Testosterone is directly causally inverse to bodyfat in men (once above some very low baseline)
Fat directly converts testosterone to Estrogen via a process called aromatization.
Personally my Testosterone close to doubled when going from 25% bodyfat to 13%. I get blood tests regularly and can see the levels fluctuate pretty closely with fat levels
“The solution that’s being promoted is that we give you testosterone,” he said. “But if you give a man testosterone, you switch off his sperm production. I’ve seen that in the clinic.”
As explained by https://www.nytimes.com/2026/05/12/magazine/testosterone-mas..., "Supplementing with testosterone sends the message to the brain that testosterone is in oversupply, shutting down the testicles’ production of testosterone and sperm... The hormone is so incredibly effective at decreasing sperm counts that it is being tested as a possible male contraceptive."
Are you being sarcastic? That has been widely known by steroid users for decades, that's why many of them supplements with hCG in an attempt to preserve their natural production.
I was diagnosed with Secondary Hypogonadism few years ago.
After a series of tests, it was determined that my Testostrone levels well below normal.
My urologist prescribed HCG after I insisted that I wanted to have children someday. It has been a life changer and the best part is that my sperm count has doubled.
Unfortunately, HCG Mono will not treat all forms of Hypogonadism, some patients have to take Testosterone Cypionate which comes with serious side effects like hair loss, infertility, etc
HCG also shares some of those side effects but it saves your fertility and prevents Testicular atrophy.. Also it doesn't shut down your natural production albeit it does suppress LH receptors by default..
My point is this: if you suspect having Testostrone issues, don't randomly inject yourself with hormones.. go see a urologist and get a serious treatment.
It's becoming clear that it's not permanent. Discontinuing exogenous testosterone will lead to restarting your own body's production - it just takes a bit, and isn't fun to deal with.
less willing to take risks and be independent. less active and staying at home for more time. but thats almost all down to controlling parents who teach their kids to be scared of everything and dont let them go out alone, and the news channels feeding that fear.
some of it might also be social media (fear of public embarrassment) but one thing its definitely not is any kind of large scale hormonal change. culture beats biology almost every time when it comes to social behavior and there is no evidence that its different in this case.
Can't help wondering to what extent the decline is directly and/or indirectly influenced by both the positive changes (eg increased women's rights and power) and the negative (presumption of masculine "toxicity" and fallibility) in socio-culture over the period surveyed.
Unsurprisingly, the authors didn’t name “women’s rights” or any other feminism-adjacent culture war issues as a cause of declining testosterone. They did name obesity and diabetes.
In other words, if you’re looking for a boogeyman, blame sedentary lifestyles and ultra processed foods.
"sedentary lifestyles" is certainly the sort of thing that can be influenced in the manner I suggested (traditional cultural roles being championed or subverted). I don't see why dietary choices shouldn't be either.
of course the demonization and social shaming of traditionally "testosterone" involved social hierarchy, behavior, and hobbies is going to have a conditioning effect. im sure that also contributes to high cortisol in men which itself is a significant impediment to healthy testosterone levels
... Wait, what would the mechanism of action be there?!
Like, if the choice of explanations is (a) obesity, and maybe some pesticide stuff, who knows, or (b) _witchcraft_, Occam's razor points a particular way.
America found the solution, put everyone on enhanced TRT and cash a shit load of bucks in the process :)
Others are trying to regulate pesticide, junk food (obesity, diabete). For instance nutriscore in Europe, also the recent change on pesticide allowed.
I'm not sure it will be enough, but at least they are attacking to the root cause. You're not just adding even more problem, like the increased cardiovascular event or erectile dysfunction with overdosed TRT.
Same for the semaglutides that everyone and their mother take in the usa, people wouldn't need them so much if they didn't eat absolute crap all the time.
We know that semaglutides have also side effects, and that rebound happen when you stop, but I guess it's better than just fixing the food lobby ?
“Obesity and diabetes could easily account for all of this,”
Wither Ozempic? I've seen several friends and family members use it to great effect and thought it might sweep the nation. But I imagine most of the same barriers that keep people from eating better or moving more are also in play when trying to engage with any new habit.
High cortisol lowers testosterone, you can increase levels by dealing with the stress component - some adaptogens like ashwagandha modulate the HPA axis and lower cortisol release, increasing T levels
Before the reactions to the headline get too out of hand, the article says the study couldn’t rule out that obesity and diabetes might drive this change.
Of course, PFAS and microplastics aren’t great for sperm health, but neither are leaded gasoline and DDT.
Good point. Age and obesity are the strongest correlates with low testosterone. Increases in sedentary lifestyles probably aren't helpful either, but not clear if that is anything other than a proxy for obesity
Which means, given GLP-1s, we should see a reversal in the next few years.
Random aside: is there a correlation between GLP-1 and vaccine acceptance? As in, given enough time, would one expect to see an obese, diseased, low-T population concentrating in on itself?
I'm an obese american (lost 10% of my body weight in the last 7 months, so almost not obese anymore) who is 30+, but my testosterone has measured between 850 and 1400 in the last 7 months.
That probably helped with my weight loss, but I have a full head of hair still and am somewhat likely to keep it.
We'll likely spend longer measuring what the hormonal effects of PFAs and microplastics are than we'll have pfas and microplastics to deal with.
I wonder how this correlates to Prostate Cancer. From what I heard, high testosterone can be one of the causes of Prostate Cancer. But that is over a long time.
So if levels are falling, is prostate cancer lowering a little bit ? But that will be hard to determine due to the advancement of Medical Treatment over the past 50 years.
That's literally the main point of the article, the stand-first: "Exclusive: Researchers warn of ‘major crisis in male reproductive health’ partly driven by obesity and diabetes"
That’s not what the article primarily addresses though and the study itself didn’t control for obesity. They make note of it at the end to say that the obesity cause is in dispute but the bulk of the article is focused on other potential causes.
It’s like we need something more interesting than “people sit too much and eat too much”.
Because it's too obvious. There needs to be some hidden, world encompassing conspiracy, so that people feel superior when they are one of the few enlightened ones that see through the matrix and start drinking raw milk to live like our testosterone pumped ancestors.
If you are a podcast host that gives hot takes on news headlines, which one are you going to choose?
Option one: obesity and weight problems. Statistically 77% of your audience is either overweight or obese because 77% of Americans are either overweight or obese.
Option two: feminism, microplastics, anime, or literally any other thing than option one.
Because especially in this forum, obesity literally does not exist and if it does is never the person's fault but rather big food producing addictive meals / not walkable cities / exercise is bad for your joints / et cetera ...
Lift weights. Nobody lifts weights or does labor like they used to.
Endocrine function can still be normal despite obesity. There are plenty of fat guys with solid testosterone levels because they work with their hands all day.
I'm not saying that's all there is to health, far from it, but what kind of bubble does one have to live in to not see this counterexample? Do we just casually ignore them because they fit undesirable stereotypes of "toxic masculinity" or what? You don't have to become that guy just to lift weights.
> Nobody lifts weights or does labor like they used to.
I'm fairly sure _vastly_ more people lift weights today than in the 70s. At that point it was, well, not niche exactly, but you didn't have anything _remotely_ like the number of gyms around. Can't offhand find figures for back to then, but apparently it's up ~60% in just the last two decades.
I guess you missed the part about physical labor in my comment.
You're looking for an answer via a really poor proxy. Lifting weight is lifting weight. Gyms are more popular because of the lack of sensible alternatives for a comprehensive workout. Any data you find about them will also be biased towards the recent decades of office work and working from home. Is there any way to tell if gyms are even picking up the slack? My guess would be overall exercise is down, even for those who go to the gym regularly.
One class of doctors thinks roughly 250 is enough for a middle aged guy - anything over shouldn’t be medically treated. Of course, the “men’s clinics” don’t rest until it’s over 1000...
With the standard range so wide (even after age adjustment), why isn’t it measured annually, like the CBC and others?
Sure, it’s easy to point at obesity, but statistical ranges completely fail the individual.
There are wide ranges but it's more about how you feel personally and what you've noticed over time. Some men have below average T but feel great and build serious muscle anyway.
The two sigma range is something like 300-900 with std being 150 and median 600. This is for what is labeled as healthy 18-39 men. It doesn't include obese men.
If you want to take something away from it, just get yourself measured a few times over a few years. Then later if you have issues that relate to low T or whatever you can flag it with your doctor. In my case, it was super important because I found out I am in the top 0.01% of (healthy) total T producers. If I had "low T" type symptoms and went to my doctor without that information - they'd be like, "no, your T is amazing actually."
Everyone has a different baseline. I only wish I started measuring before I was in my mid-30s because I feel my levels before were even more ridiculous.
The effect is so variable that the reference range is nigh meaningless. Some people feel great at 300ng/dL. Some people experience genuine low-T symptoms at 650 that are fixed by bumping it to 1000. Some people are naturally over 1000 and have otherwise average hormonal profile (hair growth, muscle growth).
Also, the reference range is defined by an age span that is too wide to be useful, something like 21-59. The reference range is completely meaningless for a 25 year old man. Also the level varies drastically throughout days and weeks, so that one test is not a useful indicator of anything unless it's off the charts.
Basically, if you have low-T symptoms you should probably just get on T regardless of what number the test says. Find a doctor who agrees.
soy, cortisol, plastics, birth control remnants in the water and food supply, adipose tissue accelerating conversion of testosterone into estradiol, and compounds acting to keep free testosterone levels low and bound testosterone levels high. combine that with sedentary lifestyle, the demonization of red meat healthy fats and cholesterols (cholesterol is extremely close to testosterone and converts easily) and the systematic promotion of a plant based heavily processed diet can easily lead to this. the traditional diets of slaves and serfs was low meat & high grain to keep them weaker dumber and shorter in general. the lowered testosterone and will to fight and resist oppression was also a "feature, not a bug" as my llm likes to say every chance it gets.
the industrial revolution has been a disaster for the human race.
65 comments
[ 3.2 ms ] story [ 63.6 ms ] threadFat directly converts testosterone to Estrogen via a process called aromatization.
Personally my Testosterone close to doubled when going from 25% bodyfat to 13%. I get blood tests regularly and can see the levels fluctuate pretty closely with fat levels
Interesting…
After a series of tests, it was determined that my Testostrone levels well below normal.
My urologist prescribed HCG after I insisted that I wanted to have children someday. It has been a life changer and the best part is that my sperm count has doubled.
Unfortunately, HCG Mono will not treat all forms of Hypogonadism, some patients have to take Testosterone Cypionate which comes with serious side effects like hair loss, infertility, etc
HCG also shares some of those side effects but it saves your fertility and prevents Testicular atrophy.. Also it doesn't shut down your natural production albeit it does suppress LH receptors by default..
My point is this: if you suspect having Testostrone issues, don't randomly inject yourself with hormones.. go see a urologist and get a serious treatment.
some of it might also be social media (fear of public embarrassment) but one thing its definitely not is any kind of large scale hormonal change. culture beats biology almost every time when it comes to social behavior and there is no evidence that its different in this case.
Lead Paint elimination started in the Early 70s IIRC, so the same time period :)
This study has more to say in comparing adult men today to their grandfathers.
In other words, if you’re looking for a boogeyman, blame sedentary lifestyles and ultra processed foods.
Like, if the choice of explanations is (a) obesity, and maybe some pesticide stuff, who knows, or (b) _witchcraft_, Occam's razor points a particular way.
Others are trying to regulate pesticide, junk food (obesity, diabete). For instance nutriscore in Europe, also the recent change on pesticide allowed.
I'm not sure it will be enough, but at least they are attacking to the root cause. You're not just adding even more problem, like the increased cardiovascular event or erectile dysfunction with overdosed TRT.
Same for the semaglutides that everyone and their mother take in the usa, people wouldn't need them so much if they didn't eat absolute crap all the time.
We know that semaglutides have also side effects, and that rebound happen when you stop, but I guess it's better than just fixing the food lobby ?
You should be highly skeptical of any claims of drastic variance in human biology over short time periods.
Wither Ozempic? I've seen several friends and family members use it to great effect and thought it might sweep the nation. But I imagine most of the same barriers that keep people from eating better or moving more are also in play when trying to engage with any new habit.
Of course, PFAS and microplastics aren’t great for sperm health, but neither are leaded gasoline and DDT.
Random aside: is there a correlation between GLP-1 and vaccine acceptance? As in, given enough time, would one expect to see an obese, diseased, low-T population concentrating in on itself?
I'm an obese american (lost 10% of my body weight in the last 7 months, so almost not obese anymore) who is 30+, but my testosterone has measured between 850 and 1400 in the last 7 months.
That probably helped with my weight loss, but I have a full head of hair still and am somewhat likely to keep it.
We'll likely spend longer measuring what the hormonal effects of PFAs and microplastics are than we'll have pfas and microplastics to deal with.
So if levels are falling, is prostate cancer lowering a little bit ? But that will be hard to determine due to the advancement of Medical Treatment over the past 50 years.
It’s the one problem you can see in plain sight at any gathering of people.
It’s like we need something more interesting than “people sit too much and eat too much”.
Option one: obesity and weight problems. Statistically 77% of your audience is either overweight or obese because 77% of Americans are either overweight or obese.
Option two: feminism, microplastics, anime, or literally any other thing than option one.
Endocrine function can still be normal despite obesity. There are plenty of fat guys with solid testosterone levels because they work with their hands all day.
I'm not saying that's all there is to health, far from it, but what kind of bubble does one have to live in to not see this counterexample? Do we just casually ignore them because they fit undesirable stereotypes of "toxic masculinity" or what? You don't have to become that guy just to lift weights.
I'm fairly sure _vastly_ more people lift weights today than in the 70s. At that point it was, well, not niche exactly, but you didn't have anything _remotely_ like the number of gyms around. Can't offhand find figures for back to then, but apparently it's up ~60% in just the last two decades.
You're looking for an answer via a really poor proxy. Lifting weight is lifting weight. Gyms are more popular because of the lack of sensible alternatives for a comprehensive workout. Any data you find about them will also be biased towards the recent decades of office work and working from home. Is there any way to tell if gyms are even picking up the slack? My guess would be overall exercise is down, even for those who go to the gym regularly.
One class of doctors thinks roughly 250 is enough for a middle aged guy - anything over shouldn’t be medically treated. Of course, the “men’s clinics” don’t rest until it’s over 1000...
With the standard range so wide (even after age adjustment), why isn’t it measured annually, like the CBC and others?
Sure, it’s easy to point at obesity, but statistical ranges completely fail the individual.
The two sigma range is something like 300-900 with std being 150 and median 600. This is for what is labeled as healthy 18-39 men. It doesn't include obese men.
If you want to take something away from it, just get yourself measured a few times over a few years. Then later if you have issues that relate to low T or whatever you can flag it with your doctor. In my case, it was super important because I found out I am in the top 0.01% of (healthy) total T producers. If I had "low T" type symptoms and went to my doctor without that information - they'd be like, "no, your T is amazing actually."
Everyone has a different baseline. I only wish I started measuring before I was in my mid-30s because I feel my levels before were even more ridiculous.
Also, the reference range is defined by an age span that is too wide to be useful, something like 21-59. The reference range is completely meaningless for a 25 year old man. Also the level varies drastically throughout days and weeks, so that one test is not a useful indicator of anything unless it's off the charts.
Basically, if you have low-T symptoms you should probably just get on T regardless of what number the test says. Find a doctor who agrees.
the industrial revolution has been a disaster for the human race.
I wonder if men nowadays don't move around or lift things as much.