The researchers asked 27 participants to eat the same breakfast, then some ate a high-protein soup with an MSG-enzyme combination while other had soup without the pairing. Everyone then sat down for an identical lunch, and the scientists tracked how much the volunteers ate as well as asked them questions about their appetite and how full they felt. The diners who ate the MSG-laced soup consumed less of their lunch, but still say they felt satisfied, suggesting that umami may have a role in regulating eating.