The Beginner's Guide to Intermittent Fasting

Intermittent Fasting: What is it and what makes it so popular?

Intermittent fasting is a popular diet to lose weight. But, does it work for everyone? Today we will look into the science behind this eating plan and help you better understand how intermittent fasting works so that YOU can decide if it's right for YOUR body!

Fasting has been around for a long time. Earlier research regarding fasting sought to investigate the benefit of fasting for breast cancer and dementia. Promising results for both breast cancer and dementia proved that there are health benefits to this diet strategy. Fasting became popularized in recent years by health gurus who sell it as an easy way of weight loss with no need to maintain strict rules or eat specific foods on top of being able to track your progress.

Intermittent fasting generally leads to a calorie restriction by limiting the amount of time you can eat and drink across your day. Of course, a person could exceed their calorie requirements in the limited hours they ate and therefore not lose weight, however, a sensible approach to fasting often results in weight loss initially. Other benefits of intermittent fasting include:

• Lower blood pressure.
• Lower blood glucose and insulin levels.
• An improved lipid profile.
• Less inflammation in the body.
• An extended lifespan.
  
  

Fasting and Metabolism

Fasting is known to increase your metabolic rate initially. The reason for this is the body needs to ramp up other systems in the body to compensate for the lack of calories, protein and nutrients being consumed. Prolonged fasting then results in a decrease in metabolic rate. Think of this as the body realising that preservation is now needed given the lack of adequate nutrition. 

Common Forms of Fasting

The three primary forms of intermittent fasting: are periodic fasting, daily intermittent fasting, and intermittent energy restriction.

Periodic fasting

The idea of alternating days where you fast has been around for a while now and it's commonly referred to as " periodic fasting." The practice allows people the opportunity not only to eat during one 24-hour period but also to experience greater feelings that lead them towards wanting more food. Fasting is often used by those looking into losing weight because studies show evidence of how this type can help reduce fat cells in your body overall.

Intermittent restriction  

The 5/2 diet is another popular regimen that consists of five days with normal eating and two fasts. The calorie limit for these periods typically sits around 4,130 kilojoules (approx 1000 calories). When the 5/2 diet is followed, individuals are likely to see improvements in:

- Fat levels.

- Insulin resistance.

- Energy restriction.

 Daily intermittent fasting (time-restricted fasting)

This is a diet that involves 16/8 intermittent fasting, with an 8-hour window to consume food or fluid while fasting for 16 hours. There’s quite a lot of evidence to support this diet, as research showcases improvements in:

- Appetite.

- Weight loss & fat mass.

- Glucose levels and insulin sensitivity.

- Blood pressure.

Time-restricted eating in line with our circadian rhythm (or sleep-wake cycles) is thought to amplify the benefits of intermittent fasting. The cells in our body know the time of day. They know when we should be sleeping as opposed to drinking coffee and binge-watching the latest series on Netflix. There are clues to indicate that we should not be eating late at night and the evidence is starting to grow around these assumptions. Our pancreas has receptors for melatonin our sleep hormone. What does this mean? Well, it is known that we produce less insulin at night, and respond better to insulin in the morning. Insulin helps us to utilise carbohydrates one of our main calorie sources. Melatonin which peaks at night inhibits the release of insulin from insulin-releasing cells in the pancreas. This means that if you're eating late at night, particularly carbohydrate-rich meals, then your blood glucose levels will remain higher for longer. What does that mean for your health? If this is a regular occurrence then it means more oxidative stress and damage to nerve tissue, blood vessels and organs. This is the onset of chronic disease. 

Fasting and Longevity

Why would intermittent fasting extend your lifespan? 

It’s a bit of a tricky question, but let’s break it down.

The mTor pathway within our cells is associated with growth and ageing. It is known to be inhibited with fasting! Anyone familiar with the mTor pathway may know it as one of the keys to growth. This may be great for muscles, however, another form of growth is ageing. We tend to grow as we age. What fuels this growth? Protein (amino acids), calories and nutrients. What inhibits this growth? Restricting protein (amino acids, calories and nutrients). Sure you could not do this forever, but short-term fasting such as alternate day fasting or time-restricted eating, have shown promising results for both cancer research, ageing, diabetes and weight loss. 

Intermittent fasting is a great way to cleanse your body and remove any damaged proteins or dysfunctional mitochondria. This is called autophagy and is an evolutionary process where the body starts to eat its own defective cells to enable the regeneration of new cells. This can reduce the risk of chronic disease, adding more years to your life!

Who is Fasting Not For

The importance of fasting being Intermittent should not be taken lightly and should only last for short periods of time. One of the downsides to this dietary process is the detrimental side effects that may occur if it lasts too long. Some of the consequences or risks associated with prolonged fasting include:

• Anxiety and depression
• Infertility
• Bone issues
• Disordered eating behaviour

If you have a history of any of these conditions then fasting is not recommended. In particular, if you have a history of eating disorders or are susceptible to disorder eating behaviours, then fasting should be avoided at all costs. 

Summary

Fasting is not for everyone, however, there are promising improvements to health that can be achieved. If wish to try fasting to see if it can improve your health, we suggest first discussing this with a dietitian or your local GP. 

There is a lot that goes into Intermittent Fasting, there is no one way to go about it. Are you interested in trying out this dietary method?  With MEALZEE, you can create a meal plan to meet your nutritional needs for your non-fasting periods. Learn more here.