Intermittent fasting for beginners: what you need to know

Intermittent fasting (IF) is a timed approach to eating that dictates when you eat more so than what you eat. 

Particularly over the past two years, IF has become one of the most popular methods of weight loss and improved metabolic health. But beyond weight loss, more and more research has been published suggesting IF could also be a great practice for managing (or even treating) more serious health issues. 

But what is intermittent fasting?

The idea with IF is to only eat at specific times of the day, allowing your body to fast for the rest. 

There are a few things that happen in the body when we eat. Firstly, blood glucose levels will rise depending on what we’ve eaten. The pancreas will then release insulin, encouraging cells to convert glucose into energy or store it as fat for later use. Once we’ve received enough food, the hypothalamus (a portion of the brain), blood sugar levels and certain hormones notify the body that it’s full.

This process has been working well for us for thousands of years. However, when we eat too much or when we include things like carbs and sugar in our diets (like so many of us now do), the body can’t keep up with the demand. Healthy processes go into overdrive and the likelihood of becoming overweight increases, as well as susceptibility to a range of diseases like diabetes and even cancer.

This is where many sources suggest intermittent fasting as a solution. Giving the body rest time between meals encourages the regulation of glucose and insulin levels. It also allows the body to normalise before getting back to work, which is why everyone can potentially benefit from intermittent fasting.  

Different types of intermittent fasting 

There are loads of different types of fasting, including alternate day fasting, one meal a day (OMAD) and intermittent fasting (IF) - all of which hold different definitions depending on who you ask.

For the purposes of this article, we’re not referring to one specific type of fasting but rather the overarching idea of giving yourself a set window to eat and a window to fast. 

Intermittent fasting for weight loss 

Arguably the most common reason people try fasting is for weight management. This is because fasting has been linked with reductions in insulin and leptin resistance, and by extension, reduced risk of type 2 diabetes. 

Let’s break it down. As mentioned earlier, carbs (and particularly sugars or refined grains) are broken down in the gut as a source of energy for our cells. Whatever the cells don’t use then gets turned into fat. But for this process to happen, the pancreas must release insulin.

When we don’t eat for periods of time, insulin levels naturally decrease and fat cells release the sugar so it can be used as energy. So the reasoning behind IF for weight loss is that if we let our insulin levels drop enough (and for a prolonged period of time) the body will begin to burn that unwanted fat.

And the other health benefits of intermittent fasting? 

The benefits of IF have been heavily debated over recent years. And while many continue to fuel this debate, the New England Journal of Medicine recently published a review article in support of the vast health benefits. 

Throughout the article Effects of Intermittent Fasting on Health, Aging, and Disease, the authors make an argument for the metabolic shift that takes place when the body begins burning fatty acids for fuel rather than glucose. As a result, ketone bodies are produced which have the potential for significant cell and organ regeneration. 

In addition to this, various studies have also shown fasting to be effective in areas of health such as the removal of cellular waste from the body, improved heart health, reduced oxidative damage and inflammation and supporting overall longevity.

So while definitive evidence is yet to put the IF debate to rest, overwhelming research points to IF as being a great tool for supporting better health and wellbeing.

References: 

https://www.nejm.org/doi/full/10.1056/NEJMra1905136

https://www.uofmhealth.org/health-library/aa155258#:~:text=Hunger%20is%20partly%20controlled%20by,brain%20that%20it%20is%20full. 

https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156 

https://pubmed.ncbi.nlm.nih.gov/20921964/ 

https://pubmed.ncbi.nlm.nih.gov/20534972/ 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7415631/ 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4257368/ 

https://www.nia.nih.gov/news/longer-daily-fasting-times-improve-health-and-longevity-mi