[Wahaika]

The reason for an empty stomach is for absorption. Taking herbs by themselves helps the digestive system to focus on only those. If you take them with meals, that's Ok too, just not the most efficient. Think of it this way, what if you eat meat (takes acid to digest) and potatoes (takes alkaline to digest) at the same time? They cancel each other out. Now, add herbs into that situation. There is a chance that they could get caught up with parts of the meal that will not digest them, or not digest them completely.

Taking the herbs all together is OK.