realwork are you doing an atkins diet or what is this keto diet you are talking about?
A ketogenic diet is high in fats and protein, and very low or no carbs at all ( usually sub 50 ). This will force the body into a state of ketosis where "ketones" are used as a fuel source instead of glucose.
Fat will be able to oxidate faster because of the extremely low insulin levels.
It is very efficient, and many bodybuilders and lifters use it for their cutting phase. Has helped some people to overcome that barrier of 10% BF, and finally hit 7/8% as well.