What is the fundamental science behind the idea of “Intermittent Fasting” and how does it work?
In: Biology
Calories in, calories out. You eat more in one meal but you eat less overall for the day (in theory).
You just eat less calories overall mostly because there’s a limited time for you to eat and you don’t get hungry enough to compensate for all the calories you would’ve eaten if you hadn’t fasted.
Your body goes through different digestive/processing stages that are triggered when you eat. So if you start fasting at 9pm the process starts, but if you eat a snack at 10pm the process starts all over again.
The first thing is your blood sugar rises as food is absorbed, and energy is stored.
Second is glucose is used for energy, once it is used up, the body starts using stored fat.
After 11+ hours, all the immediate glucose is used from the food and you’re just burning fat.
After 14+ hours you enter ketosis and start producing ketones which provide energy to organs and the brain. A lot of people have more focus at this point in the fast.
It is another fad diet trend. Losing weight means you need to change your eating habits overall and maintain that. There is no special gimmick to losing weight, and it takes a lifetime commitment to lose the weight and not gain it back.
Weight loss is about calories in vs calories out. By limiting eating to set hours, calories in are restricted. As such, intermittent fasting is an effective method of weight loss. Relative to other calorie restriction systems, it may be easier to adopt since a practitioner can eat “whatever they want” during eating hours.
It’s a way of approaching CICO (calories in calories out). If you can pick a time of the day where you don’t like to eat, then skip the meal. You’re unlikely to match the calorie intake with the remaining meal(s), so less calories in, but without a huge loss of quality of life (you didn’t like to eat at the tine anyway).
It works very well if you skip some garbage food you just felt obliged to it.
ELI5: eat all you can and then go outdoors
Intermittent Fasting (IF) is a diet protocol that works by limiting the window someone will eat. By theory if limiting your food intake to a set hourly range, you should be eating less than before. This reduction in calories would then cause weightloss.
Now the problem with IF or other restrictive diet protocols is the possible issue of binge eating within the range of the restriction. The difficulty in any diet protocol is very much the battle of hunger signaling and psychological cues that occurs from changing dietary habits. Our body loves homeostasis (staying in “balance”) and by reducing intake (or limiting a specific macro) the brain will fight that change because that change counteracts homeostasis.
It’s always important to consult your doctor and/or a dietary professional before changing dietary intake if possible. Incorporate increased non-exercise activity (stand up at your desk, more walking, use stairs instead of an elevator) as well as use exercise as a way to help influence a positive outlook towards your health goals.
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