T Nation

Can Your Body Use Fat to Help Build Muscle?


OK, stupid question I know....but when people on here say to lower the carbs, up the protein and fat intake, as well as the overall caloric intake that confuses me. I know you need omega-3s, and monounsaturated fat and all that to be healthy. But what exactly is the purpose of taking in more fat if you're trying to bulk cleanly?

I understand it's more calories, but can your body actually use it to build muscle, or is it that your body uses it for energy, and then can devote more of the protein to muscle growth?


Yes, your body can use fat for energy.

I have found that I can gain weight while keeping fat gain low if I up the calories and keep the carbs low rather than just going on a typical bulking diet. I tried a regular balanced bulk of about 40% carbs, 30% protein and 30% fat with about 4000 calories.

However, I have maintained my lean mass gains and and saw less fat gain when I switched to a general diet of approximately 60% fat, 33% protein and ~7% carbs with about 4800 calories.

Others may respond differently so you really have to just try it and be your own judge.


You pretty much answered your own question. Amino acids are the building blocks for muscle’s, I am sure most of us here know this. So, where do Amino’s come from? PROTEIN, not fats. The reason for upping the fat is for energy purposes, as well as, equating to more overall calories per day, per week. This will allow protein to be utilized for the main function we consume it for which is growth/muscle.

We basically want to prevent neoglucogenesis from occurring so that all the protein we eat is going toward building muscle and not being converted into glucose for energy. That is why fat’s are increased so that they are used as the primary source for fuel.


Strictly speaking, I’m quite sure the answer is ‘no’.


The problem with the fat is that it can be used for energy, but in simple terms you can’t use it for protein synthesis. Excess protein can be broken down and its energy potential stored in triglycerides, but the equation won’t work in reverse.


The above means you need to have enough protein and fat while you’re training so you don’t spare the protein for energy. If you’re cutting, gluconeogenesis is desireable because that is what is occurring when you’re in ketosis. The bod’s kinda funny though and if you don’t do it right you can spare your protein to a degree as well.