Much of Aging Is Just Poor Health Habits

Aging means a deterioration in the body and an increasing propensity to breakdown and disease. Scientists who study aging are keen to discover the driving force(s) that cause it, but they often seem to be unable to distinguish between aging in itself and poor health, especially when studying human beings. I believe that much of aging is just poor health habits.

Is gaining fat, losing muscle, or developing insulin resistance and diabetes a normal part of aging?


Obviously, virtually all living things age and die. (“Virtually”, because a few living things appear not to age at all.) While aging is a natural process, so infectious and genetic diseases are natural processes too, and we’ve largely discovered how to deal with the first, and are working on the second. There’s no reason that aging can’t be delayed or even abolished; it’s not necessarily inevitable.

Some manifestations of aging are visible, such as grey hair and wrinkled skin, and don’t seem obviously related to lifestyle or health habits, so far as we know. Dysfunction on the cellular level is not visible, but takes place in aging.

Scientists often consider that in humans, aging causes obesity, muscle loss, and diabetes. For example, “Studies have shown that insulin resistance increases with age, independent of changes in total adiposity.” Yet the same study concluded its results by saying, “These results suggest that insulin resistance is more closely associated with abdominal adiposity than with age.”

Similarly, sarcopenia, or loss of muscle, is considered a part of aging. Yet exercise, especially resistance training, and higher dietary protein, robustly fight the loss of muscle, so sarcopenia can’t be entirely due to aging.

Fasting, calorie restriction, and aging

Valter Longo, the well-known USC scientist who has studied intermittent and prolonged fasting and their effects on aging, believes that fasting has been shown to have profound effects on aging. Yet, as I pointed out, his studies in humans leave something to be desired, since most of the people in his studies were overweight and/or sedentary. We don’t know how much of the benefits of fasting seen in these people are due to fighting aging or are due simply to better health.

Similarly, domestic lab animals have a tendency to obesity, since they eat highly refined, processed food and are confined to cages. In calorie restriction studies on these animals, much of the benefits to their health may be due merely to preventing them from becoming obese, and not due to a true anti-aging effect.


Scientists consider metformin, the most-prescribed anti-diabetes drug, and rapamycin, an immunosuppressant, to be the best leading candidates for drugs that will actually slow or prevent or even reverse aging. A clinical trial (a trial using humans) of metformin to see its effects on aging is currently underway.

Yet look at who the participants in this trial are: “older adults with impaired glucose tolerance”, that is, these people are pre-diabetic.

We know that type 2 diabetes is caused by, or closely associated with, obesity, dietary sugar and refined carbohydrates, and lack of exercise.

How many of the participants in the metformin clinical trial are obese and/or eat lots of garbage food and don’t exercise? My guess is a very large fraction of them.

Metformin is effective at treating diabetics; it decreases blood sugar and insulin. But if metformin helps the people in the clinical trial, it won’t tell us anything about aging. They’re not healthy, and nothing leads us to think that their ill health is caused by aging rather than bad food, obesity, and lack of exercise.

Metformin may not help people who are lean and healthy and eat good food.

The only way we know if an anti-aging treatment works is if it helps people already healthy.

Everyone is fat

Some 70% of the American people are overweight or obese, although I’ve argued that the figure is closer to 80% when body fat is taken into account. Excess body fat accelerates aging. So does muscle loss.

The causes of this sad state of affairs are several. One is that people don’t know what to do, and if they go to a doctor to ask, he or she doesn’t know either. “Eat less and move more” is terrible advice. Another reason is that even when they know, most people won’t do much about it. Too hard to give up sugar, much less lift weights.

Whatever the causes, aging isn’t synonymous with obesity, diabetes, and sarcopenia.


Scientists confuse aging with poor health. They overlap but aren’t the same. Until anti-aging treatments extend the lives of healthy animals and humans, we don’t know if they truly work.

PS: My new book, Best Supplements for Men, has a chapter on life extension and anti-aging.

PPS: Check out my Supplements Buying Guide for Men.


Leave a Comment:

Matt says June 14, 2017

The one good thing about studying dangerously isolated animals eating processed cardboard “food” is that it’s an excellent model for the average first world human. Given that us top 5% fitness/nutrition types make up such a rogue element in the modern world we almost need a small research foundation just for ourselves.

    P. D. Mangan says June 14, 2017

    Good point.

      Bill says June 14, 2017

      Ummm PD, make it a ‘secret’ one and the money will roll in .
      :- )

Jm says June 15, 2017

Respectfully disagree with the premises of this post. Specifically, my understanding is that the study on metformin was in part provoked by the observation that persons taking metformin for impaired glucose tolerance outlived those considered “normal” in the observed cohort, and thus presumed not to need this drug. Also, aging involves reduced ability to tolerate bodily insults making one susceptible to the diseases cited Scientists recognize that. They aren’t confused: they are trying to devise strategies to nudge deteriorating systems back into working order..

    P. D. Mangan says June 15, 2017

    It’s true that one study found that diabetics on metformin may have a lower death rate than matched non-diabetic controls. However, in the cited clinical trial, it’s going to be the same group of glucose-intolerant patients, which won’t show whether healthy people taking metformin will live longer. Another thing is that up to 80% of the population has some degree of insulin resistance, so just as in Longo-s fasting study, the “healthy” participants aren’t all that healthy. I agree about aging meaning a reduced ability to tolerate bodily insults. But I think it’s a big stretch to say that aging means decreased insulin sensitivity and more obesity. If the obesity rate among the elderly is 30% today, but was 10% 30 years ago, how much of obesity in the old is due to aging? Very little, I’d say. What do the oldest old, say people who live past the age of 105, die from? Seems to me most of them just die of old age, for lack of a better term; they don’t seem to die of heart disease or cancer. Disentangling aging from unhealthy living isn’t easy.

    As I mentioned in my other post (linked), calorie restriction appears to work for life extension little to not at all in wild mice.

    Drifter says June 16, 2017


    I think Dennis is making a really important point here.

    You say “they aren’t confused: they are trying to devise strategies to nudge deteriorating systems back into working order..” I respectfully disagree.

    If what you say is true, where is the population of truly healthy people that these “scientists” are studying? And what systems actually deteriorate in a truly healthy person? To study this you would need a group of people who at a minimum have been doing the following for many years and preferably most of their adult life:

    • Intermittently fast
    • Do some sort of HIIT and strength training
    • Eat real, directionally paleo food, without overeating protein
    • Eat well within their insulin sensitivity
    • Do not have or provoke chronically elevated insulin (Kraft guidelines)
    • Get sensible mid-day sun exposure
    • Have healthy stress levels and sleep habits
    • Have a healthy body composition and no organ fat

    Even people who have tried to be healthy might not have met these criteria until recently since official guidelines generally recommend the opposite of these things.

    I don’t think it’s clear what those deteriorating systems are for an otherwise healthy person, but muscle/joint strength and healing capacity is a good candidate. However, the compounds that seem to benefit this area are getting very little if any research attention, to my knowledge. The recent post on Rapamycin is a good example of what might be very beneficial, although it is not clear (to me anyway) that Rapamycin’s inhibition of mTor is more beneficial than that provided by intermittent fasting. So, those of us that are trying to truly fight aging seem to be on our own with little to no help from “science”.

      P. D. Mangan says June 16, 2017

      Drifter, thanks, great comment. I’m glad you brought up Dr. Kraft and insulin resistance. For those in the audience that don’t know, Dr. Joseph Kraft found that in his patients, some huge fraction (80% I believe) had what he called diabetes in situ. When they had a glucose tolerance test accompanied by insulin tests, they had abnormal levels of insulin. In my opinion, this shows that a huge fraction of the general population are out of shape and/or eating the wrong types of food. That included the aging population. It’s probably true that aging causes some of this, e.g. a 20 year old person might be insulin sensitive in the same conditions that make a 40 year old resistant. But the fact is we’re so far from that now we just don’t know how much is aging and how much is health habits (lifestyle, environment).

Matt says June 16, 2017

Don’t forget close tribal affiliations like churches, volunteer groups, etc. Isolation is a major predictor of heart disease.

    Matt says June 16, 2017

    This was meant as a response to the above comments :p

    P. D. Mangan says June 16, 2017

    Absolutely. I wrote about that in my article on The Blue Zones.

Ole says June 17, 2017

Why is it that some people lack the discipline, when it comes to diet and exercise? Why is it that the majority tends to give up, once they have passed a certain BMI? I think these are important and interessting questions. Surely there are many answers, but the abundance of food (especially crappy foods) and its availability 24/7 is one of the major problems. Although socially un-acceptable, seen from a health perspective, regular fasting and exercise should be mandatory for everyone.

    P. D. Mangan says June 17, 2017

    Possibly because the discipline to stick to a diet and to exercise doesn’t come naturally to us. We’re hard-wired to seek out food and to be sedentary when possible. In the past, there was no need to exert discipline in these matters – food was either in short supply, or it had to be cooked and eaten at certain times, because there was no refrigeration or much in the way of food preservation. Hard work was the daily norm. So we ate when possible and rested when possible. Having to be disciplined to stay healthy is a modern phenomenon.

Ole says June 17, 2017

The ironic thing, is that my family and friends consider me extreme. No-one practise fasting, HIIT exercise, strength training or limit their sugar, protein and caloric intake. This is all considered extreme these days, although this is the way we as humans are designed to work. 1/3 of the food we eat keeps us alive. The remaining 2/3 is what keep the doctors alive.

TT says June 18, 2017

Thanks for the article!

Some not so encouraging info I’ve just read on metformin: – Ray Peat on metformin, lactic acid. Metformin inhibits mitochondria from oxidizing glucose, causes lactic acidosis. – Lactic acidosis induced by metformin: incidence, management and prevention. Lactic acidosis associated with metformin treatment is a rare but important adverse event. – Metformin directly acts on mitochondria to alter cellular bioenergetics.
– Metformin decreases mitochondrial respiration, causing an increase in the fraction of mitochondrial respiration devoted to uncoupling reactions.
– Thus, cells treated with metformin become energetically inefficient, and display increased aerobic glycolysis and reduced glucose metabolism through the citric acid cycle.

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