Am I right in saying you eat some sort of sports bar after working out ?
After workouts there is this sort of crucial window period where ingesting carbohydrates and protein is a good idea because you have maximised absorption. Not only do you replenish the depleted glycogen stores and give yourself some protein to aid in a positive nitrogen balance but it has other benefits too.
Liquids are far more beneficial than solid food here, typically 50-100g of carb powder, you can use maltodextrin based stuff like 'Maxim' if you have that in the States or just get a load of Maltodextrin from a brewing shop. Not sure if brewing your own booze is popular in the States like it is here either.
Anyway mixing this with ideally whey protein is what you want. Saving for some Whey protein and just using it after workouts would be a good idea.
You can chuck creatine in the mix too, but don't put fat in it because it slows down the absorption.
As far as Olive Oil goes, only use Extra Virgin, its not not heat damaged. Use 2-3 dessert spoons per day that should do it.
BTW Slimfast isn't that good I just read what's in it on another site. Try and replace those 10g's of protein with some whole milk, much better idea.
Last time I was in the States milk was more expensive than over here, in fact Organic milk is cheaper here than where I was in New England. If it gives you gas, then its no big deal, just move away from people or blame it on someone else.