Restricting when you eat to certain times has become increasingly popular. Helen Budworth weighs the benefits of intermittent fastingI first became aware of the term intermittent fasting (IF) a few years ago, when my eldest son mentioned it. Instantly, thoughts of annoyance and deprivation sprang to mind, and memories of those ‘intermittent faults’ with my car that the garage always failed to find. But when put together the words ‘intermittent’ and ‘fasting’ appear to bring only positive results. Thinking about it more, I realised that I have unconsciously adopted a form of IF, as have others I know who are on the slim side.
While IF might be a relatively recent addition to our vocabularies, the practice of doing it is anything but new. The Ancient Greek physician Hippocrates (c.460-370BC) advocated the practice of fasting as a positive way of treating issues as diverse as epilepsy and gout.
In the mid-17th century the benefits of IF to improve digestion and mental clarity were detailed by an English doctor, Thomas Willis, and three hundred years later, in the early 20th century, the chemist Otto Folin recommended short periods of voluntary starvation as a good way to reduce weight.
But it wasn’t until the 1940s that the term intermittent fasting was coined by the Swedish physiologist Anton Carlson, who found that restricting calories extended the lifespan of rats.
There are several popular IF routines to choose from, so it is easy to pick one that not only suits your body but also your lifestyle.
16:8 DIET
The most popular IF routine is called the 16:8 diet. Quite simply, the smaller number refers to the period in hours when you can eat during the whole day.
Without knowing I was doing IF, I realised my calorie consumption naturally falls between 1pm and 9pm – I always avoid having breakfast and have no trouble lasting until lunchtime before eating.
You might prefer to eat between 8am and 4pm or 10am and 6pm. Whatever the window for eating may be, advocates of this method often marvel that they can eat what they like and still remain slim. It certainly works for me.
5:2 DIET
Another popular routine is known as the 5:2 diet. This version of IF dictates that you eat normally for five days out of seven, and on the remaining two days only consume 500-600 calories. Some people I know have found it to be a bit of struggle and socially restricting, but others love it.
ALTERNATE-DAY FASTING
This means you eat normally every other day and restrict yourself to 500 calories on fasting days. Again, this could be socially restricting and more difficult to keep to. The best IF routine for you will be determined by your lifestyle (how easy you think it will be to stick to it) and your goal (weight loss or simply one of the other myriad benefits). You may not find the right balance first time, but of the widely used routines 16:8
is relatively straightforward and could give you good insight into how your own body reacts to IF. However, if weight loss is your primary objective, the 5:2 or alternate-day fasting could work better for you.
How does it work?Fasting helps to regulate the production and release of hormones into your system. When we eat, our bodies release insulin, a hormone that helps us convert the glucose from food into energy. If we eat too frequently we can become resistant to insulin which, aside from other health issues, can lead to weight gain. This is why it is unwise to snack between meals when you are trying to lose weight.
By adopting an IF routine, you can naturally reset your insulin levels and also improve your body’s ability to use glucose, ultimately leading to not only weight loss but also other possible health benefits that could include:
Reduced inflammation
Inflammation causes damage to healthy cells, tissues and organs, and if unchecked can lead to heart disease, diabetes, cancer, arthritis, and bowel diseases.
increased life expectancy
Some studies have shown that IF may help to extend the lifespan of laboratory animals. Whether the same effects apply to humans is not known, but is the subject of intense research.
improved brain health
Recent research has found that IF may have the potential to treat or prevent brain-related disorders.
insulin sensitivity
Intermittent fasting can help our ability to convert glucose to energy. This, in turn, can assist with weight loss and possibly reduce the risk of becoming diabetic.
Is it safe?
Intermittent fasting is considered safe for most people but, as with all diets, might not be right for everyone. If you have diabetes or heart disease you should always talk to your doctor before adopting any restrictive diet Also, remember to start slowly. Begin with a shorter fasting windows and gradually increase them until you reach the recommended target. If fasting starts to make you feel lightheaded, dizzy or weak, stop.
While there is some evidence supporting the benefits of IF for weight loss and blood sugar control, more research still needs to be undertaken to confirm the results and determine its long-term safety. IF is not for everyone, so if it doesn’t fit, don’t force it.
