Hello again, fredboy-ga!
Since no one else has stepped up to answer your question, you are
stuck with me again!!
I have compiled some excerpts from both scientific abstracts and
laymen's articles which link obesity and lowered testosterone. These
links provide further reason for you to be encouraged in your attempts
to slim down.
As for dietary fat and testosterone, the amount of fat injested does
play a role in testosterone levels. I have not run across any articles
that provide definitive dietary guidelines. All I can determine is
that dietary fat should be kept in the moderate range (neither too
high or too low) so that testosterone levels are kept in a normal
I hope the following articles are helpful.
OBESITY AND TESTOSTERONE LEVELS
From "Prevalence of Androgen Deficiency in the Ageing Male." Medscape.
"The MMAS identified obesity as the most important determinant of
total testosterone over time, with levels 25% lower in obese men when
compared to their nonobese counterparts (Gray et al., 1991b). In this
cohort, controlling for age, there was a 33% reduction in testosterone
levels in the highest quintile BMI group when compared to the lowest
(Field et al., 1994). Over 9 years of follow-up in these men obesity
predicted a greater decline in total testosterone and SHBG with ageing
(Derby et al., 2002). Whilst the lower SHBG levels associated with
obesity contribute to low total testosterone levels, free testosterone
levels may also be lower in obese as compared to nonobese men
(Vermeulen et al., 1996).
From "The "Skinny" on Obesity and Prostate Cancer Prognosis." Alfred
I. Neugut, Allen C. Chen, Daniel P. Petrylak. Journal of Clinical
Oncology, Vol 22, No 3 (February 1), 2004: pp. 395-398
"Obesity is associated with lower testosterone levels, which have been
associated with higher grade and more advanced pathologic stage in
men with prostate cancer. Obesity is also associated with higher
insulin and free insulin-like growth factor 1 levels, both of which
are mitogenic. These obesity-induced hormonal changes may mediate the
progression of subclinical tumors to more aggressive disease."
From "When Does Andropause Occur?" Andropause Canada
"Studies indicate that obesity is directly related to
over-estrogenization in both sexes. All fat cells contain aromatase,
so an increase in fat cell population will cause an increase in the
conversion of testosterone into estrogen. This will alter the
testosterone: estrogen ratios. Obesity is also known to lower
testosterone levels at all ages. This may be an excellent reason to
trim down and tone up!"
From "Does Male Menopause Exist?" by Neil Sherman. healthAtoZ
"The problem is that declining testosterone levels can't be linked to
a biological clock as lowered estrogen levels can be in women.
"There are a lot of things that can lower testosterone levels aside
from aging," Sternbach explains. "You can lower it from drug and
alcohol abuse or from stress or medications. Depression lowers
** as does obesity. **
"So the timetable for lower levels of the hormone can be variable in
men. What we do know is that every woman will go through menopause and
not all men will go through what's called andropause, and we just
don't know why."
"One of the reasons scientists cannot make up their minds about male
menopause is "there's no agreed-upon definition of the cut-off point
for low testosterone," Sternbach explains. "See, there are different
types of testosterone you can measure. So you really don't know what
level the person started from, and you really don't know how much has
been lost." Testosterone is present in the circulation both in
protein-bound forms and in non-protein-bound formats."
"Not all men lose testosterone, Sternbach adds. "Some men, as we all
know, don't get depressed and remain virile and sexually active to the
end of their days. And we really don't know why."
From "Sex Differences in Obesity." Society for Women's Health Research.
"Leptin, a molecule produced by fat cells, is an important signal in
the regulation of appetite and energy expenditure, and is thought to
play a key role in the control of body weight. The level of leptin in
the blood is correlated with BMI, and is far higher in women than men
at every BMI level. This may be part of the reason why women are more
likely than men to become overweight." 9-18
"Testosterone appears to play a large role in the regulation of leptin
levels in the blood; men with higher testosterone levels have lower
leptin levels." 19, 20
From "Health Topic of the Week: Testosterone Link with Diabetes
Studied." UAB Health System. August 26, 2005.
"Men with chronic conditions such as diabetes, hypertension, obesity,
asthma, and hyperlipidemia (elevated levels of lipids, or fats, in the
blood) are more likely to have low testosterone than other men, the
"Another expert notes that lowered testosterone is a normal function
of age, and debate continues within the field as to whether most older
men will benefit from hormone replacement therapies which can be
associated with increased risk for prostate cancer."
From "Chapter 7: Testosterone, The Male Hormone Connection: Treating
Diabetes and Heart Disease." Michael Klentze, M.D., Ph.D. Medical
Director, Klentze Institute of Anti-Aging, Munich, Germany; Member,
A4M Advisory Board - Europe."
"Testosterone deficiency in men is manifested typically by symptoms of
hypogonadism, including decreases in erectile function and libido. One
quarter of men over 65 have subnormal testosterone levels.
Testosterone also has an important role in the regulation of normal
growth, bone metabolism, and body composition.....
** "Men with testosterone deficiency also have alterations in body
composition, which includes an increase in body fat. Quantitative CT
scans that assess fat distribution have shown that testosterone
deficiency is associated with an alteration in site-specific adipose
deposition with increased deposits in all areas particularly in the
subcutaneous and muscle areas."
"Low testosterone levels are correlated with type II diabetes and
carbohydrate metabolism disorders, and low levels of free testosterone
are correlated with obesity, which is the origin of insulin resistance
and type II diabetes."
From "YOUR HUSBAND?S HEALTH: SIMPLIFY YOUR WORRY LIST," BY KATHLEEN W.
WILSON M.D. http://www.boomermedicine.com/books/yhh/vign/vignbk.asp
"Men also have a gradual reduction in testosterone levels as they age.
Whether or not such a condition as "andropause" occurs is still
debated. In the past, borderline levels of low testosterone were not
treated and were felt to be expected as a man aged. Doctors are now
reconsidering treatment of this condition if it presents with fatigue
or other symptoms of low testosterone."
"A more common, less known cause of lowered testosterone efficacy will
not be apparent from a blood test. When men acquire abdominal obesity,
even ten or twenty extra pounds, that metabolically active fat in the
abdomen converts some testosterone to the female hormone, estrogen. I
explain this to my male patients who have noticed a decrease in
erectile function and need to lose weight. It seems that nothing
motivates them quite as quickly to lose the extra pounds than the
thought of becoming less potent."
From "Serum Androgen Concentrations in Young Men: A Longitudinal
Analysis of Associations with Age, Obesity, and Race." The CARDIA Male
Hormone Study. Susan M. Gapstur1, Peter H. Gann, Peter Kopp, Laura
Colangelo, Christopher Longcope and Kiang Liu Cancer Epidemiology
Biomarkers & Prevention Vol. 11, 1041-1047, October 2002
These results indicate that the age-associated decrease in circulating
testosterone and increase in SHBG begin during the 3rd decade of life,
and that increasing obesity, particularly central obesity, is
associated with decreasing total testosterone and SHBG.
From "The male menopause - back in fashion?" Summarized by Robert W.
Griffith, MD. April 27, 2000 (Reviewed: November 11, 2002) Health and
"Heredity plays a role in the development of hypotestosteronemia, as
it has been shown that most of the variability in testosterone
concentrations and a third of the sex hormone-binding globulin decline
depend on genetic factors.
Other risk factors for early or exaggerated falls in testosterone are
a history of orchitis, trauma to the testes,
and impaired insulin utilization. Excess alcohol intake is often
associated with lowered testosterone levels, whereas the influence of
physical and psychological stress is still debatable.
"The fact that both a decline in sexual interest and potency and a
fall in testosterone levels occur with aging obviously suggests that
sexual behavior is largely dependent on testosterone levels. This is
not however not necessarily the case - there are many other causes of
impotence in elderly man, e.g. vascular changes, pharmaceutical drug
effects, neuropathies, etc."
From "Banish the beer belly," by Roger Dobson, Daily Mail. 11 February 2003
"Many men develop abdominal fat, especially in middle age. That is
also the time when natural testosterone levels begin to decline, and
the falling levels have been linked to the andropause (male
menopause). But younger men have problems, too, and the conference was
given the results of a new Russian study into the link between
testosterone and abdominal (visceral) obesity in men aged between 18
"Doctors gave patients two testosterone tablets a day for six months.
The body mass index of the men - a measure of obesity which takes both
weight and height into account - ranged from 30 to 34, with an average
of around 31. All the patients had low levels of testosterone at the
start of the treatment. After one month of taking the tablets, the
levels of the male hormone had doubled, and a positive link was found
between body mass index and levels of testosterone."
From "Is your sex drive in Neutral," by Natasha Turner. Truestar Health.
"Abdominal fat in men increases the conversion of testosterone into
estrogen. As estrogen levels rise, so does the tendency to accumulate
more abdominal fat, fueling the situation. The risk of prostate cancer
also increases with higher estrogen levels. A blood or saliva test can
assess your levels; if levels are high, consider a product called
indol-3-carbinol which may help to correct the balance of estrogen to
"Testosterone levels decrease as abdominal fat coverts it to estrogen,
and also with increasing stress. While you are under stress your body
will tend to make more stress hormone (cortisol) than testosterone.
Furthermore, researchers from the University of Washington found that
men with low testosterone are more likely to develop a potbelly and
other body fat. The researchers also found that testosterone may
actually prompt the loss of body fat when deficient levels are
From "Extra Weight Skews PSA Scores. High BMI means prostate cancer
screen can miss early stages of disease, new research reports," by
Serena Gordon. HealthDay Reporter
"The authors said they don't know exactly why higher BMIs would affect
PSA scores, but they suspect that PSA is suppressed in heavier men
because obese men have lower levels of testosterone."
DIET AND TESTOSTERONE LEVELS
From "The Male Biological Clock: A man's genes, coupled with the facts
of his life, set the limits of his sexual biological clock. But men
can still do a lot to improve their fertility and their sexual
performance," by Harry Fisch, MD.
"The old cliche "You are what you eat" contains a fair amount of
truth. A man's body, including his sex organs, is made from the food
he eats, the beverages he drinks, and the air he breathes. Eat right,
and everything improves - including sexual health. As with most things
in life, an appropriate guide for eating to promote sexual health is
"All things in moderation, including excess." The idea is to avoid
extremes in any direction and yet preserve the pleasure of eating."
"For example, much research shows that a high-fat diet, high
cholesterol levels, and obesity lower testosterone levels and increase
the risk of erection problems. That's because excess fat is converted
to estrogenlike compounds that curtail the production of testosterone,
and fat in the blood can clog the small arteries that feed the penis.
Remember, what is bad for the heart is bad for the penis. A recent
study, in fact, found that, conversely, improving cardiac health
improves erections, a fact recently illustrated by a study showing
improved erectile function in a group of men treated with a
cholesterol-lowering medication. "
"On the other hand, studies also show that very lean men - for
example, marathon runners - have lower-than-average testosterone
levels. That's because the compound used to build testosterone
molecules in the body is cholesterol, and extreme exercise lowers
cholesterol levels to abnormal levels. A man needs enough cholesterol
in his diet to maintain testosterone production, but not so much that
it produces body fat or clogged arteries."
"Optimal sexual health is also promoted by moderate, regular exercise.
Again, the key is avoiding extremes. Studies show that men who
exercise strenuously (i.e., men who run more than 100 miles a week or
who bicycle more than 50 miles a week) usually have a lower
testosterone level than men who exercise more moderately. Given that
most men do not, in fact, exercise even moderately, this is not
exactly a huge public health problem."
From "Do low-fat diets lower testosterone levels?" Christian Finn's
Facts about Ftness. http://www.thefactsaboutfitness.com/2005/03/do-low-fat-diets-lower-testosterone.htm
Q. Is there any truth that a low fat diet will lower testosterone levels?
A. Yes, there is research to show that both the amount and type of fat
in your diet will affect testosterone levels.
"Some of the early studies linking fat and testosterone in humans were
published in the 1980's. Subjects cutting their fat intake in half
experienced a 13% drop in free testosterone. When they resumed their
normal diet, testosterone levels returned to normal.
"The most recent trial I've seen was published in the Journal of
Clinical Endocrinology and Metabolism. A group of 39 middle-aged men
(50 to 60 years of age) were studied while they were consuming a
high-fat (33% of total calories) low fiber diet and after eight weeks
on a low-fat (14% of total calories), high fiber diet. Both total and
free testosterone levels fell by 10-12% after the low-fat diet. The
clearance rates of testosterone were not changed, suggesting that the
drop in testosterone was because of a decrease in production."
From "Decrease of serum total and free testosterone during a low-fat
high-fibre diet." Hamalainen EK, Adlercreutz H, Puska P, Pietinen P.
Steroid Biochem. 1983 Mar;18(3):369-70.
"The concentrations of serum total and free testosterone were studied
in 30 healthy, middle-aged men during a dietary intervention program.
When men were transferred from their customary diet to an experimental
diet, which contained less fat with a higher polyunsaturated/saturated
ratio (P/S-ratio) and more fibre, there was a significant decrease in
serum total testosterone concentrations (22.7 +/- 1.2 vs 19.3 +/- 1.1
nmol/l SEM, P less than 0.001). Furthermore, serum free, unbound
testosterone fell from 0.23 +/- 0.01 to 0.20 +/- 0.01 nmol/l SEM (P
less than 0.01). The hormonal changes were reversible. This
observation suggests that testosterone activity in plasma can at least
partly be modified by changing the composition of the diet."
From "Effects of dietary fat and fiber on plasma and urine androgens
and estrogens in men: a controlled feeding study." Dorgan JF, Judd JT,
Longcope C, Brown C, Schatzkin A, Clevidence BA, Campbell WS, Nair PP,
Franz C, Kahle L, Taylor PR. Am J Clin Nutr. 1996 Dec;64(6):850-5.
"We conducted a controlled feeding study to evaluate the effects of
fat and fiber consumption on plasma and urine sex hormones in men. The
study had a crossover design and included 43 healthy men aged 19-56 y.
Men were initially randomly assigned to either a low-fat, high-fiber
or high-fat, low-fiber diet for 10 wk and after a 2-wk washout period
crossed over to the other diet. The energy content of diets was varied
to maintain constant body weight but averaged approximately 13.3 MJ
(3170 kcal)/d on both diets. The low-fat diet provided 18.8% of energy
from fat with a ratio of polyunsaturated to saturated fat (P:S) of
1.3, whereas the high-fat diet provided 41.0% of energy from fat with
a P:S of 0.6. Total dietary fiber consumption from the low- and
high-fat diets averaged 4.6 and 2.0 g.MJ-1.d-1, respectively. Mean
plasma concentrations of total and sex-hormone-binding-globulin
(SHBG)-bound testosterone were 13% and 15% higher, respectively, on
the high-fat, low-fiber diet and the difference from the low-fat,
high-fiber diet was significant for the SHBG-bound fraction (P =
0.04). Men's daily urinary excretion of testosterone also was 13%
higher with the high-fat, low-fiber diet than with the low-fat,
high-fiber diet (P = 0.01). Conversely, their urinary excretion of
estradiol and estrone and their 2-hydroxy metabolites were 12-28%
lower with the high-fat, low-fiber diet (P < or = 0.01). Results of
this study suggest that diet may alter endogenous sex hormone
metabolism in men."
The pros and cons of testosterone therapy - is it really necessary?
From "Testosterone therapy: The answer for aging men?" By Mayo Clinic staff
"Testosterone therapy has been used successfully for years to treat
men with abnormally low testosterone levels - a medical condition
called male hypogonadism. More recently, healthy, aging men have taken
the hormone to boost waning testosterone levels. But not enough is
known about the effects of testosterone therapy for this purpose. No
long-term studies have weighed the potential benefits against the
possible risks, including infertility and prostate problems."
"At the core of the controversy is whether gradually declining
testosterone levels are a natural phenomenon or a health condition.
And the practical question for men and their doctors is whether to
treat it, particularly in the absence of scientific evidence. Before
you buy into the tempting claims, find out what's known - and not
known - about testosterone therapy so that you can make the best
decision for you and your long-term health."
"Starting around age 40, a man's body produces about 1 percent less
testosterone each year. Testosterone is the main male hormone that
maintains muscle mass and strength, fat distribution, bone mass, sperm
production, sex drive, and potency....
"For most men, testosterone levels naturally decline but still remain
within the normal range throughout their lifetime, causing no
significant problems. But about two in 10 men age 60 and older have
testosterone levels below the normal range (testosterone deficiency)."
"Testosterone deficiency can have several effects on the body, including:
Reduced muscle mass and strength
Decreased cognitive function
Less sexual interest or potency
"If you experience these signs or symptoms, you may or may not have
testosterone deficiency. Other medical conditions - such as liver
disease, hypothyroidism and depression - can cause these effects as
can certain medications, including beta blockers, pain killers and
certain drugs for depression or anxiety. In addition, some healthy men
encounter these changes as a part of the natural aging process,
possibly because of declining hormones other than testosterone."
From "MALE MENOPAUSE - a patient's guide."
"Male menopause is a term to describe a drop in male hormone levels
after middle age leading to depression, anxiety and ** low libido. **
"The term has also been used to describe a mid-life crisis that
happens to some men during their late thirties and early forties.
However, this is outside the scope of this article which deals with
physical symptoms caused by low testosterone levels. There is
controversy about whether male menopause actually exists because it is
not associated with a sharp drop in hormones and the cessation of a
bodily function like in the case of female menopause when women's
periods stop. However, testosterone is produced at smaller amounts by
the testicles and in pituitary gonadotrophin secretion in middle aged
and elderly men which is believed to lead to the symptoms of male
Take care, and keep exercising! Give it a while and see what happens!
obesity AND lowered testosterone
relation of obesity and lowered testosterone
does obesity affect testosterone levels?
diet AND testosterone levels
effects of dietary fat on testosterone levels
do high fat diets lower testosterone levels in men?
ow testosterone in males AND libido