Ketosis, or passing of excess food fat?

[Loewen]

My mind has been wandering....

Is it possible that on the Atkins diet, ketosis may actually just be your body passing through the excess fat intake and not actually true lipolysis, or burning of stored body fat?

[Georgiana]

Ketone bodies can be produced by dietary fat or by stored body fat. If you do not overeat, the body will be using some of the fat you eat, together with body fat, for energy. However, if you do overeat, you will, of course, gain weight -- you can get into ketosis by eating a pound of butter a day, but you will probably not lose any weight or even gain. In the latter case, there is obviously no net metabolic advantage from being in ketosis.