[2] Empirical tests have provided some evidence to confirm the hypothesis[3] with one study suggesting that this could be a link between ultra-processed foods and the prevalence of obesity in the developed world.
[4] In the 1980s, David Raubenheimer and Stephen Simpson, researchers now at the University of Sydney, began to study appetite and food intake in locusts.
Their experiments showed that those who aren't getting enough protein in their diet will continue to be hungry, even when their overall caloric intake is high.
The hormone FGF21, which is released from the liver, can drive savory-seeking behavior under conditions of low protein intake.
[5][6][7] In 1995, Australian researcher Susanna Holt developed the concept of satiety value, a measure of how much a given food is likely to satisfy the hunger of someone.