I consume at least 1200kcal a day in liquid form because I cannot put down enough calories otherwise without eating huge amounts of foods high in sugar or saturated fats. Until now I've used commercial weight gain powders which mainly consist of maltodextrin, but that has a high glycemic index, so consuming hundreds of grams of it in one go is probably not the best idea.

To make my own, healthier version I'm considering adding milk, protein powder, olive oil and I'm very unsure about the carb source I want to use. However, I do for sure wanna add carbs for the added energy. Something like cluster dextrine is low gi and has barely any taste but it's too expensive, considering I will take at least 100g of it every day. Fructose (in powdered form) seems like a decent option, if I find a way to mask the taste. It doesn't have to taste great but it should be somewhat drinkable, I used to drink 100ml of pure olive oil in one go every day and I'm not going back to that. Are there any other carb sources or ingredients that would be a good option? Has anyone made something like this before?