I belive the calories in/ out holds alot of truth to it. With protein being the main factor building muscle and holding on to it. Atleast for our purpose as bodybuilders.
When it comes to the carb/ fat combination. Its on a surplus of calories its going to matter the most.
High fat/ high protein. Body will have to work with the fats for longer time. Storing fat, and burning fat for energy, takes longer time for the body. I cant remember the exact mecanismns of it. But you can probably google it.
This will give you a slow and steady energy source, no spikes up and down, and for longer period of time, then you will have to eat again...
No drowsyness or extreme hunger 2h later.. and so on..
On high carbs/ high protein. You will get insulin spikes to store energy. And carbs is much easier to store and to burn as energy for the body. Its in and out much faster. Available energy easier to process for the body. Thats why you get drops in blood glucose levels, feel drowzy, and get that extreme hunger feeling much faster.
Put in some fats to the meal, and you have some energy that can be stored and processed slowly..
High fat/high carbs/high protein, or should we say high protein /medium fat/carbs, the insulin spikes from the carbs will probably help store the fats easier. But still it will take longer time to burn the fats for energy once stored. Meanwhile the carbs are available much easier.
And in a surplus of calories, if your already stored all the carbs your body needs and can store, you will store the extra calories also, fats or carb wont matter as well.
Keeping the fats low, might or might not help you not to store more or less fat. But what will happen to the exess carbs floating around you think? Its available for energy, but if you dont use it?
On a cut, all calories are burned. If your eating right.
Thats why people can cut on high carbs, or high fats. Or even a balanced diet with both.
Dont over eat, dont get fat. Eat healty foods.
I tried maintaining on both keto diet and high carb/low fat diet. Same calories.
Only diffrence is I had alot more water weight and explosive energy on carbs. Looked more full.
But felt like shit, high bloodpressure, gas.
On keto, dry, no water weight, less explosive energy and pumps. Feel great during the day, can go 4-5h without extreme hunger easy. Overall more stable energy levels is probably the biggest diffrence.
But I would never consider trying to bulk on keto. Probably prefer carbs for that.
Just my experience and research..
For what its worth.