Do we know how much body fat effects e2 levels?

[xqfq]

Hey everyone! I’ve been dieting myself down to a very low body fat % for an event next month, and I’ve been wondering if we know how much a reduction in body fat levels could effect e2?

I’ve noticed in the past, prior to TRT, that I actually had a higher sex drive when at low body fat (at least once I started eating at my caloric maintainence again). I now reason this could have been due to the low body fat decreasing e2, thus increasing free T and potentially DHT. I also noticed my pubertal gyno reducing greatly in size when dieting down to low body fat prior to TRT.

I know the only way to know is to test, but I’ve done so much blood work over the past several months I’d like to hold off a bit if I could! I’d love to know if any guys here have before / after bloodwork after losing lots of body fat, or if there are any studies on this (I couldn’t find any when I last looked).

 

[testiculus]

The only study I know of is this one:
The Effects of Injected Testosterone Dose and Age on the Conversion of Testosterone to Estradiol and Dihydrotestosterone in Young and Older Men

Older men had higher body fat levels and also higher estradiol conversion.

 

[Nelson Vergel]

Estradiol is not caused by higher fat. The body actually produces estradiol to compensate for the higher fat. Estradiol deficiency causes fat gain.

'Only over the past few years have clinical intervention studies begun to confirm pre-clinical evidence that estradiol contributes to body weight regulation and metabolic health in men. One small study examined the effects of testosterone replacement in obese men with low-normal baseline serum testosterone concentrations. Whereas treatment with testosterone gel led to significant reductions in adiposity, these changes were not seen when testosterone was co-administered with an aromatase inhibitor.(Juang et al., 2014) In a larger study of healthy men, 2 subject cohorts were administered the GnRH analogue goserelin acetate to suppress endogenous sex steroid production. Simultaneously, subjects in the first cohort received either placebo gel or variable doses of add-back testosterone gel, and the second cohort of subjects received either placebo gel or testosterone gel with an aromatase inhibitor. Strikingly, whereas androgen exposure appeared to mediate changes in lean mass, estradiol rather than testosterone was found to be the primary determinant of changes in fat mass.(Finkelstein et al., 2013) Subsequently, another clinical study similarly enrolled healthy, eugonadal men and rendered them medically castrate through use of the GnRH antagonist acyline. Subjects in this study variably received placebo gel, low-dose or full replacement dose testosterone gel, or full replacement dose testosterone gel with an aromatase inhibitor. In all 3 treatment groups rendered sex steroid deficient, significant increases in body fat mass were evident within only 4 weeks of drug treatment.(Chao et al., 2016) Again, estradiol rather than testosterone deprivation exhibited a stronger correlation with the observed increases in adiposity."

Chapter 24: Estrogens and Body Weight Regulation in Men

 

[antelopers]

Estradiol is not caused by higher fat. The body actually produces estradiol to compensate for the higher fat. Estradiol deficiency causes fat gain.

'Only over the past few years have clinical intervention studies begun to confirm pre-clinical evidence that estradiol contributes to body weight regulation and metabolic health in men. One small study examined the effects of testosterone replacement in obese men with low-normal baseline serum testosterone concentrations. Whereas treatment with testosterone gel led to significant reductions in adiposity, these changes were not seen when testosterone was co-administered with an aromatase inhibitor.(Juang et al., 2014) In a larger study of healthy men, 2 subject cohorts were administered the GnRH analogue goserelin acetate to suppress endogenous sex steroid production. Simultaneously, subjects in the first cohort received either placebo gel or variable doses of add-back testosterone gel, and the second cohort of subjects received either placebo gel or testosterone gel with an aromatase inhibitor. Strikingly, whereas androgen exposure appeared to mediate changes in lean mass, estradiol rather than testosterone was found to be the primary determinant of changes in fat mass.(Finkelstein et al., 2013) Subsequently, another clinical study similarly enrolled healthy, eugonadal men and rendered them medically castrate through use of the GnRH antagonist acyline. Subjects in this study variably received placebo gel, low-dose or full replacement dose testosterone gel, or full replacement dose testosterone gel with an aromatase inhibitor. In all 3 treatment groups rendered sex steroid deficient, significant increases in body fat mass were evident within only 4 weeks of drug treatment.(Chao et al., 2016) Again, estradiol rather than testosterone deprivation exhibited a stronger correlation with the observed increases in adiposity."

Chapter 24: Estrogens and Body Weight Regulation in Men

This is very interesting, as anecdotally myself and many others notice a big decrease in body fat by being at lower estradiol levels.

 

[Vince]

My understanding always has been. Belly fat contains high levels of the enzyme aromatase, which converts testosterone into estrogen.

 

[Vince Carter]

<<<<not fat and lots of aromatase