alt Hacker News> I would think that would be hard to do if you've already seen what appropriate portions are.
This would be true if not knowing what an appropriate portion size is was the one thing keeping most people from losing weight. If that was the case, traditional dieting would have a far better track record with long term weight loss.
People notoriously don't know what an appropriate portion size is. Usually those failed diets come from failing to appreciate the quantity of calories coming in. Those sugary drinks and snacks add up fast. I've seen it among people I know. I might drink water, they opt to drink 250 calories. Does that make them feel any full? Probably not, its merely sugar water, but it accounts for calories and can kill diets. We order a 750 calorie entree and they get a refill. We walk away from the same meal but one of us had almost twice as many calories.