Is alternate-day fasting a safe alternative to dieting?

We’ve had 5:2 and 16:8. Now meet alternate-day fasting, the latest interval eating plan making waves.

A new study has looked at the possible health benefits of alternate day fasting – or skipping meals every second day.

The research by Austria’s University of Graz looked at the effects of having no food for 36 hours, followed by 12 hours of regular eating.

The study found that, over four weeks, alternate-day fasting helps people eat about 35 per cent fewer calories and lose an average 3.5 kg.

And there were some other health benefits, too.

The levels of ketones – formed when we burn fat – were raised even on non-fasting days.

Markers in the body linked to age-related disease and inflammation improved, and alternate-day fasting also lowered cholesterol and belly fat.

What Aussie experts say about alternate-day fasting

So, is only eating on alternate days the best option if you want to try fasting?

“If weight loss is your major goal, alternate-day fasting is one way that will get you the most bang for your buck,” say associate professor Leonie Heilbronn, leader of the obesity and metabolism group at the University of Adelaide.

“You have three-and-a-half days a week when you are fasting, which is quite a big restriction on energy.”

Kate Gudorf, of the Dietitians Association of Australia, says fasting triggers a cascade of responses in the body that ultimately lead to hunger signals and hunger hormones being released.

After this, our body then breaks down glycogen stored in muscles and the liver and then breaks down and uses up fat stores – particularly around our middle.

“For generally healthy people without any medical conditions, fasting works,” Kate says.

“It helps them improve cardiovascular risk factors and helps them lose weight.”

But fasting isn’t recommended for women who are pregnant or breastfeeding, for the elderly and for people with some medical conditions.

The best way to make fasting work

“But fasting also depends on what your diet looks like on the days you are eating,” Kate says.

“You may reduce your calorie intake – but are you just eating cakes on the days you can eat?

“Overall diet quality is important for your risk factor for developing chronic disease. For example, fruit and vegetables are important for decreasing the risk of certain cancers like bowel cancer.

“What fats you eat are also important in determining your risk of cardiovascular disease and your choice of carbohydrate foods is important for your risk of developing diabetes.

“We can’t just look at calorie intake and exclude diet.”

If you want to try alternate-day fasting, try fasting from breakfast to breakfast time but drink plenty of water and top up salt levels with low-calorie stock cube broth.

Written by Sarah Marinos