Because tomatoes contain lots of water and fiber, they are considered one of the great vegetables when someone is looking to lose those extra pounds.  Their soluble fiber makes you feel full much faster and therefore you might not need to eat as much. But the most important part of weight loss is, that you have to consume fewer calories than you burn.  That leads me to my belief, that if you do like tomatoes, they are great and extra healthy vegetables, but everything needs to be consumed in moderation.