Should You Try Intermittent Fasting?

    Plate of vegetables for fasting diet and nutrition

    Want to get all the health benefits about fasting without having to go hungry? We find out how fasting could work for you and the different methods of doing so. 

    If you follow any wellness influencers, there’s a good chance you’ve heard of intermittent fasting. The concept is simple: during certain hours of the day, you eat. During others, you don’t. The buzzed-about benefits include a lowered risk of disease, more energy and slower ageing. 

    But does intermittent fasting actually work? Here’s what you need to know.

    What is intermittent fasting?

    Fasting is to go completely without any food for a period of time, which sounds pretty painful to us. Enter intermittent fasting (IF) – a new, easier to stick to form of fasting where you stop eating for a part of each day or only eat a small amount for a few days each week. Unlike food fads, IF is backed by plenty of robust studies and is considered safe and effective because it combines short periods of fasting with short periods of eating. If, however, you are on medication, do check with your GP before you try IF.

    How does IF work? 

    We have turned into a nation of ‘grazers’, so our digestive systems never get a chance to rest. 

    Cut back the amount you eat and/or the window in which you eat, and your body gets a chance to rest and repair as it should – which can give your health a major boost.

    What are the health benefits?

    Resting the digestive system means the body can switch priorities. So, instead of processing food, it can start concentrating on other important functions, such as autophagy (where the body clears away old cells to make way for new ones). This has a huge impact on many areas of the body and brain, and studies show IF can:

    • Improve the body’s ability to fight inflammation
    • Boost heart health by lowering blood pressure, cholesterol levels and making the body more efficient at clearing fat from the blood after a fatty meal, reducing the risk of heart disease
    • Improve the brain’s processing powers, and it might protect against conditions such as Parkinson’s and Alzheimer’s diseases
    • Bolster immunity (including helping to fight off cancer) by encouraging the breakdown of white blood cells and triggering stem cell-based regeneration of new immune system cells
    • Increase life span by reducing the rate at which the body produces a chemical called IGF-1, which might accelerate ageing and cancer in later life
    • Reduce the risk of diabetes
    • Improve energy and sleep by increasing levels of melatonin, the sleep-promoting hormone.

    How do you start IF? 

    Since Dr Michael Mosley introduced the concept of IF in a much-watched Horizon documentary, the science of fasting has evolved and there are now lots of options. Different types of fasting suit different personalities and lifestyles, as well as targeting health issues you might want to address. The most important factor is that the style you choose is sustainable for you. 

    These are some of the most popular ways to fast:

    The Fast800

    Dr Mosley’s original 5:2 diet, which involved eating 500 calories on two days a week, has morphed into the less punishing Fast800, on which you eat 800 calories on any two days and a healthy Mediterranean diet for the rest of the week. 

    • Pros: Simple rules to follow – you can pick your ‘fasting’ days to suit your schedule and enjoy healthy eating the rest of the week (see for more information).
    • Cons: 800 calories might seem restrictive, so you’ll have to be disciplined on ‘fasting’ days.

    Alternate-Day Fasting

    Eat 25% of your calorie needs (500 calories for women, 600 calories for men) on one day, then eat normally the next.

    • Pros: Simple and effective.
    • Cons: You’ll need to resist the temptation to overeat on ‘non-fasting’ days. 

    Time-Restricted Eating (TRE)

    New research suggests that TRE is an effective way to reap the health benefits of fasting. You simply extend your normal night-time ‘fast’ by eating an early supper, or skipping breakfast, so you eat in a 12-, 10- or 8-hour window.

    • Pros: A gentle starter to intermittent fasting. 
    • Cons: You need to eat healthily during your eating window to maximise health benefits.

    Whichever method you’re going for, it’s also important to eat healthily alongside this and make sure you’re getting the right macronutrients and micronutrients. Want to know how to understand what your body needs? We asked our Vitality Nutritionist for some advice