But the real problem isn’t going over your carb limit—it’s the protein. “If you’re eating a lot of protein, you’re breaking that down into carbs,” Giancoli explains. Your body is in desperation mode on keto, she says, and without a reasonable supply of carbohydrates coming from grains and fruits, you’ll start breaking down the amino acids in proteins to make glucose. Glucose, though it sounds like a scary sugar, is your body’s primary source of fuel. Too much isn’t good for you, but you need some just to allow your cells to function normally.
The point of keto is to force your body to deplete its glucose (and the stored form, glycogen) so it will have to use body fat as a fuel source. It’s capable of making ketone bodies from your fat, which can replace glucose as an energy-storing molecule. To do that, you have to break apart fat molecules thus ‘burning’ the fat off. But here’s the thing: your body really really doesn’t want to run out of glucose. No glucose means starvation as far as it’s concerned. And when you’re starving, your body will start to break down protein just to get those sweet, sweet carbs. Of course, you have a source of protein in your body already: your own muscles. “When in starvation mode, your body breaks down muscle in your body,” says Giancoli. “Ketosis is a way of trying to preserve that protein. It’s not ideal, but it’s your body’s way of saving you.”
So far it sounds like real science but the conclusion of above article is like this:
"So maybe not being in ketosis isn’t so bad after all—now just cut back on the saturated fats".
Holy Cow! This indicates that the author has not read Richard Feinman’s “The World Turned upside down: 2nd Low carb revolution”. If you are interested in true science with supporting evidence from basic science, please see here.