ONE Actionable Takeaway from Ketosource

Takeaway: Use the 7 Ketone Levers to Attain Your Target Ketone Level

There are different methods to achieve ketosis and drive ketone production. Depending on what your goal is your target ketone level can range between:

  • 0.5 mmol/L for appetite-reduction ketosis
  • 3.0 – 8.0 mmol/L for therapeutic ketosis

For example, in the case for therapeutic ketosis, Thomas Seyfried created the Glucose Ketone Index (GKI) to manage ketone levels for brain cancer patients. To achieve the GKI target of 1 a patient will typically need a ketone level between 5 to 8 mmol/L.

Whether your goal is appetite reduction or therapeutic ketosis you attain these levels with the use of the seven key levers: macro restriction, time restriction, caloric restriction, ketone precursors, direct ketones, exercise and sleep.


Lever 1: Macro Restriction

Restricting macros, is restricting what you eat.

You primarily restrict net carbs to boost ketone production. Protein restriction also supports ketone production, but to a lesser extent, and only where net carbs is already restricted.

This lever can be seen working in the keto diet where net carbs are limited to attain ketosis.

Lever 2: Time Restriction

Time restriction is where you restrict when you eat.

More commonly people know this as one or several of the various fasting methods. When you fast beyond a certain point, your body will begin to access and convert fat stores into ketones. The exact point is not the same for everyone – it depends on your metabolic health status.

Time Restricted Feeding (TRF) is the most common fasting method practiced with a 6 to 8 hour eating window. However, on its own, without other levers, you may require a more robust fasting method like Modified Fasting to increase your ketone levels.

Lever 3: Caloric Restriction

Caloric restriction is where you restrict how much you eat.

The extent of increase of ketones depends on the level of caloric restriction. The less calories consumed per day the greater the increase in ketones.

An example of caloric restriction is the Fast Mimicking Diet (FMD) which allows a daily limit of between 700 to 800 calories. Within 24 hours someone who is metabolically healthy will see an increase of ketones on the FMD.


Supplementation is where you take supplements with ketone-boosting properties independently of nutrition/ your diet.

Lever 4: Ketone-Precursors

Ketone-precursor supplements are converted into ketones by the liver.

The extent to which a ketone-precursor increases ketones varies depending on its type. So you select the type based on your target ketone level.

  • 1,3-Butanediol is a type of alcohol. It’s the most effective precursor.
  • C8 MCT oil is the most effective MCT at increasing ketones.
  • Mixed MCTs are a mixture of C8, C10 and C12 MCTs. They are the least effective at boosting ketones.

Lever 5: Direct Ketones

Direct ketone supplements add exogenous ketones directly without conversion.

When consumed, direct ketone supplements directly increase your blood BHB ketones.

The two types are:

  • Ketone esters is the most effective at increasing ketones but also the most costly.
  • Ketone salts (BHB salts) include two types. The mixed isomer contains both D-BHB (D-beta-Hydroxybutyrate) and L-BHB (L-beta-Hydroxybutyrate) isomers. The single isomer contains D-BHB only. The research has not yet established which increases ketones more effectively or if there is any difference.

Lever 6: Exercise

Physical activity depletes glycogen stores which is where the body houses glucose for later use.

The more intense and the longer duration the exercise the more you deplete glycogen stores, and support an increase in ketones.

You combine exercise with other levers to enhance the increase in ketones you achieve.

Lever 7: Sleep

Sleep or rather the lack of it is the only negative lever. Poor sleep can decrease your ketone level.

Poor sleep quality can lead to glucose dysregulation, higher blood glucose levels, and as a consequence a decrease in your ketone levels.

If you sleep well there’s no effect on ketone levels but ensuring adequate sleep is important to avoid decreases in your ketone levels achieved. Our guidelines to improve sleep with fasting or using other levers may help if you are having difficulty.

Actionable Takeaways

Choosing between these levers or combining them can give you greater control over your ketone production. Just remember to:

  • Set your target ketone level (e.g. 0.5 for fat loss, or 7 for therapeutic ketosis.
  • Consider your current lifestyle and choose which levers are easiest for you to integrate into your routines.
  • For the best results, combine several ketone levers, to make it easier to achieve your target ketone level consistently.

Source: Meidenbauer, Joshua J, Purna Mukherjee, and Thomas N Seyfried. “The Glucose Ketone Index Calculator: A Simple Tool to Monitor Therapeutic Efficacy for Metabolic Management of Brain Cancer.” Nutrition & Metabolism 12, no. 1 (March 11, 2015).

ONE Quote from a Credible Expert

Takeaway: The Fasting Mimicking Diet’s Impact on Waist Circumference & Lean Body Mass

This quote comes from Dr. Valter Longo. Longo is known for his studies on the role of fasting in aging and diseases. His recent research into the fasting mimicking diet has been shown to protect against metabolic and age related disease. He is currently a professor at the USC Davis School of Gerontology and the director of the USC Longevity Institute.

“[We did a study on the] five days fasting-mimicking diet (FMD) once a month for three months. The patients were asked not to change anything … in their lifestyle and just do the FMD and then go back to the exercise and nutritional routine they had before. So we compared from the point when people returned to the normal diet before we looked at their blood. So you see effects on body weight, abdominal fat, waist circumference, and lean body mass … that’s relative lean body mass, it is actually going up after FMD but the absolute stays the same and that is what we were hoping for. That we would see this major effect on fat but without reducing lean body mass.”

Source: Dr. Valter Longo | Fasting Mimicking Diet cycles, longevity and age-related diseases | Keynote Presentation at Metabolic Health Summit 2024 (timestamp 00:30.30)

ONE of Your #1 Questions Answered

The Question:  How to Compare C8 MCT Oil to Ketone Salts?

The top question sent in from you this week was from Enno Freye. Thank you Enno!

“Shouldn’t Keto Salts have the same effect on your ketone level like the C8 MCT oils?”

The Answer: 

Ketone Salts and C8 MCT Oil both increase ketones in the blood, but differ in several ways that can would lead us to choose one vs. the other depending on the situation.

Deciding between the two depends on your personal needs with respect to three specific criteria:

  • Target ketone level: From appetite-reduction ketosis (0.5 mmol/L) to strong therapeutic ketosis (8 mmol/L)
  • Ketone speed: Time to ketone increase within 30 minutes vs. 1 to 2 hours
  • Cost effectiveness: Cost per dose or per 1 mmol/L ketone boost

Choose the Supplement Based on the Use Case

Below are two hypothetical situations to help you think through this:

  • Fat Loss Support: If your goal is fat loss, you need to attain appetite-reduction ketosis (0.5 mmol/L) or higher. It’s not typically an urgent need (i.e. speed). It requires daily consistency, so you’re supplementing daily (ideally three times per day). So cost may be a bigger consideration. You may find C8 MCT oil is the best fit in this case.
  • Exercise Supplementation: For exercise people tend to supplement immediately before (e.g. on arrival at gym). So speed may be important to you. Increasing ketones to a higher level is also more appropriate. And finally, since you’re not exercising every day perhaps cost is less important. You may find ketone salts are your better option here.

Actionable Takeaways

  • Identify your specific use case and situation (e.g. fat loss on daily basis, exercise at specific times, how important cost is to you etc.)
  • Break your use case down by the three criteria: Target ketone level, ketone speed, cost effectiveness
  • Select the ketone-boosting supplement that best fits the result from these criteria

Source: Stubbs, Brianna J., Pete J. Cox, Rhys D. Evans, Peter Santer, Jack J. Miller, Olivia K. Faull, Snapper Magor-Elliott, Satoshi Hiyama, Matthew Stirling, and Kieran Clarke. “On the Metabolism of Exogenous Ketones in Humans.” Frontiers in Physiology 8 (October 30, 2017.


Damien Blenkinsopp MBA.

Damien is the founder of Ketosource and the host of the popular health tech/data podcast, The Quantified Body. He has an MBA from London Business School and both French (ESC) and UK 1st Class Hon. undergraduate degrees. His career has had a data-driven and analytical focus, spanning strategy consulting, market analyst and health tech/data. Damien has a passion for health, longevity and predictable results. The Quantified Body and Ketosource projects are both focused on leveraging data and analytical tools to help people get the results they want with confidence. Damien speaks 5 languages and has lived in 11 countries across 5 continents.