Does Semi-Starvation Prolong Life? Maybe Not


Semi-starvation has been thought to be life-prolonging in animals and perhaps even in humans. But a new experiment in monkeys casts a lot of doubt on that hypothesis:

New York Times: Severe Diet Doesn’t Prolong Life, at Least in Monkeys

In a way this is disappointing, in a way it’s good news. Who would want to be hungry forever?

Maybe there is a smarter way to actually prolong life though. Eating enough to feel great, but reducing carbs and insulin. Eventually we’ll see if the Rosedale-fans out there get really old, or not.

What do you think?


  1. Greg
    I've never been all too clear if the research has been done to show differences between CR and simple carbohydrate restriction (in animals that have fat-preferring metabolisms). Even so, there are quite a few studies showing similar health effects as those in prolonged CR to people and animals who perform intermittent fasting - eating once a day or every other day - even when those calories are ad-libitum. I've been on CR diets (before I discovered LCHF) and it's miserable. I've done different kinds of IF and while not "fun," it's doable.
  2. murray
    It seems an important factor would be the proportion of the time cell metabolism is driven by glucagon+ketones versus insulin+glucose. The level of caloric intake may or may not affect that proportion, depending on the composition, timing and doses of the calories.
  3. Galina L.
    Some time ago, maybe 3 years ago, I saw result of a study according to which calories restricted monkeys were aging more slowly ,looking younger and being healthier. What else to desire? I think most people want to be young longer, not to have an endless old age. I practice LC diet + IF , eat 2 times a day, fast 22 - 24 hours once a week.
  4. moreporkplease
    The problem with the calorie restriction thing is sadly that to have benefits, one must apparently begin at a very young age. So if you start at 30, 50, 70 - it's too late dudes. The monkeys who did well with semi-starvation were begun at young ages.

    So I don't get why you would do this to yourself when the science may suggest that there's no benefit if you start too late. If there's any benefit at all.

    Please note that the longest living person ever, Jeanne Calment, lived a typical French life style. She drank wine every day, ate chocolate, smoked (2 cigarettes a day was her limit), loved her olive oil and enjoyed sausage.

    She rode her bicycle around town to do light shopping in the usual French manner and briefly took fencing lessons. Not a big exerciser. So if you want the most proven advice on how to make it past 120 - follow her example. Live like a typical French woman of the late 19th cent. and get your genes tested to see if you have any of the known super-genes for lifespan.

  5. Charlie
    The older study on CR that showed benefit was compared to a control group eating a lousy diet while the calorie restricted was a restricted healthier diet. That why it showed some benefit. In this study the control group eats a similar diet the difference was just the calorie restriction and that showed no benefit. The take away eat a low carb healthy diet, with limit protein and good fats and you will have all the benefits you can have out of diet.
  6. Stipetic
    This study (which appears to be good) merely points out that in this species of animal a 30% calorie restriction did not prolong lifespan. It says little more. It says zilch about the life prolonging potential of less severe calorie restriction. It says nada about intermittent fasting.

    Regardless of lifespan claims, intermittent fasting probably has benefits from an autophagy viewpoint.

  7. mezzo
    I found the wording a little surprising at times. Two doctors "believe" they would be healthier and that there is merit in calorie restriction. One of the directors of the study calls himself "a hopeless calorie-restriction romantic". Is this the right attitude for a scientist?

    A little common sense may also help with this issue: even the Romans knew that "plenus venter not studet libenter".

  8. Arshad, Stuttgart
    IF => mitochondrial repair + new neurons (brain)
    So you know, what are the benefits. :-)
  9. Arshad, Stuttgart
    I see, two potential design problems in that study:

    1. Children & young should not go for CR. It hinders their growth. CR should be for mature.

    2. 30% CR is too much. The animals had been chronic stressful situation. Above 20% CR is suggested only for therapeutic intervention.

  10. Sasha
    I hate testing on animals ... what those poor monkeys had to be put through all thier lives ... so that we humans would know what and when to eat ... there is no limit to man's ignorance and arrogance ...
  11. Paleofast
    SO what were the monkeys fed on? How close was teh laboratory environment to their natural one? The life span of captive monkey is very different from the wild, how was a base line calculated???
    Moreover life span increases will always be a species and individual specific matter. A healthy dietary and life style regime can only increase your lifespan to the maximum that your genes were already programmed for.
    I am sorry but this is the kind of misleading wasteful (even cruel I agree with Sasha) science that had us all reaching for the CRISCO because we were told it was healthy and would prevent heart disease.
    I have recently adopted a 20 hour daily fast where I only eat food after 5:00 pm until 22:00 and it works great for me. This combines CR with IF leaving a 20 hour gap between meals because as hard as I try I cannot possibly compensate for all the calories I do not consume during the day. During the fast I feel lucid and sharp especially my concentration and ability to focus on soemthing. When I break the fast only healthy lchf/paleo food passes my lips. I think if you fast what you eat when you do break the fast becomes VERY important. Which ever way you look at it our ancestors would NOT have had three meals a day. They were lucky to have one if hunting and gatehring had gone well. A lot of these fasting regimes seem to encourage consumption of or even bingeing on very unhealthy processed foods in between (as a reward) wonder the metabolic parameters of those who choose to adhere to them are all over the place. I don't think a dencent CR/IF has been done in a healthy lcHF/paleo context...I am my own on going experiment...
  12. I think I like moreporkplease's idea best! I don't think I can do long fasting, and if I'm too old to start, that suits me fine. My experiment with LCHF (I've been low-carb but having small amounts of grains for 4 years) is to remove all grains, up my animal protein and see if it makes any difference to my osteoarthritic knobbly finger joints and some rather charming bunion things on my feet. Mark Sisson gave up grains and his osteoarthritis improved, so I'm hoping mine will too - if I'm lucky. I practise yoga, walk a lot and do zumba. I'm slim and generally fit apart from the osteoarthritis. I feel that it must be caused by something, and presumably eating wheat plus my dear oats, which I ate every day for about 30 years, could have something to do with it. That's my own personal experiment ...
  13. Paleofast
    I think it is very important to make a crucial distinction may be TRUE that in order to increase LIFESPAN one may have to start calorie restriction at a young age. But I believe the effects of CR/IF on HEALTHSPAN should apply at any age. I saw them within a few weeks on my blood parameters and BP that went from too high for my age to that of someone half my age even udner stress. Contemporary hunter gatherer populations (who practice involuntaty CR/IF) do not seem to experience the age related rise in BP that we take for granted for example.
    if we could base the 'healthy' values on modern hunter gatherers we would ahve to rewrite all blood test guidelines etc....
  14. Diane
    Aside from the higher quality of life you get on a good healthy diet, you will never really know if your diet allowed you to live longer or not. So why be semi-starved?
  15. BA
    In Episode 9 of Jimmy Moore's Ask The Low-Carb Experts, Mat Lalonde raises a very important methodological objection to basically all of the caloric restriction trials on animals in existence.

    In almost every calorie-restriction study on animals, the baseline diet is some kind of laboratory "chow" which is massively unnatural, so when calories are restricted, we do not know whether the positive results are from the calorie restriction itself, or simply being off of the unnatural baseline diet.

    In order to produce meaningful results, these kinds of experiments would have to be designed around a natural diet protocol.

  16. Ondrej
    I think most of dietary benefits are a result of calorie restriction and weight liss, not specific macronutrient comp. That said, fasting won't make you live till 100, but will improve the quality of your life at any good diet. The goal is to be able to live an active life.

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