rise in response to the delivery of glucose into the blood. This happens to some extent whatever we eat, however, the higher the carbohydrate or sugar content in your meal, the higher the level of glucose in your blood and the more insulin required to remove it and push it into our cells as energy. More than 1 teaspoon of glucose in the blood becomes toxic and therefore keeping levels low is important. When the cells are full the remaining glucose is either stored in the muscles and liver as glycogen (ready for when we need more energy to be released to the cells) or stored in the fat cells, ostensibly for later use but this becomes more difficult to access the more often we eat. When we are eating every few hours this becomes a continual cycle, not allowing much time in between the constant digestive processes. And when we are relying on a constant supply of glucose as our main energy source, then we are never tapping into our stored fat for energy.
When insulin levels are low we are able to release another hormone called Human Growth Hormone (HGH) and this helps our body to grow, repair and heal – it also helps to increase our metabolism. In fact, studies have shown that after fasting for 24 hours metabolism can increase in women by up to 1300% and in men up to 2000%! We typically think of HGH being released during the night (and helping us to repair and build stronger muscles after workouts) and this is because our insulin level is low due to being in a fasted state (unless you regularly get up and raid the fridge at night!). Cell regeneration, (autophagy) also takes place when we are not eating and our digestive system is having a well-earned rest. Autophagy literally means “self-eating” and is our body’s natural way of detoxing and renewing itself. It is an essential process in order to maintain cellular function, and it does this by breaking down damaged cells, organelles and mitochondria (the cell’s energy powerhouse) and creating new ones. Healthy components from damaged cells are used wherever possible and the rest is recycled as energy.
Periods of not eating, or intermittent fasting, can also help to rebalance hormones such as grehlin and leptin (our hunger and satiety hormones), allowing them to work more efficiently. Our sensitivity to insulin improves, promoting a reversal for those with insulin resistance. Insulin sensitivity is also related to the mTOR pathway (mechanistic target of rapamycin), which plays a role in cellular metabolism, energy balance, muscle building and rejuventation. Fasting down-regulates the mTOR pathway, allowing for the body to engage in the autophagy process. This decreases inflammation, offering protection against cardiovascular disease, Type 2 Diabetes, obesity, cancer and other chronic diseases and increasing longevity. During the eating, or feasting window the mTOR pathway is up-regulated, contributing to muscle building, increased cell working capacity and increased ATP (energy) production.
Fasting can also increase levels of brain derived neurotrophic factor (BDNF), a protein which plays an important role in neuroplasticity, helping the brain develop new connections and encouraging the growth, regeneration and creation of new neurons and synapses and protecting existing ones. In animal studies BDNF has been shown to increase energy metabolism in obese, diabetic animals and to lower body weight and suppress appetite. In humans, an increase in fat leads to lowered blood BDNF. Low levels can result in depression and anxiety. High levels of BDNF results in better mood, increased memory retention and an improved ability for learning. Increasing BDNF is also reputed to help diseases such as Alzheimers, Parkinson’s and Huntingdon’s Disease.
Intermittent fasting has been a normal part of life for humans since the Paleolithic era at least. Early homosapiens would have encountered times of scarcity resulting in periods of not eating, followed by periods of feasting after they had hunted and killed an animal and/or foraged for roots and tubers. Arguably our DNA is still primed for this type of eating pattern. Religious fasting practices, such as Ramadan or Lent, have also been a part of our history, and continue today, used as deliberate ways to “cleanse” the body and mind.
There are several ways to fast:
- A period of time during 24 hours of no eating followed by a window of eating (eg; 12/12 – which would be a fairly normal sleeping/waking pattern; or 16/8, thereby extending the fasting period upon waking)
- A set numbers of days of normal eating with interspersed days of fasting between (eg 5:2 – five days of normal eating & 2 days of minimal or no calories in between)
- Extended fasts (eg 2 days to a week or longer), which should be undertaken with medical supervision.
Continual eating is not a natural pattern for humans, and modern, processed foods encourage this behaviour because they disrupt hormones resulting in a distorted sense of hunger and satiety. Intermittent fasting can offer many benefits and is very different from the typical “dieting” strategy that has been tried and tested over the years, with poor long-term results. Any diet can result in short-term weight loss, due to its very nature of calorie restriction, however the metabolism will ultimately start to slow down to match the caloric intake as the body perceives that it is starving and seeks to conserve energy. In this way we would need to constantly keep restricting calories until we are literally eating practically nothing! Not terribly sustainable!!
Fasting, in contrast, allows the body to reap the benefits of increased HGH, promoting an increase in metabolism rather than a decrease. During a specific window of eating (feasting), the body is replenished with nourishing foods rather than restricting calories at this time. It is literally a “window of opportunity” to eat nutrient dense foods as your cells are primed to receive them.
The beauty of intermittent fasting is that it supports any type of eating pattern, be that omnivore, carnivore, vegetarian or vegan. However, it is important to ensure that whatever your preference, you are getting quality foods to provide essential vitamins, minerals, healthy fats, protein and fibre. Easy to implement, intermittent fasting is extremely flexible and can fit into any lifestyle. Timings can be altered to suit social occasions, shift work and changes in daily circumstances – there is no written rule and it can be personalised to suit each individual.
Recent research indicates that individuals with obesity and Type 2 Diabetes may do well on an intermittent fasting program, improving and even reversing their conditions, enabling reduction of, or completely eliminating, medications.
Leading experts in the field of cancer research, such as Dominic D’Agostino, Valter Longo and Thomas Seyfried, suggest that fasting before cancer treatment can help to reduce side effects from drugs and conventional therapies, and may also protect healthy cells and slow the progression of cancer cells. For anyone in this situation however, it is essential to do this under medical supervision.
As with many things there are caveats to fasting. Those who should not fast include pregnant women, nursing mothers, severely underweight individuals and people with disordered eating.
For me, the myriad health benefits of intermittent fasting are what make it so appealing. On a personal level I have seen a rise in energy, a balancing of menopausal hormones, resulting in diminished symptoms, improved mental clarity and better productivity during the day and I sleep through the night without waking, (no doubt contributing towards more energy the following day). I honestly can’t see myself eating any other way any more. I don’t experience uncontrollable hunger and I really look forward to breaking my fast when the time comes, enjoying the whole process of choosing quality foods and providing my body with optimal nutrients. Whilst I usually implement a 16/8 protocol sometimes I go longer depending on when I feel I need to eat, and will occasionally fast from dinner to dinner.
Through my Fast/Feast Program, individuals with a history of depression have seen an improvement of symptoms within a few weeks; those who have struggled to lose weight see substantial and consistent weight loss within 4 weeks of implementing the program. And, perhaps most excitingly, an individual with Multiple Sclerosis has witnessed an incredible rise in energy levels, and a dramatic improvement in motor skills.
Learning how to implement intermittent fasting protocols safely and efficiently is, of course, extremely important. Being part of a program that supports and guides you gives you the confidence, structure and advice often needed. This is why I developed the Fast/Feast program. It offers a well-structured introduction into implementing intermittent fasting, help with finding the right protocol for you, continued support throughout the program, and a community of like-minded individuals who can also offer their insight and experiences.
To find out how the Fast/Feast program can have a positive impact on your life, please get in touch or sign up on the next program here to join our growing community and start your own journey to better health!
“I fast for better physical and mental efficiency” – Plato