Q & A Thursday: fasting
Posted by kathryn in Q & A Thursday
The last question for today’s Q & A Thursday is about fasting. A reader asks:
do you believe in the claim that fasting allows the body to detoxify and heal any parts of it that are ill? And do you believe there are any long-term ill effects that might be associated with doing a 24 hour fast once a week?
Up front I need to say I don’t have a lot of experience with fasting. It’s not a regime I use in clinic and it’s not something I recommend to clients.
While I appreciate there are many reasons for fasting, my focus here is on doing it for health.
My short answer is it depends on why and under what conditions you are doing it.
Fasting for weight loss
I do not believe that fasting is an effective tool for weight loss. Reducing your energy intake below 3,300 kJ leads to a significant drop in metabolism. And this drop in metabolism is not conducive to long-term weight loss.
In the short-term fasting will lead to weight loss. However the difficulty comes when you stop fasting and want to keep that weight off. As well as lowering your metabolism directly, fasting reduces your muscle mass – which further affects metabolism. And when you start to eat again, this lowered metabolism makes it harder to keep the weight off.
Fasting to detox
As you may know I’m not a fan of detoxes in general, including fasting. As far as I can see there’s no evidence that fasting will detoxify your body, or even that this is necessary.
To improve your energy and improve your health, you need to eat a better diet, get plenty of sleep, exercise regularly and drink water. It’s not fashionable and it’s not glamorous – but this is the optimal way to improve your general health.
Fasting to live longer
Early studies in rats and humans have shown possible links between calorific restriction and increased life span. This is very early work though and by no means conclusive.
Plus this research has looked at energy restriction – which is not the same as fasting.
Fasting for heart disease and chemotherapy
There are also some studies which show potential benefits of fasting during chemotherapy and to reduce the risk of heart disease.
Neither of these are conclusive, but they’re interesting pieces of research. Hopefully these will be followed up by further work.
Do you have any experience of fasting? And do you know of any other research into the health benefits or otherwise of fasting?
What is Q & A Thursday?
This post is part of Q & A Thursday – a monthly burst of blogging, where you get to dictate the subject matter. Q & A Thursday is all about simple, practical answers to food and diet dilemmas sent in by readers.
For more information you can take a look at the Q & A Thursday archives.
03 July, 2008
Comments
Great answer Kathryn, I’m really not a fan of detoxes or fasting either. And for diabetics it can be actively harmful, which is a bit tricky if it is an integral part of someone’s religion!
Dear Kathryn,
Thank you for your insights on fasting.
You say: “Up front I need to say I don’t have a lot of experience with fasting.” – So may I ask if you have personally done a fast yourself and if so how many times and what was the duration of your fast(s)?
It seems you may need to do some more research on fasting as there are MANY clinical studies and results on the benefits of fasting and the massive short and long term health benefits is has. Including weight loss, self-healing, detoxification and reducing pain.
I have personally done many short and long term fasts (from 1 to 30 days) and the results and improvements have been life changing.
There are also many types of fasts that can be done, water only, juice (fruit and veges), etc…
If your readers are interested in fasting – I urge them to do their own research and more importantly try it before they judge it.
Michael.
Thanks for your comment Michael, and personal insights into fasting.
At present I have not seen any evidence compelling enough to convince me that fasting is necessary or even desirable for a healthy individual. Not from my training, knowledge of physiology or continued reading.
It is therefore not something I can recommend publicly or am willing to try privately.
While I think the early studies into using fasting in cancer treatment and heart disease are very interesting and should be pursued, these are not yet conclusive evidence. Plus it is a very different proposition using a treatment in sickness to using it in otherwise healthy people.
There are, as I’m sure you are aware, many, many different opinions, plans, regimes and broadcasts on different ways of eating. I do not believe in using myself, or clients, as guinea pigs until I am convinced of both the efficacy of a treatment and also that it will do no harm. It would be unethical for me to do otherwise.
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