What Happens to Our Metabolisms and Hormones When We Diet? Interview with Dr. Layne Norton

Have any of you already accomplished one of your biggest life goals?  I’m talking about those top 5 bucket list items- backpacking through Europe, meeting your favorite celebrity, attending the Super Bowl… if you have, we want to hear about it in the comments!  A couple months ago, I accomplished one of mine.  When I first started studying fitness, nutrition, and athletic performance in college, I discovered the work of Dr. Layne Norton.  At the time, he had just earned his PhD in Nutritional Sciences from University of Illinois.  Just a quick background on Dr. Norton- he is a coach, professional powerlifter, natural pro bodybuilder, founder of his own supplement line, and well-known YouTuber and writer.  His trademark is debunking popular ideas that we have accepted for years in the fitness & nutrition fields by simply applying real science.  Once he started posting content on the internet, it did not take long before he became an industry legend.  His drive to extensively research, self-educate, ask questions, help others, and always speak the truth even when it’s unpopular and unwelcome… it all laid the foundation for the kind of coach that I would strive to become.  To say that I respect and look up to him would be the understatement of the year.

When I moved from Texas to Clearwater in 2017 and started this blog with Jenae, we both felt this calling to speak truth to our readers.  One theme we really wanted to focus on was hormone balance and the factors that disrupt it- dieting, birth control pills, toxic skincare and makeup, and more.  We decided to partner with several local doctors to conduct interviews and pick their brains on those specific issues.  Immediately I thought, “Dr. Norton would be the perfect person to interview about dieting’s effect on hormones,” and then it dawned on me- his home base is Tampa… 30 minutes away from where I now live.  I reached out to him right away, and he kindly offered to help in any way he could.  So guess what guys??  Jenae and I had the absolute pleasure of meeting and interviewing Dr. Layne Norton!  He was even more brilliant, kind, humble, and helpful than I had hoped.

Enjoy reading this enlightening interview, or watch the full video at the bottom of the post!  It was a very windy day (thus why I kept having to wipe my eyes), so I apologize for the poor audio!

K: We would love to know generally speaking, how our hormones respond to weight-loss and dieting (in the extreme dieting sense)

Dr. Norton: There’s a lot of different responses.  What you find is that the response to caloric restriction- basically controlled starvation– is what your body recognizes as restriction.  Depending on how severe that is is going to be how severe the response is.

If you look at what we believe to be the major regulator of your metabolism as far as hormones go, which is leptin– as you diet, your fat cells shrink.  When you shrink them, they send out less leptin.  Leptin is a hormone secreted by your fat cells.  When leptin gets lower, your hunger goes up, your metabolic rate goes down.  It also impacts other things like your reproductive system, libido so it’s kind of a master control switch of metabolism in terms of regulation.  Other changes:

  • Thyroid hormone drops
  • Ghrelin goes up- the function of ghrelin is to make you hungry
  • T3 will go down
  • Testosterone goes down.  For myself when I competed, I had my testosterone assessed.  I run a very high natural testosterone level.  Just dieting down for 24 weeks getting stage lean, mine was out of the normal range (being so low).
  • Cortisol goes up
  • Hormones responsible for sleep regulation- you will get disregulated sleep

Your body doesn’t really like for you to be very very lean, so it kinda responds in a way that would make you not want to be very very lean.

If you’re just looking to lose a few pounds, is this something you really need to worry about? But if you’re someone who has been dieting for a long time, or you’re a chronic yo-yo dieter, then you’re probably going to be looking at some of these things to be happening more often.

K: So for someone that is looking to just lose a few pounds, what are some ways they can avoid these detrimental effects happening?

Dr. Norton: Make sure you don’t get caught in the cycle of yo-yo dieting. When you diet, you tend to lose lean body mass and fat, but when you gain it back, you tend to gain all fat, and you tend to gain your fat mass in your trunk as opposed to your extremities- especially if you regain it quickly.  There is some data that shows if you diet and regain it very very quickly, you produce new fat cells.  There is a range of body fat that your body likes to be in normally.  Leptin tends to be a thermostat.  As you lose body fat, you secrete less leptin.  The problem with regaining weight and putting on more fat cells is that now you’re back to your previous fat mass, but now the individual cells are smaller, because there are more of them. Leptin secretion is sensed by the size of the fat cells, so you’ll still feel like you’re in a deficit.

If you’re just looking to lose a few pounds- focus, get it done, and focus on the actions that will keep it off.  Most people regain all the weight they lose.

  • Within a year of weight loss, 70% of people will regain all the weight they lost
  • Within two years, it’s 85%
  • Within three years, its 95%

Of those people, 1/3-2/3 will add more body fat than they originally started with. So what that says is you were actually better off before you started dieting.

Weight loss can be successful, but only about 5% of people are successful. If you look at what makes someone successful:

  • They don’t yo-yo diet
  • They’re consistent
  • They practice some form of self-regulation, whether it be calorie counting, weight-watchers points, macro tracking, time-restricted eating, whatever it is- they’re doing some form of cognitive restraint
  • They’re doing it in a way that is sustainable for them


The problem with most people is they diet in a way- think about the fad diets, whatever Dr. Oz is promoting this week, the hCG diet, keto diet, intermittent fasting- not that any of those diets are inherently bad in and of themselves, but if can’t sustain that style of dieting, if you can’t see yourself doing it for the long term, it’s not going to work.  Once you go back to doing what you did before, you’re just gonna put it all back on. Really you have to focus on modifying your behaviors and habits. 

My friend SoHee Lee, she’s doing a Masters in Psychology with an emphasis on eating habits. I went to stay with her for a few days in Arizona, and she noticed my habits. She cooked banana bread and some other high calorie things. I never declined any of that- but my default for my other foods is I had egg whites for breakfast, and I used the low calorie butter spray.  By doing that, I allowed myself more flexibility to have those things that she was also cooking. So that’s an ingrained habit for me, and tracking is a habit for me, because I’ve done it for so long and it doesn’t take much out of my day.  You have to focus on those habits because will-power is not enough.  There are tons of studies to show that will-power alone is not sufficient to make big difference in your lifestyle, because that is a finite resource.

Trying to focus on lifestyle and habit change and stuff that can last for the long-term vs just saying “I can stick to this. I know it’s no carb, no fat, all protein, with whatever supplement is being promoted… but if I can just get through these 10 weeks, I’ll lose those 15 pounds.” Okay but what after that?  Once you stop doing that, you’re just gonna regain and be back in the same place or based on the data, probably worse.

J: Practically speaking, what are some other changes that we can look for in our bodies that can alert us that to check that out (negative metabolic and hormonal changes as a response to dieting)?

Dr. Norton: Yeah if you’re having difficulty losing weight on pretty low calories, that’s a sign that you might be having quite a bit of metabolic adaptions and hormonal adaptions. Also mood perturbations- that’s pretty common in the literature.  I can speak to this- I was not exactly a joy to be around when I was that (stage) lean.  Light-headedness. When you’re whole day revolves around food and when you’re gonna work out- that can be something totally separate, kind of OCD mental disorder.  If we look at something like anorexia, that’s kind of a form of OCD- it’s just a control thing.

I would say over 60-70% of people at some point have had some kind of abnormal relationship with food.

That tends to be the norm because we’re told in the media- “this food is bad, this food is bad…,” and if you went through and watched every Netflix documentary, you would walk out and say “Okay I can breath air, and I can drink like mountain purified water- I think, and maybe I can have a little bit of coffee.”  Unfortunately, this leaves the generally public completely confused about what to do.  Having a background in nutrition, I can sift through what’s BS and what’s not.  I don’t envy the average person, because keep in mind, documentaries and news agencies- they’re just trying to get headlines.  They don’t really care about the truth. They care about what we’re selling, because at the end of the day they’re for-profit and have to put money in the pockets.  For the average person, that means a lot of information gets mis-conveyed.

K: Just to wrap things up, you’ve probably walked hundreds of clients through reverse dieting.  Would you recommend that as the best approach if you’ve found you’ve had metabolic and hormonal adaptions to dieting and need to get yourself out of it?

Dr. Norton: Just to clarify, a reverse diet is a method of adding in calories slowly to get the opposite adaptations- to make your metabolism faster- so in the future, hopefully you have a more effective weight-loss platform.  For just a practical perspective, once I started talking about this stuff in 2013- and this is not a knock-

I have never met a girl who at some point didn’t call herself fat

It really is a disturbing thing, and I think that y’all would agree with me on that. So I think that the idea of not dieting is hard for a lot of women in particular.  They tend to have such an extensive dieting history, that is their default.  Over time, you are telling your body that you’re in a caloric deficit and need to be thrifty with calories.  The goal of your body is to keep you alive long enough to pass on your DNA.  It doesn’t care about you having abs.  If you’re always telling it “food is scarce,” it is going to adapt to keep you alive, which is slowing down your metabolic rate so you don’t burn through everything.  The reason we’re all sitting here today is because our ancestors were the ones with the slower metabolisms.  When famine hit, guess who died first? The lean people with fast metabolisms. What’s great for looking good on the beach isn’t really great for survival.

The idea of reverse dieting is to introduce the body to “hey food is not scarce anymore.”  Someone who has been dieting for a really long period of time- it may take a really long reverse diet.  I’ve had cases where people took years to get back to normal.  My goal is to get people to be able to lose weight on a healthy amount of calories- something that is not so disruptive to the lifestyle.

I do think, as of now, until pharmacy catches up or our knowledge increases- I’m actually working on designing a reverse dieting study here soon so we can learn more about it- but until that catches up, I think this is a good option for those people.  With the understanding that it’s not magic and it may take a long time.  I wish I had better news, but trying to get a quick fix to change out genes- it’s going to be difficult.  Obesity really started about 60 years.  Our genes didn’t drastically change in 60 years.  There is something we’re doing, whether it be activity, overconsumption, both, environmental factors possibly… that is causing this trend.  It’s going to be interesting to see what research comes up.  I think we’re going to find out a lot in the next 10-12 years.