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How Your Diet Affects Hormones

The epidemic of obesity is also an epidemic of hormone malfunction, including thyroid, testosterone, estrogen, growth hormone, cortisol, and more.

If you eat a diet full of seed oils, your hormonal systems may not communicate properly for reasons that have to do with a chemical disruption called oxidative stress. This disruption promotes inflammation, and it has an effect not unlike accelerated aging.

The Standard American Diet (SAD) Can Make Hormone Levels Drop, Including Testosterone!

A low-carb diet proponent who’d lost 180 pounds following a low-carb diet, contacted me about his revelation that in spite of his success with weight loss, his reproductive hormone levels were not up to full capacity. Salivary hormone testing had recently picked up a low testosterone level that was not obvious on blood testing done one year before. To treat the newfound problem and hopefully improve his wife’s chances for a successful pregnancy by improving sperm quality, his doctor started him on a very conservative (read “as safe as possible”) course of hormone therapy.

I suggested that, while the hormone therapy may help to improve one of the functions of his glandular system, it will not get to the root of the underlying cause of his complex glandular imbalances. Other factors would need to come into play to get his gonads whipped into shape (ouch! … maybe not the best way to put that, sorry, guys!). Here’s why:

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Kobe Bryant

It helped. I feel great.

"It’s helped. I feel great."

Kobe Bryant
NBA baskeball player
megyn kelly

This has been life changing

"Let me tell you this has been life-changing. I have all of her books, in audible and ebooks! I have gotten rid of all the hateful 8 oils. I have trained my body to eat its own previously toxic body fat. Download that pod it's a game changer!"

Megyn Kelly
Jesse Watters

Life changing

Deep Nutrition changed my life.

Jesse Watters
Fox News Primetime host

Saved my life

I would like to thank you for literally saving my life. Back in February, I had to be hospitalized while on vacation in Phoenix with an A1C of 11% and had to start taking 2 types of insulin and 2 other meds. I read the Fatburn Fix in April, and followed the program to a tee, and I’m down by 15 pounds, 6.8 A1C, and only one once weekly diabetes medicine. Prior to reading the book, it was almost impossible for me to lose weight as a diabetic. 

Leontyne Tompkins

I feel free

For the last month, I have really been reading all labels on everything. I have completely remove those 8 oils you talk about. I must tell you, I feel great! I have more energy and I am now 197 lbs (have always been around 205 to 210lbs). I eat potatoes with real butter, grass fed steak, pasta with the right toppings. I eat everything! I seem to crave less sugar. I love it! 

Robert Kirkendall

I feel so much better

I had terrible aches and pains everywhere in my body, my hands, shoulders and knees. I feel so much better and the way I feel is motivating me every day! Thank you

Mike Deb Wootan Burcin

Better than ever

I am an anesthesiologist in Orlando and a huge fan of both of your books! I have been incorporating your principles for the last 10 months and feel that my health is better than ever.

Marnie Robinson, MD

My allergies disappeared

The biggest difference for me (and a surprising one) is that my allergies have almost completely disappeared! This is a big deal for me, because I’ve had allergies most of my life and they have often affected what I do which is a teaching music in [a public school district].  In general, I feel much better and have more consistent energy throughout the day.

Erica Turrell

Heart Palpitations have Stopped

I’ve lost 20+ pounds (also fasting 16-24 hours daily) and haven’t had palpitations except for one occasion — I had a mini bag of Fritos for the first time in July. And, I feel better now on a daily basis than I ever did all through college.

Mike Wright
Deep Nutrition and Fatburn Fix reader
Mitzi Wilkinson Champion

I’ve lost over 50 pounds

I’ve lost over 50 pounds. I’m 56 years old. Cutting processed food and unhealthy fats from my diet was one of the first things I did on my health recovery journey...I went cold turkey off the bad oils. Emptied my pantry into the trash and just started eating real food

Mitzi Wilkinson Champion

Knowledge I didn’t know I needed

Your Fatburn Fix book is amazing, my friend. Thank you! I’m an Functional Nutritional Therapy Practitioner and I know my stuff. This is the extra layer of knowledge I didn’t know I needed. Well done!

Jennifer Dillman
Fatburn Fix reader

Lost a solid 20 lbs and my bloodwork is great

I have lost a solid 20 lbs and my bloodwork (after 3 months of eating your way) was even better! I was metabolically healthy (per your book) before I read your book, but barely. Lowering my weight, sealed the deal! I have been talking about you and your book to anyone who will listen...Thank you for all you’ve done and what you continue to do! You are changing lives for the better!

Missy Cramer
FatBurn Fix reader

Lost 20 lbs I could never shed

I love your Fatburn Fix!  Has helped me so so much!  I have had the dreaded weight all my life - 20 or so pounds I could never shed.  I have lost that now. I only eat 2 meals a day lunch and dinner with a glass of milk or cappuccino around 4 to hold me over. No snacking and not bad oils.  It has been the key to unlocking my fatburn.  I work out in the am and believe I am burning fat for energy not from food!

Lauren Smith

I feel great

My waist is four inches smaller. I feel great and many of the minor aches and pains that I had (knees and lower back) are gone. Also, my muscle tone is amazing, even though I have not increased my workout routine.

Richard Janelle
Completed Dr Cate's online course
Kent Matthes

The go-to for strength and conditioning coaches

Whenever I advise my clients about eating to perform I go straight to what I have learned from Dr. Cate. Her book Deep Nutrition has become the go-to for strength and conditioning coaches across the country.

Kent Matthes
Major League Baseball Agent with WME Sports
Ken D Berry

Dismantles the lie

Dr. Cate dismantles the lie that seed oils are healthy, which may the biggest lie about nutrition and health because it’s so insidious.  

Ken D Berry, MD
Author of Lies My Doctor Told Me
Dr. Drew Pinsky

She knows the chemistry

Dr. Cate alerts us to the harms of seed oils and she’s convincing because she knows the chemistry better than anyone.

Dr. Drew Pinskey, MD
Globally recognized internal medicine and addiction medicine specialist, media personality, LoveLine Host, and New York Times bestselling author
Kelly Starrett

No one is better at communicating nutritional truth

Dr. Cate has had the single greatest impact on how we talk to people about fueling for both performance or durability. While we all are a little unique, the foundational principles of human nutrition are immutable. If you are looking to create a more durable, resilient body, no one is better at communicating nutritional truth than Dr. Cate.

Dr. Kelly Starrett
Physiotherapist coach and New York Times and Wall Street Journal bestselling author
Brian Lenkzes

Highly recommend The Fatburn Fix

Dr. Shanahan has had a significant impact on my practice of medicine. I am known as a Low Carb Doctor, but I never really appreciated the negative effects of processed seed oils on the health of my patients. I highly recommend The Fatburn Fix to my patients and have a loaner copy in my waiting room. It is amazing how quickly blood sugars and overall health improves with cutting seed oils. It is not just about the carbs!

Dr. Brian Lenkzes, MD
CEO of LowCarbMD San Diego, co-host of Low Carb MD Podcast and host of Life's Best Medicine Podcast
Chris Kaman

Respected in the sports world

Dr. Cate reordered my diet when I was with the L.A. Lakers, and the benefits, for me personally, were felt immediately and have served me to this day. I’ve come to take real food so seriously I started a small family farm. I know of no M.D./nutritionist more respected in the sports world than Dr. Cate Shanahan.

Chris Kaman
NBA Player
Mark Sisson

Brought seed oil issue front and center

Cate brought the seed oil issue front and center. Healthy fats matter. So much so that I created an entire product line to swap out bad fats with good.

Mark Sisson
Founding Father of the Primal/Paleo Movement
Dallas Hartwig

Optimal health starts with food

If you want to understand how optimal health starts with food, start with Dr. Cate. Her book Deep Nutrition leaves you with an appreciation of the profound relationship between our genes and the planet, inspiring us to be good shepherds of both.

Dallas Hartwig
Attribution author of The Whole 30
Dwight Howard

Helped me with endurance

Deep Nutrition really helped me with endurance. I started to feel better as a player. I was able to run more, I was able to be more active …and I just decided to keep going with it to this day.

Dwight Howard
NBA Player
Paul Grewal

Silver bullet for me

Dr Cate’s teachings helped me lose 60 pounds like it was nothing. It was like a silver bullet for me.

Paul Grewal, MD 
Dr Grewal Internal Medicine, MD, author of Genius Foods
Joesph Mercola

Radically improve your health…

Dr. Shanahan has provided a solid reference that deserves a place in the library of anyone who is seriously interested in nutrition. Her perspective on the vital role that healthy fat has in our diet is novel and, if implemented, can radically improve your health.

Dr. Joseph Mercola
Author of Fat for Fuel and Founder of
Dave Aspery

Pull up a chair…

I have based my work on the idea that getting the right kinds of healthy fats into your body and avoiding the worst fats is essential to optimal health. I've interviewed dozens of the world's top experts about this, and I know of no one who speaks more eloquently on this topic than Dr Cate. If she’s talking fats, pull up a chair. Take notes.

Dave Asprey
Author of the Bulletproof Diet

The key to unlocking my fatburn

I love your Fatburn Fix!  Has helped me so so much!  I have had the dreaded weight all my life - 20 or so pounds I could never shed.  I have lost that now. I only eat 2 meals a day lunch and dinner with a glass of milk or cappuccino around 4 to hold me over. No snacking and not bad oils.  It has been the key to unlocking my fatburn.  

Lauren Smith

Saved my life

I would like to thank you for literally saving my life. Back in February, I had to be hospitalized while on vacation in Phoenix with an A1C of 11% and had to start taking 2 types of insulin and 2 other meds. I read the Fatburn Fix in April, and followed the program to a tee, and I’m down by 15 pounds, 6.8 A1C, and only one once weekly diabetes medicine. 

Leontyne Tompkins

> Tears of joy

 I'm crying tears of joy and appreciation for all you've done for me and my health! Without Deep Nutrition and Fatburn Fix, I would literally still be in the vicious cycle I'd been fighting all my life! In a nutshell - I am no longer a compulsive overeating addict suffering under the crushing 'thumb' of all food and alcohol.     

Penni Wicks


Three Diet Factors Can Undermine Hormone Function

The following diet factors damage your metabolism in ways that first cause hormone resistance and then often lead to weight gain:

  1. Excess carbohydrate, above about 100-150 gm per day (on the high end for men, low end for women)
  2. Unnatural fat, including hydrogenated oils and vegetable oils, falsely promoted as “heart healthy”
  3. Inadequate fasting, with frequent snacks and grazing prevents the hormones of fasting to do their job

In my twenty-plus years of clinical experience as a Family Medicine physician, I have learned to identify the subtlest, early signs of diet-induced hormonal problems associated with later-in-life health problems of easy weight gain, vascular diseases such as heart attack and stroke, and even diseases associated with aging such as osteoporosis, arthritis, and dementia.

Very often the first symptom to develop will be a need to eat to control ‘hunger’ symptoms like headaches, fatigue, irritability, shakiness, weakness, or nausea. I have also found that many young men and women, often still in their teens, with these symptoms are already on the road to developing diabetes as evidenced by an elevated fasting blood sugar level of 90 mg/dl.

Many people learn that sugar can promote inflammation and will start a low-carb, or keto diet. 

Some take a shortcut, and have resorted to hormone supplementation to treat problems like fatigue and weight gain, as well as hormonal imbalances including infertility, thyroid malfunction, andropause, menopause, and so on. But I encourage my patients not to rely on these supplementation programs.

Hormone systems are complex and interrelated, which is why supplementation does not always lead to the expected results.

With hormone supplementation, you can boost levels of the hormone(s) you are taking to feel better–for as long as you continue to take the hormones. But hormones weave a tangled web; there are numerous interconnected relationships and often your body doesn’t respond in the way you hoped. With diet, you can enable your body to regulate all of its complex hormone systems more efficiently and, in essence, even rejuvenate your biological clock.

With over two decades of clinical experience and expertise in genetic and biochemical research, Dr. Cate can help you to reverse metabolic disease and reshape your body.

Please note: Please do not share personal medical information in a comment on our posts. It will be deleted due to HIPAA regulations.

This Post Has 40 Comments

  1. I tested low on thyroid hormone for over twenty years. I’ve been on thyroid pills on and off with as long as 1 year brakes.
    I am and always was slim, had good metabolism, had no problems with my periods (they ended 13 years ago when I was 55).
    I exercise regularly, eat healthy foods with low carbs and healthy oils.
    Though, I used to have an eczema, constipation, and have dry skin and thinning hair.
    Is it possible to heal hypothyroid and stop taking synthroid?

  2. […] healthy paleo diet can help the body fortify its defenses. It can correct hormonal issues (thyroid, testosterone, estrogen, cortisol, etc.), it can prevent/correct gut damage/leaky gut […]

  3. I’ve noticed the comments about thyroid seem to focus on the excess weight often associated with hypothyroidism. Do you know of or suspect any diet/lifestyle contributors to hyperthyroidism? I’m wondering if there are any ways to correct this problem either with diet or lifestyle changes. I’m concerned about someone who is fighting a problem with runaway weight LOSS along with severe fatigue, unrefreshing sleep, high resting heart rate, among other things, all this after about a year of regular long distance run training while on the SAD. At first they were just really trim, but the sleep problem started recently and the weight loss has continued even after they were unable to continue exercising due to the fatigue. I’m very concerned. Their eyes were sunken when I saw them last and didn’t look like the person I’ve known all my life. I have limited influence since I’m not seen as an authority on nutrition or medicine, but if there is research about anything contributing to hyperthyroidism specifically or if it is addressed in a book, I’d be really interested. I’ve searched online but so far have found nothing. Everything I’ve found on sites like webmd say “The cause of hyperthryroidism is an overactive thyroid gland…” Sheesh, it’s like saying the cause of rain is precipitation.

  4. Hi Dr Cate,
    I’m a big fan of Deep Nutrition, and did a modified version (before i read it) and found the changes in my previous high carb/low fat over exercised body were extraordinary. Now in the past few years, and after discovering your book, I fell back into somewhat back habits (definitely lighter on the carbs though!) and a few failed pregnancies which threw my hormones and thyroid into a tailspin. I’m just now getting my thryroid back in shape but I’m stil experiencing the “apple” belly and a lot of hair loss which is depressing.

    I have cut back my frantic cardio to ballet-barre classes, so I think that’s helping, but have you seen any benefit to the 4 pillars with increased hair growth? I’ve lost about 40% of my hair, which wasn’t great to start,but had been in much better shape. I also can’t seem to lose an additional 6 pounds that popped up at the same time my thyroid went haywire and my hair loss started.

    Can your diet help with this? Thank you so much!

    1. I’ve heard from people who are enjoying 4-6 ounce of bone broths 3-4 days per week that it helps hair, skin, and nails. Trimming any excess carbs and eliminating pro-inflammatory oils is key to normalizing hormone function.

  5. Hi Dr. Cate,
    This question is slightly off topic but still relates to hormones. I had a miscarriage (D&C at the end of May) and want to start trying again in September. I’ve read your AMAZING book and have been sticking to the principles religiously i.e. broths, bone meat, rare meat, raw dairy and salads. However, growing up I consumed WAY too much sugar and tranfats and have always suffered with irregular cycles and mild acne. Anyhow, i’m digressing. Your book talks about 2nd child syndrome. I’m wondering how much time i should leave between the first pregnancy (which died at 8 weeks) and the next one?

    p.s since seeing a chinese dr and eating according to the principles my skin has cleared and i’ve achieved a 29 day cycle!

    Would love to hear your thoughts…


    1. Many of my patients have had good results from visiting herbalists. As far as the adaptogen theory goes, I am skeptical of all theories that do not appear to adapt as new discoveries arise.

  6. Hi Dr Cate,
    Just ordered your books and waiting for them to get here, so excited to read more! Question… so if Deep Nutrition is followed, will the hormones (hot flashes/postmenapausal,sleeping issues) go away? I have just started BIH about 3 weeks ago and havent had much relief yet, dont want to supp if diet will correct things. Thanks Dr Cate.

    1. I have seen diet changes have opposite results in different people. I suspect this is because hormones are subject to both positive and negative feedback loops. The good news is that even when women get hot flashes they feel fewer mood swings, and the hot flashes do improve w/ HRT and I suspect are short lived but when people feel better they don’t come back so I don’t always get the follow up!

      1. Well I guess I’ll see how it goes when I get started. Good thing they dont come back, means you are doing some good! Thanks

  7. Doctor C – Thanks for posting this! I am not overweight (I have always been around 115 – 120 lbs at 5′ 4″) but I have always struggled with menstrual problems such as irregular periods, discharge, yeast infections, & very low production of estrogen, progesterone, and testosterone. My family doc put me on bio-identical hormone replacement therapy about 2.5 years ago and I went paleo one year ago. I feel very out out of balance & decided yesterday to go without the hormones – any advice? Thanks!

    1. Getting your diet right is key, and while going Paleo is a great first step, there may be more you can do by carefully following a more fully fleshed out traditional diet as described in Chapter 7 of Deep Nutrition.

  8. What do you say to those who have concerns with their thyroid as a result of going paleo? What’s the best way to get iodine (I use celtic sea salt)? I have lost most of the hair on my arms/half from my legs and shed a lot every day from my head…to the point that our drains are plugging up. : ) Any recommendations?

  9. Hi all
    I’m still early in my semi-Paleo diet – i do all the things Dr. Cate recommends except i eat more carbs – sticking mostly to fermented whole grains and lentils or garbanzos, usually germinated. It has been very helpful to me, and that means a lot to me because i have a long-term chronic fatigue condition (not the syndrome).
    I commented under the ‘What’s for dinner’ section that i have for a while been fasting until 5pm every day, and then eating in the evening, up to 10 or 11 (just snacking by then). I started because from my continual observation of my own response to foods, i finally noticed that eating in the evenings didn’t make me super sleepy like it did during the day – not even carbs, which are usually by far the worst for that for me. (Various other dietary adjustments probably made it easier to detect that pattern.)
    My body most definitely responds differently to food in the evening than it does during the day. I can’t imagine having a breakfast like what i eat for dinner without it completely wiping me out for the rest of the day. Somehow, that difference has to be a hormonal thing, right?
    I just thought i’d tack that on here since most of you probably wouldn’t see that comment where it is. I have an atypical metabolism, so i don’t know how much my case applies to others. I don’t have any other ongoing health issues – i could stand to switch maybe 10lbs of fat to muscle, but i’m not overweight and have had only one or two short periods of being a bit heavy in the past.
    Perhaps i could over time move the period when i eat earlier into the day, even to the morning. Perhaps the fact that the evening works for me has to do with long-term habits, not anything essential about my body. But the results are consistent, and dramatic enough for me to be willing to not eat for 18 or 19 hours a day.

  10. The timing of your interview is great. There’s a popular real food blogger who just posted a huge article regarding how they’re leaving low carb to go high carb in order to balance their hormones. Nearing 500 comments now, people are certainly having a strong debate over there. Doesn’t it seem like a world gone mad? I don’t want to have to count this and that and measure out so much of this and take it at an exact time of day. It’s food! Just let me eat… I feel though, that grasping your four pillar concept is so much easier and allows for excellent health without excess thought. Fantastic! Anyway, I’m really looking forward to hearing “the other side of the coin”, as it were, on what you’ll have to say about food and hormones!

    1. Sabrina,
      Please tell us who it is. And please also do share our upcoming information with them in case someone wants to call in and ask questions.

  11. Hi Dr. Cate
    Thanks for sharing all this info!
    I have been eating the 4 pillars almost exclusivly now, and with amazing results, I feel so much better, I no longer need energy drinks to get through the day.
    I have so many questions, I wish you lived in my area, I would make an appointment!
    Do you do house calls over the phone?

    1. Hi Michael
      I would love to be able to help you. Please see the Make an Appointment tab and scroll down to the FAQ section: Do You Do Phone Consults?

      1. Cool! thanks Dr.! I better put together a list so I can keep the consult to under 30min. its pretty spendy, but worth it I am sure…

  12. I’m looking forward to your interview with Jimmy Moore — which happens to bring up an older topic. You kindly answered a question I posted several weeks ago regarding raw milk; the gist of the question concerning reports that patients taking a ‘raw-milk cure’ reportedly drank very large amount of raw milk (and its carbs) without accompanying weight gain. Since you’ll be talking with Jimmy, you might ask him about his tests on his own blood sugars levels after drinking various beverages, including raw milk. He wrote “Raw milk, despite having 12g carbs, saw a flatline glucose response.” If you’re interested, Jimmy describes his test at the following link (the raw milk result is about 2/3 of the way down the page.)’s-n1-experiments-atkins-protein-shakes/11363

  13. Hi Dr Cate,

    Thanks for another great post.
    I am just wondering if it makes a difference when these 2tbsp of carb are consumed i.e. if they are eaten all once or spread out so you have a very small amount with each meal?


    1. I’ve heard arguments that eating this or that macronutrient should be done at a certain time in relation to sleep. None are compelling, in my opinion.

  14. I sent Jimmy the following questions. Hopefully one if them will get asked but I wanted to post here so you know what might be coming.

    “In Deep Nutrition you say, paraphrasing,
    ‘Trans fat consumption interferes with hormone expression and daily infusions of sugar interferes with hormone receptivity.’(On my kindle it is listed at location 922, I don’t have a page #)
    In considering this could it be plausible that in the absence of trans fat (and mega trans fat) our bodies would be better able to deal with a higher carb diet? Could this perhaps help explain the French ‘paradox’?

    A second question if there is time

    In the LLVC interview episode 459 you discussed the phenomenon called apoptosis which is possibly the only way to eliminate stored trans fats. Extremely fascinating! You mention the importance of exercise and nutrition for this process to occur but didn’t go into details. Would you be able to expand on what type of nutrition is needed and if the type of exercise matters?”

    1. and by ‘french paradox’ I don’t really mean as it is commonly understood (what do you mean satruated fat doesn’t cause heart diesases?!?!) but rather their love of pastries… at least that is how I precieve it.

  15. […] Changing our diet can also help rebalance our hormones How Your Diet Affects Hormones: Optimizing Weight, Moods, and More | […]

  16. Dr. Cate, I loved your book and I appreciate you taking on the vital role hormones play in fat accumulation. Do you plan to discuss the role of leptin and insulin on fat accumulation? I didn’t see the endocrine effect from fat tissue in the diagram since leptin is secreted by fat. The figure is intriguing and helpful. I’d love to hear your thoughts on the importance of keeping leptin and insulin levels low via high fat diets, and how keeping these hormone levels low enables fat burning. Thanks also for teaching caution with regard to hormone replacement.

    1. The diagram represents only the tip of the iceberg of the known hormone interactions. Or biology is far too complicated for our limited probing to enable us to manipulate it effectively or intelligently from the top down, ie by artificially modulating our hormone levels. Far better to do whatever we can to limit interference in this natural ecosystem, and I plan to describe that aspect of my approach on Thursday’s program.

      1. Thank you for trying to put our complex endocrine system into perspective. If any one can do it, you can. Do you consider Vitamin D3 supplementation as a hormone replacement? I find it hard to get enough D through food and sunlight exposure in winter is limited for me.

        1. Hi Patrick
          D3 is one of the few supplements I recommend. It’s a hormone, technically, but our bodies have never made this hormone completely by ourselves. We either needed to expose our skin to it or eat it.

          1. Thanks for the response. The vitamin D council recommends 1,000 IU per 25 pounds of body weight so at 161 lbs, I’ve been taking about 5,000 to 7,000 IU per day.

            The only other hormone I’ve considered is Pregnenolone. Dr. Ron Rosedale, whom I also greatly respect, recommends 50mg/day for those who are over 50 and letpin/insulin resistant, due to research showing improved mood, neural, and memory function. What are your thoughts on supplementing with pregnenolone?

          2. I’m a minimalist. If you have sx and supplementing makes you feel better, that’s one thing. If you feel fine an want to prevent something, I’m not sure taking hormones is a great idea because you can end up suppressing normal gland function.

  17. erm Effects Of The High-Carb SAD Diet’ | Dr. Cate Shanahan | Jimmy Moore Presents: Ask The Low-Carb Experts says:

    […] studied ethnobotany and her healthiest patient’s culinary habits. She’s a big believer in hormone regulation and the impact diet plays on it and will be answering YOUR questions related to the long-term effects of eating a SAD diet. If you […]

  18. Yay! Finally someone to talk about the hormones and the dis-regulation without leading us to the alleged only solution of “Hormone Supplementation”.
    And of course it is you, Dr Cate who can step up to the plate and deliver the news, Mahalo nui loa!
    I look forward to the show you and Jimmy…Great Team!

    Aloha, Gina

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