| I don't see where it makes much difference...it's difficult to "test" from one meal to another since our food is usually varied and so is our body chemistry at any given moment.
Humalog is designed to take either prior or immediately after a meal. Neither is "right or wrong"...most doctors only tell patients to take prior and that works for most people. It gives the Humalog a few minutes to get a "head start" on the food.
Problem is that different foods digest and break down differently. So that "one size fits all" direction doesn't work meal-to-meal.
Some meals I take early and some meals I take afterwards. Read the package insert for manufacturer info...you'll see the "afterward" clearly stated. Just don't wait too long.
Restaurants and dinner with friends...I always take afterwards for obvious reasons. Sometimes I take a few units at start of a long meal and follow=-up with a more exact amount afterwards. | 
