I’ve been trying to understand how your metabolism works and I’ve been stuck on a few things that I think I’m just totally misunderstanding
This is just out of curiosity of course

1) I’ll read/hear that insulin is the “growth” hormone but every cell in the body can take glucose from the bloodstream without it when they want to burn energy (or build muscle even) but only fat cells need it to get the glucose into the cell - is this true or is insulin required for all cells to take in glucose including when it is going to take it in and immediately burn it for energy/not store it? If insulin is always required even for when the cells are going to take glucose and burn energy then I am a little confused on when it turns to fat/stores instead of burns and why it would be a growth hormone if it’s also used for burning? And why would insulin issues be related to increased fat or weight gain (because isn’t it supposed to be helping cells burn energy as well then?) or is it that insulin gets the glucose in the cell but when the cell tries to burn energy is cannot do that when insulin is present?

2) when a calorie is measured in a calorimeter, does it account for how much energy is needed to burn the food? Like for example it takes more energy to breakdown protein than carbs right - so when those foods are measured for calories is that something that is accounted for at the measuring process. Like let’s say there are 2 foods and for both water temp changed 10 degrees but to light the food on fire it took 20x the energy for one of the foods - are they both labeled as 10 calories or does the one that took more energy get labeled lower in calories?