How to find the best intermittent fasting method for you

Intermittent fasting may be a popular approach to weight loss and healthier living but is it right for you? Here’s the lowdown on this dietary trend.

From reducing blood glucose levels to boosting weight loss, intermittent fasting appears to have several health benefits.

With growing evidence from scientific studies, it’s no surprise that more people are turning to this dietary trend.

But what’s the go with intermittent fasting? And is there a right way to do it?

Here is what dietitians have to say.

What is intermittent fasting?

Intermittent fasting is a way of eating that restricts calories for set periods of time, dietitian Susie Burrell says.

“It is effective in helping to achieve both weight loss and significant reductions in inflammation in the body,” Susie explains.

“When we first heard the words ‘intermittent fasting’ a few years ago, it was the 5:2 diet that caught our attention.

“More recently, the 16:8 fasting diet has emerged as a popular alternative to the relatively strict 5:2 diet.”

Will intermittent fasting help you lose weight?

Sydney sports dietitian Chloe McLeod says there’s a reason why intermittent fasting has gained popularity across the nutrition industry and she has seen the results first-hand.

“A recent client was a 40-year-old male with a high-pressure job who travelled regularly and needed to lose some weight, but was also very time poor,” Chloe says.

“After three months of intermittent fasting, he had a loss of body fat.”

Writing about her personal experience with intermittent fasting for The House of Wellness, Jenna Meade recounts that she lost a little weight and had more mental clarity.

A recent study analysing 27 trials found intermittent fasting resulted in weight loss, regardless of changes in overall caloric intake.

How do you do intermittent fasting?

The 5:2 fasting diet

The 5:2 program is a diet that consists of eating normally for five days a week, with two non-consecutive low-calorie eating days of around 500 to 600 calories, Susie says.

“Research suggests significantly restricting caloric intake for brief periods of time appears to ‘reset’ a number of metabolic hormones that play key roles in fat metabolism and glucose regulation in the body,” she explains.

“While the caloric restriction does not directly result in weight loss, moderate weight losses over time may be observed as these metabolic variables work more efficiently.”

One small study found the 5:2 diet may be as effective as traditional dieting for weight management, with participants reporting feeling more satisfied with the strategy.

How to eat on a 5:2 diet

According to Susie, a typical fasting day on a 5:2 diet may look like this:

Breakfast: Small skim cappuccino

Lunch: Two egg omelette with vegetables

Dinner: 70g chicken breast, plus one cup green veggies in soy sauce

Snack: One cup of popcorn, one cup of berries

The 16:8 diet

This method involves eating across an eight-hour window during the day, then fasting for the other 16 hours, Chloe says.

While it requires going without food for an extended period of time, a 2018 study on 23 obese participants found it may be a viable weight-loss technique.

How to eat on a 16:8 diet

To do the 16:8 diet, Chloe suggests starting your day with plenty of water to prevent hunger pains and eating your first meal at around 11am or noon.

During the eight-hour period, she recommends aiming for two larger meals and a more substantial snack.

“For example, eggs with roast vegetables, wholegrains and avocado to start, then a snack of yoghurt, fruit, oats, nuts and seeds,” she says.

“Finally, a dinner of fish, sweet potato and veggies.

“Plan for your final meal of the day to be by 7pm or 8pm.”

Can you drink water or coffee when fasting?

Drinking coffee while you’re fasting is unlikely to compromise your fast in a significant way, so long as you’re careful with adding ingredients.

That’s why zero-calorie beverages are generally recommended during the time period when you’re not eating.

This includes water, black coffee and plain tea.

Are intermittent fasting diets healthy?

Intermittent fasting has famously been adopted by celebrities such as Hugh Jackman and Halle Berry.

Using a variety of intermittent fasting routines on different clients, dietitian Jaime Rose Chambers says she has had positive results.

“Like any lifestyle intervention, it’s not for everyone, and it’s important to match a particular method of fasting with a particular person,” Jaime, the author of 16:8 Intermittent Fasting, says.

“As an evidence-based practitioner, I’ve certainly been able to take it on as a dietitian and, while the main drawcard is weight management, there’s a roll-on effect because when you do lose weight, your blood cholesterol and blood pressure goes down.

“Your inflammatory markers go down, your insulin sensitivity improves, (and) you sleep better.”

Is intermittent fasting right for everyone?

While intermittent fasting may bring health benefits, some people may experience side effects such as low energy levels, headaches, fatigue, constipation and heartburn, Chloe says.

“Extreme hunger may also result in overeating when not fasting,” she adds.

Regardless of the intermittent fasting method you choose, Chloe says there are general guidelines to follow to ensure effectiveness and safety.

“It’s important to listen to your body and ensure you’re still meeting your daily nutritional needs,” she notes.

“Fasting is a good way to get into a routine, but remember it’s OK to have flexibility in the routine when needed.”

If you’re planning on fasting, Chloe says, it’s important to keep well hydrated and make healthy food choices when you’re eating, including plenty of veggies, wholegrains, legumes and healthy fats rather than highly processed foods.

How long does intermittent fasting take to work?

For effective intermittent fasting, Susie says it’s important to choose the fasting style that you will be able to sustain, ideally, for at least eight to 12 weeks.

“It is not so much a question of which method is better, but which method you will stick to,” she explains.

“Like any diet, results will only be achieved when you can actually commit to the regimen.”

Which intermittent fasting method is best for you?

Susie recommends considering your lifestyle before choosing an intermittent fasting method.

“A crucial point when considering a regular fast in your weekly dietary regimen is what your energy demands are like,” she says.

“For busy, active individuals who have high-energy demands, the 5:2 diet is especially tough and may even be inappropriate.

“On the other hand, for those who do not eat a lot throughout the day and instead tend to eat a larger meal at night, if they can keep the size of their evening meal controlled, the 5:2 can work especially well.”

Ultimately, Susie says to remember that fasting is not a quick-fix diet solution but rather a lifestyle choice that can help with weight control.

More on healthy weight loss strategies:

• Is this the trick to maintaining weight loss?
• Why healthy living is a better long-term goal than weight loss
• Is alternate-day fasting a safe alternative to dieting?
• Is this the winning formula you need for weight loss results?

 Originally written by Susie Burrell, April 2021. Updated by Melissa Hong, April 2024.