I learnt a new word today: ‘ghrelin‘. It’s a hormone produced by the stomach that regulates hunger. If you have more ghrelin in your system, you’ll tend to feel hungry; if you have less of it, then you’ll tend to feel full.
So if you want to gain weight, increasing your ghrelin levels can be beneficial; and if you want to lose weight, you’ll benefit from lower levels.
Experiments on rodents showed that a daily administration of ghrelin caused weight gain:
However, as with so many things, it’s not as straightforward as that.
Here’s a thing, courtesy of Rachel, that underscores my distrust of advertising: if you believe that you’ve eaten something fattening (even if it’s not), your body will behave as though you’ve eaten more than you actually have. Contrariwise: if you believe that you’ve eaten something ‘fat free’, you’ll still feel hungry. This short video details an experiment that shows this.
So: labels matter. Perhaps it’s best not to dwell too much on them.