hun seriously stop thinking like that cos it really isnt true...
they may go shopping and pick up what they like but they still have to watch what they eat.... its subconsciously though...
i have alot of skinny friends... to a stranger you would think they eat loads and what they want... but for example... if they have a big meal one day, they know to tame it the next day!! My smallest friend ate loads when she was pregnant, brownies, chocolate you name it, I was quite surprised when she said how she would never dream of eating like that when she wasnt pregnant, cos to me she looks like she isnt that fussed about what she eats...! But it just prooves she is... !