Water Fasting: Healthy or Dangerous? We Ask an Expert

There are various ways to fast. One of the most popular is intermittent fasting – following an eating pattern that focuses on when you eat. The 5:2 diet is based around this method which makes you restrict your food intake for two days out of seven. Aside from juice cleanses, there’s also water fasting.

It’s a craze that hit the news at the end of last year. By definition, its consuming only water for a set amount of time. With summer approaching and people once more fixating on diet, we speak to clinical nutritionist Suzie Sawyer.

Suzie is the founder of Nutrition Lifestyle – using nutritional therapy to improve health and well-being. She’s also a qualified personal trainer, a writer and guest TV presenter, and is a regulatory expert in the food supplement industry.

Here is what you need to know about water fasting:

water fasting
Photo by Daria Nepriakhina on Unsplash

What are the common reasons for people to do a water fast?

“The most common reasons for doing a water fast is to try to overcome serious illness, using it as a method of detoxification.  Clearly a water fast is fairly dramatic, therefore people are generally very motivated to try and improve their health.  Obviously, people also fast for religious reasons.”


How long should water fasting typically last?

“I wouldn’t recommend a water fast to last for more than three or four days.  However, I generally don’t recommend a pure water fast (unless for religious reasons) because the detoxification reactions can often be very severe, particularly if someone is loaded with toxins.  I would normally recommend a three day fresh juice fast which better supports these ‘die-off’ reactions.  Juice diets can be carried out for longer, therefore greater health benefits can be gained.  Generally, fasts contain some kind of juice such as carrot or watermelon.  Fasting for one day a week and just having juices is really effective for many health conditions and as an aid to weight loss.”

water fasting
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Is there a way to prepare beforehand?

“People should certainly be avoiding caffeine, alcohol, fizzy drinks, sugary foods and high saturated fats.  People should be eating very ‘cleanly’ beforehand, including plenty of green leafy vegetables and quality protein to encourage the liver to release toxins prior to starting the actual fast.  Otherwise, the reactions are going to be extremely severe.  The last meal before starting the fast is best to be only fresh fruits and vegetables.”


What are the key benefits?

“Many people have found dramatic relief from IBS, rheumatoid arthritis, psoriasis, depression, acute digestive issues and various skin complaints.  Obviously, people frequently use fasting as a weight-loss method, which of course will be achieved, purely because of the vast reduction in calorie intake.  Generally people feel really energised after a fast, skin glows and eyes are bright.”

water fasting
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 Are there any dangers involved?

“Fasting is too dramatic for people who are weakened by serious illness.  However, a short three day fast (preferably a juice fast) can be undertaken under supervision for those with illnesses or at home if the body is not too weak.  The other problem is that the body will be missing out on essential nutrients it needs to properly function on a daily basis.

The body needs around 45 nutrients a day.  We already know that from National Diet and Nutrition Surveys (NDNS) that we have deficiencies, particularly in our key trace minerals.  Energy levels will be low during a fast because there will be a shortage of B vitamins which are needed for energy production.  Clearly, there will be no macro nutrients being eaten therefore people will feel weak, maybe slightly depressed and also struggle to keep warm (during the winter months especially).  Water fasting is not recommended for diabetics as blood sugar levels could drop and cause a diabetic coma.”


What side-effects can be expected?

“A water fast is generally going to bring about detoxification reactions.  This will depend on how ‘toxic’ the individual is prior to starting the fast, hence the recommendation above.  Symptoms can include light-headedness, headaches, and tiredness.  However, symptoms are often slightly less on a juice diet partly because the vitamin C naturally within the juices helps improve the reactions.  Day three is generally the worst day for symptoms.”

water fasting
Photo by Francesca Hotchin on Unsplash


How would you recommend to break a water fast?

“Gently!  Solid foods should be introduced gradually by limiting portions and do not overeat.  Chew thoroughly so that the digestive system does not have to struggle and wait a few days before re-introducing caffeine and alcohol (if at all!).  Eat warm but not overly hot foods.”


Is there anything else worth knowing beforehand?

“It’s best not to exercise during a fast; the body will be tired and therefore you should take plenty of rest.  Blood pressure and body temperature generally drop during a fast because the body’s metabolic rate will slow, therefore it’s important to keep warm.  It’s best to make sure you’re not nutrient-depleted a month before a fast, therefore the diet should be nutrient-dense but should also include a high potency daily multivitamin.  I recommend taking the Alive Ultra Wholefood Plus range which are complete multivitamins and minerals and contain a blend of 26 fruits and vegetables, together with other health-giving green foods.”

You can find Suzie on twitter @nutritionsuzie .


What are your thoughts on water fasting? If you’re in interested in intermittent fasting, check out out article with personal trainer Sam Whittle who shares her thoughts on fed or fasted exercise.

Always consult a doctor or health profession before drastic changes to your diet.

Post Author: Laura Jane Bradbury

Laura Jane Bradbury
I am a trained makeup artist turned writer. When I am not editing articles, I will be glued to my lifestyle blog: thestyleoflaurajane.com, or copywriting for various brands. My passions include poetry, cooking and proving to my friends that a plant-based diet is delicious. Catch me on Instagram @thestyleoflaurajane

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