Assuming a diet of only glucose, is it possible to gain weight? I know that fructose can be converted by the liver to triglycerides and be stored as fat. However, my understanding is that glucose can only be utilized immediately by body, and there is no way for it to store as a fat reserve of any type. So, if this right it should be impossible to gain weight from consuming only glucose. Is that true?

Not that I NOT asking mixed diets that include glucose. I am asking about a diet that includes only glucose.

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    If you consumed "a diet that includes only glucose" rather than a "mixed diet", you would die. It's pretty difficult to gain weight when dead. Besides that, what is your source for "glucose can only be utilized immediately by body, and there is no way for it to store as a fat reserve"?
    – Bryan Krause
    Jun 29, 2020 at 23:34
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    @BryanKrause That is not the question. Jun 30, 2020 at 5:08
  • And the second part? It's completely biologically meaningless so I'm curious what your source is.
    – Bryan Krause
    Jun 30, 2020 at 5:09
  • @BryanKrause Just general knowledge. If you read the Wikipedia article on glucose, for example, it says only that glucose is metabolized to glycogen only, not triglyceride. So, if that is true, then it would seem to not be possible to gain weight via triglycerides from just consuming glucose. So, the question is whether either (A) glucose gets metabolized to something else that could indirectly result in triglycerides, or (B) the body would make glycogen, if it had no other nutrients. We know that the body makes glycogen if it has other nutrients, but what if it does not? Jun 30, 2020 at 5:15
  • Have you looked at it the other way? Where do triglycerides come from? Where does glycerol come from? Where do fatty acids come from?
    – Bryan Krause
    Jun 30, 2020 at 5:55

1 Answer 1


Yes it is most certainly possible.

Glucose can be metabolised to glycogen, but it can also be metabolised to fatty acids and triglycerides.

Glucose is converted into Acetyl-CoA through the anaerobic glycolysis, and Acetyl-CoA is used for the synthesis of fatty acids. An intermediate product of the anaerobic glycolysis is glycerinaldehyde-3-phosphate, which can be converted into glycerol and then be used as the backbone for triglycerides, which in turn can be stored in adipocytes and lead to increased weight. This graphic gives a good overview of the metabolism pathways.

As a side note regarding "my understanding is that glucose can only be utilized immediately by body", glucose can also be used to synthesise ribose through the pentose-phosphate pathway, and ribose can be used to synthesise DNA among other important molecules. Acetyl-CoA is also used for steroid and cholesterol synthesis.

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