If you have been struggling with your weight or just wanted to shed a few kilos, then inevitably you would have tweaked your eating habits at some point. While some may have succeeded in maintaining a lower weight, many have failed, regressing completely and even putting on extra weight. Is intermittent fasting an option?
you may have heard of or have experimented with this nutritional fad or, for lack of a better word, ‘diet’. Perhaps this has become your way of life, perhaps you have abandoned it, or perhaps you are keen to give it a try (again) and would like to know more. Intermittent fasting (IF) has made its way into the ‘dieting’ hall of fame over the past few years following the publication of The Fast Diet by Dr Michael Mosley, a BBC broadcast journalist.
To be accurate, IF is more an eating pattern than a diet per se. It exists in various forms but essentially involves fasting (not consuming any calorie-containing foods or beverages) for extended periods during the day or week depending on the selected regimen. IF allows unlimited consumption of water and black tea/coffee without sugar during fasting intervals.
Popular IF regimens include:
- 12/12 – fasting for 12 continuous hours and eating all your food during a continuous 12-hour window every day
- 16/8 – fasting for 16 consecutive hours and eating all your food during a continuous 8-hour window every day
24 hours – fasting for 24 hours once or twice per week
- 5:2 – consuming only about 25% of your recommended caloric intake on two non-consecutive days of the week
Fasting is by no means a new concept. While some choose to fast for religious and/or spiritual reasons, fasting has coexisted with humans over the ages. Our ancient hunter-gatherers did not have supermarkets, fridges, or food available year-round. At certain points during the year there just was not enough food to go around. Thus, the human body biologically evolved to function without food for extended periods of time.
What is the bottom line? Research emerging from Harvard Medical School seems to strongly suggest that IF can ‘make a more realistic, sustainable, and effective approach for weight loss as well as for diabetes prevention’. Our bodies have evolved in a such manner that any excess food is stored as fat. When we eat, we consume some combination of carbohydrates, proteins and fats. Digestion involves breaking down these complex food molecules into their respective simple building blocks – monosaccharides (simple sugars such as glucose), amino acids and fatty acids. Following digestion, the pancreas secretes insulin in response to rising blood sugar levels driving the absorption and assimilation of these simple molecules into our fat stores. However, insulin can be likened to an escalator – it moves sugars, amino acids and fatty acids in one single direction only − that is, into our fat cells as a store of energy.
Constantly eating all day from the time we rise until the time we snooze results in a constant secretion of insulin (even in small quantities) resulting in a one-way uptake by our fat cells. Without a break in insulin secretion, we deprive the fat cells from being able to release this stored energy. This is where IF comes in. By limiting our eating window, we can allow the body to enter ‘fasting states’ in which insulin secretion is turned off and our fat cells are able to release their stored products. With time, results become noticeable as our fat stores are depleted on a net basis.
Sure, some discipline is required, and one has overcome some, albeit manageable, bouts of hunger; a sensation our hunter-gather ancestors knew all too well. Many people start with the 12/12 regimen, initially taking weekends off, and work up to the 16/8 regimen weekends included. Depending on whether you prefer an early breakfast or can go hours without food after rising can help you decide when to choose your window. I generally eat from 11.30 to 19:30 and delay my eating window on days when I know I have a late dinner planned. There may be days (especially when you first start) that you accidentally eat something during your fasting window, or you are forced to eat a bit later than planned outside your planned eating window. One consolation can be to shorten the next day’s eating window to account for the longer window of the preceding day.
The beauty of IF is that it does not require calorie counting, has some flexibility and does not require drastic dietary changes. Needless to say, however, it is underpinned by conscious nutritional choices. For effective weight loss and disease prevention, refined and/or ‘white’ carbohydrates should be kept to a minimum. Daily consumption of a variety of fruits and vegetables goes without saying. Consumption of plant-based fats such as avocados, coconut, seeds and nuts should be increased in favour of animal-based fats. Convenience foods and junk foods should also be kept to a minimum, while red meat and alcohol should be moderated. Getting at least seven hours of shut eye also plays a pivotal role in your overall wellbeing and nutritional goals.
While I encourage you to give IF a try, please realise that this article does not constitute medical advice and any changes to your eating habits or diet should be discussed with your healthcare provider first, especially if you have co-existing medical conditions or you have battled with weight loss before.