I am kicking myself that I can't find this blog post I stumbled across a month ago or so - it was one of these same kinds of ads, with a "before" and "after" photo claiming some preposterous amount of weight lost in a short amount of time. The two girls looked alike, at least (same skin tone!), but the person noticed something fishy about the image...
Turns out the diet ad people had taken a photo of two girls (sisters presumably) and cut it down the middle, then switched it so the right girl was on the left. Their arms were around each other in the original photo, so when the guy reversed the editing that was done, the arms lined up again...
The bigger sister became the "before" and the thinner sister was the "after"....
