I could be way off, but I thought that it was better not to have caffeine with meals. Please set me straight on this one. Thanks.
My suggestion for 1 cup (5 ounces) of coffee per meal is so people can keep track of how much coffee they drink, not because of the effect coffee has on food. You could drink 3 coffee cups all in one meal or 2 cups at one meal and one cup at another. Just don’t exceed 3 cups (16 ounces) of coffee per day because of the caffeine content. Most people need some kind of cue to keep track of their eating.
Another thought is since one 5 ounce cup of coffee is the amount in one coffee cup, 10 or 15 ounces of fluid like coffee would make a person feel full faster. It is likely that a person drinking 2 or 3 cups of coffee at a meal may eat less simply because their stomach is filled to capacity.
If anything, caffeine helps absorption because it increases the secretion of acid by the stomach which is needed for some nutrients like protein and vitamin B12. However, food also stimulates the secretion of acid by the stomach which is necessary for digestion which starts in the mouth.