Intermittent fasting: all you need to know
How intermittent fasting works, what benefits it has for health and what you must bear in mind before you follow it
For some people, the advice to “cut back on food” appears impossible. Still, new research comes to support those already claiming that intentional abstention from food for some hours every day or some days a week can contribute to weight loss, changes in body composition, to health improvement, even to the prevention or remission of important illnesses, starting with cancer.
Intermittent fasting (IF), also known as 16:8 or 5:2 is one of the most popular tendencies globally, as its timetable and not its content appears to constitute an important “weapon” for the human body, causing metabolic changes. It is a nutritional pattern which includes time “windows” where the body receives no food and “windows” where it consumes normal meals. That is why it is not considered a “diet”, but more a nutrition method.
Intermittent fasting types
There are different protocols for intermittent fasting, such as fasting on alternate days, fasting for a whole day or time-restricted eating.
The most popular method – and the easiest one – is called the protocol of time-restricted eating or 16:8 method. In this method we skip breakfast (and snack) and the day’s meals are restricted to an eight-hour interval, for example 13.00 to 21.00. Subsequently we are forbidden to eat for 16 hours. The “waiting” hours include sleep, but also work hours.
Fasting on alternate days: in this method, days with unrestricted food consumption are alternated with days during which one meal is allowed which contains approx. 25% of daily energy needs (~400-600 calories). Of course, the number of fasting days may differ from program to program.
Method 5:2 or whole-day fasting: here unrestricted food consumption is allowed on most days of the week and there is a big caloric restriction or total abstention from food on 1-2 days a week. The protocol 5:2 supports fasting on 2 non-consecutive days of the week with consumption approx. at 25% of daily energy needs. On the remaining 5 days one can eat without restriction.
Intermittent fasting is considered beneficial for the human body, as its operation leads to fat loss and increase of muscular mass. Insulin levels drop significantly, and these lower levels make stored fat more “available” for consumption, while the cells during fasting hours activate regeneration mechanisms which remove “old” and non-functional proteins from the inside of the cells. At the same time, the consumption of fewer meals leads to weight loss, since the calories the body receives on the day are reduced. Of course, if one consumes too “heavy” meals during the hours it is allowed to eat, they may not lose any weight in the end.
Besides weight loss, intermittent fasting seems – according to scientific research – to help reduce inflammation in the body, reduce “bad” cholesterol and triglycerides, prevent cancer, protect from Alzheimer’s and in anti-ageing.
Points of attention
Intermittent fasting is not for anyone. If one is too thin or has history of eating disorders they should not fast without first consulting a specialist. Those suffering from diabetes or taking medicine requiring food intake, those in an active growth stage (children / adolescents) and pregnant or lactating women should also take special care.