Wednesday, August 28, 2019

More fasting research

At phys.org, a report on a dieting method that sounds a little hard to stick to:
In recent years there has been a surge in studies looking at the biologic effects of different kinds of fasting diets in both animal models and humans. These diets include continuous calorie restriction, intermittent fasting, and alternate-day fasting (ADF). Now the largest study of its kind to look at the effects of strict ADF in healthy people has shown a number of health benefits. The participants alternated 36 hours of zero-calorie intake with 12 hours of unlimited eating. The findings are reported August 27 in the journal Cell Metabolism. ...

"We found that on average, during the 12 hours when they could eat normally, the participants in the ADF group compensated for some of the calories lost from the fasting, but not all," says Harald Sourij, a professor at the Medical University of Graz. "Overall, they reached a mean calorie restriction of about 35% and lost an average of 3.5 kg [7.7 lb] during four weeks of ADF."

The article goes on to note the health benefit changes recorded in the study, and it does point this other simple advantage:
"The elegant thing about strict ADF is that it doesn't require participants to count their meals and calories: they just don't eat anything for one day."

Yeah, I must admit, I have found during bursts of 5:2 dieting that I start to spend too long in the supermarket reading calorie information on things I can try for a variation on how to get my 600 cal in a day.

I am due to start dieting again.  Not sure if will try this method.  3.5kg for four weeks of intermittent sounds a bit less that I might have expected, especially as it always seems to me that the first couple of kilos drop fast, but it gets slower as you go along.

3 comments:

Anonymous said...

4 weeks studies and 6 months studies are useless. I will pay attention to 3 year studies. Most diets "work" but are unsustainable.

cheers

Geoff

Steve said...

Hi Geoff,

I am sure you are right: for the last 2 or 3 years, I have gone on the 5:2 diet maybe three times in total, and have dropped maybe 3 to 4 kg, which feels pretty good; but as I say, it seems to have diminishing returns and it feels good to go off it and not spend any days counting calories. The weight creep back on.

My lack of exercise no doubt does not help.

In any event, I guess I am not completely dismissive of this research into the fasting diets (of any variety) because (as far as I can) it seems to suggest that this type of dieting may carry other health benefits compared just to the daily reduced calorie type of diet.

Of course, those benefits are lost when you stop the diet, but hey, having them for a couple of months a year might be better than nothing! Maybe...

John said...

If you dig into the details there are some interesting findings:

Reduced methionine: that points to a rather particular diet or perhaps a loss of methyl donation. Reducing total methionine intake has been consistently associated with longevity and a strong marker of aging in many species is hypermethylation of DNA. There is only one way to reduce total methionine intake: stop eating so much meat, dairy, and eggs.

sICAM-1: cell adhesion molecule, might be a proxy for VCAM which increases with endothelial damage.

Possibly reduced thyroid hormone activity: studies show that sub-clinical low thyroid function is associated with longevity.

reduced visceral fat: absolutely critical for good health.

I'm not an advocate of sustained dieting of any kind. The problem is that these restrictive diets also reduce the principal growth factors(IGFs) and I'm concerned about the long term implications of that(eg. reduced IGF might impair brain repair over the long term). Immunosuppression can also occur.