Your logic only works if the food you are eating has absolutely no other effect on your body than to be burned for it's calories. Our bodies derive things from the foods we eat, and uses them for different purposes. A calorie is not just a calorie. If that was the case, then nothing would ever cause an insulin spike because nothing we ingest has any effect on our physiology. Your logic is internally inconsistent, which it has been from the very beginning. And I realise that you are not going ot be swayed, and that you will either ignore this, or just say you look better than everyone, insult me, and say I'm wrong "just because"; but I thought that it was important to point out that you owned yourself
The amount an INSULIN spike is Directly proportion to the AMOUNT of the Carbohydrate in question.
When in Low calories, a few cookies can equate to a cup of oats based on Glycemic Load.
The lower the calories go, the less and less it becomes a factor.
Throw in a defecit with an intense workout(demand for Carb and fat usage) the concern becomes even more non-existant.
Furthmore you require LOW amounts of protein to build muscle and sustain it.
The only thing that WILL cause you to atrophy is lack of training.
This can be seen when Astronauts,who eat well in space prefectly balanced, lose muscle tissue not due to lack of nutrition, but due to no gravity and lack of use.