Ketone bodies and how to measure them
The benefits of a ketogenic — or even near-ketogenic — diet are finally more widely understood. I wouldn’t say “going keto” is mainstream yet, but it’s definitely more popular than it was 5 years ago.
Also becoming more popular is testing one’s self for the levels of ketones present in one’s system, to see if one is in the state of ketosis and if so, how deeply.
For those new to the benefits of a keto diet (and I’m using the term loosely to include diets less strict than the 20 grams (or fewer) of carbohydrate typically found in the daily diet) and why anyone would care about the level of ketones in their system, I’ll give a bit of background.
Our bodies evolved in a way that allows us to store some of the energy we ingest at a meal and use it during periods when we are doing other things — working, relaxing, sleeping, etc. This ability centers on the pancreas and two hormones it produces: Insulin and Glucagon.
Insulin transports and makes glucose (derives from carbohydrate) available to our cells for use and storage (as glycogen); it also transports dietary fat, and fat the liver generates out of glucose, to our fat cells. Creating fat out of glucose is only done if our cells are full of glucose and/or glycogen. Leaving the glucose floating around in the blood is dangerous — so the liver converts it to fat and insulin shoves it into fat cells.
Glucagon controls the process of deriving energy from both dietary and stored body-fat. If all systems are working to spec, glucagon will allow us to use stored fat when we need it.
If you eat the Standard American Diet (SAD) — think The Food Pyramid — your body will be using glucose for most of its needed energy during the day. This glucose will be derived from the carbohydrate you eat. The SAD recommends that as much as 65% of the energy you ingest come from carbohydrate. This is typically too much for the body to use as either glucose or glycogen, so some gets stored as fat.
The problem that can arise from a diet high in carbohydrate content is that your cells can become resistant to the insulin needed to manage the level of glucose being absorbed into your system — so your pancreas needs to produce ever more insulin to handle the load, day after day, year after year.
Insulin resistance, then, leads to higher levels of resting insulin in your blood. The problem here is that high levels of resting insulin inhibit glucagon from doing its job of using your fat for energy. So eating a high-carb diet can lead someone to only store fat. When their body needs more energy a couple of hours after eating (when stored glucose runs out) it makes you hungry, so you eat more, instead of using body fat. It’s a slow but steady process toward obesity and Type 2 diabetes.
This is where the ketogenic diet comes is. By lowering the carbohydrate intake, the pancreas needs to produce smaller amounts of insulin (because there is less glucose in the system to manage). People who keep to a keto diet for even four or five weeks, typically see significant improvements in fasting blood glucose and insulin levels in addition to improvements on many other health markers. This happens because the lower level of resting insulin allows glucagon to utilize body-fat for energy.
If carbohydrate intake is low enough, like what is achieved at 20 or fewer grams of carbohydrate per day, glucagon will initiate a process called ketosis. While in ketosis, the liver produces something called ketone bodies, of which there are three types:
· β-hydroxybutyrate (beta-hydroxybutyrate, or, BHB)
Acetoacetate is typically the first ketone body to be produced. It, along with BHB, are energy-rich and can provide the body — including the brain — lots of energy to function on. That ketone bodies are usable by the brain is key here. The brain needs energy — lots of it. Glucose can cross the blood-brain barrier to feed the brain. Fatty acids cannot cross this barrier. While the liver can create glucose out of fatty acids, it couldn’t keep up with the needs of the brain in a low-carbohydrate environment. Instead, it converts fatty acids from our body-fat (or dietary fat) into ketone bodies that will pass through the blood-brain barrier. So , we can have our low-carbohydrate environment and feed our brains, too.
The advantage, especially for those looking to lose weight, is that the body switches to metabolizing primarily body-fat for energy.
So how do you know if you are in ketosis? There are some clues you might notice like your breath smells a little sweet or you have more energy or you don’t feel as hungry (or hangry) during the day — because your body is getting all the energy it needs from your body-fat and doesn’t need to “remind” you to eat by making you hungry.
You can also measure the amount of ketone bodies in your system with various measurement instruments.
The cheapest instrument is the urine strip. You basically pee on the active end of the strip — depending on the amount of acetoacetate in your urine, the strip turns a different color. You match the color with the guide that typically comes with the package of strips. A package of 150 strips can be found online for as little as $6.99. The one in the photo below tests for more than just ketones but the ketone test strip is the same idea — pee on the strip and match the color.
There are two problems with this measurement instrument. First, it is measuring the ketones your body ISN’T using — that’s why they are in your urine. So is having a high level of acetoacetate in your urine a good sign? It’s hard to say — yes, there are ketones in your body, but if you have a high concentration in your urine, you seem to be wasting a lot of them. Also, when your body starts relying more on these ketone bodies for energy, the level in your urine will go down. So is a low level good? A low level can occur because you aren’t in deep ketosis or because you are in deep ketosis.
For me, even at 5¢ each, the urine strips are a waste of money — if they aren’t accurate, they are of no real use.
The next level, in terms of cost, comes in the form of a breath analyzer. The breath analyzer looks and works like the instrument the police use to measure alcohol in the breath: You breath into a tube and the device measures the amount of acetone in your breath. A ketone breath analyzer can be found online for about $50.00.
Like the urine strips, however, the breath analyzer is measuring ketones that aren’t being used by the body — acetone is a byproduct of fat metabolism that you end up exhaling (and, therefore, you aren’t using). As such, the level of acetone in the breath is an indication of the process of ketosis, but it’s an indirect measure of the ketones that are in a more readily-usable form in your system. Also, if you smoke, drink coffee, use the analyzer too soon after brushing your teeth or using mouthwash, you can clog the device. You also need to breath into them in a consistent manner to obtain comparable measurements. In a nutshell, while their measurements have been shown to correlate with weight loss (which is why most people want to be in ketosis), they are tricky to use.
BHB levels in the blood can be measured directly with a meter like the one used for testing blood glucose levels — in fact “ketone meters” can typically also be used measure blood glucose levels. Ketone meters are priced like razors and inkjet printers. You can get a bundle of a meter, ketone and glucose strips (10 each), 10 lancets and a lancing device for about $50. Then the ketone strips are about $1 each after that. So, you’ll end up spending a lot more than the cost of the meter on test strips.
You measure BHB levels like you see people testing their glucose level: you prick your finger and put some blood at the end of the ketone test strip. The test strip takes up some blood and 10–15 seconds later tells you the concentration of BHB in your blood. I can put a glucose test strip in my device and, with blood from that same finger prick, measure my glucose level. If you go this route, be sure to ask when the ketone test strips expire and only buy them if you think you will use them up by that date.
Personally, I like the fact that I’m measuring actual serum BHB levels and not an indirect measure of being in ketosis. I also like being able to measure my blood glucose level. The breath analyzer also seems like a good option as at least what you measure is correlated with the desired result of ketosis. But the fact that they are so tricky to use turned me off — true, you don’t need to stick yourself, but you need to worry about how hard you breath into it and when you brushed your teeth or had coffee.
I wrote a book about nutrition, metabolism and weight management where I cover ketosis in more depth — but not so much that you need an advanced degree to understand it! See my profile page for more details, if you are interested.