Intermittent fasting has become one of the recent and hottest topics in the health and fitness community. Many are using it to lose weight, improve health and simplify their lifestyles. International celebrities like Chris Hemsworth, Hugh Jackman, Beyoncé and Ben Affleck are known to practice this method.
What is intermittent fasting (IF)?
It is an eating pattern that consist of periods of fasting and eating. It does not specify which food to eat, but rather when one should eat. Fasting in general is also often done for religious or spiritual reasons, as practised in Islam, Christianity, Judaism and Buddhism.
10 Benefits of intermittent fasting
Intermittent fasting methods
Common IF methods are as follow:
- 16:8 diet
Also known as the Leangains protocol, involves skipping breakfast and restricting one’s daily eating period to 8 hours (e.g: 1-9pm). The remaining 16 hours will be the fasting period. One can still drink water, coffee (no added sugar/milk/cream) and other non-calorific drinks during the fast. NHS recommends those who are overweight to lose about 5-10 % of their starting weight by losing 0.5 – 1kg a week.
- Weekly intermittent fasting
A 24-hour fast once a week is the most practical IF strategies as it allows one to choose the most convenient day to fast. In the example, you will have lunch as your last meal on Monday, followed by fasting till lunch on Tuesday.
- Alternate day fasting (ADF)
This method incorporates longer fasting periods on alternating days throughout the week. The picture above shows fasting on Monday night till Tuesday evening. On Wednesday, you can eat all day and start the 24-hour fasting cycle again after dinner. Studies have shown that ADF may aid in boosting endurance exercise performance, reducing cravings due to satiety feeling and helps in weight loss.
- 5:2 diet
This method involves one to consume about 500-600 calories on 2 non-consecutive days of the week and eat normally on the other 5 days. This diet was made popular by a British journalist and doctor; Michael Mosley. This strategy was found to improve insulin sensitivity and body fat reduction.
By reducing the calorie intake, the above methods can cause weight loss as long as you don’t compensate by eating much more during the eating periods.
Safety and side effects
The main side effect of IF is hunger. In addition, you may feel weak and your brain may not be able to perform as well as you’re used to. Nevertheless, this may be temporary as it takes some time for your body to adapt to the new meal schedule.
Intermittent fasting may not be suitable for everyone. Consult your doctor before trying intermittent fasting. This include those who:
- Have diabetes
- Have issues with blood sugar control
- Have hypotension (low blood pressure)
- Are underweight
- Have history of eating disorders
- Are a woman trying to conceive
- Are pregnant or breastfeeding
- Are a woman with history of amenorrhea (absence of menstruation)
Despite the above, intermittent fasting has an outstanding safety profile. As long as you are healthy and well-nourished, there is no harm about not eating for a while.
References:
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Best Intermittent Fasting Strategies & How to Fast - DrJockers.com. Accessed August 6, 2020. https://drjockers.com/best-intermittent-fasting-strategies/
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The Beginner’s Guide to Intermittent Fasting. James Clear. Published December 10, 2012. Accessed August 6, 2020. https://jamesclear.com/the-beginners-guide-to-intermittent-fasting
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Intermittent Fasting 101 — The Ultimate Beginner’s Guide. Healthline. Published April 21, 2020. Accessed August 6, 2020. https://www.healthline.com/nutrition/intermittent-fasting-guide
- Harvie M, Wright C, Pegington M, McMullan D, Mitchell E, Martin B, et al. The effect of intermittent energy and carbohydrate restriction v. daily energy restriction on weight loss and metabolic disease risk markers in overweight women. Br J Nutr. 2013;110(8):1534-47.
- Marosi K, Moehl K, Navas-Enamorado I, Mitchell SJ, Zhang Y, Lehrmann E, et al. Metabolic and molecular framework for the enhancement of endurance by intermittent food deprivation. FASEB J. 2018;32(7):3844-58.
- Harris L, Hamilton S, Azevedo LB, Olajide J, De Brun C, Waller G, et al. Intermittent fasting interventions for treatment of overweight and obesity in adults: a systematic review and meta-analysis. JBI Database System Rev Implement Rep. 2018;16(2):507-47.
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