The ketogenic diet requires significant effort and discipline replacing high-carb foods like bread and pasta with lower-carb foods like leafy greens and avocados. Not surprisingly, you’ll want to know if your efforts are paying off and you’re on the right track to reaching ketosis. The good news is there are a number of ways to tell if your body is in ketosis, but some of these methods are more reliable than others. First things first, let’s start with the basics.
What exactly is ketosis? When you cut down on your carbohydrate intake or fast, your body will shift from burning primarily sugar (or glucose) for energy to burning fat. ⛽ In this fat-burning mode, your liver will use fat to produce fuel molecules called ketones. This is where the metabolic state of ketosis gets its name.
A diet with less than 10% of calories coming from carbohydrates is generally the ticket to achieving ketosis but, individual variability does exist. Tracking a few days of eating using an app that provides macronutrient (carbs, protein & fats) percentages is useful for assessing how much of your diet is comprised of carbohydrates. Alternatively, counting number of net carbs (net carbs = total carbs – fiber and sugar alcohol) with a goal of approximately 30g or less can also be effective. Before investigating if you’re in ketosis, start with this step to make sure you aren’t consuming too many carbs.
Once you have the foundation of the diet down there are a number of other tell tale signs of ketosis, as well as more accurate measures that can be used. To start, we’ll talk about actual tests you can do to see if you’re in ketosis.
3 Test Methods to See if You’re in Ketosis
When your body is in ketosis, your liver will produce three types of ketones: beta hydroxybutyrate (BHB), acetone and acetoacetate. You can actually measure the levels of these ketones in your body to see if you’re in ketosis by testing your blood, urine and breath. While testing your ketone levels isn’t a requirement for people following the keto diet, lots of people like to do so to make sure they’re on track.
All of these test methods can usually be purchased at your local pharmacy or online so you can track your ketone levels from the comfort of your own home. A test reading of 0.5-3 mmol/L is considered positive for ketosis.
1. Increased Ketones in your Blood.
Beta hydroxybutyrate (BHB) is a gold-standard marker of ketosis. Your body makes this ketone from fat as an alternative energy source when carbs are low. Levels of BHB in the blood can be measured at home with a simple finger prick using a blood ketone monitoring meter. A lot of these meters can also measure blood glucose which makes them ideal for people using the ketogenic diet to better control blood sugar.
BHB monitors and strips are considered by many to be the most accurate way to test for ketosis but they are also the most expensive option. The monitors themselves can be upwards of $50 and you have to buy replacement strips if you decide to continue testing your ketone levels after reaching ketosis.
If you’re leery of needles or if the price doesn’t make sense for you, don’t worry. The next two options are cheaper and painless.
2. Increased Ketones in your Breath
When you’re in ketosis, the ketone acetone will show up in your breath in a bad way. Bad breath that is described as fruity or sweet is a hallmark symptom of ketosis. You can measure your breath acetone levels (BrAce) by using a breath ketone analyzer to see if you’re in ketosis.
These breath analyzers are moderately expensive, with prices ranging from $50 and up, but once you have one, you don’t need to purchase additional test strips or equipment to continue testing for ketosis. Additionally, breath ketone analyzers are considered a reliable indicator of ketosis without a needle stick.
3. Increased Ketones in Your Urine
Measuring urinary ketones is the least expensive method for detecting ketosis and it’s also super easy to do. All you have to do is pee on a small testing strip, and the color will change to indicate if you’re in ketosis. If you shop around, you can usually purchase 100 of these urine test strips for less than $15.
Similar to blood serum ketones, urinary ketones also rise during ketosis. However, this method isn’t the most reliable and is recommended primarily for people who are just starting out with a ketogenic diet. As your body adapts to using fat for fuel, fewer ketones will be spilled into your urine, making the strips less accurate with time. Your own hydration levels can also impact the reading.
If you decide to test your urinary ketone levels, the best time of day for an accurate reading is first thing in the morning or after dinner.
3 Signs You’re in Ketosis
You don’t need to purchase a fancy testing system to find out if you’re in ketosis. There are plenty of other tell-tale signs that your body is burning fat for fuel.
After following the keto diet for several days you’ll likely experience one or more of the following signs of ketosis.
1. Absence of Hunger and Stable Energy
Say goodbye to food cravings and that afternoon slump. Reduced hunger and consistent energy are common and welcome side effects of the keto diet. Your body is happily burning fat for energy and because this is a longer lasting and more stable fuel source, it’s not necessary to eat as often to maintain stable energy. Ketones also suppress ghrelin, your hunger hormone.
2. Weight Loss
Many people following the keto diet will experience rapid weight loss within the first week. The initial weight loss is mostly water weight. As you shift into ketosis, your body will naturally get rid of its carbohydrate stores of glycogen. For every gram of glycogen stored in your muscle there are three grams of stored water! This process also kicks off a change in your body's fluid balance. After this first week, you'll move beyond water weight and begin losing pounds of body fat.
3. Increased Mental Clarity and Focus
Increased brain function and mental clarity are often reported as benefits people experience after following a ketogenic diet. While there is not as much information available on the benefits for healthy individuals, many studies support a keto diet improving the cognitive functions for those with mild cognitive impairment, dementia and other neurological disorders. One explanation for this reported increase in mental sharpness, could be that the brain is able to use ketones for energy fairly efficiently. Another possible factor that may help improve brain function is that the blood sugar levels in the body are stabilized during the keto diet.
Before you decide to purchase a fancy monitor or wake up early to pee on a strip of paper – ask yourself if it’s necessary. The answer may be yes if you have diabetes or another closely monitored health condition. Or perhaps you’re trying to fine tune your food choices and looking for a little extra motivation to stay on track. In this case, it may be worth it to make the investment.
If you’re getting the results you're looking for – such as weight loss, sustained energy, appetite control etc. then hold off on spending any time, money or other resources on extra measures. If you hit a plateau or are losing steam, then get what you need to start monitoring and get back on track.