What is intermittent fasting?
Intermittent fasting is a pattern of eating where you occasionally shake up your dietary routine by drastically reducing your kilojoule intake for a day.
This fast may occur twice a week, or five days a month, and is usually around a quarter of your usual kilojoule intake.
Why do intermittent fasting?
The idea is to replicate the way we used to eat as hunter/gatherers, where days of abundant food intake were interspersed with scarcity.
This is a drastic shift from our current food culture, where abundance is the daily norm, and three square meals are often accompanied by high kilojoule beverages and snacks in between.
Get the latest in wellbeing news
Sign up to the fortnightly wellbeing update and get the latest articles, recipes and more delivered straight to your inbox!
The benefits of intermittent fasting
A healthy waistline
As you might expect from a diet that cuts down your kilojoule intake, there are clear weight loss benefits.
published in the journal of Science Translational Medicine
found that subjects who fasted five days a month for 3 months reduced body weight, waist circumference and BMI, and also lost total body and trunk fat.
The important result for body shape is that these improvements originated from a loss of body fat, and not from total body weight or muscle mass.
The study mentioned above also showed that the benefits of fasting extend beyond weight control.
It was found that fasting led to improvements in important markers of health, including blood pressure and inflammation. The researchers concluded that periodic fasting is effective in improving an array risk factors associated with poor health and aging.
It has also been theorised that the fasting practices followed by some religious groups in countries such as Crete and Greece could be a hidden component in the health boosting Mediterranean diet and lifestyle.
What to consider before you fast
Are you getting enough nutrients?
Any diet that severely restricts your kilojoule intake will also restrict your nutrient intake. It is therefore vital to include nutrient rich foods in your diet on both fasting and normal eating days to compensate. Look to include fruits, vegetables, nuts, lean protein sources and whole grains, which are all high in vitamins and minerals
It is also best to avoid processed foods high in kilojoules, but low in nutrients such as white bread, soft drink, and packaged snack foods.
Other strategies that may reduce the risk of nutrient deficiency during a fast include:
- Taking a multivitamin or other nutrient supplement
- Avoid fasting for two days in a row
- Avoid fasting any more than twice a week
It won't do wonders for your social life
Any diet where meals are eliminated, or where your usual kilojoule intake is drastically reduced is going to bring with it challenges. Research has shown the up to 25% of participants in a recent study on intermittent fasting dropped out before finishing the trial.
Food offers more than just kilojoules for survival, and plays many roles in our life. Eating with family and friends is one of life’s great cornerstones for social interaction, bringing people together and building connections. To avoid isolation, plan ahead to ensure fasting days don’t clash with important family and social functions.
I'm so hungry!
While intermittent fasting is thought to help us become better at regulating our food intake and reducing portions, it will also trigger feelings of hunger.
While the degree of hunger you experience may vary between individuals, the drive to eat is a powerful survival instinct that can be hard to resist. You will have to rely on will power, and resist temptation if you are to succeed at drastically reducing your kilojoule intake on fasting days.
It can also result in binge eating, or periods of extreme over eating afterwards, where the body over-compensates for the “famine” it has just experienced.
A little bit of hunger is not a bad thing, but it will require effort to keep the beast under control.
Who shouldn’t try intermittent fasting?
Until further long-term research confirms the safety and effectiveness of intermittent fasting, it is certainly wise to approach with caution.
In fact, there are some people who should avoid intermittent fasting, such as diabetics, who depend on a steady stream of dietary glucose to best manage their condition.
Other people who should avoid intermittent fasting include women who are pregnant or breastfeeding, people on certain medications which need to be consumed with a meal, where there is an underlying medical condition that won't respond well to a fast.
Before undergoing a fast, or if you have any concerns talk to your doctor or naturopath.