Could it be that the act of looking at and consuming it suppresses the appetite more than whatever supposedly happens once it reaches your stomach? The Guardian reports that Birmingham, England scientists are developing a diet solution for overeaters described as "an aqueous solution that gels into a solid structure in the stomach, thereby helping to curb appetite." The paper says:
The target market is those for whom bingeing is not just for Christmas, but a habit that dogs them all year round. "But, yes, it could also be used short-term to get back on track after the festive excesses. Why not?" suggests Dr Fotis Spyropoulos, one of the project team.
The gel will be intended not as a meal replacement (thank God) but for consumption when hunger strikes between meals, as a way to tide you over. Maybe it'll be like those GU energy gels -- difficult to choke back but the pay-off is good. You'd think they could at least make it have the illusion of desirability though. What's wrong with appetite suppression looking like a cookie?