You can do either. I find they sit better if I take them after I eat.
More important is WHEN you take them. Divide Days' amount up into at least 2 if you're taking a smallish amount or 4 if taking more than 8 scoops a day and spread them out to 4 times a day. They work more effectively that was as they understood and used as food. So thte same way you don't take all your day's food in one meal, don't take all your glycos at one time either.
bless you.