Science News Magazine article: High-fat diet cuts brain’s food brake

[Saul]

High-fat diet cuts brain’s food brake

IN SECTION: BODY & BRAIN

Mouse study hints at neural changes related to overeating

BY LAURA SANDERS

A gut-busting diet may set the brain up for more of the same. After mice ate fatty food for just two weeks, cells in their brains that send a “stop eating” signal were quieter than those in mice that didn’t eat high-fat chow, researchers report in the June 28 Science.

Food is key to survival, which may be why the brain has built-in redundancy — a multitude of overlapping systems to make sure animals eat enough. Neuroscientist Garret Stuber of the University of Washington in Seattle investigated one area known to be involved in eating.

Called the lateral hypothalamus, this brain structure contains a large number of diverse nerve cells. Stuber and colleagues looked at gene behavior in single cells there and found that one group, called glutamatergic nerve cells, showed particularly big changes in which genes were active when the team compared lean mice with obese mice.

Earlier work suggested that glutamatergic cells act like a brake on feeding: When the cells were artificially blocked from firing signals, mice ate more food and gained more weight. But it wasn’t clear how these cells behave over a more natural shift from leanness to obesity.

“Obesity doesn’t just happen overnight,” says Stuber, who conducted some of the work while at the University of North Carolina at Chapel Hill. To study that transition, the researchers fed mice high-fat mouse chow and periodically checked the glutamatergic cells’ ability to fire signals.

Two weeks into the binge, even before mice plumped up, the nerve cells showed more sluggish activity, both in their spontaneous behavior and when an animal was given a sip of sweet liquid. That reduction continued as the mice grew larger, for up to 12 weeks in some cases.

The results imply that “these cells’ decreased activity is removing the brake on feeding and obesity,” says neuroscientist Stephanie Borgland of the University of Calgary in Canada, who wrote a related commentary in the same issue of Science.

The researchers don’t know whether these cells would regain their normal behavior if the mice stopped eating highfat food and shed weight. And it’s hard to say whether similar appetite-suppressing nerve cells are at work in people.

[mikeccolella]

Omg Saul this is so totally true in my case. I have posted numerous times how much more fulfilling a low fat diet is from a hunger perspective. When I cut out the fat I feel almost challenged by how much I can eat! I always assumed it was the fiberous foods replacing the fatty foods that explained. The sheer volume of food also. But this adds another aspect that may be a factor.

[TomBAvoider]

Mike, have you tried a true ketogenic diet? By true, I mean you are actually in physiological ketosis, and that can be measured. It means basically having very little carbs and very limited protein, with the vast majority of the calories coming from fat. Again, this is not the same as eating tons of meat - protein is very limited too, along with carbs. You really are eating FAT. 

Now, under those circumstances, how do you react? I'm not advocating it, just curious as to whether you've tried this route to see what effect it would have. I personally have never tried it. 

For many years now, I've eaten a low fat, low protein high carb diet. This after trying a somewhat higher protein, medium fat, medium carb diet (higher protein because of Albatross). After the higher protein was deprecated, at least until old age (where higher protein might be useful again), I went to low protein, low fat high carb. I suppose I could have gone higher fat, low protein and low carb, which is the general ketogenic direction (even if you don't actually enter ketosis), but I never had a taste for fat. 

[Todd Allen]

Formulated lab chow "high fat diets" are typically 40 to 45% fat and often just as high in carbohydrates.  To control content the diets are typically formulated with highly refined ingredients such as soybean oil for fat, sucrose and powdered cellulose for carbohydrate and fiber, and casein for protein.  This should be called a "highly processed diet" or a "highly unnatural diet".  Lowcarbers call it a high sugar diet.  I call it a high inflammation diet as the choices for each macro are just about the worst one might pick for producing an inflammatory response.  It's a diet well designed for producing disease and despite being called a high fat diet the percentage of fat is probably not the problem.

Imagine housing mice in a natural low stress environment through which they could forage a diet of natural foods such as very fatty nuts, seeds and grubs.  They could be eating foods much higher in fat than the HFDs and I'd expect it would result in lean, vigorous mice with excellent health.  But raising happy healthy mice is not nearly as interesting as producing sick diseased mice.

 

Edited August 11, 2019 by Todd Allen

[mikeccolella]

15 hours ago, TomBAvoider said:

Mike, have you tried a true ketogenic diet? By true, I mean you are actually in physiological ketosis, and that can be measured. It means basically having very little carbs and very limited protein, with the vast majority of the calories coming from fat. Again, this is not the same as eating tons of meat - protein is very limited too, along with carbs. You really are eating FAT. 

Now, under those circumstances, how do you react? I'm not advocating it, just curious as to whether you've tried this route to see what effect it would have. I personally have never tried it. 

For many years now, I've eaten a low fat, low protein high carb diet. This after trying a somewhat higher protein, medium fat, medium carb diet (higher protein because of Albatross). After the higher protein was deprecated, at least until old age (where higher protein might be useful again), I went to low protein, low fat high carb. I suppose I could have gone higher fat, low protein and low carb, which is the general ketogenic direction (even if you don't actually enter ketosis), but I never had a taste for fat. 

Tom I have not tried such a diet. To me it sounds insane! I suppose the Inuit ate something like it? Not sure, but generally it’s just weird and I don’t like weird because I want something that’s been shown to be safe in the long run. That’s why I don’t like prescription drugs most r not tested for a lifetime and so we really don’t know their effects.plant based diets have been a mainstay of human evolution and therefore something not weird. We don’t have any evidence like that for ketogenic diets

[Ron Put]

Hm, I can't even imagine how I can personally cut out more fat from my diet and still get my nutrients. I personally find what I eat fulfilling and generally end up at a bit of a caloric deficit at the end of the day, except that a few times a month, usually at a party or a restaurant, I could go way over, even 1500kc on occasion 🙂

According to Cronometer, I am on a close to high-fat diet (last 4 weeks, top 3 sources for each group):

CARBS: 50%

1. Legumes/roots/whole grains

2. Oats (steel cut)

3. Cacao nibs

 

FAT: 34%

1. Organic milled flax

2. Walnuts

3. Cacao nibs

 

PROTEIN: 13%

1. Organic milled flax

2. Legumes/roots/whole grains

3. Cacao nibs

 

ALCOHOL: 2%

I guess I eat a lot of cacao nibs 🙂 Usually 20-30g a day. I don't use any EVOO or other oils, or cheese or eggs, unless I eat at a restaurant which serves it (I go to Italian (with my older friends 🙂 ) maybe 4 times a month, so that's it, and usually have some burrata at the same time).
 

 

Edited August 11, 2019 by Ron Put