It’s name is Leptin (derived from the Greek word leptos, meaning “thin”), and it’s without a doubt the most important hormone you probably never heard of.
You see, leptin was only first discovered just over 10 years ago, and as far as weight loss is concerned, that’s extremely recent.
Leptin’s function? To communicate your nutritional status to your body and brain.
Leptin levels are mediated by two things. One is your level of body fat. All else being equal, people with higher levels of body fat will have higher leptin levels than those with lower levels of body fat and vice versa.