If fasting extends life, what is the ideal daily kilojoule intake to boost life expectancy?

[mad_scientist]

Anyone here have any ideas?

 

I believe the average person consumes 8700kJ each day.

 

But what is the optimum daily kilojoule needed to be consumed to boost life expectancy, taking into consideration that intermittent fasting has been shown to extend life expectancy?

Edited June 6, 2017 by mad_scientist

[Delta1212]

I don't believe there has been enough research to be able to pin down an optimal number, and this is something that I think would likely be highly variable between individuals as well as at different ages.

[dimreepr]

The title of this thread and the OP seem to be at odds, there's evidence IIRC (I'm not able to trawl for evidence ATM) that periodic fasting is beneficial, so a daily/average intake is irrelevant.

[Phi for All]

But what is the optimum daily kilojoule needed to be consumed to boost life expectancy, taking into consideration that intermittent fasting has been shown to extend life expectancy?

 

It wouldn't really work that way, would it? You're looking for an average that assumes a certain amount of fasting, rather than figuring out an optimum average daily intake that is interrupted by optimum periods of fasting. It seems to me this would decrease the benefits of fasting rather than optimizing them.

 

I don't understand the mechanism that makes a certain amount of fasting beneficial. Is it supposed to force the body to clear up the leftovers? Does not eating signal a need that the body responds to with chemical goodies to help us live longer?

[StringJunky]

I don't believe there has been enough research to be able to pin down an optimal number, and this is something that I think would likely be highly variable between individuals as well as at different ages.

Okinawans are a good base point, I think:

 

 

....The dietary intake of Okinawans compared to other Japanese circa 1950 shows that Okinawans consumed: fewer total calories (1785 vs. 2068), less polyunsaturated fat (4.8% of calories vs. 8%), less rice (154g vs. 328g), significantly less wheat, barley and other grains (38g vs. 153g), less sugars (3g vs. 8g), more legumes (71g vs. 55g), significantly less fish (15g vs. 62g), significantly less meat and poultry (3g vs. 11g), less eggs (1g vs. 7g), less dairy (<1g vs. 8g), much more sweet potatoes (849g vs. 66g), less other potatoes (2g vs. 47g), less fruit (<1g vs. 44g), and no pickled vegetables (0g vs. 42g). [4] In short, the Okinawans circa 1950 ate sweet potatoes for 849 grams of the 1262 grams of food that they consumed, which constituted 69% of their total calories.[4]....

 

....An Okinawan reaching 100 years of age has typically had a diet consistently averaging about one calorie per gram of food and has a BMI of 20.4 in early adulthood and middle age.[8]

 

https://en.wikipedia.org/wiki/Okinawa_diet

So they were on about a 1000 calories less than the European recommendation of about 2500. I think fasting will not benefit your gut bacteria and may detrimentally alter the species proportions.

Edited June 6, 2017 by StringJunky

[Sensei]

I believe the average person consumes 8700kJ each day.

 

Daily consumption is typically measured in kcal, instead of kJ (multiply/divide by 4.1355 J/cal to convert)

 

8700 kJ = 2100 kcal

 

Here is list of countries with mentioned daily kcal consumption:

http://www.dailymail.co.uk/femail/article-2722815/Daily-calorie-intake-countries-world-revealed-surprise-U-S-tops-list-3-770.html

 

Not surprisingly USA is on the (infamous) top of the list.

Edited June 6, 2017 by Sensei

[swansont]

taking into consideration that intermittent fasting has been shown to extend life expectancy

 

 

I was not aware that this has been conclusively demonstrated in humans. Citation?

 

Consumption requirement depends on body mass, so there probably will not be a single optimum value. At best, there will be a formula. And then, given the context, you must also determine the fasting regimen that is optimal. Different regimens may have different optimal total intake.

[Endy0816]

Have been studies on Caloric restriction with decent results. Not sure fasting itself is strictly necessary though.

[CharonY]

Have been studies on Caloric restriction with decent results. Not sure fasting itself is strictly necessary though.

 

Evidence in humans is still very limited. There are short-term studies that may indicate benefits, but long-term information were mostly gained from retrospective cohort studies which are difficult to interpret. People are trying to get mechanistic insight in cellular studies (e.g. using adipose cell lines) but they are of course difficult to translate to the organism level. There are a handful of controlled studies which do suggest that some markers found in mice may also be activated in humans under moderate calorie restriction (not fasting!), in young people. The health benefits are still unclear, though. Major benefits are expected in the areas of metabolic syndromes and inflammation.