I remember the first time I experienced a hot flash while I was keto. You may be thinking that’s kind of odd since I’m a male, but it’s quite common for many individuals, including males. While hot flashes are typical symptoms of menopause, there are other reasons yet to be understood about keto hot flashes.
Keto hot flashes are usually a result of dehydration, low blood sugar (hypoglycemia), or an electrolyte balance. Due to a keto diet's diuretic nature, you may be urinating more frequently, thus expelling vital electrolytes, especially sodium.
In this article, I’ll go into more depth about how keto may lead to hot flashes, what they are, signs and symptoms to look out for, and then how you can resolve these symptoms.
Does Ketosis Cause Hot Flashes?
Many people associate hot flashes with menopause.
I then ask, how would you explain a healthy 20 or 30-year-old female (or male) and someone that went through menopause a decade ago experiencing hot flashes?
And while the answer may not be so simple, these individuals all experienced these signs and symptoms of what could be described as hot flashes during the first few weeks of starting a ketogenic diet.
Coincidence? I think not.
There are varied reasons why you may be experiencing hot flashes when starting keto, and I’ll do my best to explain why this is and what you can do about it.
Before diving in too deep on the whole subject of hot flashes, many people feel they run warmer while following a ketogenic diet. There are generally two reasons why this happens:
- Thermogenic Effect of Food (TEF)
- Brown Adipose Tissue Stimulation
Specific individuals run so warm that they sweat more or sweat when they usually wouldn’t have. Can keto make you sweat? Keto can make you sweat through increased thermogenesis and activation of brown adipose tissue.
You may also experience more sweating, especially during the adaptation phase, which I described in another article.
Thermogenic Effect of Food (TEF)
Keto can make some people sweat through what’s referred to as thermogenesis or the thermogenic effect of food (TEF).Thermogenesis is generally defined by the dissipation of energy through heat, especially in the skeletal muscle and brown adipose tissue.
When we eat food, it takes a certain amount of calories to digest it.
Out of the three macronutrients, protein causes the most thermogenesis. You burn upwards of 30% of the calories from protein through digestion.
You may have heard of the term “meat sweats,” and now you know why… it’s a real thing.
Here is the TEF of the different macronutrients:
- Fat: 0-3%
- Carbohydrates: 5-10%
- Protein: 20-30%
Many people who follow a ketogenic diet will increase their protein intake, thus burning more calories through digestion, and generating more heat as a byproduct.
Brown Adipose Tissue
Ketogenic diets and supplements have been shown in studies to increased brown adipose tissue (brown fat). 1 2 Additionally, when white fat is exposed to ketones, white fat will begin to act more like brown fat.
Wait, isn’t that a bad thing?
Brown fat is a GOOD thing. There are two types of fat, yellow or white and brown. Brown adipose tissue, or brown fat, is one of the two types of fat that is considered the “good” fat.Brown fat is more metabolically active, and the central role it has in our body is to provide heat when we’re cold. This is why constant cold exposure, to the point you’re shivering, also works to activate this brown adipose tissue.
Some studies even show promise for brown fat to help treat obesity. 3
If anything, we want MORE brown fat, because brown fat can burn a lot more energy, thus helping you lose weight.
What Are Hot Flashes?
If you’re not merely experiencing extra warmth, and have sudden intense bursts of heat, possibly followed by the chills, then keep reading.
Hot flashes are sudden feelings of warmth (hotness), and usually most intense over the top half of the body, but especially the face, neck, and chest.
Symptoms of hot flashes include:
- Rapid heartbeat
- Perspiration, usually on the chest, neck, and face
- Chilled or cold and clammy feeling afterward
- Flushed appearance
- Red and blotchy skin
- Tingling in your fingers
How flashes usually come on suddenly, without warning, but how long they last will vary. Some hot flashes last a few seconds, while another hot flash may go on for 10+ minutes.
On average, hot flashes seem to last about 3-5 minutes for most individuals.
What Causes Keto Hot Flashes?
While the exact trigger of hot flashes isn’t precisely clear, most of the scientific literature seems to point at hormonal changes being a likely culprit.
There are other connections to health problems, such as diabetes, that are currently being studied.
A few things that may trigger hot flashes:
- Stress and anxiety
- Tight clothing
- Cigarette smoke
And who knows, maybe you just so happen to be going through menopause at the same time you decided to begin a ketogenic lifestyle.
Additionally, I’ve found that when people first begin a ketogenic diet, they are more susceptible to a few issues, but most notably:
- Low blood sugar
- Electrolyte imbalance
When first starting a ketogenic diet, many people often find themselves dehydrated, which leads to an array of negative symptoms, one of which may include “hot flashes.”
During the first couple of weeks on a ketogenic diet, people experience a rapid decrease in their weight. While some of this is fat, the vast majority of weight initially lost is due to water loss.
Stored carbohydrates (glycogen) in the body act like mini sponges, also holding water.
The average adult can house ~500 grams of stored glycogen, and for each gram of glycogen, an additional three grams of water is also stored.
When you limit carbohydrates from the diet, your body begins burning through these glycogen stores and also releasing the water that’s carried with it.
It’s not uncommon for people to lose 3-4 lbs of water in just the first five days of starting a ketogenic diet. This may be why you find yourself peeing more when first starting keto.
The electrolyte imbalance and dehydration kind of go hand in hand. Since you’re expelling a lot of water when first starting a ketogenic diet, you’re also expelling tons of electrolytes.
Since carbohydrates are out of the equation, sodium and potassium are even more critical for helping regulate fluid balance within your body.
Without replacing sodium and potassium, along with water, it’s almost like a feedback loop that keeps you in a constant state of feeling less than optimal.
This electrolyte imbalance is just another part of why you may be feeling less than optimal when first starting a ketogenic diet. Lack of electrolytes and dehydration is a significant cause of why people experience what’s referred to as the “keto flu.”
Low blood sugar
Lowered blood sugar is almost to be expected when following a very-low-carbohydrate diet, such as the ketogenic diet.
However, when the blood sugar gets too low, you may experience what’s called hypoglycemia.
Hypoglycemia is a condition that is a result of very low blood sugar.
How this plays out in the context of a ketogenic diet is that when blood sugar drops, ketone production generally ramps up. In a sense, you can say that ketones and blood sugars balance each other out.
High blood sugar = Low to no ketones
More ketones = Lower blood sugar
Now, when first starting a ketogenic diet, your body isn’t efficient and producing or utilizing ketones. This interim period, usually one to three weeks, is when people may experience hot flash episodes.
Blood sugar gets too low, and there isn’t an adequate amount of ketones to compensate…
Or you may have an adequate amount of ketones, but your body just isn’t efficient at using them…
This is why people who only test their ketones using urine test strips see high levels of ketones in the early weeks of starting a ketogenic diet.
As time passes, they see fewer and fewer ketones being excreted through their urine and wonder what’s going on.
They just became more efficient at utilizing ketones, so less ketones are wasted and excreted.
What foods can cause hot flashes while keto?
There are certain foods that people consume that can trigger hot flashes, the most notorious one for people following a ketogenic diet is coffee.
If you notice that you experience these hot flashes around the time you drink your morning bulletproof or keto coffee, now you know.
Here are a few foods that may cause hot flashes during keto:
- Coffee or caffeinated products
- Spicy foods
Many people notice hot flashes after consuming a lot of sugar, but since you’re keto, this doesn’t apply to you specifically.
However, there may be certain foods that trigger YOU, so paying attention to the foods you eat may help you identify foods that can trigger these hot flash episodes.
How To Get Rid Of Keto Hot Flashes
So now that we have a variety of reasons that you may be experiencing hot flashes on keto, how do we get rid of them?
Assuming your hot flashes are not due to a hormonal balance such as menopause, here are a few things you can do to help alleviate and hopefully get rid of your hot flashes while on keto.
Supplement exogenous ketones
Since one reason for hot flashes may be due to low blood sugar and insufficient availability of ketones in the initial stages, supplementing exogenous ketones may prove to be effective.
I like to use exogenous ketones almost like a “bridge” between transitioning from a carbohydrate-based diet to a ketogenic diet.
You may even consider using them to bridge the yucky feeling you may have if you decide to have a cheat day while on a ketogenic diet.
I recommend a powdered exogenous ketone supplement as pills would be too much to have an effective dose.
Supplement with electrolytes
Since hot flashes can occur from dehydration and an electrolyte imbalance, you must replace these essential minerals, especially sodium and potassium.
Make sure you’re salting your foods liberally and getting adequate amounts of potassium from keto-friendly sources like avocados and green leafy vegetables.
You may also try supplementing with electrolytes that are formulated with a ketogenic dieter in mind:
I recommend Perfect Keto Electrolytes or Keto Vitals Electrolytes, which have both the right amount of sodium AND potassium. Most other off the shelf electrolyte supplements don’t have much sodium and even less potassium.
- My first choice is Perfect Keto Daily Electrolytes
- My second best choice goes to Keto Vitals Electrolyte Powder (Check current prices here)
Limit caffeine and alcohol
You may think caffeine and alcohol help you de-stress, but their effects on the body, especially in excess, can have adverse effects.
Caffeine and alcohol are two big culprits when it comes to hot flash triggers.
Whatever you need to de-stress, aside from caffeine and alcohol, may help with decreasing or ridding yourself from these hot flash episodes.
Hot flashes have a strong link with stress and anxiety, as seen in this study, where anxiety tended to precede hot flashes. 4
Go for a walk, pick up a book, or try a meditation app like Headspace!
Everyone’s carb tolerance and threshold are different, even on a ketogenic diet. Some people may do better with keeping them as low as possible, but some may do better with a little more.
Most people fall between 20-50 grams of net carbs per day, so experiment and find your sweet spot.
Generally, the more active you are, the more carbohydrates you can tolerate while achieving and maintaining a state of ketosis.
Are Hot Flashes Part Of The Keto Flu?
Hot flashes may just be one symptom that many experiences as part of the keto flu.
As I’ve stated in an earlier section, keto flu is usually a result of dehydration and lack of electrolytes, so be mindful of your intake and supplement if necessary.
Some of the keto flu symptoms:
- Brain fog
- Difficulty concentrating
- Muscle cramps
Try supplementing with electrolytes:
- My first choice is Perfect Keto Daily Electrolytes
- My second best choice goes to Keto Vitals Electrolyte Powder
While hot flashes are typically seen amongst women suffering from menopause, that’s not always the case.
People who experience hot flashes when starting a ketogenic diet usually do so because of dehydration, an electrolyte imbalance, or possibly hypoglycemia.