Seth Roberts in NYTimes

Seth Roberts may soon be waking up to see his own face on television.  That ought to make him happy!  Roberts, as you may recall, is the Berkeley psychologist whose novel self-experiments have led to some strange but important new ideas.  Stephen Dubner, who read about Roberts on MR, and Steve Levitt have just profiled him in the NYTimes Magazine; they do an especially good job of explaining Seth's theory of weight loss:

[Roberts] had by now come to embrace the theory that our bodies are regulated by a "set point," a sort of Stone Age thermostat that sets an optimal weight for each person. ...But according to Roberts's interpretation of the set-point theory, when food is scarcer, you become less hungry; and you get hungrier when there's a lot of food around.

This may sound backward, like telling your home's furnace to run only in the summer. But there is a key difference between home heat and calories: while there is no good way to store the warm air in your home for the next winter, there is a way to store today's calories for future use. It's called fat....

During an era of scarcity - an era when the next meal depended on a successful hunt, not a successful phone call to Hunan Garden - this set-point system was vital. It allowed you to spend down your fat savings when food was scarce and make deposits when food was plentiful. Roberts was convinced that this system was accompanied by a powerful signaling mechanism: whenever you ate a food that was flavorful (which correlated with a time of abundance) and familiar (which indicated that you had eaten this food before and benefited from it), your body demanded that you bank as many of those calories as possible....

So Roberts tried to game this Stone Age system. What if he could keep his thermostat low by sending fewer flavor signals? One obvious solution was a bland diet, but that didn't interest Roberts. (He is, in fact, a serious foodie.) After a great deal of experimenting, he discovered two agents capable of tricking the set-point system. A few tablespoons of unflavored oil (he used canola or extra light olive oil), swallowed a few times a day between mealtimes, gave his body some calories but didn't trip the signal to stock up on more. Several ounces of sugar water (he used granulated fructose, which has a lower glycemic index than table sugar) produced the same effect. (Sweetness does not seem to act as a "flavor" in the body's caloric-signaling system.)

The results were astounding. Roberts lost 40 pounds and never gained it back.

I can verify the appetite suppressing properties of the fructose water.  A glass of fructose water and I can easily go without lunch.  The only problem is that the sophists lure the unsuspecting to lunch anyway.