What is fasting or intermittent fasting?
It is an eating routine that either restricts calorie intake on certain days or restricts eating for a time window daily.
Why does it contain "fast"?
I always wondered, still no clue, when you can't eat the exact opposite happens, time will slow down, painfully. 🙂 Tell me if you have a theory!
Goals and history
The main goal is usually to keep your fridge closed, as it's plain and simple: the less you have access to food, the less you will consume. Calorie deficit = Losing weight.
The worst habit most people have is binge eating in the evening, casually consuming another 1000 kcal, when you already reached your daily need before it.
Check your chips, it will say around 150-200kcal per serving, now measure that 30g, which is a "serving" based on the manufacturer, now realise that you usually eat the whole bag 150-250g, multiply that calorie per serving... wonder why you don't lose weight, right?! 🙂
Early in my life I heard the rule: don't eat after 6pm.
Simple, effective, because it kills the binge.
Research money well spent, now we have multiple types of routines that we can follow and we also know that they even have health benefits additional to losing/maintaining weight.
What are the benefits?
Researches show that indeed people are losing weight with fasting for the reasons mentioned.
Researches also show that while fasting:
- insulin levels drop - helps fat burning
- growth hormon levels increase - helps fat burning, muscle growth and more
- cellular repair - the janitor, after 14-16 hours of fasting (other researches say 24-48 hours, so as usually with a complex system, it depends), comes and removes waste material from cells - as anything else cells are working better when in good shape - the process is called autophagy
- gene expression - helps changes in genes and molecules that lead to longer life, less sickness, better protection
Additionally, if you can keep it, you are successfully making yourself more disciplined.
What are the downsides?
Everything has pros and cons, no exception here, based on your progress you can encounter fatigue, headaches, irritability, hunger and low energy.
By my experience these are also there with a calorie deficit, losing weight, especially if you are aiming for a higher rate of weight loss. Somewhat these can be handled by eating at the best times - don't fast for too long if it affects your performance, when you start to feel you are getting far away from your best self, just eat your meal. It's more important to be kind and useful than having cellular repair. Especially when you are only doing it for the first few weeks, really give yourself months on this, it gets easier.
Warning
As usual, intermittent fasting is for the regular healthy adult, in youth, during pregnancy, having any kind of eating disorder or other existing health problems that require a strictly followed eating routine you should consult with your doctor first.
What types of intermittent fasting are there?
1. Calorie restriction
Most followed type by some sources, when you are eating as you usually do for 5-6 days a week, but on 1-2 days you restrict your calorie intake to 500 kcal.
For example you should be eating 2000 kcal per day but you eat 2500 kcal, that's a 3500 kcal surplus (7*(2500-2000)=7*500), but if you have a day when you only consume 500 kcal, that's a 1500 kcal surplus (6*(2500-2000)+(500-2000)=6*500-1500), if you have two days, that's a 500 kcal deficit (5*500-2*1500). So for 5 days you can eat as you usually do, then 2 days only some nice chicken+salad or a few kilo vegetables for volume and you are losing weight already.
2. Time restriction
From easier to harder:
- 12:12 - not eating from the evening till the morning for 12 hours - you might be already doing this without knowing
- 14:10 - delaying breakfast - doing the ancient no eating after 6pm, continue 8am.
- 16:8 - THE intermittent fasting with the listed benefits; there is no one way of choosing the 8 hours; usually its 12pm-8pm, I was doing 10am-6pm more, I couldn't wait till lunch, but I was coping well with not eating in the evening, I wasn't even hungry most of the days.
- 18:6 - 6 hours, I haven't tried, went straight for the next one.
- 20:4 - 4 hours, meaning that you get a lunch and an early dinner with 3 hours in between; I did this too with an early window 10am-2pm, now this was definitely harder to keep, as I got hungry around 5pm, it introduced some daily struggle, for this the key could be to get yourself occupied, so you don't get to think about food.
- 23:1 - the warrior diet, eating once a day; I tried this one as well for a few weeks, around 1-2pm, eating around 2000 kcal in one sitting with a reduced stomach volume due to dieting for 9 months already, it was definitely a challenge to eat that amount from low calorie vegetables and meat. It was a struggle to get till 1pm. Some research says that our mind is working better when we are not digesting, so if you believe that, then this should be your choice. Body building research shows that protein should be taken in portions of max. 50g per meal, requiring 3-4 meals a day, that's not compatible.
- 24 hours a week - not eating for a day in a week, one of my instructors is doing this for a long time, she has her last meal at 7pm on Saturday, then has the next at 7pm on Sunday. She highlighted that it's important that it's an off/rest day, so she doesn't need energy for physical activity, nor mental energy for dealing with any task.
Have you done it before? Which one is your favorite?