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  • Writer's pictureGemma Westfold

Is fasting good for you?

It's as good for you as eating is.

I’m a nutritionist so of course I would say that what you eat really matters.  But as science into the area of fasting explodes, what we are becoming increasingly aware of is that not eating is almost as important. Through not eating, you create a natural process in the body called autophagy - the incredible clean-up function mother nature has given us.

What I want to tell you about today is a little bit more about this process and why it matters. I’ll then show you exactly how to do it yourself. *


Why the cells in your body need a clean-up

Our cells are small but they are tiny industrial hubs of activity which, like any industry, constantly create waste. Each cell contains a nucleus, where the genetic material is stored, and various organelles – tiny “organs” that have a job to do. But organelles can wear out: mitochondria – the cells’ “batteries” – get old and malfunction and other organelles and parts of the cell break down. All this debris cannot be left floating around, so there are organelles for waste collection: phagophores. Like the bin men of the cell world, they collect all the bits and pieces that no longer work, even mopping up invading microbes such as bacteria and viruses as they go.

They move this debris to our lysosomes – the dump –a little bubble inside the cell where enzymes break down the waste, recycling what they can. When an old protein is broken down into its components, those components – amino acids – can be recycled to make new proteins or be used as extra fuel for the mitochondria. In times of famine, this process can even provide nutrients missing from the diet. It is called autophagy, or “self-eating” and it is a wonderful, wonderful thing

Side effects of a good clean-up

In addition to providing energy, scientists now think that autophagy may offer some protection against brain diseases, such as Alzheimer’s and Parkinson’s. Nerve cells are particularly active. Their mitochondria have to work especially hard and as a result break down sooner. Autophagy mops them up before they can do too much harm. Indeed, researchers believe that damaged mitochondria that have lost their ability to use fuels – fat and glucose – efficiently may be behind a whole range of illnesses.

Autophagy does a great job of keeping everything healthy. Clearly, you’ll want autophagy to work properly in your own body.

Is your clean-up switch on or off?

Many processes in the body oppose each other, and there are feedback mechanisms that make them work. Think of this as a bit like a light switch -when one process is happening, the other cannot.

The magical state of autophagy is opposed by the activity of mTor, an enzyme required for growth that monitors the body’s fuel supplies closely.

When you eat, and food is plentiful, mTor is switched on and works in growth and repair mode.

If you’ve not eaten for a while and nutrients seem in short supply it is switched off, and autophagy kicks in to clean up and extract fuels from the waste like I described earlier.

It’s not that one of these processes is good and the other bad. To live, we need both. This incredible system evolved to get us through lean times … only there are hardly any lean times anymore.

When there is always plenty of fuel (the food you eat), mTor is working overtime and autophagy hardly gets a chance to kick in. No surprise then, that waste builds up, and you become vulnerable to disease.

Autophagy works when you are not eating (and have not eaten for a little while), and this is the reason why fasting is so good for you.

Now, let's get you in to autophagy!

The easiest way to make it work is ‘intermittent fasting’

Don't worry, that doesn’t mean that you need to stop eating for a week. Just hours is enough to trigger autophagy.

You can do the 5:2 fast but I don't like being so restrictive and counting calories. That's not how I work. My preferred way of intermittent fasting is time-restricted eating, in which you stop eating for a varying number of hours within a 24-hour period, aka 16:8 (eating only within an 8-hour window each day) or 14:10 (10-hour window). This is easier for men than women and women need to fast with hormones in mind (i.e. where are you in your season or where are you in your cycle). I don’t ted to go as strong as a 16:8 in this case.

In a 14:10 scenario, for example, you would have breakfast at 9am and stop eating after an early dinner, thus not eating anything from 7pm to 9am the next morning. In practice, this cuts out much of the mindless eating we can do on the sofa with Netflix. Oh yeah, that.

Or, if you favour an early breakfast then start and stop early. You would have a good breakfast and stop eating earlier in the evening. Studies found that not eating in the evening led to better weight loss results so trial this if that is your driver.

Why I love intermittent fasting

A lot of research has been and is being done on intermittent fasting, and the results are amazing. Not only does it promote weight loss - it has also been found to normalise blood sugar levels, reduce blood pressure and total cholesterol. At the same time, those who were well to begin with remained so. Their blood pressure, cholesterol and weight stayed the same. With M.E., it can be a useful tool to help keep our mitochondria healthy – there is much debate about M.E. being a mitochondrial illness, although please seek professional advice before starting any fasting.

Foods that trigger autophagy

Good news for coffee drinkers: coffee can trigger autophagy. Hurrah!

Other foods that contain nutrients to promote autophagy are seeds, fish and shellfish, olives and olive oil, brassica (plants from the cabbage family, such as cauliflower, Brussels sprouts, kale and broccoli), mushrooms, blackcurrants, berries, turmeric, ginger, resveratrol green tea, hibiscus, mint, ECGC and bergamot (in green and in Earl Grey tea).

Foods that block autophagy

On the other hand, there are foods that block autophagy, such as excess carbohydrates and excess protein, the latter especially from meat and dairy. I love protein and ask you to have it in every meal. I am not going back on that, merely stating that you need the Goldilocks amount which will be personalised to you and I can discuss that with you at any time.

You'll need to add in the right exercise

It is important, if you are going to promote autophagy, not to forget to exercise. Remember, when you scale down your carbohydrate intake or restrict calories, mTor, the protein for growth – including muscle growth - is switched off. When the body’s fuel supply is cut off, this is perceived as famine and – with the help of autophagy – proteins from muscle can be broken down to serve as fuel. Regular resistance exercise briefly switches autophagy off and mTor back on and that way helps to protect your muscles.

So, for better health, give your body a break from eating now and then. Try out intermittent fasting and see which version works best for you. It doesn’t need to be every day of the week, I do it two or three times a week. It doesn’t always suit my day.

When you do eat, stick with real food as that gives you the best chance of stocking up on those vital nutrients that help autophagy work better.

*Please note that if you have a current eating disorder or history of eating disorders then fasting is not advised.

How I can help with Nutritional Therapy

Using the functional medicine approach, I work to understand why you are fatigued or suffering with a chronic health condition. You can expect from me:

  • A personalised nutrition plan rich in nourishing foods to assist your bowel function

  • Test recommendations and full interpretation either privately or through your GP

  • Personalised supplement protocol to support your digestive function

  • Regular consultations and coaching to support new choices

Note: as a Nutritional Therapist, I do not diagnose or prescribe, however I do use functional nutrition testing to help find the best way to support my client’s health.


My programmes are designed with people like you in mind. I see many clients with fatigue, gut health issues, autoimmunity etc. and they all have different symptoms, family health histories, lifestyles, work and family life which may may have contributed to where they are. This is why a personalised nutrition and lifestyle rather than a 'one size fits all' gets such good results. Book your free Reboot your Health 20 minute call to discuss your health goals and if working with me would benefit you.

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