Earlier this year I released a YouTube video entitled “Keto Wrecked My Thyroid and My Metabolism”. I don’t have a link for it because I unpublished it. I also unpublished the accompanying blog posts and social media posts. Because I was wrong. Stress wrecked my thyroid and metabolism.
I thought that keto had wrecked my thyroid and metabolism but the actual problem went much, much deeper than that. Keto seemed like the obvious culprit but with everything, what it seems on the surface doesn’t add up once you look a bit deeper.
I was wrong about keto. Wholly wrong. Keto did not damage my thyroid or metabolism. Stress wrecked my thyroid and metabolism.
Read on to find out how I got it so wrong and what I am doing to fix it.
How it went wrong
I started on a ketogenic diet back in 2016. I weighed 120kg and I had been morbidly obese for decades after starting to gain weight around 8 years of age.
I was at the end of my rope having tried every single diet out there and failing spectacularly on them. I always lost a few kilos before putting back on even more, despite sticking religiously to the programmes.
I got so desperate I started to research bariatric surgery. This led me to nutritional ketosis and so I began my new regime. Keto worked so spectacularly well, I truly believed that I had found my panacea, my magic pill.
This was the thing that had been missing for all of these years. I was completely intolerant to carbs and stored them as fat when I ate them. Once I got my carbs consistently below 20g, the weight literally fell off me.

Fasting is better … right?
After a year and a half on keto things slowed down and I stopped losing at 71kg. That is still an impressive weight loss of more than 45kg but I was not happy because I was still in the overweight category. As my weight loss slowed and eventually stopped I tried literally every trick in the book to kick start it again.
So in comes fasting. I started to skip breakfast every day. It felt really good and I was high on the fact that I could go for so long without eating. I was just like the people I had always envied. Those naturally slim people who “forget to eat”. I think I went without breakfast for almost 2 years.
For someone with hypothyroidism, this is NOT a good thing to do every day. Especially skipping breakfast. For women, and especially for women with hypothyroidism, skipping dinner is better for us.
Occasionally skipping breakfast is ok but not every single day. Eating two meals a day is ok as long as you are getting enough nutrition and calories. I wasn’t. I was skipping breakfast and not eating enough in my other meals. It was a recipe for disaster.
The red flags I ignored
By the end of 2017, I had come off my thyroid medication that I had been taking to treat hypothyroidism. I came off of it because I was feeling really good and thought that it was time to wean myself off and see what happened.
I started to notice that I was feeling cold a lot but put it down to the massive fat loss that I had experienced. The fact that I had lost all of the insulation had left me feeling the cold more than usual. It was a red flag that I missed.
Despite being a qualified nutritionist and health coach, I didn’t feel the need to investigate further which led to my eventual issues. I made assumptions and was willing to put up with feeling cold and a bit tired as long as I was still losing weight.
I was so desperate to finally get into a healthy weight category, I started to cut everything. Carbs and calories.

Thyroid problems
Throughout 2018 and 2019 I slowly gained back about 6kg and ended up at around 77kg. Then my weight fluctuated between 75kg and 79kg, no matter what I did, which was hugely frustrating. I tried everything I could to get it moving. Then in 2019, I was feeling cold all of the time , I had no energy and I noticed that some of my hair was falling out in the front, so I decided it was time to see my doctor.
My TSH (Thyroid Stimulating Hormone) came back at 8 mU/L. Just to put that into perspective, if you are seeking fertility treatment they won’t touch you until your TSH is under 2 and the clinical range in Switzerland is 4.78 mU/L at the top end.
For most women however, the range is arbitrary. You feel it when you feel it, not at some predefined level. Personally I start to feel the effects physiologically when my TSH gets to 3 mU/L. Technically below the top range but too high for me. So I went back on Levothyroxine (synthetic T4).
No more weight loss
But weight loss didn’t follow when I started the medication again, as I had expected. So I cut my calories right down to 1200 and tried to eat as low carb as I could. My weight still crept up. No matter how little I ate, no matter how much exercise I did, the scale stubbornly either stayed the same or crept up little by little.
I started to look for reasons in the food I was eating. Maybe something else could work. I tried Carnivore diet, Ted Naiman’s P:E Diet, longer term fasting and nothing worked. At this point I should have realised that I had pushed my body too far and the weight wasn’t coming off because I slipped into starvation rationing. I was eating around 900 calories a day.
The big stressors
In January 2021 I had the first of two major surgeries to remove loose skin. On the morning of my surgery I was 79kg. I went into the surgery 28 hours fasted. It was a crazy thing to do. It was a huge procedure and I am prone to bleeding so after the surgery I was losing too much blood through my drains. That meant that I needed two blood transfusions as my blood pressure was very low.
The stress on my body was immense. Despite taking 7kg of skin from my body, after the surgery I was 82kg. I knew that there was swelling and local inflammation which was a part of the healing process. But once the healing part was over, my weight stayed the same.
How could it be that they had removed 7kg of skin yet I was up at 82kg and staying there? I couldn’t understand it. In hindsight, of course I know that it was the physical and mental stress, but at the time I thought my body was betraying me.
How could I be still gaining weight when I was hardly eating and skipping breakfast every day? In the year following my surgery, my weight stayed the same at around 82kg on average.

Was 4 years on keto the problem?
I created my own weight loss program Protein Priority Diet. It was still low carb but not necessarily ketogenic at that point. I wanted a program that reflected research showing how much more protein we need and should be eating. This is more than the recommended amount.
I put it together for myself at first and I lost 4kg but within 6 weeks it had come back on. Protein Priority Diet was having huge success with other people who joined me on the plan but despite an initial loss of about 4kg, it went back on even though I hadn’t changed what I was eating.
I was feeling a huge amount of pressure to lose weight because that was literally my job. To help people lose weight on low carb diets and to get healthy. How could I show up every day and do that when I couldn’t even do it for myself?
I felt like a total fraud even though I was eating right. I found my way to a group of women saying how bad they had felt on keto and how their thyroid had tanked on it and I thought, YES THAT IS ME!!! Maybe I finally had an answer.

Yes, this is me!
As I uncovered the link between cortisol and thyroid hormones, I started to put together the pieces of the puzzle. Keto increases cortisol and high cortisol stops the thyroid working properly. I thought that this was the answer.
I whipped out my camera and made a YouTube video about it (since deleted because it was wrong). Within hours I had more than 200 women saying OMG YES THAT IS ME!!!
Many well known keto figures reached out to me to say that there is no mechanism by which keto by itself could impact the thyroid and that I had to be missing something.
You don’t need very high cortisol for ketogenesis (the creation of ketones). So clearly I was missing something. There was a big fat elephant in the room waving frantically at me, and it wasn’t keto.
Maybe it’s not the carbs
As I researched I found more and more nutritionists and weight loss experts saying how you don’t need to remove carbs to be healthy and that you should be eating carbs for good hormone health (confirmation bias). What I failed to notice is that these women were all lean. Naturally lean. They had done keto and fasting and tanked their hormones and thyroids. But they were missing the big fat elephant too and they were blaming keto.
I decided to follow their advice and reintroduce carbs. I felt ON FIRE. I felt so good, so healthy, so vital, I felt high. The first two weeks were amazing. My energy was through the roof, my skin glowed and I felt healthy for the first time in years. I figured that I had found the answer.
The advice was to increase calories and carbs. I was eating about 1800 calories a day and around 60g to 80g of carbs. So not a high carb diet by any means.

Back on the blood sugar rollercoaster
Then the problems started. I started to have hypoglycemic attacks after eating. I know that physiological insulin resistance happens on keto but after a month, my body should have adjusted to manage the extra glucose. It didn’t.
I was still badly hypo after some meals. And my weight had increased dramatically and the day I stepped on the scale and said 89kg I knew that something was drastically wrong with what I was doing.
After spending significant time crying at the sheer frustration of my situation I dusted myself down and decided to go back to basics. Relearn everything I knew about keto. I read the books, I read the studies, I dove into how the thyroid works, how the liver interacts with it and how cortisol levels play a role in metabolism.
The word that came to me over and over again was high cortisol which is caused by stress. Stress interferes with every single system of the body. I asked myself “could stress be the thing that is causing all of this, not the small amount of cortisol needed for ketogenesis?”
The stress that wrecked my thyroid and metabolism
So I made a list of all of the major stressors in my life since 2017:
- Rapid weight loss (45kg in 18 months)
- Stopping thyroid medication
- Severely restricting calories
- Fasting too much
- Not eating enough after fasting
- Skipping breakfast every day (bad for hypothyroidism)
- Exercising while fasted
- Drinking caffeine while fasted
- International move to a country where I didn’t speak the language
- Gallbladder attacks that hospitalised me twice (once for a week 9 days before Christmas!)
- Gallbladder removal surgery
- Skin removal surgery 1
- Blood loss and anaemia from surgery 1
- Skin removal surgery 2
- Running my own nutrition practice with live weekly coaching sessions
- Going through all my weight struggles publicly
- The stressors of needing to look slim to be a keto nutritionist for weight loss
With a list like that you might wonder why the I didn’t realise that stress wrecked my thyroid and metabolism, not keto. As you can see I haven’t put keto as a stressor because its contribution to higher cortisol is actually negligible. You don’t need high cortisol to produce ketones, some cortisol yes but not high. However if you already have high cortisol due to other stressors, then it doesn’t help.
What you need to do is tackle the other stressors, not stop doing keto. Stress was the culprit. Stress wrecked my thyroid and metabolism.

Full circle back to keto
My answer wasn’t to reintroduce carbs, my body is wholly carb intolerant as I found out by the rapid and pretty spectacular weight gain I experienced when I reintroduced them. I tipped the scale at 89kg after reintroducing them.
Once I cut back down to 20g total carbs, my weight came back down and as of writing this, I am at 83kg and losing consistently, if a little slower than I would like but I will take it!
I feel so much better now. I have less hunger, no hypoglycemia and no wild energy fluctuations.
To fix my metabolism, I needed to deal with all of the other stress in my life. I had to stop the weekly live coaching because it was burning me out. So I shut down my Protein Priority Diet membership (you can still buy the program) and stopped posting on social media.
I spent all of August and September 2022 literally doing no work. I walked every day, I swam, I read books, I listened to music, I did my crochet and I watched movies.
The stress of public weight loss
Being a weight loss coach on a public platform while trying to figure out my own weight loss puzzle was probably the number one culprit for stress for me. Put so much pressure on myself.
I needed to remove myself from the public eye so that I could actually figure this out for myself without that added pressure and without the constant questioning of my own weight struggles.
One comment on YouTube was actually someone betting how long it would take me to regain all of the weight I lost. Imagine how sad and unhappy that person is about their own weight loss.
It’s not that I needed to hide anything. You have all been with me through the ups and downs. On my YouTube channel I have talked openly about my struggles to get to a healthy weight.
Including discussing what things I had tried to fix the problem. I didn’t know that it was a toxic diet based restriction regimen because even the other keto experts told me to “keep going”.
I was wrong – keto didn’t wreck my thyroid or metabolism. Toxic dieting did, stress did. Eating far too little for too long in an attempt to get to my lowest weight.
I stressed my body with low calories, fasting daily (bad idea for hypothyroid women), surgeries, fasted cardio and all the other ways that raised cortisol in my body, blocking proper metabolism.
When I asked so many keto experts and their message was always the same, cut down more, cut out more, do more fasting, do more exercise. Nobody, at any time, asked me “are you actually eating enough?”
Toxic Diet Culture
Toxic diet culture says we need to eat less and move more. That is what causes weight gain. If you have been dieting (conventionally) for decades then you know this. You are probably heavier now than when you started dieting in the first place. This is because of the big fat elephant. Stress wrecked my thyroid and metabolism because of the pressure from toxic diet culture and restriction.
So the big fat elephant in the room is restriction. Restricting calories daily never works long term. Especially for women and even more for hypothyroid women. Ultimately that is what we all did on keto, pushing ourselves further tracking only the number on the scale as our definition of success. I would bet that the majority of people who commented on that video saying “ME TOO” had been in long term calorie restriction and/or chronic fasting without balancing out calories and nutrition afterwards.
Learning from stress that wrecked my thyroid and metabolism
Keto doesn’t suit everyone, we know that. Some people are able to stay lean and healthy whilst eating carbs, but some of us do not. Especially those of us who fatten easily, just like me. We do better on low carb and ketogenic diets. There we must stay, to be leaner and healthier than we would be eating carbs.
However, if we have high stress in our lives then we need to make doubly sure that we are eating enough and not skipping meals at the wrong time of day or restricting so much that we add to that physical stress.
This has been a huge lesson for me. I thought I was doing the right things, I thought I had not been influenced by toxic diet culture but it got me. It was still there, ingrained in my psyche. But stress wrecked my thyroid and metabolism, not keto. Stress from too much restriction.
It wasn’t until my body protested loud enough that I stopped to listen. I was thoroughly burned out trying to tackle my own weight loss and keep up with the behemoth social media beast. Doing anything publicly isn’t easy and this was too much pressure for me. I had to walk away for the sake of my health.
The future is keto
So I am keto and there I will stay. For me, going forward, my measurement of success will be health markers. I will be asking myself questions like “how do I feel?” and “what is my energy like?”. Looking at other health markers like sleep quality and 6 monthly blood tests to check thyroid function. We know that weight does indicate your health status but if every other health marker is good then a bit of extra weight is not necessarily unhealthy. So I will not stress about it.
For those who will say “You’re so flaky Christina” I will just say this. Prof. Tim Noakes tore the pages about the importance of carbs out of his book The Lore of Running. He stood up and said he was wrong. I am doing the same. Why would you want to take advice from someone who isn’t open to searching for more answers or doesn’t question mainstream advice, even if that advice comes from the so called experts.
I will always be learning, always looking for ways to improve the service I give to clients and to apply to myself and my family. If this still seems flaky to you, it’s ok to stick with your doctor who went through medical school 30 years ago. Science doesn’t move on that quickly … right? And it’s almost never wrong … right?