When your eyes are bigger than your stomach

So you are eating this meal...

Turkey sub sandwich, 75 carbs
Half an odwalla juice drink (16 oz bottle), 35 carbs
Baked potato chips, 26 carbs

Total carbs, 136; total bolus, ~9 units Novolog

...I know this will differ between pump and syringe users, but how exactly do you bolus/inject?  I'd give myself 6 units before starting to eat and then, depending on how much of the sandwich and chips I actually eat, I'll add a few more units.  If I eat everything I'd give myself 9 units based on my 1:15 insulin to carb ratio.  But, if I only eat half of the sandwich I'll probably only give myself about 6.5-7 units.

Does anyone else do this?  Two sets of boluses based on how much you think you'll eat and how much you actually eat?  I guess that's what I like most about my pump.  And to what lengths do you go to ensure your calculations are correct?  Do you just use mental math or do you sometimes just do a "ballpark guess" based on how much carbs you think you're eating?

My doctor has my on symlin injections before eating.. and advised me not to bolus my humalog until after I've eaten. The symlin slows down digestion which makes you feel fuller, faster. There are plenty of times that I would have over-bolused if I had taken my insulin first. What you're doing makes complete sense!

I tend to bolus based upon what is on my plate so to speak or napkin. Since going on the pump, I have been able to cut down on what I eat and will usually eat what is on the plate in front of me. I try not to over estimate or count what I am eating. However, if post meal I decided to add something else like an apple, I will bolus again to cover the apple. But this is just myself as I normally eat allI put in front of me, be it a big or small meal, unless the food is not right than I find somethign else to cover the insulin i took.

i don't even have that many carbs in my diet. in a regular meal. i have a small appetite.

for something like that for lunch? i'm on a 1:15 ratio..so i would do about 9 units depending on if my level to start was lower in which case I don't really worry about the .3333 or the .7777 from the last to calculations. I prefered it when my ratio was 1:10 cuz it made it easier for me. 75 carbs? oh that's 7.5 units! I think i end up giving myself 1:10 more often than 1:15 anyways..cuz i usually just go "oh 60 carbs? 6 units please!" which i never really thought about til now....haha i take insulin for the whole thing, whether i eat it or not..cuz usually by the time i do eat, i'm starving! lol