Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies

[Kvothe]

Keep the butter on the bread, especially if you're a white dude!? A meta-analysis on the effects of low-fat diets on testosterone levels.

Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies

Higher endogenous testosterone levels are associated with reduced chronic disease risk and mortality. Since the mid-20th century, there have been sign…

www.sciencedirect.com

The Journal of Steroid Biochemistry and Molecular Biology
Volume 210, June 2021, 105878
Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies
Joseph Whittakera Kexin Wub

Background

Higher endogenous testosterone levels are associated with reduced chronic disease risk and mortality. Since the mid-20th century, there have been significant changes in dietary patterns, and men’s testosterone levels have declined in western countries. Cross-sectional studies show inconsistent associations between fat intake and testosterone in men.

Methods

Studies eligible for inclusion were intervention studies, with minimal confounding variables, comparing the effect of low-fat vs high-fat diets on men’s sex hormones. 9 databases were searched from their inception to October 2020, yielding 6 eligible studies, with a total of 206 participants. Random effects meta-analyses were performed using Cochrane’s Review Manager software. Cochrane’s risk of bias tool was used for quality assessment.

Results

There were significant decreases in sex hormones on low-fat vs high-fat diets. Standardised mean differences with 95 % confidence intervals (CI) for outcomes were: total testosterone [−0.38 (95 % CI −0.75 to −0.01) P = 0.04]; free testosterone [−0.37 (95 % CI −0.63 to −0.11) P = 0.005]; urinary testosterone [−0.38 (CI 95 % −0.66 to −0.09) P = 0.009]; and dihydrotestosterone [−0.3 (CI 95 % −0.56 to −0.03) P = 0.03]. There were no significant differences for luteinising hormone or sex hormone binding globulin. Subgroup analysis for total testosterone, European and North American men, showed a stronger effect [−0.52 (95 % CI −0.75 to −0.3) P < 0.001].

Conclusions
Low-fat diets appear to decrease testosterone levels in men, but further randomised controlled trials are needed to confirm this effect. Men with European ancestry may experience a greater decrease in testosterone, in response to a low-fat diet.



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"The largest decreases in TT were seen in the 2 studies with vegetarian LF diets (Hill 1979; Hill 1980 NA) [44,49]. These diets may have been lower in zinc, which is a common feature of vegetarian diets [64], and marginal zinc deficiency has been found to decrease TT [32]. Nevertheless, studies well matched for micronutrient intake showed similar, albeit smaller changes in TT [45,48] (Fig. 2); suggesting the decrease in TT was mostly due to other dietary factors."

"Dietary fibre intake was likely higher on LF vs HF diets, which has been suggested to increase T excretion by modulating the enterohepatic circulation of steroids [25]. However, we found LH (P = 0.16) and UT excretion (P =0.009) decreased on LF diets, which suggests decreased T production rather than increased T excretion (Figs. 5 and 6)"

"The LF vs HF diets were consistently lower in monounsaturated fatty acids (MUFA) and saturated fatty acids (SFA), and had higher polyunsaturated to saturated fatty acid ratios (P:S). This suggests a beneficial effect of MUFA and SFA, and/or a deleterious effect of polyunsaturated fatty acids (PUFA) on androgens. (Seems this is slowly getting mainstream @haidut )"

High PUFA vs MUFA or SFA diets result in decreased T production via increased testicular oxidative stress, decreased steroidogenic enzymes and decreased testicular free cholesterol available for steroidogenesis [71,]

 

[looking2grow96]

I know you're into lowish protein, highish carb/fat diets. Do you find this negatively affects your body composition at all? Do you have troubke staying at a normal weight on such a diet?

 

[Kvothe]

I know you're into lowish protein, highish carb/fat diets. Do you find this negatively affects your body composition at all? Do you have troubke staying at a normal weight on such a diet?

No. I have significantly more lean mass than I had on a diet with a higher relative protein intake. My total intake is probably the same or a little higher. I don't see any reason to assume a lowish-protein diet should negatively affect your body composition. When your diet is low in protein, you will automatically eat more calories, and therefore you're unlikely to end up with a protein deficiency, unless all your foods are extremly low-protein.
In fact, high-protein diets are likely to negatively influence your body composition, and increase the incidence of obesity, dysbiosis, liver problems, etc. This effect is most pronounced in babies and children, but the pattern is more or less the same for adults.

High protein intake in young children and increased weight gain and obesity risk1

See corresponding article on page 389.

academic.oup.com

Protein Intake from Birth to 2 Years and Obesity Outcomes in Later Childhood and Adolescence: A Systematic Review of Prospective Cohort Studies

Statement of Significance: This is the first systematic review that summarized the evidence from the prospective cohort studies examining the association betwee

academic.oup.com

 

[looking2grow96]

No. I have significantly more lean mass than I had on a diet with a higher relative protein intake. My total intake is probably the same or a little higher. I don't see any reason to assume a lowish-protein diet should negatively affect your body composition. When your diet is low in protein, you will automatically eat more calories, and therefore you're unlikely to end up with a protein deficiency, unless all your foods are extremly low-protein.
In fact, high-protein diets are likely to negatively influence your body composition, and increase the incidence of obesity, dysbiosis, liver problems, etc. This effect is most pronounced in babies and children, but the pattern is more or less the same for adults.

High protein intake in young children and increased weight gain and obesity risk1

See corresponding article on page 389.

academic.oup.com

Protein Intake from Birth to 2 Years and Obesity Outcomes in Later Childhood and Adolescence: A Systematic Review of Prospective Cohort Studies

Statement of Significance: This is the first systematic review that summarized the evidence from the prospective cohort studies examining the association betwee

academic.oup.com

Awesome! Thanks for taking the time to answer my question man, your posts really intrigue me. Would you say you're particularly active? II ask because I lift weights 3-4x a week, and I have started rock climbing when possible (also live in NYC so lots of walking + biking). I'm assuming the low protein diet doesnt affect recovery? also, are there any other significant physiological changes you noticed? Thanks again dude

 

[Sitaruîm]

I just started a low protein diet and I feel like a million bucks. I have a theory that excess protein and protein imbalance is at the core of ageing and especially by ditching gluten and casein my health took a dramatic turn, especially my depression and cognition. I developed this new paradigm after going through Travis' corner. My depression was linked to my impaired cognition because I was aware that my abilities where nowhere near my peak, as if my well was being poisoned. My fat intake comes mostly from cream/butter and some olive oil sparingly. Sources of carbs are rice, oats, fresh fruit, sucrose, and honey. I'm at the early stages of testing a fruit fasting protocol where for two days in a row every week I will only eat fruit to increase autophagy without inducing stress.

 

[Kvothe]

No. I have significantly more lean mass than on a diet with relatively more protein. I also don't see any reason to assume a lowish-protein diet should negatively affect your body composition. In fact, high-protein diets are likely to negatively influence your body composition, and increase the incidence of obesity, dysbiosis, liver problems, etc. This effect is most pronounced in babies and children, but the pattern is more or less the same for adults.

High protein intake in young children and increased weight gain and obesity risk1

See corresponding article on page 389.

academic.oup.com

Protein Intake from Birth to 2 Years and Obesity Outcomes in Later Childhood and Adolescence: A Systematic Review of Prospective Cohort Studies

Statement of Significance: This is the first systematic review that summarized the evidence from the prospective cohort studies examining the association betwee

academic.oup.com

Awesome! Thanks for taking the time to answer my question man, your posts really intrigue me. Would you say you're particularly active? II ask because I lift weights 3-4x a week, and I have started rock climbing when possible (also live in NYC so lots of walking + biking). I'm assuming the low protein diet doesnt affect recovery? also, are there any other significant physiological changes you noticed? Thanks again dude

I go hiking a lot, play soccer, like to do things in the garden, and work out once or twice a week. Nothing extreme. Recovery is very good. When I was intentionally eating more protein, recovery was always slow. Peat has talked about how eating a lot of protein (when it's rich in tryptophan and methionine) can actually cause muscle weakness. The most noticeably changes are more energy and most of all more heat production.

 

[Yonebayashian]

Did they mention the fat sources? Would be interested to know how a highly nutritious fat like raw butter would stack up against say coconut oil.

 

[Nebula]

I just started a low protein diet and I feel like a million bucks. I have a theory that excess protein and protein imbalance is at the core of ageing and especially by ditching gluten and casein my health took a dramatic turn, especially my depression and cognition. I developed this new paradigm after going through Travis' corner. My depression was linked to my impaired cognition because I was aware that my abilities where nowhere near my peak, as if my well was being poisoned. My fat intake comes mostly from cream/butter and some olive oil sparingly. Sources of carbs are rice, oats, fresh fruit, sucrose, and honey. I'm at the early stages of testing a fruit fasting protocol where for two days in a row every week I will only eat fruit to increase autophagy without inducing stress.

I currently feel much better on low protein too. My only animal protein is usually beef heart 4 ounces per day. My theory is you can only assimilate the amount of protein your metabolism can handle. An excess can be inflammatory and create metabolic acidosis. I feel like I’m taking several aspirin eating mostly rice, tropical fruit, potatoes and beef heart. I would like to be able to eat dairy and more animal protein in the future but for now I seem to be increasing metabolism and healing from chronic inflammation keeping it low and restricted to a small amount of beef.

 

[BRBsavinWorld]

I’m currently going low fat to lose some weight (but I eat sat fat without inhibition on Sunday’s).

But I agree, I know I feel way better on a high fat/sugar diet (I’m white as sourcream lol), but no matter what I do, I gain weight when I do it. Before I started this low fat diet, I gained 40 lbs in 6 months of eating all the carbs and fat I craved. After about 2 weeks of this diet, I’m down 6lbs.

 

[BRBsavinWorld]

Shouldn’t the inflammatory factors of protein be neutralized by consuming glycine? That’s why Ray advocates gelatin from cracklings or bone broth.

 

[Nebula]

Shouldn’t the inflammatory factors of protein be neutralized by consuming glycine? That’s why Ray advocates gelatin from cracklings or bone broth.

For me it doesn’t have the same effect. Low protein is much more anti inflammatory for me right now. I’m hoping it’s just temporary. Maybe another month or two while gradually increasing calories and my metabolism will be able to handle more animal protein as I seem to be losing some muscle mass.

 

[Sefton10]

For me it doesn’t have the same effect. Low protein is much more anti inflammatory for me right now. I’m hoping it’s just temporary. Maybe another month or two while gradually increasing calories and my metabolism will be able to handle more animal protein as I seem to be losing some muscle mass.

There’s some good discussion on protein in this old thread.

RP Says Glucose Helps T4 To T3, Then Why Fructose?

I am reading this statement below i got from a site: Did you know that your liver stores sugar (called glycogen), and that you NEED a steady flow of sugar to keep glycogen stores topped off? Without a healthy storage of glycogen, your liver won’t convert thyroid hormone T4 (inactive) to T3...

raypeatforum.com

 

[GreekDemiGod]

I’m currently going low fat to lose some weight (but I eat sat fat without inhibition on Sunday’s).

But I agree, I know I feel way better on a high fat/sugar diet (I’m white as sourcream lol), but no matter what I do, I gain weight when I do it. Before I started this low fat diet, I gained 40 lbs in 6 months of eating all the carbs and fat I craved. After about 2 weeks of this diet, I’m down 6lbs.

My highest T levels tested were when I was eating a 40-45% carbs, 35-40% fats, 20% protein split. And I'm seeing a few of these primal influencers who do plenty of Saturated Fats in their diet, but also do not restrict carbs. And they show proof of very high T levels.
One particular guy I follow has been influenced by Peat too

I agree with you that lower fat works in dieting phases.

 

[Androsclerosis]

I just started a low protein diet and I feel like a million bucks. I have a theory that excess protein and protein imbalance is at the core of ageing and especially by ditching gluten and casein my health took a dramatic turn, especially my depression and cognition. I developed this new paradigm after going through Travis' corner. My depression was linked to my impaired cognition because I was aware that my abilities where nowhere near my peak, as if my well was being poisoned. My fat intake comes mostly from cream/butter and some olive oil sparingly. Sources of carbs are rice, oats, fresh fruit, sucrose, and honey. I'm at the early stages of testing a fruit fasting protocol where for two days in a row every week I will only eat fruit to increase autophagy without inducing stress.

Everytime I start a low protein diet I feel better mentally for a few days and then I crash, weakness and low motivation begins. It´s not sustainable long-term.
How long have you been on low protein?

 

[Sitaruîm]

Everytime I start a low protein diet I feel better mentally for a few days and then I crash, weakness and low motivation begins. It´s not sustainable long-term.
How long have you been on low protein?

Two weeks now. It should be noted that on the weekends I have a a big meal of red meat 500-750g. Overall I consume less protein but I think that what's also making a difference is that 4 days per week my protein intake is almost 0. I'm hoping that autophagy will be upregulated this way. My protein intake is lower but I don't think it's low enough to cause problems, my sources are mostly meat and some eggs which are ideal.

 

[Nomane Euger]

Everytime I start a low protein diet I feel better mentally for a few days and then I crash, weakness and low motivation begins. It´s not sustainable long-term.
How long have you been on low protein?

hi,i prefer to eat fruits/coconut water/honey up until i truly crave meat,or i feel that i am missing something because i start to experience negatives symptoms such as cold extremities,worst digestion,insatiable,not feeling as good as i should despit eeating these foods that usually make me feel wonderfull

 

[skittles]

I just started a low protein diet and I feel like a million bucks. I have a theory that excess protein and protein imbalance is at the core of ageing and especially by ditching gluten and casein my health took a dramatic turn, especially my depression and cognition. I developed this new paradigm after going through Travis' corner. My depression was linked to my impaired cognition because I was aware that my abilities where nowhere near my peak, as if my well was being poisoned. My fat intake comes mostly from cream/butter and some olive oil sparingly. Sources of carbs are rice, oats, fresh fruit, sucrose, and honey. I'm at the early stages of testing a fruit fasting protocol where for two days in a row every week I will only eat fruit to increase autophagy without inducing stress.

For solidarity with a friend at work who wanted to experiment with food, I'm just finishing up the reintroduction phase after a month of the Whole 30. I drank a lot of apple cider and orange juice (apparently breaks the rules but idgaf), lots of bananas and potatoes. Lots of meat. And frankly, I'm so sick of meat lol.

I was honestly shocked at how amazing I felt on the reintroduction days for sugar and dairy, and I even felt pretty good reintroducing rice, corn, legumes. I went /hard/ on those days, and had no room for meat.

I kind of joked early on that I was going to do an Anti-Whole-30 afterward, starting with (pretty much) nothing but sugar, dairy, and refined grains, and slowly reintroducing things from there. But now I'm actually gonna give it a shot.

 

[BRBsavinWorld]

My highest T levels tested were when I was eating a 40-45% carbs, 35-40% fats, 20% protein split. And I'm seeing a few of these primal influencers who do plenty of Saturated Fats in their diet, but also do not restrict carbs. And they show proof of very high T levels.
One particular guy I follow has been influenced by Peat too

I agree with you that lower fat works in dieting phases.

Wow, that’s awesome.

But, sometimes I wonder if that’s not got to do with stressors just from low protein, ie, a temporary survival trait.

For instance, Peat says if you eat much more sugar than protein, you will eventually elevate serotonin, which is the chief hormone to other stress hormones like cortisol... so I can’t help but wonder if it’s the same misinterpretation of phenomena as when I did keto-carnivore, mistaking elevated cortisol and adrenaline as my testosterone getting fixed, which most lay-carnivores mistakenly believe is happening.

Ps, I went with a theory of breaking down macros of human milk for my diet (about 3 months); so, Closer to your current macro breakdown. And at some point in trying to fix my chronically elevated serotonin, I learned that tidbit from Ray. I can’t say my serotonin levels are a whole lot better yet, but a word of caution.

 

[BRBsavinWorld]

For me it doesn’t have the same effect. Low protein is much more anti inflammatory for me right now. I’m hoping it’s just temporary. Maybe another month or two while gradually increasing calories and my metabolism will be able to handle more animal protein as I seem to be losing some muscle mass.

Interesting, thanks.

 

[Sitaruîm]

Wow, that’s awesome.

But, sometimes I wonder if that’s not got to do with stressors just from low protein, ie, a temporary survival trait.

For instance, Peat says if you eat much more sugar than protein, you will eventually elevate serotonin, which is the chief hormone to other stress hormones like cortisol... so I can’t help but wonder if it’s the same misinterpretation of phenomena as when I did keto-carnivore, mistaking elevated cortisol and adrenaline as my testosterone getting fixed, which most lay-carnivores mistakenly believe is happening.

Ps, I went with a theory of breaking down macros of human milk for my diet (about 3 months); so, Closer to your current macro breakdown. And at some point in trying to fix my chronically elevated serotonin, I learned that tidbit from Ray. I can’t say my serotonin levels are a whole lot better yet, but a word of caution.

In my opinion milk is shifted towards protein for growth, so unless you are destroying your tissues by working out a ton or have a very physical job I'd be wary of the excess protein.