I keep hearing that carbs are the body’s fuel, but fats contain more calories per gram. Surely that means fat is the body’s primary source of fuel?
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* Calories are just a measure of energy.
* Coal and uranium have calories….but both would be pretty useless if your body tried to use them for fuel.
* The body uses fat as long term storage whereas it uses carbs for short term energy.
I think you’re wrong, carbohydrate are just a form of a macronutrients that are kinda part of the calorie category but in all calories give you the energy if that makes sense
Calories are a way of measuring how much energy is in food. Carbohydrates, fats and proteins all have calories in them. Just that eating nothing but fats to get the calories your body needs is rare. Most people get the majority of their energy, from the calories found in carbohydrates in rice, pasta, potatoes, bread and sugar.
IIRC Carbs are meant for short term energy and are used or stored as fat within about 24 hrs fat is higher energy and meant to be kept for the in case of emergency energy. Calories is a measure of how much energy from the carbs fats and protein given to you by the food/drinks you consume.
Calories measure energy, regardless of source.
Carbs are best way to get energy into the body.
Fat is best way to store energy inside the body.
Body cannot store many carbs in tissues, and its bad to have too many carbs floating around in the bloodstream (it leads to diabetes). So if body cannot use all the energy from the carbs that you ate, it will turn that energy into fats.
Energy exchange here is chemical. Breaking down carb or fat releases energy, creating a fat cell uses up energy.
a “calorie” is a measurement of energy and in food what we call calories are really “kilo-calories” or calories x 1000.
It doesn’t matter what energy you are measuring, you can measure the energy generating from burning wood or gasoline or a nuclear bomb in calories, we just don’t.
So in the case of food humans are capable of deriving energy directly from carbohydrates and getting X calories out per unit of carbs. The same with proteins and fats, we can extract energy from a ton of different food sources if we need to.
Our metabolism prefers to burn carbohydrates directly from our blood stream as it’s primary energy source, and typically a surplus blood-stream carbs are converted to fats for long term storage.
If your diet or situation requires it, we can draw from stored fats directly for energy but it’s not preferred. For example, if you’ve heard of endurance athletes “hitting the wall” that’s typically when they run out of carbs and start burning stored fats directly.
Similarly for low carb diets like Keto, you are training your body to prefer the burning of fats due to a lack of carbs.
In extreme cases the body can start burning its proteins (essentially your muscles) directly into energy but this is not preferred and is basically a stage of starvation.
Calories is a unit of energy like Joules, Wh, or any other unit you like to use. For food, it is a measurement of the available energy a human can use. The food calorie is technically a kilocalorie and is by definition 4184 Jules.
It is a way we humans quantify something just like we use, a meter or any other unit for measuring distance. So a Calorie is nothing by itself but a measurement of how much usable energy our body can extract from it
Out body can extract usable energy from carbohydrates, fat, proteins, alcohol, it might possible to use more stuff I am not sure.
What we use to power use will depend on what we eat. So if you eat primary carbohydrates is it what you primarily use. If you just eart meat more of it will come from proteins and fat.
The energy density of it is not what is important it is what you body have access to and how hard it is to use it.
That’s like saying “if my car runs on gas, then what exactly is a gallon?”
A unit of measure. But unlike gallon, we’re not measuring fuel quantity but the amount of energy released by that fuel.
Calories are an amount of energy in food. 4 calories per gram of protein, or carbs and 9 calories per gram of fat. Your body can turn carbs into energy faster than it can turn fat into energy so it prefers to use carbs. You can condition your body to use primarily fat for energy which is what the keto does does.
The body can use carbs, fats and protein as an energy source.
A calorie is the unit of energy used when working out how much energy is in food made of carbs, fat and proteins.
Fats and protein are also used for other biological processes, so you need to eat them to live.
Carbs are only used as an energy source. In theory you don’t need to eat carbs(see keto diet).
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