Intermittent fasting, is it healthy?
Many people are probably familiar with the term ‘intermittent fasting’. We look take a look at the pros and cons of intermittent fasting and what it involves.
What is Intermittent Fasting?
In very simple terms intermittent fasting is an eating pattern with a cycle of eating periods and fasting periods. It isn’t about which foods you eat but, when you eat them. There are various ways to carry out intermittent fasting. The most extreme is the Eat-Stop-Eat method where you eat nothing from dinner one day until dinner the next day (24hrs). There is also the 5:2 diet which restricts calorie intake to 500-600 calories on two days per week with the other five days consuming a regular diet.
If like me though, the thought of going a whole day without food or severely restricting your calorie intake fills you with horror, then fortunately there is an easier but equally effective option.
Introducing the 16/8 method
This type of fast allows you to eat your normal diet but within an eight-hour period, which means you are fasting for the remaining 16 hours of the day. You can either skip breakfast and eat between the hours of 12pm – 8pm for example or skip dinner and eat between 9am – 5pm. Personally I find it easier to skip breakfast but everyone is different and you have to go with what works best for you.
No food is allowed during the fasting period (unless it’s the 5:2 diet) but you can drink water, coffee, tea and other non-caloric beverages with no sugar or artificial sweetener (artificial sweeteners are not allowed as they still trigger your body to release insulin).
What Are the Health Benefits of Intermittent Fasting?
Humans have been fasting for thousands of years, sometimes it was done out of necessity in times of famine or lack of available food. In other instances, various religions, including Islam, Judaism, Christianity and Buddhism have emphasised fasting during certain periods.
Our bodies are adapted to cope with extended periods of restricted food intake. Does this mean it’s healthy though.
For most people it is and the benefits include the following:
• Various changes occur in the body when we don’t eat for prolonged periods. Our bodies undergo hormonal, genetic and cellular repair processes in order to survive and stay healthy during a period of famine (1).
• In a fasted state we can improve blood sugar control, fasting insulin and insulin sensitivity (2, 3) as well as dramatically increase our levels of human growth hormone (4, 5).
• It is also a great way to lose weight and burn fat (6).
• There is also good evidence that fasting can activate ‘anti-aging’ genes and extend life span (7, 8).
• Cognitive function and neurological health may also improve (9, 10).
• Inflammation may be reduced (11).
• Cardiovascular health may also be enhanced (12).
With so many health benefits it seems like a no-brainer to adopt this dietary habit, especially if it allows you to skip breakfast as this is often rushed due to our busy schedules. I recommend this type of diet to clients who are looking to lose weight as well as those with Type 2 diabetes or metabolic syndrome. It suits most people but there are exceptions when intermittent fasting isn’t recommended.
When is Intermittent Fasting Not Recommended?
This type of dietary regime can place extra stress on the body which means it’s usually unsuitable for those who are experiencing chronic stress, ‘adrenal fatigue’/HPA axis dysfunction, or are not sleeping well. Due to hormonal disruptions these health conditions make it difficult for the body to keep blood sugar stable, so skipping meals can make matters worse. It may also be unsuitable for those who struggle to get enough calories or who are underweight.
I would also not recommend such a diet to anyone who has a history of an eating disorder or food restriction, by providing a further reason for the person to restrict or control their food intake.Finally, it may have a negative effect on fertility (unless being overweight is a potential cause of infertility) and this isn’t a diet recommended during pregnancy.
Feature Article by Nutritionist – Alex Georgiou