Mice become Obese WITHOUT Consuming Any More Calories
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Dont mice nibble all day? What would an unnatural time to them be? I know my hamsters at least used to just nibble little bits all day.0
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Very Interesting ... thanks for sharing0
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I think this is a fascinating and well-done study. First, the researchers used a gene knock-out approach to remove the fat cells' ability to time-regulate their own metabolic processes, and the mice showed disregulated eating times (which, for a normal mouse, is eating during the day, so actually there is an 'unnatural' time for a nocturnal foraging animal to eat).
Appetite is driven in a complex way but is strongly dependent on the activity of the hypothalamus, a brain region that was not altered.
So the study shows that messed-up fat cells alone can cause appetite dysregulation and consequent weight-gain, effectively overriding the normal 'master- clock' in the brain. Then they showed the same effect by merely having normal (non genetically altered) mice eat at the same odd times, and they got fat too.
Now, the study does not say that activity was the same, the amount consumed was the same, or that other aspects of physiology were the same, but this is what makes it so interesting: By ONLY changing the time that food was consumed, the mouse's metabolism and appetite were different, with that difference consistently resulting in weight gain.
For everyone crying 'I lost weight on shift work!' - good for you. Humans have more self control than mice, but the study is aimed at revealing conserved physiological, not psychological, processes.
For everyone's "I'm not a mouse and rodent studies are WORTHLESS"" Actually in physiological terms, you pretty much are. Mammals are mammals, and almost all we know about human disease and drugs that treat them, is founded on studies of mice and rats.0 -
what is an unnatural time for a mouse? I'm hungry, I'm gonna nom on something!0
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I think this is a fascinating and well-done study. First, the researchers used a gene knock-out approach to remove the fat cells' ability to time-regulate their own metabolic processes, and the mice showed disregulated eating times (which, for a normal mouse, is eating during the day, so actually there is an 'unnatural' time for a nocturnal foraging animal to eat).
Appetite is driven in a complex way but is strongly dependent on the activity of the hypothalamus, a brain region that was not altered.
So the study shows that messed-up fat cells alone can cause appetite dysregulation and consequent weight-gain, effectively overriding the normal 'master- clock' in the brain. Then they showed the same effect by merely having normal (non genetically altered) mice eat at the same odd times, and they got fat too.
Now, the study does not say that activity was the same, the amount consumed was the same, or that other aspects of physiology were the same, but this is what makes it so interesting: By ONLY changing the time that food was consumed, the mouse's metabolism and appetite were different, with that difference consistently resulting in weight gain.
For everyone crying 'I lost weight on shift work!' - good for you. Humans have more self control than mice, but the study is aimed at revealing conserved physiological, not psychological, processes.
For everyone's "I'm not a mouse and rodent studies are WORTHLESS"" Actually in physiological terms, you pretty much are. Mammals are mammals, and almost all we know about human disease and drugs that treat them, is founded on studies of mice and rats.
We metabolize differently.0 -
what is an unnatural time for a mouse? I'm hungry, I'm gonna nom on something!
Mice, like rats, are primarily nocturnal. So a mouse will naturally eat at night and sleep during the day. The study states that the mice with messed up internal clocks ate during the day, when they should have been sleeping. So there really is an unnatural time for a mouse to eat.We metabolize differently
How? Can you give some concrete examples?0 -
We're not mice.what is an unnatural time for a mouse? I'm hungry, I'm gonna nom on something!
Mice, like rats, are primarily nocturnal. So a mouse will naturally eat at night and sleep during the day. The study states that the mice with messed up internal clocks ate during the day, when they should have been sleeping. So there really is an unnatural time for a mouse to eat.We metabolize differently
How? Can you give some concrete examples?
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The study mentions a hormonal problem that is caused by disabling the "clock gene" in the mice. They then claim it is this hormonal problem in relation to fatty tissues that is the cause of their weight gain.
It makes no claim what so ever that the time period of when a mouse eats determines its weight gain.0 -
So glad I'm not a mouse!0
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what is an unnatural time for a mouse? I'm hungry, I'm gonna nom on something!
Mice, like rats, are primarily nocturnal. So a mouse will naturally eat at night and sleep during the day. The study states that the mice with messed up internal clocks ate during the day, when they should have been sleeping. So there really is an unnatural time for a mouse to eat.We metabolize differently
How? Can you give some concrete examples?
^^^ thanks for some fresh air on here (and OP, couple of other posters). Opportunity to learn something or at least consider possibilities. I think there is a new wave of understanding coming with weightloss...but as per usual with science it requires years of study etc etc. Now if the mice lifted heavy...it'd be more interesting for some
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I don't read fitness mags because they're not much more than broscience and supplement hype - but I'll keep my "protein shakes and weight lifting", thankyouverymuch. I was able to lose over 40 pounds while working graveyard shift with highly irregular eating patterns and I know plenty of other people who were very successful at it as well. I'll take that over somebody using mice as an excuse for why they're still fat and can't lose weight any day....People need to get their heads out of the gym and actually read something other than a work out magazine and learn something new for a change. Broaden your horizons and open your minds to the world around you. Life is more than protein shakes and weight lifting.0 -
Those lazy mice should've made up for it by using the elliptical traine--oh wait...0
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Cherry picking a few things because I don't want to read the whole study.....
Scientists have recently looked at a mammalian clock gene in fat cells that is known under two names: "Arntl" and "Bmal1." The researchers found that when mice carry a deletion of the clock gene Arntl/Bmal1 in their fat cells, that the mice do two things: they shift their normal eating pattern from nighttime to daytime…and they become obese. This deletion of the Arntl/Bmal1 gene results in a broken molecular clock that disrupts the brain-body timing involved in eating.
The Penn team found that only a handful of genes were altered when the clock was broken in fat cells and these governed how unsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were released into the blood stream. Interestingly, these are the same fatty acids that are typically associated with fish oils. Sure enough, levels of EPA and DHA were low in both plasma and in the hypothalamus at the time of inappropriate feeding.
However, when the Arntl/Bmal1 deleted mice were fed EPA and DHA, their normal metabolism was restored.
ETA. The last line, and that it appears they were mutant mice, by the researchers I am assuming, once the were given back what was missing because of having their fat cells broken they went back to normal.
Upon reading about broken fat cells though I think I am going to use that, I am not really obese my fat cells are just broken.
Well that make some sense, but it has already been proven that the lack of fatty acids, themselves, increase hunger. This isn't relevant to feeding timing in anyway. And it is not simply the lack of fatty acids that caused obesity, but rather the physiological trigger from the lack of it that led to excessive consumption.0 -
For everyone's "I'm not a mouse and rodent studies are WORTHLESS"" Actually in physiological terms, you pretty much are. Mammals are mammals, and almost all we know about human disease and drugs that treat them, is founded on studies of mice and rats.
I put more faith in studies involving mice than humans anyway. Studies utilizing mice are controlled studies in which scientists can monitor and regulate every waking moment of the mice's lives. Controlled studies allow for a much smaller probability for error. This can't be done with humans. The problem with human subjects is not only can their daily activities NOT be controlled, but they really can't be trusted to tell the truth either. This exponentially increases the probability for error in comparison to controlled studies. Studies involving human subjects are correlative studies and must be repeated multiple times by multiple unbiased groups before the scientific community will accept their findings.
Of couse, I'm sure based on your post that you already know this, but I'm explaining this for anyone who might not know.
As far as this paticular study goes, admittedly I didn't read it and didn't give it a chance. But I don't believe the real result of this study was fully articulated by the media. To me, this study just furthers our understanding of the positive and negative impact of fatty acids in our diets. While timing may not impact the metabolism, it does seem that it could interfere with the body's ability to process fatty acids. Based on established fact, the lack of fatty acids will cause a release in grehlin, the hormone regulating appetite, and ultimately, increased appetite would lead to obesity. Too many dots have to connect to come to that conclusion though.0 -
what is an unnatural time for a mouse? I'm hungry, I'm gonna nom on something!
Mice, like rats, are primarily nocturnal. So a mouse will naturally eat at night and sleep during the day. The study states that the mice with messed up internal clocks ate during the day, when they should have been sleeping. So there really is an unnatural time for a mouse to eat.We metabolize differently
How? Can you give some concrete examples?
I'm trying to find actual research on this but my understanding is that de novo lipogensis occurs much more readily in rats vs humans.0 -
Did the researchers give them an air hose?0
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what is an unnatural time for a mouse? I'm hungry, I'm gonna nom on something!
Mice, like rats, are primarily nocturnal. So a mouse will naturally eat at night and sleep during the day. The study states that the mice with messed up internal clocks ate during the day, when they should have been sleeping. So there really is an unnatural time for a mouse to eat.We metabolize differently
How? Can you give some concrete examples?
I'm trying to find actual research on this but my understanding is that de novo lipogensis occurs much more readily in rats vs humans.
I believe these are relevant but I'll be brutally honest in that I just skimmed these but this should show differences in lipogenesis between species:
http://www.sciencedirect.com/science/article/pii/002604957190059X
http://www.jlr.org/content/44/11/2127.full.pdf
EDIT: I don't have the full text for the top one unfortunately.0 -
In the time most people take to read the OP article, I will have completed 1000 pushups 0
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In the time most people take to read the OP article, I will have completed 1000 pushups
Nice. Just dont eat at night.0 -
For those of you asking how the metabolism of a human and rodent differ-Rats are carb burners; they consume and rapidly use large amounts of carbohydrates to survive. Humans are fat burners, meaning we don’t need carbs constantly since our body can easily store energy in the form of fat. Therefore, something that prevents obesity and activates lipid metabolism in rodents will have different effects in humans, unless those rodents’ metabolisms have been altered to mimic those of humans.0
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BS for humans. At least for this human who has lost 70 lbs eating my dinner at 7 pm and a snack at 11:30 pm. Oh, and I don't eat breakfast until 1 in the afternoon. Maybe the mice should copy me.0
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When the **** did mice start learning to tell time? And exactly where do they get their watches? Last I heard that the last time mice had anything to do with a timepiece, it turned out badly for them, Hickory, Deekory, Dock.0
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Were the mice eating back their exercise calories?
And did they count coffee in their water glass count?0 -
what is an unnatural time for a mouse? I'm hungry, I'm gonna nom on something!
Mice, like rats, are primarily nocturnal. So a mouse will naturally eat at night and sleep during the day. The study states that the mice with messed up internal clocks ate during the day, when they should have been sleeping. So there really is an unnatural time for a mouse to eat.We metabolize differently
How? Can you give some concrete examples?
I'm trying to find actual research on this but my understanding is that de novo lipogensis occurs much more readily in rats vs humans.
I believe these are relevant but I'll be brutally honest in that I just skimmed these but this should show differences in lipogenesis between species:
http://www.sciencedirect.com/science/article/pii/002604957190059X
http://www.jlr.org/content/44/11/2127.full.pdf
EDIT: I don't have the full text for the top one unfortunately.
So both of those refer to rats only, with no mention of mice. In mice, it is known that the cholesterol metabolism is different, presumably because mice are almost exclusively herbivorous, in contrast to humans (and rats), so dietary cholesterol is much lower in mice.
In both of the studies you cite, (BTW, I do have a full-text of the first, if you are interested I would be happy to send it to you) the focus is in lipogenesis that occurs in adipose tissues. In humans this is a smaller proportion than in rats, because most FAM occurs in the liver in humans. That study is from 1971, and it seems since then there is a better understanding of the larger role of the liver in humans in FAM. I cannot say that overall, lipogenesis occurs more readily in rats, because the studies only examine rates in one tissue type.
In the study that is the topic of this thread, the conclusion is that a change in a gene in fat cells has substantial downstream effects, but not that adipose tissues changed their own contributions to lipogenesis (although this may be occurring, but I can't tell from the study).
So there are differences in rats and humans in where fats are primarily metabolised, but perhaps not in overall rates acroos various organs. Also, these are mice, not rats, which have their own differences from humans, but are generally a very good genetci models for humans.0 -
For those of you asking how the metabolism of a human and rodent differ-Rats are carb burners; they consume and rapidly use large amounts of carbohydrates to survive. Humans are fat burners, meaning we don’t need carbs constantly since our body can easily store energy in the form of fat. Therefore, something that prevents obesity and activates lipid metabolism in rodents will have different effects in humans, unless those rodents’ metabolisms have been altered to mimic those of humans.
This is false. Both humans and rats (and again, this study used MICE) store energy both as fat and glycogen, and utilise both in very similar ways. Rats have an omnivorous diet very much like humans, will consume both fat and carbohydrate readily, and will gain weight on a caloric excess of either. Humans and rats both deplete free glucose, muscle gylcogen and stored fats during exertion, and all are converted to glucose for use as cellular energy. The terms 'carb burners' and 'fat burners' are not scientifically valid - all mammals burn a combination of both fuel types (if we assume 'carb burning' refers to glycogen).0 -
For those of you asking how the metabolism of a human and rodent differ-Rats are carb burners; they consume and rapidly use large amounts of carbohydrates to survive. Humans are fat burners, meaning we don’t need carbs constantly since our body can easily store energy in the form of fat. Therefore, something that prevents obesity and activates lipid metabolism in rodents will have different effects in humans, unless those rodents’ metabolisms have been altered to mimic those of humans.
I don't know if I agree with your 'carb-burning vs fat-burning' theory, but the main difference and problem that I see with this study is that mice and humans have a different biological clock. I made the mistake earier saying that mice weren't nocturnal... but they are. The point I was trying to get at with that was that the mice were being fed at time when they are used to being inactive. As someone else pointed out, we have the will to defy our own natural instincts. We can choose to be active when we choose too. Therefore, I could see why feed-timing would have a different effect on mice than humans. But usually, scientists don't expect to prove definitively that what happens to mice also happens to humans, but more that if it the effect in mice exists, then to some degree the effect could also occur in humans. One controlled study is never considered to be the end of all that is relevant to the topic. Now that the controlled study has proven that the effect could exist. It is up to correlative studies with human subjects to investigate the occurrence to further determine if and how frequently the effect occurs in humans. This is generally the process for information becoming accepted as fact. Either controlled studies instigate correlative studies... or vice versa. Once enough reputable scientist come to a consensus, then feed-timing could become relevant to how obesity occurs, but again, it is not a direct cause and the resultant physiological reaction that it creates could be countered just by cooking with olive oil, occassionally eating some fish, and enjoying some yummy peanut butter at will.0 -
what is an unnatural time for a mouse? I'm hungry, I'm gonna nom on something!
Mice, like rats, are primarily nocturnal. So a mouse will naturally eat at night and sleep during the day. The study states that the mice with messed up internal clocks ate during the day, when they should have been sleeping. So there really is an unnatural time for a mouse to eat.We metabolize differently
How? Can you give some concrete examples?
I'm trying to find actual research on this but my understanding is that de novo lipogensis occurs much more readily in rats vs humans.
I believe these are relevant but I'll be brutally honest in that I just skimmed these but this should show differences in lipogenesis between species:
http://www.sciencedirect.com/science/article/pii/002604957190059X
http://www.jlr.org/content/44/11/2127.full.pdf
EDIT: I don't have the full text for the top one unfortunately.
So both of those refer to rats only, with no mention of mice. In mice, it is known that the cholesterol metabolism is different, presumably because mice are almost exclusively herbivorous, in contrast to humans (and rats), so dietary cholesterol is much lower in mice.
In both of the studies you cite, (BTW, I do have a full-text of the first, if you are interested I would be happy to send it to you) the focus is in lipogenesis that occurs in adipose tissues. In humans this is a smaller proportion than in rats, because most FAM occurs in the liver in humans. That study is from 1971, and it seems since then there is a better understanding of the larger role of the liver in humans in FAM. I cannot say that overall, lipogenesis occurs more readily in rats, because the studies only examine rates in one tissue type.
In the study that is the topic of this thread, the conclusion is that a change in a gene in fat cells has substantial downstream effects, but not that adipose tissues changed their own contributions to lipogenesis (although this may be occurring, but I can't tell from the study).
So there are differences in rats and humans in where fats are primarily metabolised, but perhaps not in overall rates acroos various organs. Also, these are mice, not rats, which have their own differences from humans, but are generally a very good genetci models for humans.
Sorry, never even made the connection that the original study was on mice and I linked you rat studies. Oops
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I'm sorry, perhaps my reading comprehension skills are low tonight, but the very first line of that article states "shows that deletion of the clock gene Arntl, also known as Bmal1, in fat cells, causes mice to become obese, with a shift in the timing of when this nocturnal species normally eats" Yes I copy pasted that. They deleted a gene AND shifted timing? How does that apply to us at all?0
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The mice must have eaten at 46:98 o'clock. <
an unnatural time.0 -
How does that apply to us at all?
^ This would be the key question and this is also why it's important not to take the findings of a study and draw them out of context.0
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