Intermittent Fasting 101

Intermittent Fasting, also known as IF, is becoming quite popular in recent years. IF is not a diet that eliminates any food group or calorie consumption. It’s about eating in a certain window of time and fast for the rest. However, it’s still important to choose nutrient-dense food that is going to keep you full longer. During the fasting period, only food with no calories is allowed, such as water, tea, and black coffee. 

Forms of IF:

1. The 16/8 method, also known as Time-restricted feeding: 
   1. This method involved eating 8 hours and fasting 16 hours repeatedly in a cycle. For example, you can eat from 8 am to 4 pm and fast until the next morning at 8 am. The time of eating and fasting can be adjusted as long as you keep a good 14 to 18 hours fasting window.
2. The 5:2 diet, also known as Whole day fasting 
   1. This method involved no fasting window 5 days of a week, but fast two days of a week. In these two days, you can eat 25% of your daily intake or fast completely. 
3. Alternate-Day Fasting:
   1. As what the name sounds like, a person is going to fast every other day. This method is probably the most extreme one (not so recommended). You can do it by having no food restriction for one day, and eating only 25% of your daily intake the next day.1

Why should you practice IF? 

IF has been proven to help with weight management and fat loss. Research has shown that fasting results in a reduction of the body’s insulin release, a hormone that regulates glucose level in our body. When the insulin level is low, our body will burn fat as an energy source rather than glucose.

In addition, fasting can also increase Human growth hormone release. Increase amount of Human growth hormone is able to enhance athletic performance, build muscle, and burn fat. Some lab results have shown that IF can significantly decrease blood pressure and resting heart rate.

IF has also shown to improve gut health, which helps with bloating, digestion, and elimination.

All of these benefits of fasting are going to promote the longevity of our life.   

Who should practice IF and who shouldn’t? 

Even though Intermittent fasting sounds fascinating with numerous health benefits, people should still ask permission from their doctors, especially people with special conditions, such as women in pregnancy, adolescents, athletes, and people with eating disorders.

IF is suitable for people with obesity, healthy people who want to improve their general wellness, and busy people who like to eat less frequently with a bigger meal. However, nobody has to improve their wellbeing by doing IF because you may lose dinner with friends and family.  It’s more important to find a sustainable and positive lifestyle that fits you the best!

Personal views

I like to practice 16/8 when I am at home. I would fast until noon to eat my breakfast. In that way, I only need to cook two meals a day, which saves a lot of time. However, it’s important to keep in mind that missing a meal means skipping nutrients. You still need to incorporate an adequate amount of vegetables, quality protein, healthy fats, and whole grains into the two meals. I find it challenging to eat vegetables during IF, so I always have a big glass of green smoothie as my first meal. When I am fasting, I do find my mind is sharp and I experience less bloating throughout the day.

Sources:

1. Persynaki A, Karras S, Pichard C. Unraveling the metabolic health benefits of fasting related to religious beliefs: A narrative review. Nutrition. 2017;35:14-20. 
2. Heilbronn L, Smith S, Martin C, Anton S, Ravussin E. Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. Am J Clin Nutr. 2005;81(1):69-73.
3. Mattson M, Longo V, Harvie M. Impact of intermittent fasting on health and disease processes. Ageing Res Rev. 2017;39:46-58. doi:10.1016/j.arr.2016.10.005
4. Heilbronn L, Smith S, Martin C, Anton S, Ravussin E. Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. Am J Clin Nutr. 2005;81(1):69-73.