Intermittent fasting is basically choosing a time period during the given day to allow the consumption of your calorie intake with the rest of the time being in a fasted or non-eating state.
There are a few popular methods of introducing this eg- time restricted- 16/8 or 14/10
Theres the 5/2 method where you eat normally for 5 days usually the work week and then have two days following either a time restricted slot or in some cases 1 day of which you would proceed to do a 24 hour fast.
There are a lot of success stories from people following this diet, with many praising its ease of use and results based process, we all know dieting can be either time consuming or confusing to some degree if were following a hyper or hypo caloric diet for instance, so you can see why its popularity is growing.
As we know though from a body re comp standpoint, (muscle retention) due to the use of the nutrient timing principle, this diet structure does not seem best suited to our end goal especially if your active or partaking in physical activity regularly.
Adherence as described above is usually quite easy, but there have been no correlating evidence to suggest that it is easier to follow than any other hypo caloric diet eg- eating regular meals (every 3-4 hours) with a lot more evidence showing that total adherence to the allowed eating window being significantly less during times of rest and relaxation, due to our hunger ques not being suppressed by activity.
For the people who can adhere better to there calorie allotments following a fasting protocol it comes with a trade off for better body composition as explained above (nutrient timing principle)
As noted any diets success lies in the fact it follows the simple process of either calorie restriction for weight loss, calorie balance for weight stablity or calorie over consumption for weight gain.
Calories in vs Out
You will hear a lot of people talk about Autophagy the body’s process by which it breaks down and destroys is own tissues and cells, its an extremely vital system critical to health, without this the body’s systems would wear down and begin to function poorly.
Advocates of the diet will talk about this being the greatest aspect of the diet, for gut health and other reasons, stating that this diet is the only one to produce such results, where studies have shown that following a hypo=caloric diet has shown some of the same benefits, your body must cannibalise its self when there is a lack of fuel for survival (take gluconeogenisis as an example)
The fact that hard exercise also boost Autophagy where the body breaks down muscle tissue to rebuild stronger more adapted muscle in its place.
Interestingly intermittent fasting has shown to increase GH (growth hormone) or at least increase its levels, GH give the signal for fats and carbs to be used as fuel instead of being stored in the muscle, when you fast your body produces GH in order to feed on some of the stored contents of some of its cells. the anabolism effect of GH is stunted though as it can only be anabolic when there are an abundance of protein and calories, hence if you fast to increase GH levels, the lack of excess nutrients leave you lacking the potential for muscle growth benefits.
I mean how are you supposed to get bigger by not eating?
If you feel that intermittent fasting could be for you than by all means give it a go, it has produced some amazing results and touts some benefits, but just remember that during long periods of fasting the increased likelihood of muscle being used as energy substrate is increased.