Welcome to a series of blogs on Intermittent Fasting!  This first blog is an introduction to the concept of intermittent fasting and this will be followed by other blogs which summarising the current research as well as providing recipes and menu plans!

What is intermittent fasting?

Intermittent fasting is one of the latest trends for weight loss, but it is claimed to be more than a diet.  There are a number of claims linking fasting to better health as well as promoting its potential to slow the aging process.

Intermittent fasting is an eating pattern which restricts the amounts of meals and snacks you have a day.

The aim is to increase the length of time between meals (known as fasting).  You will fast for 10 hours if you do not eat between  supper until breakfast the following day.  Intermittent fasting takes this to the next level by extending this fasting time by a few hours, for example pushing your breakfast back to 10 am, or even waiting to eat your next meal at lunch time. It is this simple! You skip meals so you eat less, and you lose weight.

Types of intermittent Fasting

16/8. This involves fasting for 16 hours and then having a window of 8 hours where you eat.  For example, skipping breakfast, having lunch at 1 pm and then supper before 8 pm.  There is no fixed time for eating and fasting, providing you keep to the 16 hours fasting window.

Alternate day fasting This is tougher!  It ultimately involves fasting completely for 1 day and then eating ‘normally’ the next day.

5/2 diet  This is an adapted and gentler form of alternate fasting which allows you to eat very lightly on 2  fasting days, anything from 500 to 800 calories. You then eat ‘normally’ on the other 5 days.  This type of approach can also be combined with the 16/8 approach, consuming your 500-800 calories during an 8-hour window.

Benefits of intermittent fasting

• Weight.  You naturally end up eating less, by skipping meals and snacking less which helps with weight management.
• Flexibility.  There is an element of flexibility which is very appealing.  It does not need to be followed every day and can be easily adapted to your lifestyle.
• Health.  Intermittent fasting is associated with improvements in health.  Our cells and tissues function more efficiently after a period of fasting. Current research indicates this might be linked to an improvement in stem cells function.

What are stem cells and why are they important?

Stem cells provide new cells for the body as it grows, replacing specialised cells (for example cells found in the liver and digestive tract) that have become damaged. They ensure that the body keeps operating effectively!

Is intermittent fasting more effective than other diets?

The jury is out!  It does not seem to be more effective than other diets for weight loss.  Any ‘diet’ works if you follow it correctly-  low calorie, low carb, keto, low fat…the problem is how to follow it for the longer term and stablise your weight.

The element of flexibility and not having to ‘diet’ every day, makes intermittent fasting a suitable choice for people who struggle with ‘full time’ diets.

There are health issues associated with being overweight, so any diet which promotes weight loss will help to improve health.   Does intermittent fasting add an additional health boost? Further research is needed to confirm whether intermittent fasting really does boosts our stem cells!

Is there anyone who should not try intermittent fasting?

Anyone with a medical condition that requires regular meals, such as diabetics type 1 as well as certain life stages such as childhood, adolescence, and pregnancy, should not follow intermittent fasting.

It is also not recommended for anyone with a history of eating disorders who also need structured meals and regular mealtimes.

I also would not recommend intermittent fasting or skipping meals just before a session of intensive sport!  The flexibility of this approach means that you can fuel up before (and after) your sport and do your fasting session later in the day.

You might here have seen online that long term fasting risks lowering the rate at which you burn energy, and causing weight gain when you then eat ‘normally’.  This does not apply to intermittent fasting, because the fast is ‘intermittent’!  There is no evidence linking intermittent fasting to a permanent reduction in energy requirements.  The issue is more ‘psychological’, skipping a meal can lead to overeating at the next meal.  This is why your meals should be bursting with fibre, protein and other nutrients in order to help you manage your hunger and appetite!

A nutritionist’s perspective! 

I am a fan of intermittent fasting for weight control and have co-written a book on the 5/2 diet with Delphine De Montalier ! I am really interested in the emerging research on additional health benefits and like the flexibility of the approach – as someone who has never really eaten breakfast, I follow a 16/8 form of intermittent fasting naturally.

The quality and quantity of your meals on the non-fasting days or feeding windows is important. If you overeat on the other ‘normal’ days, you will not lose weight!   For your health, the aim is to eat nutritious meals outside of the fasting period – good quality protein (either animal or vegetable), whole grains, nuts, seeds and vegetables and fruits, rather than fast food and sugary drinks!

It is one of the many strategies I use in my ‘weight control’ toolbox.  It can be combined with other diets and you can choose when to follow it.  It’s indeed a win win for me!