Drink mix recipe
I've used this tasty drink mix for years. It's a fairly low carb content. I use it to encourage more fluid intake, and the calories do help too. It's somewhat based on a diluted Gatorade idea.

2 1/2 cups white sugar.
4 packets of Lemon Koolaid.... this contains natural flavors, no artificial sweeteners.
Original recipe: 1/2 tbsp salt, and 1/2 tbsp "lite salt". But I don't really need that much sodium, I get plenty otherwise.
Now: 1/2 tbsp Lite Salt, which is about half sodium, half potassium, with some calcium and magnesium salts. I'll add a little more in hot weather.
Mix well.

This is 20 bottles at 2 tbsp mix per bottle. Or 13 bottles at 3 tbsp each.
a tbsp of salt is 7000 mg sodium, so this 1/2 tbsp of lite salt is around 3500 mg / 50% sodium / 20 bottles = 90 mg sodium per bottle.

I store this in a small plastic tub, and put 2-3 tbsp in a 22 ounce water bottle.
Two tablespoons sugar is 30 grams of carbs, 120 calories.
For a really long ride, I'll bring a snack ziplock with another 2-3 tbsp, but normally the other bottles are all water. And there's usually a store stop, with a can of soda, etc.