Sunday, August 25, 2019
ABS 394
Subtopic 3A!
•What specific part of the brain determines whether we are hungry or
not?
hypothalamus
•Which three hormones have critical roles in telling our brains whether
we are hungry?
insulin, leptin, ghrelin
•Which hormone is responsible for telling our brains that our blood sugar
levels are high?
insulin
•Which hormone signals that our fat storage is full?
leptin, Leptin regulates our energy balance by inhibiting hunger and
opposing the actions of the hunger hormone ghrelin. When our fat cells
have high energy stores, they produce leptin, telling the brain to stop the
feeding behavior.
!
•Based on new evidence, what functions other than digestion do our
microbiota have?
obesity, maintaining a healthy body weight and normal metabolism,
suppress and increase cravings
•Lean individuals tend to have a wider variety of which bacterial phyla?
Bacteroidetes
•What are some differences in the gut microbiota of infants that were born
vaginally and breast fed, versus those that were born via cesarean
section and fed baby formula?
Studies have shown that both formula-fed babies and infants delivered by
cesarean section have a higher risk for obesity and diabetes than those
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who are breast-fed or delivered vaginally. Newborns traverse the birth
canal swallow bacteria that will later help them digest milk. C-section
babies skip this bacterial baptism. Babies raised on formula face a
different disadvantage: they do not get substances in breast milk that
nurture beneficial bacteria and limit colonization by harmful
ones.!!Babies drinking formula have bacteria in their gut that are not seen
in breast-fed babies until solid foods are introduced. Their presence
before the gut and immune system are mature, says Dominguez-Bello,
may be one reason these babies are more susceptible to allergies, asthma,
eczema and celiac disease, as well as obesity.
•How do bacteria alter our satiety signaling?
Bacteria in the gut produce appetite-suppressing proteins
about 20 minutes after a meal, a new study has found,
suggesting that we have less control over how much we
eat than we thought. They discovered that the proteins
these bacteria release when they’ve had enough nutrients
influence the signals sent between the gut and the brain,
and can even activate appetite-related neurons to make
you feel full.
• How did the researchers confirm that the bacterial protein was responsible
for reducing appetite?
Fetissov and his colleagues came to this conclusion when analysing the proteins produced by!E.
coli!colonies living in the guts of mice and rats. At around 20 minutes after a meal, the bacteria
started producing different kinds of proteins than they were before. Which is interesting, because
in humans, this is around the time when we get that feeling of fullness and satisfied sleepiness
after a big meal. The researchers isolated these after-meal proteins, called ClpB, and injected
them into mice to see if an increased dose would affect their appetites. They found that
regardless of whether the mice had been eating a normal or restricted diet, they all displayed a
diminished appetite and ended up eating less.!Publishing the the journal!Cell Metabolism,!the
team says the proteins released by ‘full’ bacteria stimulated the release of a hormone called
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Sunday, August 25, 2019
peptide YY, which has been linked to a feeling of satiety. They also found that the ClpB proteins
increased the firing of neurons in the brain that are associated with a reduce appetite.
•What is one “go to” ingredient the food industry uses to get people hooked
on their products?
sugar
•What was the major habit-forming ingredient in the original formulation
of Coca-Cola?
dcocaine
•What are the two habit forming ingredients in the current formulation of
Coca-Cola?
caffeine, sugar
•What are two relatively new diseases that are linked to excessive
consumption of sugars?
type 2 diabetes, non-alcoholic fatty liver disease
•What are some tricks food companies are using to make us buy their
products?
keep prices down, advertisements, stocked at eye levels for children,
famous sport figures
•What is a “food desert”?
an urban area in which it is difficult to buy affordable or good-quality
fresh food. No access to grocery store
•About how many choices do we make each day regarding food? How
many of them are conscious?
over 200 decisions about food a day, majority are unconscious to use
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Sunday, August 25, 2019
•What are some practices that were shown to be very effective in
improving people’s choices of food?
size of a plate, use smaller glasses, serve vegetables first, fruit next to
cash register, order of food
•What are likely health consequences of drinking one can of soda a day?
increases the risk of type 2 diabetes, heart attacks, obesity, can cause
some cancers grow
•What is the French paradox? How do we explain it?
eat more like the French do. They eat fatty food often, lavish desserts,
drink wine, but not as fat as Americans and less heart disease and longer
longevity. They are rigid in the way that they eat, they eat at the exactly
same time. Reliance on tradition makes life easier. They serve less food
and smaller portions. Food is something you enjoy, they eat slowly.
Everything to do habit. Culture is the best guide we have. Enjoy as long
as it took to prepare, don’t eat anything great grandma wouldn’t
recognize as food, break the rules once in a while.
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