I agree that they make you feel full more quickly and for longer but a good amount of obese people don't overeat because they're hungry, they overeat because it's their way of dealing with problems. It's an unhealthy coping mechanism like alcohol and drug abuse and should be treated as such.
Don't get me wrong, I'm all for having higher food standards and healthier foods, I just don't think it'll help with obesity as much as you'd think.