Ketones inhibit fat synthesis

Metabolite regulation of nucleo-cytosolic trafficking of carbohydrate response element binding protein (ChREBP): role of ketone bodies.

Without going into all the technical details, here's the punchline....

 These observations show that ketone bodies play an important role in regulation of ChREBP activity by restricting ChREBP localization to the cytoplasm, thus inhibiting fat synthesis during periods of ketosis.

ChREBP is a transcription factor that is activated by increased glucose levels, and ChREBP increases synthesis of enzymes like fatty acid synthase that are responsible for lipogenesis.

Anyway what this paper implies is that high ketone levels will inhibit glucose induced lipogenesis.  I think potentially if your in ketosis this could probably mean that you can eat carbs for 1-2 days while stimulating only very limited lipogenesis. Basically the ability of carbs to cause fat gain should be curbed by high ketone levels. ( in theory ). However ofcourse repeated carb feeding will eventually kill your ketone levels and this will allow ChREBP to frontload its lipogenic power.

Now, who knows the answer to this question....... lets say you eat some carbohydrate, you activate ChREBP and it subsequently causes your cells to manufacture some fatty acid synthase enzymes. Now, how long do these enzymes sit around for? Whats their half life?



EDIT*

From the paper it seems oleate and linoleate also appear to be quite good at inhibiting ChREBP.