Brain cells determine obesity -- not lack of willpower: study

September 8, 2010, Monash University

An international study has discovered the reason why some people who eat a high-fat diet remain slim, yet others pile on the weight.

The study, led in Australia by the Monash Obesity and Diabetes Institute (MODI) at Monash University, found a high-fat causes to become insulated from the body preventing vital signals, which tell the body to stop eating and to burn energy, from reaching the brain efficiently.

MODI director and Australian Life Scientist of the Year Professor Michael Cowley said there were two clear outcomes from the findings.

'We discovered that a high-fat diet caused brain cells to become insulated from the body, rendering the cells unable to detect signals of fullness to stop eating," Professor Cowley said.

"Secondly, the insulation also created a further complication in that the body was unable to detect signals to increase energy use and burn off calories/kilojoules."

The research showed that support cells in the brain developed overgrowth in a high-fat diet. This prevented the regular brain cells (the melanocortin system or POMC ) from connecting with other , which determine appetite and .

Professor Cowley said the study findings provide a critical link in addressing the obesity epidemic.

"These regulate eating behaviours and energy expenditure and are a naturally occurring process in the brain. The circuits begin to form early in life so that people may have a tendency towards obesity even before they eat their first meal," Professor Cowley said.

Eating a high fat diet causes more "insulation" in the nerve cells, and makes it even harder for the brain to help a person lose weight.

"Obese people are not necessarily lacking willpower. Their brains do not know how full or how much fat they have stored, so the brain does not tell the body to stop refuelling. Subsequently, their body's ability to lose weight is significantly reduced."

Professor Cowley and fellow MODI researcher Dr Pablo Enriori collaborated with Research Chair and Professor of Comparative Medicine and Professor of Neurobiology Tamas Horvath and his team at the Yale School of Medicine in the United States, together with teams of scientists in Cincinnati, New Jersey, Mexico and Spain.

For a period of four months, the researchers monitored the eating and body composition of groups of mice and rats and found that those with a neural predisposition to gained 30 per cent more weight compared to six per cent of the group with obesity-resistant cells.

More information: The publication is available online at the Proceedings of National Academy of Sciences (PNAS) www.pnas.org/content/early/201 … /1004282107.abstract

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16 comments

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StarDust21
5 / 5 (1) Sep 08, 2010
Fat people shouldn't feel guilty really, it's 95% genes 5% willing. I'm hungry all the time and can eat whatever I want and I never get fat, if someone else eat exactly the same he might get super fat..
BigTone
not rated yet Sep 08, 2010
This study went from really cool to mildly interesting - mice and rats were the test subjects...
marjon
3.3 / 5 (4) Sep 08, 2010
"An international study has discovered the reason why some people who eat a high-fat diet remain slim, yet others pile on the weight."
That has already been determined. It is called adaptation.
High fat diets don't make people fat anyway. What makes people fat is eating too much sugar and the wrong kinds of fats.
Humans need fat and protein. They don't need sugar or carbohydrates to survive.
mcebrowski
not rated yet Sep 08, 2010
'We discovered that a high-fat diet caused brain cells to become insulated from the body, rendering the cells unable to detect signals of fullness to stop eating," Professor Cowley said.

So here is a thought...why couldn't the same cell insulation theory be used where as the signals of hunger were blocked via the same process?

I'm no rocket scientist. I barely got out of high school...but if it can block signals of fullness.....it should also block signals of hunger. Electrical signals are blocked, so how would it discriminate from one source or another? This doesn't add up.
ArcainOne
5 / 5 (1) Sep 08, 2010

I'm no rocket scientist. I barely got out of high school...but if it can block signals of fullness.....it should also block signals of hunger. Electrical signals are blocked, so how would it discriminate from one source or another? This doesn't add up.


Actually it does. Even in your electronics, electrical signals are not just zaps of electricity moving from wire to wire. Your brain must also interpret electrical signals and it runs off of ions, electrically charged atoms or molecules, and many neuron receptors only respond to specific kinds ions (electrically charged molecules). So your neuron MUST be able to understand the difference between the "hunger on" and "Hunger Off" signal just like low voltage current indicates off and high voltage current indicates on in your calculator using and array of logic gates, voltage resisters, and capacitors.
Yellowdart
1 / 5 (1) Sep 08, 2010
This study went from really cool to mildly interesting - mice and rats were the test subjects...


Yeah Im not sure how you get a determination on human willingness through rats and mice...

However, it is interesting if fat is insulating our brain cells into dormancy.

Mind over matter...
Roderick
3 / 5 (2) Sep 08, 2010
The study is rubbish. In France only 15% of the population is overweight or obese whereas in the States the figure must be closer now to 75%.

It's culture that makes the difference. French parents follow the rule that when in doubt, do not feed your child. Snacking is stricly forbidden. Breakfast is very light, usually a croissant or just coffee. Lunch is light. The only big meal is dinner.

megz0rrr
5 / 5 (1) Sep 09, 2010
It is not rubbish, this study is by no means saying that diet and lifestyle do not play a role in a person's weight. Instead it is saying once a person is obese or overweight, their brain stops responding to the hormone 'leptin'. Normally, leptin acts upon receptors in the brain to increase energy expenditure and reduce food intake. However, in obese people the receptor for leptin is down regulated so they do not get the appropriate signals telling them to stop eating and exercise more. Therefore, obese people find it more difficult to lose weight.
mjb_TO
not rated yet Sep 09, 2010
It is triglycerides that interfere with leptin sensitivity in the hypothalumus. triglycerides are elevated by dietary carbohydrates, not dietary fat. Examine the study details and I expect you will find they juiced the feed with fructose syrup to get them to consume excess fat calories.
mysticshakra
1 / 5 (1) Sep 09, 2010
They sure are trying hard to give people an excuse to stay fat and eat whatever they want. Any excuse......no self control or responsibility. Must go along with the american agenda to get obesity declared a disability.
Djincs
not rated yet Sep 09, 2010

High fat diets don't make people fat anyway. What makes people fat is eating too much sugar and the wrong kinds of fats.
Humans need fat and protein. They don't need sugar or carbohydrates to survive.

This is not the case, you cant sintesize carbohydrats out of fats , but you can do the oposit thing(here i dont mention the esential fats that are used for other things in the body not energy), when the glucose in the blood drop, you start to metabolise the proteins to make glucose(the fats give the energy but the proteins give the stuf) becauce brain use mainly glucose to work, no fats, in this proces amonia is emmited, which just make it hard for your metabolism, the best thing to do is to eat small portion of carb, regularly.
my point is that it is not good not to eat carbs, you wont die but it is pointless.
rgwalther
not rated yet Sep 12, 2010
They sure are trying hard to give people an excuse to stay fat and eat whatever they want. Any excuse......no self control or responsibility. Must go along with the american agenda to get obesity declared a disability.


I thought that the triglycerides were assimilated by the BORG.
gwrede
1 / 5 (1) Sep 13, 2010
I'm hungry every day. Some days screaming hungry. But being hungry doesn't automatically mean a trip to the fridge or McD.

The fat people I know never miss a mealtime. Nothing in the world is important enough to skip a meal. Likewise, they always remember "that you should eat small snacks between meals".

I can agree that for a naive individual, being hungrier, or hungry more of the time, may be the cause of weight rise. But for those who know they should lose weight, I say it's an attitude problem. Look down the street: who's eating? It's the fat. Ice-cream, hot dogs, chocolate.

I can't possibly believe that Americans have that different genes from, say Swedes. Look at Google city views. No fat people in Stockholm.
Javinator
not rated yet Sep 13, 2010
Does the high fat diet insulate the cells in your eyes?

When I look in the mirror or look at the scale and see that I'm looking a bit chubby it's a pretty simple conscious decision to start eating chicken and salad instead of a Baconator.

Just because you're not feeling full doesn't mean you shouldn't be aware that you don't need to eat the entire pizza or that third or fourth pound of chicken wings. I'm sorry, but this kind of thing is definitely will power. Just because some people can have high fat diets and others can't isn't an excuse to be obese.
Yellowdart
1 / 5 (1) Sep 15, 2010
No fat people in Stockholm.

Swedes walk/bike everywhere. They use the car less frequently than we do, partly cause of cost, partly cause the towns are conditioned to bikes/walking still.

People in America live 20 minutes from work, play, grocery store...so they drive.
rgwalther
not rated yet Sep 16, 2010
The study is rubbish. In France only 15% of the population is overweight or obese whereas in the States the figure must be closer now to 75%.

It's culture that makes the difference. French parents follow the rule that when in doubt, do not feed your child. Snacking is stricly forbidden. Breakfast is very light, usually a croissant or just coffee. Lunch is light. The only big meal is dinner.


Roderick, Time to recheck your statistical data on the French.

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