Transcript Going for the 3 Increases

Physiology of Food Cravings
Going for the 3 Increases: Increase in Health, Increase in
Happiness & Increase in Energy
Strategies for
Success in Weight
Management
By: James J. Messina, Ph.D.
Key areas in a cross-section of the
brain


Amygdala:controls
emotion
Parts of the cortex:
used for higher-order
thinking in humans &
send messages to
the "central
switchboard" that
stimulates appetite
Food is far more than fuel to most
of us
It’s tied in with our emotions, motivations
 Maybe even an ancestral impulse to
store energy for leaner times ahead
 In a study that could lead to more
effective treatments for obesity,
researchers have traced brain impulses
to show how appetite may be linked to
higher-order processes such as emotion
and judgment

The Researcher

In the Science March 2001 Issue: Jeffrey
Friedman of Howard Hughes Medical
Institute at The Rockefeller University
and his colleagues describe a novel
glow-in-the-dark technique that allowed
them to see how cells within a mouse’s
brain interact to send the “I’m hungry”
signal to the rest of the body.
What we already knew

The body has a sort of fat thermostat,
which regulates weight by influencing
appetite, metabolism and other functions.
Some people may be obese because
their “set point” is too high. It’s also
possible that obesity is on the rise
because the thermostat mechanism
evolved in an environment where food
wasn’t as readily available as it is today.
What we already knew

A key component of the fat thermostat is
the hormone leptin, which is produced
mainly by fat cells and triggers neurons in
the hypothalamus, the brain’s central
switchboard for regulating conditions
inside the body.
What we already knew

In general, an increased amount of fat
leads to the production of more leptin,
and vice versa. A change in leptin levels
sparks a set of responses aimed at
returning weight to the starting point,
such as increasing or decreasing food
intake.
What we already knew

When Friedman and other scientists first
discovered how leptin regulates weight in
mice, their findings raised hopes the
hormone might be a long-awaited obesity
treatment for humans but initial attempts
at using leptin to reduce people’s weight
met with limited success, however. One
likely explanation is that leptin levels
probably aren’t the only factors involved
in the decision to start eating
What the new study explored

Friedman’s team wanted to know
whether neurons that responded to
leptin’s signal might also be in
communication with neurons from other
parts of the brain seemingly unrelated to
feeding. “Feeding is a motivational
behavior, not a reflex. We wanted to
understand more about how the higher
order and more basic neural systems talk
to each other,” said Friedman.
What the Study found

Their findings indicate that the brain’s
appetite-regulation system responds to
additional signals, besides the simple “we
need more energy” message that comes
from fat cells. “Feeding strategies have
developed by evolution. When an animal
finds food, it has to decide whether or not
to feed…”
What the Study found
“It’s going to take many factors into
account, such as its own energy stores,
its emotional state, the safety of the
environment,”
 “Our research suggests that many of the
signals are sensed by key neurons in the
hypothalamus.”

What their studying next
 Friedman’s
group now hopes to
identify the type of neurotransmitter
that’s carrying the additional signals
from one neuron to another in the
feeding pathway.