Well, thanks for your judgement of fat people and the advice you have given. Now, if you will step off your fat hate soapbox for a moment, let me try to get you to see things from a different perspective.
For YOU water suppresses cravings. For YOU this is common sense. You lack a fundamental understanding of how excessive sugar affects the body, and the mindset of an overweight person. For an obese person food, especially sugar, are drugs. They cause the same response in the body that any other addictive substance or activity does for a normal person. When an obese person eats a large pizza or a tub of ice cream it is causing a pleasure response in their brain. Stopping this behavior (cutting out sugar or fat or whatever from the diet) causes withdrawal symptoms. How easy do you think it would be for you to detox from heroin, or even cigarettes? The addiction to food causes a feedback loop, the brain sitting there saying "You can have more. Come on, it will make us feel good, we will worry about the diet tomorrow" and when you give in it just reinforces the cycle. In the end it takes a great amount of willpower and determination, and not a little physical pain, to truly adjust your eating habits and lose weight. Just like any other addiction this feeling doesn't go away, it just lessens over time. A formerly obese person needs to exercise constant willpower to not regress into the addiction.
It's a much more subtle addiction then drugs or porn or whatever, because when it starts it is very hard to know that it is a bad thing. When you snort a line of coke or shoot some heroin you have at least some idea that what you are doing is bad and could lead to a severe problem, with food it is not so easy to draw the line between normal and problem eating. Stop judging fat people as lazy or worthless, and instead see them for what they are, addicts.