KetoVatru : In fact, breath acetone is actually a good predictor of ketosis. When we are in ketosis, a portion of the ketones get converted into the ketone acetone, which is excreted via our breath. What this looks like is no more than 50 g of total carbohydrates, roughly 1 to 1.8 g of protein per kg of lean body mass, and fat to make up the remaining calories.