Just thought I'd relay back my experience of using dextrose in case someone else comes back. Dextrose 100% glucose, as opposed to sugar (sucrose), which is 50:50 fructose:glucose. Dextrose is still sweet, but not as sweet as sugar, has a slight bitterness.
I found taking 4 teaspoons of dextrose in a mug of water had a rapid effect, increasing my concentration and body temperature for about 45 mins or an hour. However, it seem to give me a "sugar crash", worse than plain white sugar. The effect was very noticeable if I was already tired before taking the dextrose.
I also found it didn't work as appetite suppressant, the way sugar water did. I felt much hungrier on the day I took it.
So altogether I wouldn't recommend it. I noticed in Seth's book that he recommends either sugar or one of it's components (fructose) but not the other component (ie glucose/dextrose).
The reason I did this was because I found the ELOO hard to take each day - I also found it difficult to avoid any aftertaste - and I seemed to get better results on sugar water. However, I don't want to take too much sugar so was looking at alternatives.
I don't know if anyone else find this, but we cook at home mainly with olive oil, and I wonder if the mild aftertaste of ELOO was in fact triggering a flavor-calorie association with me.
I also wonder if it is in fact the fructose-ness of sugar that makes a difference for SLD, rather than the purely sweetness. Fructose is metabolized differently to most other things and I wonder if that's got something to do with it.