How do we know how much food to eat?

Fruits and vegetables arranged in word 'food'

In order to know how much food to eat, the human body needs

Fruits and vegetables arranged in word ‘food’

a way of assessing how much energy it currently has in storage.
Leptin – more commonly known as the ‘fat hormone’ – essentially
acts as our internal fuel gauge. It is made by fat cells and tells the
brain how much fat the body contains, and whether the supplies are
increasing or being used up.
Food intake is regulated by a small region of the brain called the
hypothalamus, which manages many of our hormones. When fat
stores run low and leptin levels drop, the hypothalamus stimulates
appetite in an attempt to increase food intake and regain lost energy.
When leptin levels are high, appetite
is suppressed, reducing food intake
and encouraging the body to burn
up fuel.
It was originally thought
that leptin could be used as a
treatment for obesity. However,
although it is an important
regulator of food intake,
our appetite is aff ected
by many other
factors, from how
full the stomach is
to an individual’s
emotional state or
food preferences.
For this reason, it’s
possible to override the
leptin message and gain
weight even when fat stores
are suffi cient.