The best is watching people who are obviously trying very hard to lose weight the low-fat way. Their carts are always piled with fat free pringles, popcorn, sorbet, bananas, orange juice, bread, fruit jam, dry cereal, skim milk...occasionally a few chicken breast fillets. I almost never see fresh vegetables in there...

Often, these low-fatters will look into my cart to see if I'm trying to lose weight, too. I guess my cart doesn't give away the way I eat - it's full of paradoxes. Mayonnaise...romaine lettuce?