Sup, /fit/ I dont normally browse this board but I need to settle

>>39447647
>calories in
>calories out
why is this so fucking hard to understand

>>39447687
Well because of the reasons and situations I listed and clearly I'm struggling with understanding the mechanics of metabolism thanks

>>39447957
Totally depends on how many calories you burn (aka "calories out") and that varies widely from person to person based on age, gender (real gender, not made up shit), muh conditions, and so on.


So, any advice that tells you to eat a specific number of calories is automatically wrong. You kinda have to work backwards: If you know how many calories you're eating, just observe your weight over the course of a month. If your weight is holding steady, then you are eating "at maintenance", i.e. you are burning as much as you eat, no more, no less. If you are steadily losing a pound a week, you are eating 500 calories a day deficit. If you are steadily gaining a pound a week, you are eating 500 calories a day surplus.

But again, the most important point here is that your "calories out" number depends on YOU. If you're a 70 year old granny, it's probably like 1000. If you're Michael Phelps, it's probably like 6000. If you're a normal male it's probably somewhere between 2000-3000. If you're a normal female it's probably somewhere between 1500-2000.

>>39447647
If you eat at a slight deficit, you will lose weight. This is because what you are eating is below your total daily energy expenditure (TDEE). Eventually, as you lose weight, your TDEE will decrease. When you have less mass, you require less energy. When you TDEE decreases to the point it matches your calorie intake, you will stop losing weight.

So for your first question, yes, probably. Assuming 1,500 was your maintenance intake and was keeping your weight stable enough to be BMI 17.3. That would mean your TDEE was 1,500. If you eat 2,000, you would slowly gain weight. However, if your TDEE was actually 2,000, but you were eating 1,500 and still losing weight at a BMI of 17.3, returning to an intake of 2,000 calories would not make you gain weight. It would simply be enough to keep you from losing weight.

For your second situation, you will continue losing weight until your decrease in mass makes your TDEE drop to 1,500. At that point, your weight loss will plateau and your weight will stay the same. Most humans can survive on 1,500 cal if they are sedentary. They will be thin and weak, but still able to survive and be "healthy". Especially small women, less so with larger men.

There's a thing called a BMR. Its your body's metachloric rating. Basically its how many calories your body burns at rest, just keeping your heart beating and lungs inflating etc... Everyone's is different and determined by a bunch of bullshit like height, weight, bf%, etc... All them 1500 and 2000 hypotheticals you conjectured are meaningless. If you eat below your BMR, weight loss. You eat above how many calories you burn in a day, known as your TDEE (totalitarian dystopian earthling equivalent) and you will gain.

As you gain you need more cals to maintain. As you lose you need less cals to continue to lose.

Hope I helped fagoot.