High-Fat Diet Can Disrupt Body's Clock

[kebaldwin]

High-Fat Diet Can Disrupt Body's Clock
Like a midnight raid on the fridge for junk food -- sleep often suffers, study says

TUESDAY, Nov. 6 (HealthDay News) -- There's more bad news about a high-fat diet -- it disrupts the body's 24-hour internal (circadian) clock, which regulates sleeping, waking, eating, as well as the daily rhythms of many metabolic functions, U.S. researchers say.

A team from Northwestern University and Evanston Northwestern Healthcare (ENH) found that mice fed a high-fat diet gained weight and showed a sudden disruption in their circadian clock, eating extra calories when they should have been sleeping or resting.

The team also found that a high-fat diet caused changes in genes that encode the circadian clock in the brain and in peripheral tissues (such as fat), resulting in reduced expression of these genes.

The findings are published in the Nov. 7 issue of the journal Cell Metabolism.

"Our study was simple -- to determine if food itself can alter the clock," senior author Dr. Joe Bass, assistant professor of medicine and neurobiology and physiology at Northwestern and head of the division of endocrinology and metabolism at ENH, said in a prepared statement.

"The answer is, yes; alterations in feeding affect timing. We found that as an animal on a high-fat diet gains weight, it eats at the inappropriate time for its sleep/wake cycle -- all of the excess calories are consumed when the animal should be resting. For a human, that would be like raiding the refrigerator in the middle of the night and binging on junk food," Bass said.

More information

The U.S. Food and Drug Administration offers advice on healthier eating.

-- Robert Preidt

SOURCE: Northwestern University, news release, Nov. 6, 2007

Copyright © 2007 ScoutNews, LLC. All rights reserved.

http://www.healthday.com/Article.asp?AID=609710

[kebaldwin]

What a load of excrement.

I don't even know how to manipulate a study to conclude this ... which makes me wonder if this study has any truth at all.

High fat diet curbs hunger and reduces weight.

[LessLiz]

A team from Northwestern University and Evanston Northwestern Healthcare (ENH) found that mice fed a high-fat diet gained weight and showed a sudden disruption in their circadian clock, eating extra calories when they should have been sleeping or resting.I guess that we now have proof positive that mice make a poor substitute for humans in studies.

Their reported results run so contrary to everything else in the field that I wonder if there is anything to back up what they are saying.

[Dodger]

For some reason the editors decided that the article was so important that it was the cover article!

OK, I looked at the graphs (http://download.cellmetabolism.org/supplementarydata/cmet/6/5/414/DC1/mmc1.pdf) from the paper and the fat fed mice did gain weight. On the other hand, their eating habits seemed to improve! They ate more during the 'light' phase and less during the 'dark' phase. They also seemed to sleep more when it was dark. To me this means that the high fat diet improved their body's clock. The normal mouse food seemed to have disrupted their normal cycle.

[kebaldwin]

I wonder if it is one of these high fat and high glycemic diet things?

Whereas we are all familiar with high fat and low glycemic diet.

[lcgrrl2006]

High fat high carbs I would think.

[Rachel1]

Mice are nocturnal, so we'd expect them to eat more at night. If they're eating during the light phase, that's presumably not a good thing (for mice). Weight gain is also not a good thing.

Many questions come to mind. First, what were the mice eating besides high-fat? High carbs as well? Second, can we extrapolate from mice to humans? Third, even if the diet was high in fat and low in carbs, is this a natural or an unnatural diet for mice? Fourth, how long did the study continue - would the results have held over time?

All these questions (and more I haven't thought of offhand) add up so a big "so what?".

Rachel

[Rachel1]

The cover of the journal shows the mice eating french fries. I don't know if that's what the study mice were actually fed, but I think it tells us something about the quality of the study.

Rachel

[probiotic]

The bias of the publicizing of this study, if not the study itself, came out clearly in the phrase "there's more bad news" about high fat diets.

[LessLiz]

From Taubes book I now know enough about mice studies to want to know exactly what type of mice were used, as well as what exactly "high fat" diet means. Mice diets tend to be extremely low in fat, and while Taube reports studies indicating that mice do gain weight on high fat diets, those diets tend to be extremely high in fat vs a "natural" mice diet, and the particular type of mice makes a huge difference in what is found.

Mice are likely not good analogs for humans when one is investigating nutritional effects.

[waywardsis]

Personally, I've never slept better in my entire life. I haven't had insomnia now for ages. And even if I sleep less (sometimes I do, bc I have more energy) I sleep DEEPLY and feel refreshed in the morning. It's nice.

Of course they were feeding high-fat mouse chow, right? Whoop-dee-doo.

[pbowers]

lessliz, i think taubes refers to rat diets being naturally low fat, not mice. nevertheless, it's safe to assume these mice were being fed a high-carb diet in addition to the high-fat:
The circadian clock programs daily rhythms and coordinates multiple behavioral and physiological processes, including activity, sleep, feeding, and fuel homeostasis. Recent studies indicate that genetic alteration in the core molecular clock machinery can have pronounced effects on both peripheral and central metabolic regulatory signals. Many metabolic systems also cycle and may in turn affect function of clock genes and circadian systems. However, little is known about how alterations in energy balance affect the clock. Here we show that a high-fat diet in mice leads to changes in the period of the locomotor activity rhythm and alterations in the expression and cycling of canonical circadian clock genes, nuclear receptors that regulate clock transcription factors, and clock-controlled genes involved in fuel utilization in the hypothalamus, liver, and adipose tissue. These results indicate that consumption of a high-calorie diet alters the function of the mammalian circadian clock. ahhh, the old bait and switch; a "high-fat" diet becomes a "high-calorie".

i've emailed one of the authors to get more info.

http://www.cell.com/webfiles/images/covers/cmet/cmet.6.5.lrg.gif

[LessLiz]

Hmm, now that you mention it I think you are right, it was rats not mice.

[Locarb4mee]

Just glad I'm not a mouse!

[pbowers]

one of the authors was kind enough to send me copy of the original article. as suspected, the "high-fat" (HF) diet was also 35% CHO. also of note, the regular chow (RC) curiously contained more protein than the high fat diet (27% vs. 20%). draw your own conclusions:Three-week-old mice were placed in standard mouse cages equipped with infrared sensors to detect locomotor activity. For the first week of activity recording, mice were maintained on a 12:12 LD cycle and fed regular chow (RC; 16%kcal from fat, 27% kcal from protein, and 57% kcal from carbohydrate; 7012, Harlan Teklad) diet. Starting at 4 weeks of age, animals were maintained in constant darkness (DD) for 2 weeks and then fed either RC (n = 12) or a high-fat (HF; 45% kcal from fat, 20% kcal from protein, and 35% kcal from carbohydrate; D12451, Research Diets, Inc.; n = 10) diet for 6 weeks. The free-running period was calculated as the duration of time between the major activity periods on consecutive days. The amplitude of the locomotor activity rhythm was determined by fast Fourier transformation (FFT) analysis. Total activity counts were quantified as the total number of infrared sensor beam breaks (The Chronobiology Kit, Stanford Software Systems).

For analyses under entrained 12:12 LD conditions, 3-week-old mice were placed in combined feeding and activity monitors, provided regular chow ad libitum for 3 weeks, and then fed either RC (n = 6) or HF (n = 7) diet for 6 weeks. Food intake (Feed-Scale, Columbus Instruments) and locomotor activity were continuously monitored throughout the experiment.

posting the OA here (http://www.box.net/shared/icc2hgrq68) for anyone interested.

[deirdra]

Thanks for posting the OP link.

[deirdra]

Thanks for posting the OP link. All changes to my clock have been positive - I sleep deeply instead of tossing & turning or waking in the middle of the night like I did on high carbs.

I notice n=10 and n=7 on the "HF" diets. Normally you need at least 30 subjects to get valid statistical results.

[scottyp62]

Well the first thing I notice is the following statement:"...all of the excess calories are consumed..."

Duh! Excess calories are ALWAYS a problem for those desiring to LOSE EXCESS fat. I don't have a PhD but dang!

[LessLiz]

Well the first thing I notice is the following statement:"...all of the excess calories are consumed..."

Duh! Excess calories are ALWAYS a problem for those desiring to LOSE EXCESS fat. I don't have a PhD but dang!Excess calories are not always a problem.

[Groggy60]

The mice feed fat where awake during the day because they were getting together and planning how to take over the world!

What are we going to do tomorrow Brain?

[Locarb4mee]

Thanks for posting that followup. I'm not in the least surprised.

[confession]

I sleep very soundly on high fat and Low Carb. I know I would not sleep well if I read studies like these before bed, as irritation/ anger do not help me sleep well. LOL

[deb34]

this was like the mouse version of scarfing down bags of chips. They add oil to the lab mouse chow(which is mostly carbs of course) and then experience a Eureka! moment when the rodents gain weight....they didn't need to do a study to determine this, i could have told them. When i ate mostly junkfood, i was up and roaming when i should have been sleeping because i always had heartburn and acid reflux. I ate more carbs during the night mistakenly thinking it would soak up the excess stomach acid.

Did they ask the poor mice if they were restless because their poor tummies were upset? Do mice expericence heartburn and reflux? How about a study to determine if mice need to use Nexium or not?

[Kendal]

It's probably a high fat carby diet that affected their sleep. I've dealt with insomnia all of my adult life, until I eliminated wheat from my diet and went on Atkins (pretty high fat). I'm amazed at how deeply and easily I fall asleep now.

[amberview]

so why is that these scientist never list the menu. What were they eating...doughnuts?

[teaser]

I'm sure wild mice eat lots of nuts and seeds and bugs. Not exactly low fat. What they don't eat is the sugar and cornstarch that is the bulk of most laboratory mouse and rat chow. A Dean Ornish style low-fat diet is only necessary in a high sugar/starch diet. Mice and rats on ketogenic diets give entirely different results from those on high fat plus sugar and cornstarch. In case I haven't made myself clear, I'm saying I think it might be the sugar. Or the cornstarch. Or maybe even the sugar and the cornstarch?

[ElleH]

By any chance was that "high fat diet" also high in carbs??? That would explain the raids on the fridge...