Should I fast Mr Nutritionist?

Fasting, or ‘voluntary not eating for a finite period of time’, can be very helpful in regards to overall health.

I’ll shortly give you my ‘rules’ if you want to try a fast.

But first, there are some caveats.

For 90% of us mere mortals who have busy lives, families and work, fasting for a day or even half a day just won’t suit.

It really is a cliche, but I want you to walk before you run. Maybe think of it as doing a 10km fun-run before you launch into a full marathon.

Is there evidence that fasting helps?

Yes there is.

Mainly animal research, shows an improvement in cell regeneration, cell repair, DNA repair and increased metabolism. Fasting may also have an anti-inflammatory effect.

There have been some human studies, and one of the best showed that if we eat in an ‘8-hour window’, there are improvements in blood sugar/insulin levels, reduced weight and reduced blood pressure.

An example of this may be to eat between 10am-6pm, 7am-3pm or noon to 8pm. You could eat 2 meals of fat, protein and greens in this window and then fast for the other 16 hours.

There are unlimited permutations and all are ‘allowed’, because there is no one-size-fits-all rule.

There is no specific science for a ‘5 and 2’ (5 days eating normally and 2 days reduced eating, a la the Michael Mosely diet). Not to say it doesn’t work, it is just brilliant marketing for a 7-day week.

Other options?

Have 2 meals a day and don’t snack. It really is up to you.

Do you need to fast for 12, 24, 72hrs (or more!) to be healthy?

No you don’t. 

I do get frustrated with some zealots who say you ‘must fast’, you must have mountains of coconut oil, you need to have ‘fat-bombs’ and butter in your coffee and you can’t have breakfast, ever.

You don’t have to do any of this. I would rather you follow my ‘loose rules’, and follow this way of eating for years and decades rather than do some doomed ‘fasting detox’.

Important: If you do reduce your carbohydrates, or you do decide to fast for longer than 12 hours, you may ‘waste’ or excrete extra sodium, potassium and fluid. This occurs due to a drop in chronically-elevated insulin in the body and may manifest as cramps, headaches, aches/pains, irritability, constipation, disrupted sleep and ‘flu-like’ symptoms (keto ‘flu).

To overcome this, increase salt in cooking/food, increase greens/avocado and drink soda/mineral/water. Ask if confused.

These symptoms must be seen as a positive rather than a negative.  Blood sugars, insulin and triglycerides (fats) that may have been elevated for decades, are starting to fall, and this literally, may be a life-saver.

Now, those ‘loose rules’:

  1. Start off by not eating between meals. That’s right, NO snacking or grazing. Fuel up on quality and then nothing until the next main meal. 
  2. Reduce the carbohydrates you eat with those main meals-this will help you get off the ‘carbohydrate-roller-coaster’, where you are hungry two hours after eating
  3. Hypoglycaemia (low blood sugar) will reduce the longer you abstain from the carbohydrates/snacking, so be patient.
  4. If you have been eating a certain way for decades, the body WILL take time to get used to a new way of eating. Again, this isn’t a negative, it is a positive!
  5. Don’t just change for change-sake. Why do you want to change? What do you expect from this change, and how will you measure this change?
  6. Medications may effect blood sugars and insulin, especially for those who have diabetes. So plan for these changes.
  7. Don’t change diet and increase exercise at the same time. Don’t change when there is upheaval at work or in the family. Don’t take on too much change all at once. This is a recipe for failure.
  8. Stress and emotional-eating is a HUGE part of overeating/eating too many carbohydrates/snacking. Plan to fill that ’emotional hole’ before you make dietary changes. 
  9. Alcohol can make you hungry, can make you overeat, and can make you make the wrong food choices, so consider abstaining (yes, completely) until you see some real, sustainable change  
  10. Between meals you can drink water, clear soup/broth, have stock cubes in hot water, have herbal teas. Ideally, take a break from tea and coffee whilst you fast.
  11. Ask me if you have any questions!


If you are breast-feeding, pregnant, have a low-BMI, have a history of disordered-eating you should not be fasting. And repeating that diabetics must plan ahead before making significant changes.


A diabetic said to me recently that they weren’t ‘allowed’ to fast or reduce their carbohydrate-intake according to their health-professional. 

This is poor, outdated and not best-practice advice.

Planning is the key. 

I am a regular on ABC Radio Brisbane if you would like to have a listen to past episodes or you can watch some short videos that may explain in a simple way, complex ideas.  

If you would like to book an individualised appointment, simply do thaton-line.

Or visit my website Twitter or Facebook should you want to know a bit more about me. Instagram has a few more recipes as well.

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