It’s summertime and it’s that time of year when fad diets start trending again all over social media and otherwise, delivering the promise of offering the perfect formula to get you to lose an x amount of weight in an otherwise impossible timeframe, just in time for your holiday. One of those fad diets that has been getting a lot of buzz lately is the “water fast”.

A water fast, as you have probably already guessed, requires the people taking part in it to go through long periods – sometimes days on end – ingesting nothing but water. While water fast proponents cannot get enough of boasting the supposed benefits of the plan and its effects on their appearance, dietary experts have been less than complimentary about it.

Fasting for an extended period of 24 to 72 hours is considered the maximum amount of time a healthy person is usually able to tolerate without medical supervision, according to Ryan Raman, M.S., R.D., a New Zealand-based registered dietician who wrote for healthline.com on the subject last year. However, it is possible for people to suffer the ill effects of the regimen within that time frame.

Whitney Linsenmeyer, Ph.D., R.D., an instructor at the Saint Louis University department of dietetics and nutrition and spokesperson at the Academy of Nutrition and Dietetics told Women’s Health Magazine that refraining from food for extended periods of time – even between 24 and 48 hours – can have deleterious effects on health. Effects of extended fasting can include drops in blood pressure, arrhythmias, loss of consciousness and seizures.

Furthermore, Linsenmeyer also adds that despite the anecdotes surrounding this diet, as it has not been well-researched, there is no way of knowing its true impact on people’s bodies.

And like many diets, it’s also unlikely to work in the long term. In addition to not being sustainable, long-term calorie restriction, in general, can drive the body’s metabolism to slow down in order to conserve energy, making weight-loss efforts even more difficult.

Dr Jason McKeown, one of the UK’s leading neuroscientists also concurs. He told The Independent earlier this year that the parts of our brains that regulate our weight, metabolism and hunger levels will thwart calorie-restricted efforts to lose weight. He adds that on such diets, the majority of people will reach a plateau weight and eventually gain the weight they have lost.

What should we do instead?

A diet that is rich in fruits, vegetables, legumes, high-fibre carbohydrates that also includes unsaturated fats and lean proteins appear to be what’s universally recommended by experts for weight loss as well as maintaining a healthy lifestyle. High-fat and high-sugar food doesn’t have to be off-limits either, according to an Academy of Nutrition and Dietetics article on its Eat Right website that discusses food cravings. They assert that having a bit of what we enjoy from such foods can stop us from feeling restricted and bingeing on them later.

Some dietitians also advocate a more holistic approach to nutrition and exercise by advocating being in tune with hunger and fullness cues, giving your body a wide range of foods and moving your body in ways that you enjoy. Amy Beth Shen, R.D., a US-based registered dietitian and nutritionist favours this approach and talks more about it in an article on her blog titled “How do I lose weights if diets don’t work?”

Overall, extreme attempts to lose weight don’t fair out well in the long term, and adopting a healthy lifestyle does not have to be arduous or restrictive. And as always, seek professional advice if you want to make changes to your diet or lifestyle by consulting a doctor or a well-qualified registered dietitian.