If you’ve heard of time-restricted feeding or intermittent fasting, but assumed it was too complicated or difficult to follow, read on. The following extract highlights just one of the suggestions I make in the Eat section of my book The Four Pillar Plan. Give it a go and see how easy it is to feel better, starting today.

It’s tempting to believe that there is, somewhere out there, the perfect diet and all we need to do to achieve perfect health is find it. Many people, of course, believe they’ve already done so: low-fat, high-fat, high-protein, low-carb, vegetarian, vegan, the list goes on. And it’s true that each of these options will be effective for some people, but none is a one-size-fits-all solution.

A huge problem with today’s food culture is the sheer amount of conflicting advice that’s flying about the place. Contrary to what you might think, I don’t necessarily have a problem with any of it. If being a vegan or sticking to your own interpretation of ‘paleo’ is working for you, that’s fantastic. But I simply refuse to believe there’s One True Diet that’s optimal for everyone. Remember, humans have always been opportunistic omnivores. All through history our diets have been dictated by geography and climate. We ate whatever food was available. This means the evolved human machine is capable of thriving on a whole range of diets.

The optimal diet for you is likely to evolve and change as you grow older. A child will usually have different health priorities from those of an octogenarian, just as a bodybuilder will, compared to an expectant mother. Having said all that, there do appear to be some very broad and basic principles that are consistent among the world’s healthiest, longest-lived populations.

• None has a processed-food culture. By and large, they eat fresh, unprocessed, local produce.
• They all sit down and eat meals together.
• They eat what’s in season.
• They have treats, but only at very special festival times such as Christmas and Easter, not every day after school, or every Friday or Saturday.

They also tend to have specific times for eating, with gaps in between and minimal snacking. So that’s what I’d like you to try. Can you get into the habit of eating all of your food within a 12-hour time window?

Why Daily Micro-Fasts Work

Humans evolved during periods of regular feast and famine. Our bodies are designed for going without food for certain periods of time. But the modern environment, in which we’re surrounded by temptations to eat – be they social pressures, via advertising or the simple fact we have that delicious half-eaten trifle sitting in our fridge – means we tend to inundate our systems.

As soon as you start to give your body a break from all the gorging, incredible things start to happen. An extraordinary health-promoting cascade effect is triggered. After six to eight hours, the liver will have used up its internal fuel stores, in the form of glycogen, and soon after this the body will start to burn its own fat. Once we get to about 12 hours, a process called autophagy will have well and truly kicked in.

Autophagy is a hot area of new research that I wasn’t taught about at medical school. Much of what we know about it is thanks to the Japanese biologist Yoshinori Ohsumi, who won the Nobel Prize for Medicine for his work into its mechanisms. Imagine that you never spent time cleaning up your house. You’d leave dirty plates hanging around for weeks, stinky clothes on the floor, kids’ toys everywhere, washing baskets overflowing, the sinks machine-gunned with toothpaste splats. This is basically what happens in the body, every day, as a by-product of it going about its daily functions. The scientific term for this is ‘oxidative damage’. It’s actually a little bit like the rust that builds up on cars. This build-up is an inevitable consequence of function – and it’s all fine as long as we give our body a chance to clean up. This is what autophagy does. Think of it as your built-in Cinderella. It’s your body sorting out its mess and busying itself with cellular repair, immune system repair and a host of other essential maintenance projects. Eating all your food in a restricted time window – for example, within 12 hours – allows your body to enhance its own natural house-cleaning.

Being such a new area of science, there’s still limited data on human studies into exactly how and why time-restricted feeding (TRF) assists our repair processes. However, one likely mechanism that’s been proposed is that when we don’t eat for several hours, the liver stops secreting glucose into the bloodstream and instead uses it to repair cell damage. The liver is simultaneously stimulated to release enzymes that break down stored fat and cholesterol. Therefore, during our fasting period, the liver is helping to repair our bodies and burn off fat!

And these are by no means the only benefits of restricting our hours of eating. An incredible American neurologist, Professor Dale Bredesen, has actually managed to reverse memory loss in early-Alzheimer’s patients by taking a multipronged approach that has, as an essential component, regular 12-hour fasts. Yet more compelling research is coming out of the lab of Dr Satchidananda Panda, a biologist at the Salk Institute for Biological Studies in San Diego. Dr Panda is a passionate promoter of the idea that restricting the timing of our food intake may be an extremely effective public health stratagem. He argues that simply trying to eliminate unhealthy foods and restrict calories hasn’t really proved successful – so perhaps a limited eating window might work better.

If all that wasn’t enough, early studies are showing that when animals are given exactly the same diets over varying time periods, the metabolic effects on their body are significantly different – they put on less fat and have larger muscle mass when they are fed over a shorter period. This is hugely exciting. Human trials are under way.

So far the reported benefits are:

• Lower levels of inflammation
• Improved blood sugar control
• Improved mitochondrial function (read on, for more on this)
• Improved immune function
• Enhanced detoxification – TRF improves
• The elimination of waste products
• Increased production of Akkermansia muciniphila (a really important gut bug, more on this on page 98 of the book)
• Improved appetite signalling

It is possible to enhance these benefits by shortening our eating window even further, but I recommend 12 hours because fasting for longer can be problematic for some. Most people I meet are chronically overstressed. They need more rest-and-recuperation time, not more time under stress. Although perhaps not truly optimal, 12 hours is both manageable and long enough for most of us to see real benefits.

Which 12 hours should you choose? When I first started, I experimented by not eating after 7pm. I found it surprisingly easy. As it turned out, eating later was just a habit, just as feeling hungry later was a habit, mostly based upon the readily available access to food in my house. When I stopped eating during the evenings I felt more energetic, had better sleep and was just generally a little lighter in myself. I came to think of that evening craving for food as having a kind of ‘itchy mouth’. That’s become the way we talk about it in my house now. Am I really hungry? Or do I just have an itchy mouth?

Meet Your Mitochondria

Mitochondria are the energy factories of your body. Every cell contains hundreds of thousands of them. They convert fuel, in the form of oxygen and food, into energy. If we want to reach optimal health, we should try to enhance mitochondrial function in any way we can.

Most mitochondria are found in highly active organs such as the brain and the heart and in muscle tissue. Mitochondrial function is central to almost every single physiological process in the body.

Poor mitochondrial function can result in:

• Low energy level
• Brain fog
• Pain
• Poor memory
• Premature ageing

As mitochondria produce energy, reactive oxygen species (ROS) are formed. These cause oxidation, which is a bit like rusting on a car. In order to mop these potentially harmful reactive oxygen species up, our bodies need to produce sufficient antioxidants from the fruit and vegetables in our diet. Small amounts of these ROS are helpful, but too many cause problems.

When mitochondria don’t function optimally, the increase in ROS is known as increased oxidative stress.

In the short or medium term, this can contribute to the symptoms listed above such as fatigue and poor memory. Over the long term, this leads to chronic inflammation which can be a significant driver of many different diseases in the body including obesity, type 2 diabetes and stroke.

Eating an anti-inflammatory wholefood diet (more on this in the book) helps provide mitochondria with the correct fuel and necessary repair materials. In addition, the mitochondrial walls are made up of fat, so having healthy sources of natural fat in your diet such as avocados, olive oil and oily fish is important. They also need the right fuel, which can be obtained from eating an anti-inflammatory wholefood diet.

 Working With Your Circadian Rhythm

Although the science in this area is still in its infancy, human studies are already hinting that scheduling an earlier evening meal, or skipping it completely, may be more beneficial than not having breakfast. This appears to be because certain bodily functions shut down and don’t function optimally in the evening. Intuitively, this makes a lot of sense, but in the scientific world this is actually quite surprising. Isn’t a body like a machine? As in, it either works or it doesn’t? Why should one bit of it work better at a certain time of day?

I find it incredibly exciting that much of our biological machinery actually has its own daily cycle, not dissimilar to the one that makes us feel sleepy or alert at different points of the day. Even if we’re not deeply familiar with the science of the ‘circadian rhythm’ – how the body floods with melatonin to make us drowsy and cortisol to wake us up – we’ll certainly be aware of its effects. It’s now becoming clear that our bodies work on any number of these kinds of routine cycles.

Last year I was on my way to a conference in San Diego and, on the plane from Manchester to Heathrow, I happened to find myself sitting next to Andrew Louden, a professor of animal biology from the University of Manchester. We started chatting and before I knew it, we’d landed. We both had some time to wait before our next flight so continued the conversation over coffee. As I sipped at my short black Americano, I mentioned I was travelling to a conference on sleep- cycles and I started talking to him about body clocks. ‘Well, yes, I actually study body clocks,’ he chuckled. ‘And it’s not all about sleep, you know. Did you know that if you take a bunch of human liver cells and put them in a test tube, they start operating by daily rhythms?’

I found this extraordinary. Andrew told me that all of our bodily functions are determined by a circadian rhythm. This made me wonder if one potentially major failing of many health and nutrition studies might be that they haven’t accounted for this. When I looked into it, I found some fascinating recent research to suggest that certain pharmaceutical drugs could work better at different times of the day. Certain genes are also more or less active at various points. Even the composition of our gut microbiome changes with the hours. Interestingly enough, traditional Chinese medicine has been making this kind of observation for thousands of years. They’ve long believed that various organs have increased function at certain times of the day.

All this explains why it’s a good idea to start your time-restricted feeding window earlier. Hunter-gatherers tended to do their ‘work’ either in the morning or at twilight. Have our bodies kept this ancient programming and could this be one of the reasons that gene activity, for example, peaks at these times? I don’t think we know the exact answer to this question yet, but it seems logical. If you ask me, we’re not meant to be eating just before we’re about to go to bed. We’ve evolved to eat in the light. Indeed, researchers in Scandinavia found that, in some people, when the body is preparing to sleep, and we’re feeling tired, the pancreas stops making insulin. You can’t override that. Today, we’re eating out of sync with our natural rhythms. Time-restricted feeding helps us readjust and give the body what it’s expecting at the time it’s expecting it. This helps it make the most efficient use of the fuel we swallow.

Six Tips To Help You Micro-Fast

1. Choose a 12-hour period that suits your lifestyle. Note that your 12-hour eating window is from the beginning of your first meal to the end of your last meal.

2. Your body likes rhythm, so try and keep to the same times every day, even at weekends. Occasionally you may need to change your eating window – this is absolutely fine.

3. Outside your eating window, stick to water, herbal tea or black tea and coffee. Be careful with caffeine so you don’t adversely affect your sleep.

4. Try to involve other members of your household, or even work colleagues. This will help to keep you motivated and increase your chances of success.

5. Don’t be disheartened if you miss a day, or even two. It really doesn’t matter. When you feel ready, try again and see how you get on.

6. When you’re feeling comfortable within 12 hours, you may choose to experiment with shorter eating windows on different days. If you do this, pay attention to how the change makes you feel and adjust accordingly.

This is a special extract from my first book, The Four Pillar Plan. It outlines my foundational philosophy of health, which is that optimum wellbeing comes from achieving balance across all four pillars: Relax, Eat, Move, Sleep. If you’ve enjoyed this extract and you’re keen for more, you can find the book as a paperback, Kindle or audiobook, read by me, here.