The idea of fasting may be daunting.
For as long as we can remember, we’ve been told about the importance of having a balanced diet and eating three square meals a day (the numerous Tim Tams in between are less of an instruction, but life’s for living, right?).
However, there’s a significant body of evidence pointing to the idea that intermittent fasting (IF) can hold important benefits for our bodies. So how does it work, and what could you stand to gain?
What is intermittent fasting?
At its core, IF involves alternating between periods of fasting and periods of regular eating.
There are several different approaches to doing this, which usually vary the ratio between time spent abstaining and time spent eating as normal.
Common examples include:
- 16:8 - In this framework you only consume food during an 8-hour window, and then fast for the next 16.
- 5:2 - Here you divide your eating schedule by days, instead of hours. Eat as normal for five days, then reduce your calorie count to a quarter of your recommended daily intake for the remaining two.
If you’re looking at that information and thinking, “is intermittent fasting really a good idea for me?”, you won’t find the answer in this article. Any significant dietary change, and especially one involving fasting, should be talked through with a doctor beforehand.
What we will give you here are scientific explanations of health benefits that can arise as a result of IF.
Health benefits of intermittent fasting
The Harvard T.H. Chan School of Public Health reports that a review of 40 studies shows that following IF can produce weight loss, with participants typically losing 3-4kg over ten weeks. However, there was a lot of variability across the different study designs.
One particular study, which followed 100 obese people for one year, showed that IF was no more effective as a weight loss method than daily calorie restriction. It all comes down to basic science – in very simple terms, if calories in are less than calories out, your body will burn fat to compensate. If IF helps an individual to reduce their overall calorie intake to a level below their calorie burn rate, it is likely that he or she would see weight loss.
The article does mention however that prolonged periods without eating may increase the chances of overeating during the ‘non-fasting’ periods.
Overall, these studies showed that there is not enough evidence yet to confirm that IF is a superior method to general continuous calorie restriction. It’s also still unknown if IF is safe for everyone and what long-term effects on the body might be.
Control of blood glucose levels
Research from the University of Adelaide shows that IF dieting has similar benefits as continuous energy restriction regimes in blood glucose control for people with type 2 diabetes.
In the trial, participants with the disease were separated into two groups - one followed a 5:2 IF diet, and the other a more conventional program with food intake restricted seven days a week.
The results showed that incidences of hypoglycaemia (where blood glucose becomes too low) and hyperglycaemia (where blood glucose becomes too high) were comparable across both test groups in the first two weeks of treatment.
The scientists therefore suggest that 5:2 dieting can be an alternative for people with type 2 diabetes trying to gain better control over their blood glucose levels. If you have type 2 diabetes, you should definitely check with your healthcare team first whether IF is appropriate for your personal situation.
Improved heart health
Coronary artery disease, also known as Ischemic heart disease, is the world’s leading cause of death, according to the World Health Organisation.
In preclinical studies, IF has been shown to ameliorate risk factors associated with heart disease, including reducing body weight, and triglycerides and low density lipoprotein (LDL) cholesterol levels (this is ‘bad’ cholesterol).
Regularly cutting out food for extended periods can improve a brain process known as autophagy.
‘Autophagy’ comes from the Greek terms ‘auto’ meaning ‘self’, and ‘phagein’ meaning ‘to eat’, and refers to the important bodily process of ingesting old cell components.
However, our eating food can get in the way of this. Glucose, proteins and insulin halt autophagy - and in the brain this can lead to accumulations of old cells, which has been linked to Alzheimer’s Disease.
By fasting, you allow your body to continue with its process of clearing cells, helping to keep your brain healthy.
It appears, therefore, that if you can push through the hunger pangs, there may be benefits to be had from intermittent fasting.
However, it’s worth stressing again that depriving your body of food for prolonged amounts of time isn’t a decision to be taken lightly. Have a word with your doctor to ensure that doing this won’t have any adverse effects on you as an individual.