De novo lipogenesis

[Wintran]

I've been reading some about the term de novo lipogenesis but not really understood its exact meaning.

I read it's the process of converting excessive carbohydrates into fat, but are they actually implying that glucose can itself be converted into fatty acids?

According to Wai's article called Food Causing Diabetes, glucose cannot be converted directly into adipose tissue without at least some fatty acids available in the blood. From what I understood, fatty acids can only be provided either by dietary fat or by certain amino acids that can be converted into fatty acids. That's why we should ingest fat together with carbohydrates, to guarantee that excessive glucose in the blood can always be converted into body fat rather than exhausting our insulin system.

I have tried to search for more information and scientific data on the fat conversion process, as this should be easy to prove, but have been without success so far.

Did I misunderstand something?

[RRM]

I've been reading some about the term de novo lipogenesis but not really understood its exact meaning.

Its indeed the conversion of glucose into fatty acids (via pyruvate). It particularly happens when liver glycogen stores are full (400 to 500 kcal)

According to Wai's article ... glucose cannot be converted directly into adipose tissue without at least some fatty acids available in the blood.

Directly is the key word here. (our article is unclear, indeed!)
When fatty acids are available, the glucose can be stored (as glycerol) in adipose tissue without stimulating the conversion of glucose into fatty acids by insulin. It has been shown that the more adipose fat is already present, the less effective glucose is converted into fatty acids, thus creating an extra load on the insulin system.

From what I understood, fatty acids can only be provided either by dietary fat or by certain amino acids that can be converted into fatty acids.

Yes, thats the more direct way. Excess glucose however also provides fatty acids, but not directly, as dietary fat and ketogenic amino acids do. Excess glucose is converted into fatty acids when liver glycogen stores are full.

That's why we should ingest fat together with carbohydrates, to guarantee that excessive glucose in the blood can always be converted into body fat rather than exhausting our insulin system.

Exactly; it prevents spiking the insulin system as much as only carbs.
Not only because carbs stimulate insulin more than fats do, but also because it readily prevents insulin secretion by storing fat.

[Wintran]

Nice, that makes sense! Thanks a lot for the more in-depth explanation.