Do You Need to Test Ketones at All?

No, most people on keto for weight loss do not need to test ketones; testing is useful for a short learning period or under a doctor's direction, and for everyone else, carb intake and how you feel tell you more than a strip.

On this page

• The short answer
• When testing helps
• When testing is noise
• Why a ketone number is not a weight-loss number
• How KetoDick's position changed
• If you do test: a two-week plan
• Who should test under a doctor
• Related

The short answer

You can get into ketosis without ever testing. The thing that puts you there is eating few enough carbohydrates; see How Many Carbs on Keto?. A test only confirms what your food already decided.

When testing helps

Testing earns its place in a few cases:

1. Learning. In the first weeks, a positive strip shows you that your new way of eating is doing what it should.
2. Finding a problem food. If you test positive most days and go blank after a new sauce, bar or drink, that food may carry hidden carbs.
3. Doubt. If you feel you are doing everything right but not getting the benefits, a test can rule ketosis in or out.
4. Medical monitoring. For some people with diabetes, ketone testing is a safety step their care team sets up.

KetoDick on this: in 2017 he gave the same uses: strips as biofeedback for people who doubt they are dieting effectively or worry about hidden carbs (video 8wOheKcBEd8).

When testing is noise

Testing stops being useful, or starts doing harm, when:

• You chase a darker strip or a higher number. The shade on a urine strip says little about blood ketones (video 8wOheKcBEd8). See Urine Ketone Strips.
• You are fat adapted. Strips often fade by month three to six while you are still in ketosis, by KetoDick's account (video GojQvo_2GS0).
• The cost adds up. Blood strips at a few dollars each run to hundreds of dollars a month if used daily, by his figures (video 8wOheKcBEd8).
• It feeds anxiety or rigid rules. Checking numbers several times a day can turn food into a test you pass or fail.

If you have a history of disordered eating, number-tracking of any kind is worth discussing with your therapist or doctor first. KetoDick warns that "clean eating" can become an eating disorder, and says anyone with an eating disorder should involve a therapist and a doctor (video xyEZL0HuejI). See Keto and Eating Disorders and Clean eating and orthorexia.

Why a ketone number is not a weight-loss number

Weight loss depends on eating less energy than you use over time. Ketones show that your body is making ketones, not how much stored fat you lost.

• In a metabolic ward, 17 men switched to a ketogenic diet at the same calories; their body-fat loss slowed after the switch (Hall et al., 2016).
• Over 12 months, 609 adults on a healthy low-fat or healthy low-carb diet lost similar amounts: 5.3 kg and 6.0 kg, not a significant difference (Gardner et al., DIETFITS, 2018).

What keto offers many people is less hunger, which makes eating less easier. See Hunger and Appetite on Keto and Do you have to be in ketosis to lose weight?.

How KetoDick's position changed

His view moved over 18 months. Both positions are his, and both are stated here as he gave them.

The 2019 view comes from his reply to a Men's Health article that told readers to check their levels with a device. See Men's Health keto article rebuttal.

The two positions are not far apart on the facts. Both say testing is optional and strips fade. What changed is the weight he puts on learning: in 2017 strips were a teaching tool, and by 2019 he treated them as mostly unnecessary.

If you do test: a two-week plan

If you want to learn from testing without making it a habit:

1. Pick one method. Urine strips are the cheapest way to start. See Chapter 8 for all three.
2. Test once a day, at the same time, for about two weeks.
3. Write down the result and anything new you ate the day before.
4. Look for patterns, such as a food that turns a usual positive into a blank.
5. Stop. Go back to tracking carbs, or to no tracking at all. See Tracking on Keto.

Who should test under a doctor

For these readers, ketone testing is a medical decision, not a diet choice:

• Type 1 diabetes, or type 2 diabetes on insulin or other glucose-lowering medication. Ketone monitoring in diabetes helps tell ketosis from ketoacidosis (Laffel, 1999). The American Diabetes Association accepts low-carbohydrate eating as one option when it is individualised (ADA Standards of Care 2025), so set the plan with your care team. See Medications and Keto.
• Kidney disease or risk for it. KetoDick says many people with type 2 diabetes have some early kidney issue and should talk to a doctor before starting (video GojQvo_2GS0).
• Pregnancy or breastfeeding. Talk to your obstetric team before any diet change that raises ketones.

The clinical overview of the ketogenic diet covers monitoring and how nutritional ketosis differs from DKA (StatPearls, The Ketogenic Diet). See Ketosis vs Ketoacidosis and Who Should Talk to a Doctor Before Starting Keto.

Related

• Chapter 8: Testing for Ketosis: Urine, Blood and Breath
• Urine Ketone Strips · Blood Ketone Meters · Breath Ketone Testing
• Your First Month on Keto, Week by Week
• Blog: Is there an optimal ketone level for weight loss?
• Videos: What do I need for the keto diet? · Common beginner questions · Men's Health rebuttal

Last verified: 2026-10-31