It's an observation, but it's a good rule of thumb.

Always try & get the fattest person in Subway to take your order.

Fat people in fast food outlets always make food servings as though they are serving themselves, therefore, you end up with all the fillings in abundance instead of the paltry offerings normally received by thinner staff.

I have a local Subway & I now always get my order which looks as substantial as the ones used in promotions, all bursting out of the roll & actually looking like value for money!