It seems somewhat intuitive that filling your stomach with a zero-calorie substance would prevent you from subsequently filling it with other, more fattening substances.

I'd take it one step further though with eating something with fiber (like broccoli, carrots, etc.) a little bit before the full meal or drink some water with psyllum husk or metamucil or any fiber packed drink.. that would actually fill you up as compared to water, which might fill you up for the moment but it'll just leave u hungry a little earlier by the time of the next meal ..

For some people it can also trigger dumping syndrome: quicker-than-normal evacuation of food from the stomach, peaking insulin and dizzy spells.

http://en.wikipedia.org/wiki/Gastric_dumping_syndrome

I'm confused. Did it work because people felt more full and ate less, or did they eat the same amount but the water reduced the number of calories the stomach could generate from the food?

I dont see this to be hacker-related topic. Not all hackers have problems with their weight. And I doubt that this "hack" is good for your stomach.

Flagged.