Intermittent fasting has been touted as the easiest way to lose weight and improve health. It is said to fortify the body against diseases and improve long-term health by repairing the body at the cellular level. Potential benefits include better diabetes control and prevention, cancer prevention, improved cholesterol profile, boosted brain power. Some people even believe fasting can result in a longer lifespan.
Some of our favourite celebrities reportedly swear by intermittent fasting. Famous faces who adopt this approach include:
- Hugh Jackman – The Wolverine star only eats during an 8-hour window each day
- Nicole Kidman – The Australian actress only fasts for up to 16 hours a day and tucks into lean proteins and vegetables for the rest of the time
- Chris Hemsworth – Best known for his role as Thor, the Australian actor is known to fast for up to 15 hours a day as a means to maintain his physique
Currently we do not have enough evidence to recommend it as studies have been small-scaled and done mainly on overweight individuals and animals.
What is intermittent fasting?
Intermittent fasting is not about denying yourself your favourite food. Instead, it’s all about when you eat them. This means you follow set periods of eating and fasting throughout the day. Specifically, how long you fast for depends on your compliance and what best fits into your eating patterns.
There is the 16:8 method. These people fast for 16 hours overnight, leaving an 8-hour window during the day to eat food normally. Some choose to skip breakfast and eat lunch and dinner; others choose to eat breakfast and lunch and skip dinner.
Another popular option is 5:2 method. These people choose to fast for 24 hours twice a week and eat normally for the rest of it. During fasting period, they restrict their intake to only 500 – 600 calories a day. They should also drink adequate fluids, such as water, zero-calories drinks to help them stay hydrated and keep energy levels up.
Can intermittent fasting help me lose weight?
Intermittent fasting could be a way to help you maintain a healthier weight as people tend to consume lesser calories during a restricted window for eating. Calorie restriction and different forms of fasting have been shown to have major physiological effects from health benefits to longevity. During fasting periods, your body may produce more fat-burning hormones that help boost your metabolism and allow you to drop pounds without losing muscle tone.
However, it’s crucial to maintain a well-balanced, healthy diet during your set eating periods too. Consuming unhealthy junk food when you’re not fasting could hinder weight loss in the long term.
Instead, make sure your body is still getting all the nutrients it needs and continue exercising regularly for at least 30 minutes a day, 5 times a week.
How to fast safely
- Keep fasting periods short – Fasts that last over 24 hours could leave you feeling irritable, dehydrated or tired
- Stay hydrated – Don’t forget to drink water even while you’re fasting to avoid developing a headache, dry throat or getting dehydrated
- Eat plenty of protein – This will help to minimise muscle loss and help you manage your hunger more effectively
- Slow down while fasting – Some people find it easier to exercise during eating periods and only do mild exercise during fasting periods
- Don’t overeat – Breaking your fast with a big meal may make you feel bloated, uncomfortable or tired. It may also eventually make you put on weight
- Stop fasting if you feel poorly – Seek medical help if you feel extremely weak or experience unexplained discomfort
What risks are associated with intermittent fasting?
While intermittent fasting can have its benefits, it’s important to remember that it’s not the right choice for everyone. You don’t need to fast to be healthy and happy.
It may interfere with some women’s menstrual cycles, so if you have abnormal menstrual patterns or if you’re trying to conceive, you may wish to hold off trying it for now.
It may be dangerous to fast if you have a pre-existing medical condition such as diabetes or low blood pressure. Individuals with a history of eating disorders may also find it’s not the right choice for them.
If you’re considering trying intermittent fasting, make sure you book an appointment to speak to your doctor or dietitian first. They’ll be able to help you plan a safe eating plan and monitor how well it works for you.
Article reviewed by Daphne Loh, senior dietitian at Gleneagles Hospital
Gunnars, K. (2017, Jun 4). 6 Popular Ways to do Intermittent Fasting. Retrieved 09/07/2019 from https://www.healthline.com/nutrition/6-ways-to-do-intermittent-fasting#section2
Gunnars, K. (2018, Jul 25). Intermittent Fasting 101 — The Ultimate Beginner's Guide. Retrieved 09/07/2019 from https://www.healthline.com/nutrition/intermittent-fasting-guide
Koman, T. (2018, Aug 2). 10 Celebrities Who Swear by Intermittent Fasting. Retrieved 09/07/2019 from https://www.delish.com/food/g22617665/celebrities-intermittent-fasting/
Leicht, L. (2018, Nov 26). Intermittent Fasting. Retrieved 09/07/2019 from https://www.webmd.com/diet/a-z/intermittent-fasting
West, H. (2019, Jan 2). How to Fast Safely: 10 Helpful Tips. Retrieved 09/07/2019 from https://www.healthline.com/nutrition/how-to-fast
Yavangi M, Amirzargar MA, Amirzargar N, Dadashpour M. Does Ramadan fasting has any effects on menstrual cycles?. Iran J Reprod Med. 2013;11(2):145–150. Retrieved 16/09/2019 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3941357/#.
Lessan, N and Ali, T. Energy Metabolism and Intermittent Fasting: The Ramadan Perspective. Retrieved 16/9/2019 from https://www.ncbi.nlm.nih.gov/pubmed/31137899