Those who’ve just started the keto diet are always anxious for one important event to occur.
“Am I in ketosis?”
Sure, most people’s primary goal on a ketogenic diet is to lose weight. A lot of weight.
But the body has to go into “fat-burning mode,” more accurately known as ketosis, before the weight begins to disappear. Going into ketosis is the first important signal that the diet is starting to work.
Fortunately, it doesn’t take a lot of time for most people. And when the body is entering that all-important phase of the keto process, it’s usually not a secret.
Here’s how to tell when you’re in ketosis.
How Ketosis Works
Experts could write long dissertations on the biology and physics of ketosis. But we’ll try to explain it in three short paragraphs, so you can understand why it’s so important.
The body relies on carbohydrates for the energy it needs to function. Those carbs come from the food we eat; they’re broken down into glucose, a type of sugar that’s utilized by the body as fuel. Any glucose that’s left over is stored in a form called glycogen.
When you start a keto diet you’re virtually eliminating carbs as an energy source. That forces the body to look for fuel somewhere else. It starts by using previously-stored glycogen, but what happens when the glycogen runs out?
It starts burning stored body fat to create a secondary energy source known as ketones. And when the body begins producing ketones for energy, it enters the metabolic state called ketosis. (You knew we’d get there eventually.) That’s why you lose weight on the keto diet: you’re withholding carbs to force the body into ketosis, so it will burn stored fat for energy.
So ketosis signals that you’ve entered the stage of your diet when you’ll be able to start shedding pounds.
The Physical Signs of Ketosis
You can tell when you’ve entered ketosis by using one of two methods. You can test your blood, breath or urine for the presence of ketones. Or you can simply recognize the physical signs of ketosis that your body is exhibiting.
The Keto Flu
The body doesn’t normally use ketones for energy, so when it has to make the “switchover” from glucose things don’t go smoothly at first. Ketosis begins in fits and starts, which usually result in a series of very noticeable symptoms. Taken together, the symptoms have been dubbed the keto flu, since they closely resemble the effects of a bad case of influenza (even though there’s no virus or bacteria involved).
Within a day or two of starting a rigorous keto diet you’re likely to feel tired, even exhausted. It will be difficult or impossible to complete your normal workouts, and you may suffer muscle cramps even if you haven’t exercised. You’ll also have to urinate a lot, because excess ketones bind to water in your body and have to be excreted.
In more serious cases, you can experience nausea and vomiting, difficulty in focusing, constipation or diarrhea, headaches and insomnia. The good news is that the keto flu lasts no longer than a week for most people, and there are ways to short-circuit it.
Many of the symptoms are because frequent urination leads to dehydration and the loss of important minerals. Drinking lots of water or broth, and getting more salt, magnesium and potassium (via diet or supplements) will help quite a bit – but don’t do it with store-bought electrolyte drinks, because they contain sugar that will knock you right out of ketosis.
Get lots of sleep, slow down on exercise and stick to your diet, and you’ll get past it – and remember, it means you’re going into ketosis.
Dry Mouth and Bad Breath
The frequent urination associated with the keto flu often leaves your mouth feeling dry, and you’re thirstier than usual, since it’s easy to become dehydrated. You’ll often notice the smell of one ketone, acetone, on your breath as well; most people simply notice this as bad breath that’s difficult to get rid of. These are both signs that you’re going into ketosis.
Digestive Problems
It probably won’t come as a surprise, but your digestive tract has to adapt to functioning in a very different way when you enter ketosis. That’s not just because of the glucose/ketone energy switch, but also because of the drastic micronutrient changes you’re making in your diet. That can result in stomach pains, constipation and diarrhea above and beyond the effects of the keto flu. Those will go away, too.
The Start of Keto’s Real Effects
When you start to feel less hungry, your focus and concentration improves, and you start to lose some weight, it’s time to relax. Those are all signs that not only have you entered ketosis, but your body has become “fat adapted.” In other words, it’s made the long-term metabolic adjustment to run completely on ketones rather than glucose. This usually occurs after 2-3 weeks on keto.
Just don’t be disappointed if the weight loss isn’t extreme or only lasts for a little while; at first, you’re just losing water weight. The real keto weight loss comes as you continue to stick with your diet.
Measuring Your Ketones
It’s unlikely that your body will enter ketosis without making you very much aware of it.
However, some people who only experience a mild case of the keto flu – or don’t really notice anything different at all – will understandably be anxious to find out what’s going on with their body.
There are three ways to test for the presence of ketones in your body, and the most reliable is with a blood test. You can certainly ask your doctor or lab to do it, but there are also home testing kits which will analyze your blood. The tests look for a ketone called BHB, and results are measured in millimoles per liter (mmol/L). Once the reading is above 0.5 that means you’ve started ketosis, and a reading of 1.5-3.0 (or above) means you’ve reached stable ketosis,
The second-best choice is to use a different meter to check for the presence of acetone in your breath. Those readings are measured in parts per million (PPM) and you should be between 10 and 40 PPM if you’re in ketosis. Finally, you can use urine strips which change color to indicate whether you’re in ketosis; they’re not as reliable, but they’re less expensive and easier to use.
Even if you rely on physical symptoms to know if you’re in ketosis, it’s still a good idea to have some method of testing your ketones if you plan to stay on the keto diet. It will allow you to make minor adjustments to the diet and remain comfortably in ketosis for the duration.
