thyroid function and carbs

Thyroid Function and Carbs

What’s the link to thyroid function and carbs?

A massive one apparently!  Many of us seem to know little about this, until we undertake a low carb, Keto or Carnivore diet and our thyroid tanks, our metabolic rate declines, weight gain increases along with other issues and we’re left wondering why.

Delving into a pro metabolic diet for the last 8 or so years has enlightened me as to why thyroid function and carbs are so important and I’ve found an article that explains it perfectly – so our pro metabolic crew can learn as well.

It’s from a website called Chews Food Wisely…

“If you’ve been told to cut carbs to “fix” your thyroid, I want you to lean in for a second—because the truth is, the exact opposite might be what your body actually needs.

I work with women every day who are exhausted, bloated, constipated, foggy and stuck—despite following “clean eating” plans and cutting carbs in the name of health. Their thyroid labs might even come back looking “normal.” But they still feel anything but normal.

Here’s the thing no one is talking about: Your thyroid doesn’t just need nutrients to function. It needs fuel. And that fuel is glucose—the simplest form of carbohydrates.

The Carb + Thyroid Connection

Your thyroid is responsible for producing hormones that regulate energy, metabolism, body temperature, digestion, and even your menstrual cycle. But in order for it to work properly, the entire Thyroid Hormone Journey has to be supported:

  1. The brain’s ability to trigger the thyroid (signaling)
  2. The ability to make hormone (production)
  3. The ability of the body to carry thyroid hormones (transport)
  4. The ability to convert T4 to T3 (conversion)
  5. The cells’ ability to absorb thyroid hormones (absorption)
  6. The ability for cells to use those hormones (utilization)

Carbohydrates—especially from whole-food, nutrient-rich sources—support all three.

Let’s break this down.

1. Carbs Support Thyroid Hormone Production

Let’s start at the source: thyroglobulin—a protein that your thyroid uses to make hormones. What most people don’t realize is that thyroglobulin is a glycoprotein, meaning it actually contains carbohydrate. Without enough carbs, your thyroid can struggle to make adequate hormone in the first place.

And that’s not all…

The Na+/I- symporter—the transport system that brings iodine into the thyroid gland—is also glucose dependent. Iodine is one of the key raw materials for thyroid hormone production, but it can’t even get inside the gland without enough glucose in circulation.

Low carb = low glucose
Low glucose = poor iodine uptake + reduced hormone production

2. Carbs Are Essential for T4 ➞ T3 Conversion

Your thyroid mainly produces T4, but your cells need T3—the active form. That conversion happens in the liver, kidneys, and peripheral tissues. And guess what? It’s highly sensitive to stress.

Here’s what happens when carbs are too low:

  •  Blood sugar drops
  •  Cortisol and adrenaline spike to compensate
  •  Cortisol blocks T4-to-T3 conversion
  •  More T4 gets converted into Reverse T3 (inactive)

This is your body’s way of saying: “We don’t feel safe. Slow everything down.”

Symptoms of poor conversion + high Reverse T3:

  •  Crushing fatigue
  •  Brain fog
  •  Slowed metabolism
  •  Cold hands + feet
  •  Constipation
  •  Weight gain despite a “clean” diet

Carbs help buffer the stress response, stabilize blood sugar, and send a safety signal to your metabolism that it’s okay to use energy again.

3. Carbs Help Cells Use Thyroid Hormones

This part gets overlooked—even in functional medicine circles.

It’s not enough to have T3 available. Your cells have to:

  • Recognize it
  • Transport it into the cell
  • Use it to make ATP (your body’s energy currency)

That last part happens in the mitochondria, and it’s glucose-dependent. Without enough glucose, your mitochondria struggle to respond to T3 and produce energy.

So even if your labs show “perfect” T3, you can still feel hypothyroid if your cells don’t have the fuel to act on it.

Wait… So Carbs Aren’t the Enemy?

Exactly. The quality, quantity, and distribution of carbs matter far more than the outdated idea of “cutting carbs to lose weight.”

Quality Matters

Note: The type of carbohydrates this article recommends – I disagree with some of them because of the issues Dr Ray Peat outlined. Please see below… they say:-

Choose whole-food, nutrient-dense carbs that come with fiber, minerals, and color. Think:

  • Fruits: berries, apples, pears, citrus, kiwi, mango, melons
  • Root veggies: sweet potatoes, carrots, beets, parsnips, turnips, rutabaga, yuca
  • Starches: winter squash, peas, corn, plantains
  • Whole grains (gluten-free): quinoa, certified gluten-free oats, brown rice, buckwheat
  • Legumes: lentils, black beans, chickpeas
  • Dairy (if tolerated): plain yogurt, kefir, whole milk

Note: from this list the following are NOT recommended in a Ray Peat inspired Pro Metabolic Diet

Starches – 100% glucose, raise blood sugar & stress hormones too high, cause gut endotoxins

Grains – are starches, issues as above plus gluten issues

Legumes – are starches, also have anti thyroid properties

 

What carbs are recommended in a Ray Peat inspired Pro Metabolic Diet

Fruits – citrus & tropical mostly, any others depending on personal tolerance

Fruit-like vegetables – tomatoes, cucumbers, zucchini, capsicum, pumpkin, squash,

Root veges – as in first list with potatoes only sparingly and definitely not at the start of a pro metabolic journey or if insulin resistant

Fruit juices – especially Orange Juice,

Sugar – plain white, so long as rest of diet is highly nutritious

 

Quantity Matters

Most women with thyroid issues are eating too few carbs to support hormone function, especially earlier in the day. Under-fueling = over-reliance on cortisol = slowed conversion and metabolism.

Distribution is KEY

Eating most of your carbs at night or being wildly inconsistent sends mixed messages to your blood sugar and thyroid.

Better strategy:

  •  Include balanced carbs earlier in the day
  • Pair carbs with protein and fat
  • Keep them steady throughout meals and snacks

What Happens When You Don’t Get Enough Carbs?

Low or inconsistent carb intake leads to:

  •  Poor thyroid hormone production
  •  Blocked T4-to-T3 conversion
  •  Increased Reverse T3
  •  Reduced carrier proteins (like albumin + TBG)
  •  Poor hormone transport
  •  Low cellular utilization of T3

Translation?

Your labs might look normal, but you feel anything but.

The Big Picture

If you’re still:

  • Tired no matter how clean you eat
  • Bloated or constipated
  • Brain foggy with slow thinking
  • Cold all the time
  • Holding onto weight despite restriction

… it’s time to stop fearing carbs and start using them strategically.

When you give your body the fuel it needs to produce, convert, and use thyroid hormone, everything changes.”

 

Brilliant article on thyroid function and carbs, apart from some of  the carb sources, and explains EXACTLY why carbohydrates are essential to optimise thyroid function all through out the process.

ZEN Beach Diet

This is why the ZEN Beach Diet has over 250g of carbohydrates in it’s daily meal plan along with the balanced amount of protein and fats to optimise thyroid, hormones and health without unnecessary weight gain.

Read more about the ZEN Beach Diet HERE.

Join our Ray Peat Pro Metabolic Diet Facebook group HERE.

To our health,

 

Kristy

slimbirdy.com

bedtime snack

Bedtime snack. Yes or No?

In our private Facebook group, I asked the question – do you have a bed time snack?

Some said they do have one and some said no they don’t. For some, they advised the bedtime snack still didn’t help with sleep, yet for others it did. It just demonstrates how very different we all are.

Weight Loss not Sleep

The initial reason I brought it up was actually in the context of weight loss rather than sleep. The original post in the other RP group that triggered this topic was someone asking if —

…not having a bedtime snack, but ending your food consumption at dinner and elongating the non-eating window (ie longer “fasting” overnight) was helpful to weight loss.

My short answer to this is— yes it is helpful to weight loss, based on my experience. I will explain more on this later.

However one answer had me shaking my head. I wanted to explain more for those who may come across this supposed “rule” for a pro metabolic diet. If you blindly followed this, the likely outcome would be weight gain or the inability to lose weight.

The contentious comment

Her response was “ The only time for fasting is only when you sleep, especially as a woman. Never go to bed hungry. Always have a snack before going to bed, fruit with cottage cheese, orange juice, jello, milk with sugar (or honey, sugar works wonders though) In order to balance hormones, blood sugar must be steady and not letting it drop. While you sleep and not eat for 8-9-12h, your liver’s storage of glycogen gets depleted, cortisol and adrenaline rise=thyroid function is suppressed. Must eat before going to bed! You’ll feel much better. You’ll sleep better too!”

So let’s break it down. On the surface of it, most of what she is saying is correct. However as Ray Peat always said, context matters.

When a bedtime snack helps

In the context of a person coming off Keto, Low Carb or Carnivore with poor glycogen storage, who wakes up constantly in the middle of the night with a cortisol or adrenaline surge—then the advice to eat prior to bed is sound. This will likely help the person’s energy levels to get through the night with enough energy to sleep through and not wake up.

When a bedtime snack doesn’t help

However, if a person has restored insulin sensitivity, has good glycogen storage, finishes dinner at say 6pm and is only mildly hungry before bed at 10pm and sleeps soundly for 8 hours without having a pre bed snack, then the advice of “must eat before bed” is not correct at all. Eating before bed in this case, just because you think it’s a definite rule, would be most likely be counter productive to weight loss. It was for me.

Your meal at 6pm, depending on what you have, will take hours to digest and assimilate. It will steadily provide you energy overnight if you are healthy AND if you eat a decent sized meal and have eaten enough during the day.

This is why meal construction, macro & calorie balancing as well as meal timing are so important. You can read more about this in my pro metabolic guidebook here.

How much glycogen do we store?

When it comes to glycogen storage, the body can store about 100-120 grams in the liver which in terms of calories is 375 to 480 calories. This is what is used for blood sugar regulation at night.

About 350-400grams are stored in the muscles, but this is only for use when utilising the muscles. (This is why it’s important to use your muscles after eating, to help with blood sugar regulation by using and replenishing muscle glycogen stores.)

Knowing how much glycogen the liver stores above, it is interesting to see how much energy you use at night while sleeping…

“You use an average of 320 to 480 calories during 8 hours of sleep. This number varies based on your basal metabolic rate (BMR), which is influenced by factors like age, gender, body composition, and overall health. The body uses this energy to maintain vital functions such as breathing and circulation, with Rapid Eye Movement (REM) sleep requiring more energy due to intense brain activity”

So while you sleep, your body will utilise the energy it pulls out of your last two meals as well as liver glycogen storage as needed.

Bedtime snack composition

If you are having a bedtime snack then it should be high carb, moderate fat & low protein. This is because your digestion is slowest after sunset and eating anything high protein at this time, including cottage cheese, will put unnecessary strain on your body. This is why Ray Peat recommended traditional ice cream like a Haagen Daz Vanilla for example which is 3g protein, 13g fat & 16g of carbs. Eat this with fruit and you will be balanced perfectly.

For me, when I was recovering from Keto, I needed to eat like every 2 hours.  See the What I eat in a Day article, which was at the beginning of my pro metabolic journey. This included a bedtime snack because it’s what my body needed in the 2 years it took me to recover my insulin sensitivity.

Keto Recovery

When I recovered, I was able to space out my meals to 3-4 hours apart without feeling overly hungry or like I was going to pass out. I continued the bedtime snack for a while. But found I was putting on weight while doing this. So I stopped having anything after dinner, even if I was mildly hungry. The result was no interruption to sleep and weight started to reduce. I felt nicely hungry in the morning, which is what is supposed to happen when you are healthy and your metabolism is firing well.

So from the weight loss point of view, yes your bedtime snack may be hindering your progress. However, because we take a health first approach, tackling the glycogen storage issue and ensuring sound sleep first, is far more important than weight loss at that time.

It reminds me of something I heard once—you need to be healthy to be able to lose weight properly and for the long term.

Sleep specifically

Now the other issue that arose from people’s responses in this post were that some were saying a bedtime snack didn’t help their sleep. Or it helped at first, then stopped working. So I think a future thread needs to be about sleep specifically because poor glycogen storage may be only one issue that hinders sleep. There are many more that we need to list or touch on, so that people can explore different contributors to poor sleep, to see what may be their specific issue.

The health of your teeth & meal spacing

I’ve written about these before in these two articles— Tooth Sensitivity & Migrating Motor complex— and it’s relevant here too. Briefly, if you don’t have enough space between your meals, you are stopping the remineralisation of your teeth and the elimination process in your body. Please read the articles to learn more.

However if glycogen issues are the main problem, then the priority is to resolve that first. Once solved, the above two reasons are enough to stop to bedtime snack protocol, when you really don’t need it.

Also from the comments people have said, “I have orange juice, salt & gelatin by the bed to have drink if I wake up.” If they do this, I certainly hope they at least have some water by the bed to rinse their mouth from the sugar & acid. (Even better would be water with a pinch of salt or xylitol crystals to ensure your mouth returns to the right PH level.)

One of the worst things you can do is just go back to sleep with that sugar & acid sitting in your mouth. It will erode your enamel and lead to decay and cavities. In the daylight hours, it is your moving saliva that helps neutralise the acid and bacteria in the mouth but when you sleep, saliva production is decreased and it all makes it worse.

I hope this was helpful!

Remember nothing is an absolute rule. Understand where it’s coming from and why & make the best decision for your own body.

Always learning,

Kristy

blocks weight loss

What blocks weight loss?

What causes low energy and blocks weight loss?

We did a poll in our private Facebook group as to what health issues are still plaguing people, despite eating a pro metabolic diet. The highest two selections were weight loss and low energy, with some people ticking both.

This is not surprising as interestingly, these two issues are often inter-related.

I recall hearing somewhere that obesity is actually an issue of lack of energy—it may have been a Jay Feldman Wellness video. This seems like a crazy notion as the mainstream view is that a state of overweight is caused by excess food.

But if you are not creating energy efficiently from the food you are taking in, then you will suffer from low energy and likely store it as fat.

Let’s start at the beginning and see what blocks weight loss.

  1. The right energy-creating carbohydrates are essential

Under this category, all of the following are important…

A) Just having enough carbs total—like 260g of carbs per day and not just 50g— the body needs lots of energy just to carry out bodily functions, let alone any activity.

B) The right type of carbs—fruit, fruit juices, fruit-like veges—which are easily digestible and contain vitamins & minerals to help the conversion into energy. (More on this later.)

C) Not complex carbohydrates that take longer to digest (already low energy & probably have slow motility, so this will make it worse.) Not to mention too much fibre & likely starch, which will cause endotoxin in a slow moving body. Causing more issues.

D) Not avoiding carbs altogether like in Keto, Carnivore or Low Carb—making the body work too hard to convert fats or protein for the necessary glucose—this will constantly raise stress hormones, which will lead to more issues. I’ve heard many fans of these diets parrot “carbs are not essential.” This is true from a survival point of view, but not if your aim is optimal health.

If we are having enough of the right type of carbohydrates, then we need to…

Consider any ways the body is blocking the conversion of carbohydrates to energy

A) Digestion issues

B) Assimilation issues (gut health)

C) Liver issues (fructose processing & glycogen storage)

D) Insulin resistance/diabetes

E) Lack of intake of necessary nutrients to enable the conversion to energy

F) Intake of too many substances that block vitamin & mineral absorption – phytic acid, oxalates, lectins etc

G) Excessive stress

H) Any other illnesses/issues, like thyroid problems, inflammation, etc

Essential nutrients in energy creation

In our private Facebook group & on Instagram, I did a quiz asking if people knew what nutrients were essential for energy creation in the body & the choices were:

A) B Vitamins

B) Magnesium

C) Iron

D) All three

The answer was actually D—all three in that instance. The truth is however, that there are way more involved. This is why the nutrient-rich aspect of a Pro Metabolic diet is critical to it’s success and the Sugar Diet will never measure up.

So here is the total list of vitamins/minerals directly involved in energy creation: –

  • Vitamin A
  • All B Vitamins
  • Vitamin C
  • Vitamin D
  • Magnesium
  • Iron
  • Chromium
  • Zinc
  • Manganese
  • Iodine
  • Copper
  • Selenium

And when I look up others like Vitamin K for example, apparently they are not directly involved but have support roles.

This is why the certain foods are critical in a pro metabolic diet. It’s not about taking endless supplements. It’s making sure you understand which foods provide the above nutrients and to make sure you get enough of them.

An example of some of recommended factors…

Fruit, Juices & fruit-like veges— Vitamin C, range of Vitamin B (in oranges) & a range of minerals

Dairy—Vitamin A, some B, D & a range of minerals especially the highest source of calcium

Shellfish—Vitamin B12, D, A, Selenium, Zinc & a range of other minerals

Beef/Lamb— Range of Vitamin B, & a range of other minerals

Coffee—magnesium & other minerals

Beef Liver— highest source of Vitamin A, one of the highest sources of B12 & a range of other vitamins & minerals

Sunlight— at least 20-30 minutes daily gives recommended daily amount of Vitamin D—apparently no food source gives enough.

 

So if you are still battling with something that blocks weight loss or struggling with low energy, despite being pro metabolic for some time, become a detective in your own diet & lifestyle. Look into each factor above to see what you are missing or blocking. Do some experiments and see what makes a difference for you.

True health and clearing what blocks weight loss, is more complicated than most realise.

Dr Ray Peat actually knew all this, and we are so lucky he left us with enough information to point us in the right direction. Forever grateful.

Kristy x

PS: Get started on your Ray Peat inspired Pro Metabolic Diet today…

Zen Beach Diet

sugar diet issues

Sugar Diet Sugar Fasting Issues

Have you heard of the latest fad – the Sugar Diet or Sugar Fasting?

If you have, you may not have heard the Sugar Diet issues that go along with it!

In a Ray Peat inspired Pro Metabolic Diet, we are encouraged to eat fruit for carbs and even sugar for optimal health –  so that lines up with our beliefs so far – sugar is not the problem.

If you have already been following my ZEN Beach Diet version of a pro metabolic diet, you would already have lost weight, improved your health and wouldn’t need to search for other alternatives. You can find the guidebook here.

In these two different versions of a sugar diet though, critical changes and omissions are made. This demonstrates a lack of understanding of how the body works to raise metabolism without harm, and what is required to gain and maintain health, while losing weight for the long term.

Let me explain:

Continue reading →

red meat inflammation

Red Meat Inflammation. A Pro Metabolic way around it.

Do you believe the mainstream view that red meat causes inflammation?

Or maybe you have experienced the inflammation from red meat yourself, and now you believe it to be true and stay away from it as much as you can?

On this pro metabolic journey, I’ve found that unless you open your mind a little and as Ray Peat always said – explore the context around what is being said – then you may just very well miss out on highly nutritious food. As with so many other foods like coffee, sugar and dairy which are given a bad wrap, it’s often how you eat it, when and with what other foods that makes all the difference.

Continue reading →

migrating motor complex

Migrating Motor Complex & a Pro Metabolic Diet

Interesting side effect of meal spacing! Have you heard of the Migrating Motor Complex?

In our private FB group a while ago, I mentioned teeth & the Dr Ellie mouthcare system. I have been implementing a few things from her regime and made a surprise discovery.

Continue reading →