Mark Twain once said a little starvation can really do more for the average sick man than can the best medicines and the best doctors.
There may be something to Twains belief, as we increasingly hear that skipping meals or even fasting is good for us.
Celebrities like Hugh Jackman, Beyonc and Benedict Cumberbatch swear by fasting diets, while BBC science presenter Dr Michael Mosley created a sensation in 2012 when he devised his 5:2 diet.
Fasting diets come in various forms.
The 5:2 diet allows you to eat normally five days a week and restrict calorie intake to a quarter (500 to 600 calories) on two days.
Alternate-day fasting is one day of fasting, one day normal eating.
Theres also time-restricted fasting, or eating only during certain hours of the day, like the so-called Warrior Diet, which involves minimal calorie intake for 20 hours a day, and eating normally only between 6pm and 10pm.
Weight loss seems to be the main one.
A 2018 study by the UKs University of Surrey found that one group doing time-restricted fasting lost on average more than twice as much body fat as those in a control group that ate meals as normal.
The American Heart Association also stated in 2017 that there was evidence that both alternate-day fasting and periodic fasting may be effective for weight loss, although there are no data that indicate whether the weight loss can be sustained long term.
Dr Mosley argues that not only does fasting lead to weight loss, but also cellular repair and improved brain function.
Accredited practising dietitian Kate Gudorf says fasting appears to produce weight loss as does any form of calorie restriction.
Some studies have found that fasting can reduce fasting glucose levels, HDL (bad) cholesterol, body-mass index, triglycerides (fats in blood) and some inflammatory markers, she says.
The question is, are these outcomes a testament to fasting diets, or because weight loss is produced, which feeds into these other benefits? At the moment we lack good data on fasting diets, says Ms Gudorf, of the Dietitians Association of Australia.
She recommends instead simply eating a healthier diet, with more vegetables and fruit, meaning both fewer calories and meeting nutritional needs.
Weight loss is not always a good indication of diet quality its much easier to eat fewer calories if you simply eat a healthy diet, and nutritionally you would be meeting all your needs.
Basically Australians are not eating very well and getting about a third of their energy from junk food.
Source: The 5:2 Diet Book, by Kate Harrison
Written by Mike Bruce
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