Daniel Lemire's blog

, 8 min read

The rate-of-living theory is wrong

8 thoughts on “The rate-of-living theory is wrong”

  1. There are clues to aging already discovered. Such as food deprivation (even temporarily – 5 years in our relative youth) can extend average lifespan. It could be nature’s way of giving us more reproductive cycles when things look bleak – or compensating for the likely failure of our offspring to thrive by letting us live longer – perhaps into better times when we can reproduce successfully.

    As a short term adaptation it would lack much value – but if it exists, it must do so for a reason.

    1. Caloric restriction can extend lifespan in some animals. It is doubtful that there is any strong effect in human beings. People eat a lot more today than in the past, but they also live quite a bit longer. Jeanne Calment ate a kilogram of chocolate a week. She lived up to 122. There are religious communities where people practice strict caloric restriction: they do not seem to produce centenarians.

      What I can tell you for sure is that if you starve yourself, you will lose muscle mass. The health gains are much more speculative.

  2. Mark Dennehy says:

    The “rate of living theory” you describe originally stated that for all mammals (it never applied elsewhere), the amount of oxygen delivered to cells by the respiratory and cardiovascular system per gram of body weight was approximately equal (at 18 litres of O2) over the lifespan of the mammal.

    It wasn’t claiming that you could expand the lifespan. That claim was invented by those reporting it, as has become deplorably standard in the reporting of anything from the scientific world these days.

    It also never applied to humans because we developed medicine and so have much longer lifespans than other apes of our approximate mass, which puts us off the trend line in the graph to begin with.

    1. Quoting from Wikipedia:

      The rate of living theory postulates that the faster an organism’s metabolism, the shorter its lifespan. The theory was originally created by Max Rubner in 1908 after his observation that larger animals outlived smaller ones, and that the larger animals had slower metabolisms. After its inception by Rubner, it was further expanded upon through the work of Raymond Pearl. Outlined in his book, The Rate of Living published in 1928, Pearl conducted a series of experiments in drosophilia and cantaloupe seeds that corroborated Rubner’s initial observation that a slowing of metabolism increased lifespan.


      1. Mark Dennehy says:

        The problem with wikipedia is that it’s not well curated.
        For example, it’s definition of the theory differs from, say Cornell university’s : https://courses.cit.cornell.edu/psych527_nbb420-720/student2005/nrb26/Page_2.htm

        1. Quoting from the Cornell site you link to :

          The rate of living theory originated in 1908 when a physiologist, named Max Rubner, discovered a relationship between metabolic rate, body size, and longevity. It states that living organisms possess a certain amount of a “vital substance” and when all of that substance is used up, we die. This belief is very old and today would be deemed unscientific. In todays scientific world a more plausible model for this theory is oxygen metabolism and energy. The thoery looks at the rate of energy production through respirationg by the conversion of oxygen to water.

          This theory was initially developed to explain why most larger animals live longer than most smaller animals. Animals with the most rapid metabolism tend to have the shortest life spans, while animals with slower metabolic rates tend to have longer life spans. This has to do with the belief that all organisms are born with a certain amount of energy. If we use this energy slowly then our rate of aging is slowed. If the energy is consumed quickly aging is hastened. Long-lived animal species are on average bigger and spend fewer calories per gram of body mass than smaller, short-lived species. Although this is true among many species in the animal kingdom, it does not apply universally, particularily amongst mammals.

          The rate of living theory is a scientific version of “live fast, die young”.

  3. Yvan Dutil says:

    I short literature review indicates that the oxydative stress hypothesis on longevity is almost dead, that metabolisis scaling is tricky and the caloric restriction is not much related to both previous phenomena.

    1. @Yvan

      I am not even sure it is wise to talk about “caloric restriction”. It seems to be all about methionine restriction. It just happens that mice eating little also eat few proteins and thus get little methionine. I think you are right that it has little to do with oxidative stress or metabolic rates per se. These theories are pretty much dead.

      However, they are still very popular “on the Internet”.

      I think that they lead to the wrong kind of logic… as in… “I am not going to wear myself out”. Well. I think that highly active people can probably live longer, if anything.