The Low Testosterone and Obesity Vicious Cycle

It’s well known that the hormone testosterone — the hormone which makes a man a man — declines with age, and that it’s declining also in all men over time. Low testosterone and obesity reinforce each other in a positive feedback loop, which is the low testosterone and obesity vicious cycle. Check out the chart below for the decline, both age-related and secular. A man about age 60 has a full 100-points lower testosterone in 2002-04 than in 1987-89.

testosterone secular decline

The secular decline could be caused by environmental chemicals — endocrine disruptors. Just yesterday, a report was published that found that sperm quality in dogs has declined, fewer male dogs were born, and phthalates and PCBs, i.e. endocrine disruptors, were found both in the dogs and in their commercial food.1 (Another good reason not to feed your pets commercial pet food.)

What about the age-related decline in testosterone? Much of this seems to be due to decreased muscle and increased fat mass.2

Fat tissue is a potent source of the enzyme aromatase, the sole function of which is to convert testosterone to estrogens, mainly estradiol. This hormone functions in feedback inhibition of testosterone, so that more estradiol leads to lower testosterone.

As a result of less muscle and more fat, more aromatase converts testosterone to estradiol, which in turn increases fat mass even more, especially visceral fat mass.

In turn, greater visceral fat mass leads to insulin resistance, dyslipidemia, and higher risk of cardiovascular disease. Further changes then occur. Quoting from the paper:

All of these factors eventually contribute to the CHAOS Complex: coronary disease, hypertension, adult-onset diabetes mellitus, obesity and/or stroke as permanent changes unfold. Other consequences of the chronic hypogonadal state include osteopenia, extreme fatigue, depression, insomnia, loss of aggressiveness and erectile dysfunction all of which develop over variable periods of time.

Man, that’s some bad stuff — basically almost anything that can go wrong with a man in older age.

That’s the vicious cycle of low testosterone -> obesity -> more estradiol -> even lower testosterone -> low quality of life and disease.

Don’t let it happen to you.

Preventive measures

How do you stop this vicious cycle from getting started, or if you’re in the midst of the cycle, how do you get out of it? The first two on this list are all but mandatory; if you still need help after those, consider the second two.

  1. If you’re overweight or obese, lose fat. Cut the carbs and sugar and lift weights. Losing fat tissue will decrease the amount of aromatase in your system, lower estradiol, and increase testosterone.
  2. Lift weights. Weight lifting will maintain or increase muscle mass. Don’t think that because you’re young that you’re immune from muscle loss. Losing muscle begins when a man is in his thirties, and accelerates thereafter. By the time a man reaches 80, he typically will have lost a full 50% of his entire muscle mass, leading to frailty, dependence, and low quality of life.
  3. Take an aromatase inhibitor, which is a drug that will lower estradiol and thus increase testosterone. That requires a doctor’s prescription, and as I’ve discussed here a number of times, many doctors are reluctant to prescribe them, but if you’re obese with low T, then odds of getting a prescription are better.
  4. Testosterone replacement therapy (TRT). This involves supplementing with testosterone, either by injection or gel, and also requires a prescription, which again, may doctors are reluctant to do.

To know whether you have a problem to begin with, you should get tested.

PS: Read my book Muscle Up for much more on the benefits of lifting weights. Check out my Supplements Buying Guide for Men.


  2.  Cohen, P. G. “Aromatase, adiposity, aging and disease. The hypogonadal-metabolic-atherogenic-disease and aging connection.” Medical hypotheses56.6 (2001): 702-708.

Leave a Comment:

Hannibal says August 10, 2016

I personally went to the other extreme – low bodyfat (BIA scales [consistent measuring conditions] no longer gave me BF readings), very low carb diet, both for way too long. Ultimately I suffered absolutely massive decline in sports performance and ulitmately found out that sure enough, my testosterone levels had totally crashed. Restored carbs to my nutrition and got over my self-induced carb phobia and both sports performance and testosterone levels are climbing back to normal.

    José Carlos says August 10, 2016

    Hannibal, this interests me. I’m also on a low carb diet, but not very low. Although I am not a sportsman (yes, I lift weights, but that is about all I do), I haven’t experienced no decline so far. Can you share what carbs you are cirrently eating and how much of your diet is composed of carbs either in weight or volume. Thanks.

    Stuart Matber says August 10, 2016

    Just curious whether you were making sure gelatin was about 30 % of your protein intake and that you weren’t consuming too much protein for your LBM (anything above .8 g/ kg ). In my experience people on even VLC diets never experience the probllems with thyroid function etc vlc are notorious for, even after decades of following such a diet. Also potasssium and bicarbonate. Most people on lc get far too little potassium. AT LEAST 5g/d . More is even better. And potassium bicarbonate is so cheap and easy to obtain.
    Stuffing up their potassium/sodium ratio seems to be the SINGLE biggest mistake any human born after about 8000 BC makes, particularly males.
    It’s why vegetarians/vegans generally live longer than meat eaters. They automatically consume enough potassium.

      P. D. Mangan says August 11, 2016

      Meat has lots of potassium in it.

        Stuart Mather says August 12, 2016

        P.D. 3 oz of muscle tissue (beef) has about 300mg. Pork has the highest. But unless you ate the stomach and intestine contents of a slain herbivore, to get 5g of potassium a day from just eating meat would necessitate eating far too much protein wouldn’t it? Organ meats are even lower in potassium than muscle AFAIK.
        It really brings me back to my earlier point about how important starchy tubers have been throughout human evolution. As soon as early hominids developed an opposable thumb , digging sticks opened up a whole new source of nourishment. Cattails anyone? Traditionally living Australian aborigines get most of their calories from starchy tubers to this day. Sure the men polish their egos and physiques chucking spears at kangaroos. And occasionally they get lucky. But meat is a very small fraction of their calories. Women do most of the work digging up starchy tubers..
        What’s the best source of potassium by a country mile? Potatoes Even bananas are much lower. ( in addition to ancestral fruits, including bananas being nothing like high fructose modern selectively bred fruits).
        No problem with eating regular small amounts of whole body animals of course. But as usual dose is everything. Humans have never and should never IMHO eat as much meat as the SAD provides. Not getting enough potassium if they do is but the tip of the iceberg waiting to sink the health boat.

        Just curious, are you on a ketogenic diet long term? Or do you cycle carbs?

AJ says August 10, 2016

Thanks for the excellent and timely post. My personal belief is that ALL of the above are necessary for the fat / skinny fat man older than 40, especially if bloodwork shows Testosterone in low / low-normal range.

Question: What is a good dose of arimidex to start with? Certainly you don’t want a complete shutdown of estrogen.

    JP says August 11, 2016

    Dosage varies from person to person. You need to work with a physician and monitor your T and estradiol levels to determine your correct dosage. My dosage is 0.5mg three times a week but that’s what’s right FOR ME.

The Low Testosterone and Obesity Vicious Cycle – Transhumanism and Longevity Feed says August 10, 2016

[…] Original Article: The Low Testosterone and Obesity Vicious Cycle […]

Thompson says August 10, 2016

Great article as usual. Three months ago my testosterone was at 360ng. After being on high-dose vitamin D-3 for the past three months, I had my testosterone checked again last week. It came back at 350ng, with my free testosterone actually being a little higher than before.

I’ve seen numerous sites advise taking vitamin D-3 to increase testosterone, and was shocked when my numbers came back virtually the same, especially considering my D-3 was in the tank at the time. I’m 6’1 and 160lbs, so fat levels are fairly low. My estradiol also came back normal, at 20.9.

So I’m not obese and my estrogen is normal, so I suppose the only option left is TRT? I just started lifting weights but I don’t expect to put on much muscle mass with sub-optimal testosterone levels.

    JP says August 11, 2016

    I have been taking 2000 IU of Vitamin D daily for many years, and (unbeknownst to me until recently) this wasn’t doing jack shit to raise my T. Recently I started TRT and T levels are now awesome!

    It is quite annoying that my general practitioner, who I saw several times a year for many years, was closely monitoring my Vitamin D levels, blood sugar, cholesterol, etc., but simply didn’t care about T level. When he did check it once he dismissively said it was fine (“eh you’re getting old deal with it”). I had to go to a specialist to get T levels repeatedly checked and then get on TRT when he discovered I was low and had been low for many years. If you complain about your sex life, GPs will happily prescribe cialis but they won’t do anything about the root cause of the problem (low T) so you simply have to go elsewhere to address that.

      Thompson says August 11, 2016

      That’s awesome, man. Do you feel a big difference now in how you feel? Did you end up going with the injections or the gel? I’m still in my 30s but have always just assumed my lack of energy was normal, until the past year.

        JP says August 12, 2016

        Yes, HUGE difference. Much more physical energy – I now do easily 15 or 20 times more sets per week in the gym than I used to, and at higher weight and intensity. Already paying off in more muscle. Much more sexual desire and energy, much higher ability to focus, much calmer.

        I am doing weekly injections per doctor’s advice. It is surprisingly easy. Needle doesn’t sting or leave marks, goes right into the thigh. Estradiol went up so I am taking 0.5mg arimidex three times a week. (Just took one now!)

        As for common side effects, thus far it has not increased my red blood count. Have noticed a lot more zits cropping up on my body. Thus far my nuts have NOT shrunk. So all is good!

    P. D. Mangan says August 11, 2016

    Wow, that vegan site does a brisk business.

Ole says August 11, 2016

I just couldn’t resist, knowing what a great admirer you are of this McGregor guy 🙂

Father O'Hara says August 12, 2016

What about dietary changes, cruciferous veggies help get rid of estrogen? Should we be eating more sauerkraut..

    P. D. Mangan says August 13, 2016

    Cruciferous vegetables should indeed help keep estrogen lower, but how much you need and the extent of the effect I don’t know – probably no one does.

battle bots says September 4, 2016

well, I’m concerned about this. I am early 40’s.
anyway…my T is the test is obviously wrong/broken low, especially considering my gf says I am built like a linebacker with a gut, but here I am, my waistline is increasing and I barely eat. I wonder if nice skin and hair is a result of low T, an offset to a bit of a belly.
Here’s the skinny:
I interval fast a few days a week. I’m not religiously low carb but I do what I can when I eat.
I lift, bro.
I drink regularly, no where near that 1 bottle of hard booze a day from the other article. More like a bottle of red a night.

I don’t know but thanks to this article I will talk to someone about the armoatase inhibitor. Any bad side effects? Will I lose my hair?

    P. D. Mangan says September 5, 2016

    Doubtful that an aromatase inhibitor would affect your hair – that effect is usually from dihydrotestosterone (DHT) produced in the skin. If your T is seriously low, by all means go see a doctor; you may need more than the AI, you could get TRT. Good luck, let us know how it goes.

    BTW, a bottle of red wine a day is 5 drinks, fairly high for daily consumption. It also has about 400 calories.

Johnny says September 30, 2016

PD I looked further into zinc, found more than meets the eye. I propose that zinc deficiency (very common nowadays) is the underlying cause of lower T. Zinc status and serum testosterone levels of healthy adults.

Also zinc:copper ratio affects immune system and secondary sexual characteristics, there is indirect evidence that zinc deficiency/copper toxicity is likely to lead to homosexuality. Also zinc deficiency weakens immune system so would explain high AIDS incidence among gay men. HIV patients on zinc supplementation have much slower progression of disease, low zinc:copper ratio worsens progression to AIDS (

Also very recently they reversed Alzheimers in mice with IL-33 injection, which removed AB plaque and restored damaged memory, they will do human trials soon. IL-33 injection awakens immune system (macrophages) to deal with plaque, but I strongly suspect that zinc:copper ratio is what leads to weakened IL-33/ST-2 channel response in the first place.

So zinc is involved in many things as it appears, also HSV viruses, prostate cancer (very big role) etc.
I also suspect that restoring zinc:copper ratio could repair damaged pancreas after diabetes, so paleo moves T2D->carb intolerance, and zinc could further restore full carb tolerance. Antioxidant role of zinc in diabetes mellitus

So a healthy person (good zinc:copper ratio) should just get infinitely fatter from carbs, but otherwise be healthy and withouth diabetes/hyperglycemia; like sumo wrestlers. It would thus appear that current health problems/insulin resistance is not due to excess carbs, but due to low zinc.

PS check out ; 28% of homosexual men had more than 1000 partners, crazy 😀

That’s quite a lot of points, but I’m quite excited about this zinc connection. Your book on Iron is excellent, maybe it would be worth exploring zinc too?

    P. D. Mangan says September 30, 2016

    Zinc is important for T levels, but the studies I’ve seen (seem to) show that zinc replete men don’t get a boost in T from it. That doesn’t mean that there isn’t a lot of zinc deficiency though – there probably is. I came across a study on zinc biology which claims that zinc is very non-toxic, contrary to most other sources. So supplementing could be worthwhile – as I wrote in my book on supplements.

Johnny says September 30, 2016

A good link:

I suspect zinc:copper ratio and zinc deficiency is the key to why some skinny people have diabetes, while some fat people don’t.

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