Have you heard about intermittent fasting before? You might have come across it especially for those who try to obtain weight loss. Essentially, intermittent fasting is a cycle between fasting and eating. IF is not to tell how or what to eat, but is talking about when to eat.
Type of Intermittent Fasting(IF)
There are several ways to do IF. Common methods are ‘16/8 method’, ‘5:2 diet method’ and ‘Eat Stop Eat’ method.
First of all, the ‘16/8 method’ is fasting for 16 hours and only eating for 8 hours. For instance, you can start your meal time at 10 a.m. and end at 6 p.m. The time adjustment is fairly free based on your condition.
Secondly, the 5:2 diet indicates that 5 days to eat and 2 days (non-consecutively) to restrict your calories within 500-600kcal.
Thirdly, Eat Stop Eat method is a way of fasting for the whole 24 hours once or twice in a week.
What is allowed during fasting?
During the fasting period, water or drinks like coffee, tea, or non-caloric beverages are still allowed.
While many said strictly no any calorie allowed during fasting, some will obtain some low calorie food.
Supplements are still allowed to be taken during the fasting period as long as it is calorie-free.
Studies on IF
Studies that support
Many studies supported IF as a tool to assist in weight loss and improve certain health conditions. A review of studies had concluded that there is a weight-loss trend of 3 to 5 kg after performing IF for 10 weeks among studies. Other than weight loss, few studies showed there is an assistance to reduce BMI, waist circumference, and hip circumference.
Studies that do not support
However, a study showed that it is not superior to daily caloric restriction to lose weight. This may be because IF is not easy to sustain compared to a simple daily caloric restriction of which you only have to reduce food without any time restriction. Yet, weight loss is still obtained for these two groups and it is similar.
On the other hand, IF does improve the function of hormones, cells, and genes, assist in losing weight and visceral fat, reduce insulin resistance and risk of type 2 diabetes, lowers oxidative stress and inflammation in the body, and benefits the brain.
Possible side effects
However, there are some minor side effects for this type of fasting method although it is generally safe for most people. For instance, hunger, craving, headaches, lightheadedness, digestive issues, mood changes, fatigue, low energy, bad breath, sleep disturbance, dehydration, malnutrition is a possibility, as so with other diets..
Who is not suitable
Certain populations are discouraged to perform IF. This includes breastfeeding mothers, young children, teenagers, elderly with weakness, people with immunodeficiencies, dementia, eating disorders, brain trauma, and post-concussive syndrome. To be safe, should you have any medical conditions, please check with your healthcare provider should it be safe for you to perform IF.
Should you try it? IF you fall into the categories above, the answer is No. Otherwise, can give it a try if you wish too.
Just mind that it is not the only way to improve your health. If it doesn't work for you, don't give up, find another sustainable way of eating that fit you!
Want to start intermittent fasting? You may consult our dietitian.
Prepared by Gey Yi Len,
Final Year Student, 2022
BSc (Hons) Dietetics with Nutrition,
International Medical University (IMU)
Checked by Mohd. Siddeq Azha,
Diet Ideas Sdn. Bhd.