7 replies to this topic

[ta5]

Here's a new negative study on Intermittent Fasting/Every-Other-Day/Alternate Day Fasting (IF/EOD/ADF).

 

Br J Nutr. 2014 Mar 28;111(6):979-86.

Food restriction by intermittent fasting induces diabetes and obesity and aggravates spontaneous atherosclerosis development in hypercholesterolaemic mice.

Different regimens of food restriction have been associated with protection against obesity, diabetes and CVD. In the present study, we hypothesised that food restriction would bring benefits to atherosclerosis- and diabetes-prone hypercholesterolaemic LDL-receptor knockout mice. For this purpose, 2-month-old mice were submitted to an intermittent fasting (IF) regimen (fasting every other day) over a 3-month period, which resulted in an overall 20 % reduction in food intake. Contrary to our expectation, epididymal and carcass fat depots and adipocyte size were significantly enlarged by 15, 72 and 68 %, respectively, in the IF mice compared with the ad libitum-fed mice. Accordingly, plasma levels of leptin were 50 % higher in the IF mice than in the ad libitum-fed mice. In addition, the IF mice showed increased plasma levels of total cholesterol (37 %), VLDL-cholesterol (195 %) and LDL-cholesterol (50 %). As expected, in wild-type mice, the IF regimen decreased plasma cholesterol levels and epididymal fat mass. Glucose homeostasis was also disturbed by the IF regimen in LDL-receptor knockout mice. Elevated levels of glycaemia (40 %), insulinaemia (50 %), glucose intolerance and insulin resistance were observed in the IF mice. Systemic inflammatory markers, TNF-α and C-reactive protein, were significantly increased and spontaneous atherosclerosis development were markedly increased (3-fold) in the IF mice. In conclusion, the IF regimen induced obesity and diabetes and worsened the development of spontaneous atherosclerosis in LDL-receptor knockout mice. Although being efficient in a wild-type background, this type of food restriction is not beneficial in the context of genetic hypercholesterolaemia.

PMID: 24176004

 

Below are some older negative studies on IF discussed in this thread.

 

Long-term intermittent feeding, but not caloric restriction, leads to redox imbalance, insulin receptor nitration, and glucose intolerance.

Free Radic Biol Med. 2011 Oct 1;51(7):1454-60. 

PMID: 21816219

 

Chronic alternate-day fasting results in reduced diastolic compliance and diminished systolic reserve in rats.

J Card Fail. 2010 Oct;16(10):843-53. 

PMID: 20932467 Free PMC Article

 

Caloric restriction and intermittent fasting alter spectral measures of heart rate and blood pressure variability in rats.

FASEB J. 2006 Apr;20(6):631-7.

PMID: 16581971 Free Article

 

Intermittent food deprivation improves cardiovascular and neuroendocrine responses to stress in rats.

J Nutr. 2003 Jun;133(6):1921-9.

PMID: 12771340 Free Article

[xEva]

The heading should not have been truncated but include "... in hypercholesterolaemic mice". In other words, this scary headline applies only to the genetically messed up mice -- and the authors are the first to admit it. What relevance does it have to an average human?
 
There are vast differences in metabolism --simply time wise-- between humans and mice. Here is some rounded off mouse statistics for you:  a mouse  takes ~165 breaths per minute and its heart beats ~650 times per minute. Throw in there 100 times faster telomere attrition rate and you start to appreciate the incredible pace at which these little furry things live.
 
Now regarding fasting. A mouse looses 10% of its body weight in 24h. A question for you: How much weight a 70 kg human looses in 24h? Surely, not 7 kilos! To loose 10% of his body weight, a man of 70 kg will take more than a week. An obese man may take a month.
 
How can this study be even applied to a human? The schedule they put their mice on is roughly equivalent to humans eating not every other day, as intermittent fasting implies, but every other week -- a week of eating followed by a week of fasting; and again; and again; for 90 weeks!  Looked under this light, I'm surprised to hear that wild type mice can handle this, apparently well. 
 
What I find the most shocking is that, even though they surely know the basics of rodent physiology, these type of "researchers" seem oblivious of the obvious implications. I'm at loss trying to explain them apparently implying that every-other-day eating for a mouse is about the same as eating every-other-day for a  man.


Having said that, yes, long term fasting --and that's what those mice eating every other day do-- similarly to a ketogenic diet, will skew glucose metabolism and many other things, which are actually adaptation to living on fat, be it from diet or your own reserves. It's a different metabolic mode. It's not better or worse, it's just different.

Edited by xEva, 03 June 2014 - 06:53 AM.

[Luminosity]

Although I'm not a mouse, I have had a similar experience.  Fasting, cleanses, dieting, skipping meals, etc. made me heavier than before in spite of now eating healthy and exercising for many years.  These behaviors damaged my metabolism and caused other serious health issues.   So if you want all that, do what I did.  

[ta5]

xEva, excellent points about these being genetically messed up mice, and EOD frequency being different for mice vs humans.

 

Having said that, yes, long term fasting --and that's what those mice eating every other day do-- similarly to a ketogenic diet, will skew glucose metabolism and many other things, which are actually adaptation to living on fat, be it from diet or your own reserves. It's a different metabolic mode. It's not better or worse, it's just different.

 

But, as far as this, it seems worse, not just different since it "induced obesity and diabetes and worsened the development of spontaneous atherosclerosis". 

[xEva]

lol

xEva, excellent points about these being genetically messed up mice...
 
But... it seems worse, not just different since it "induced obesity and diabetes and worsened the development of spontaneous atherosclerosis".

I thought the point was that every-other-day eating "induced obesity and diabetes and worsened the development of spontaneous atherosclerosis" in genetically messed up mice. But you seem headstrong in your conviction that this must apply to both normal mice and even humans.

Incidentally, last week in c60 forum Logic posted a couple of studies that suggested that even mice and rats differ in their metabolic response to EOD eating.


Re fasting being "harmful", people here tend to forget that fasting in the wild is a norm, due to the simple fact that food is hard to come by. All animals fast. Even plants fast sometimes. Even fungi, protozoa and bacteria fast. Frequent periods of fasting, short and long, on a regular basis or striking at random, is the way of life for all lifeforms on the planet. All species alive today are the descendants of survivors of several extinction events where the main cause of death was starvation. That's how we evolved. Not only are we well-adapted to it, but it can be argued that our physiology requires fasting for optimal functioning.


Re Luminosity negative experience: maybe some important metabolic genes are underrepresented in her genome -- or perhaps she was doing something wrong -? (like following the unnatural method of American Hygienists, popularized by Shelton). I can't believe that fasting, which has been the integral part throughout our evolution, can be harmful to an averagely healthy person. Of course, there are exceptions to everything, maybe she fell under one of them -?

[ta5]

I thought the point was that every-other-day eating "induced obesity and diabetes and worsened the development of spontaneous atherosclerosis" in genetically messed up mice. 

 

You're right, that was silly. 

[Hip]

How does this tally with the fact that fasting was in the news recently as a potential cure for type 2 diabetes?

 

The interesting thing is that the return of normal blood sugar levels in type 2 diabetics occured after just one week of fasting on 800 kilocalorie a day.

 

 

Type 2 diabetes and the diet that cured me | Life and style | The Guardian

 

[Primal]

That's unsettling. I'd like to fast to boost NAD but don't want to make things worse. Most people who reach a really nice physique do so by eating 5-6 small meals a day, not by IF :(

 

I dont think the fact that they had genetic hypercholesterolaemia changes things that much. But maybe with more nutrients the IF would have produced better results?

Edited by Primal, 21 June 2014 - 12:43 AM.