Keto Lie #1: ‘Optimal ketosis’ is a goal. More ketones are better. The lie that started the keto movement.

If keto is about anything, it’s about ketones. 

One of the most confusing things about keto is the concept of ‘optimal ketosis’. 

Many people believe that a higher level of beta-hydroxybutyrate (also known as β-hydroxybutyrate, BHB, or ‘blood ketones’) is better. 

While this belief was based on the best information at the time, as more people have followed a ‘ketogenic diet’ for months and years, we now have better data, yet the recommendations have not been updated. 

To encourage people to strive for ‘optimal ketosis’, or really any level of consistently elevated ketones is unlikely to empower you to reach your goal of improved metabolic health.  It may even be dangerous as it encourages many people to pursue a low satiety nutrient-poor diet that leads to energy toxicity (i.e. a build-up of excessive levels of energy in the body). 


  • Your body produces ketones from your fat stores as an alternative fuel source for your brain and organs when there is no glucose (i.e. when you go without food).  This is called endogenous ketosis because your liver makes the ketones from the fat on your body.  When the supply of glucose and protein in our diet is reduced, your body can make ketones from the fat you eat.  This is called exogenous ketosis. 
  • Most of the beneficial things that we associate with ketosis (e.g. autophagy, lowered blood sugars, diabetes reversal and fat loss) occur when we are drawing down on our body’s energy stores because we are eating less.  We can’t ‘biohack’ all these benefits by artificially elevating our blood ketone levels with what we eat.
  • We tend to see higher levels of beta-hydroxybutyrate (BHB) initially after a few days or weeks when people switch to a low-carb or ‘ketogenic diet’.  These tend to peak once they have drained the excess glucose (in the blood) and glycogen stores (in the liver and muscles) but tend to decline afterwards as people continue to lose body fat and improve their metabolic health.
  • Any diet that produces fat loss is likely to be ‘ketogenic’ because you will be burning stored body fat.  However, over time, blood ketones tend to decrease as we lose fat and improve our metabolic health.
  • Unfortunately, it’s hard to make much sense of the number you see on your blood ketone to understand whether:
    • you are in the early stages of fat loss and starting to release stored energy into your bloodstream, or
    • overloading your system with excess energy that you are not using efficiently.
  • Most people do not achieve the minimum ketone level to qualify for ‘nutritional ketosis’ (i.e. BHB > 0.5 mmol/L) let alone ‘optimal ketosis’ (i.e. BHB > 1.5 mmol/L) without adding significant amounts of refined fat to their diets.  
  • Merely adding more dietary fat will slow fat loss from your body, increase your insulin levels across the day and may worsen your metabolic health.
  • While reducing the carbohydrates in your diet may help to stabilise blood sugars and improve satiety, tracking BHB is of limited use to help you optimise your diet or make more intelligent nutritional choices.

What does this mean for ‘keto’?

So, it seems that ‘keto’ fundamentally has an identity problem. 

  • The most widely accepted definition of a ‘ketogenic diet’ is one that increases BHB greater than 0.5 mmol/L.
  • However, we tend to only see BHB ketones greater than 0.5 mmol/L in people who:
    • have recently transitioned to a low-carb or ketogenic diet, 
    • are fasting for an extended period, or
    • are adding copious amounts of refined dietary fat or exogenous ketones to their diet.
  • To maintain elevated ketone (BHB) levels means that you have to continue to increase the amount of nutrient-poor low satiety dietary fat which can quickly lead to weight gain. 

While there are innumerable benefits of a diet that contains less processed carbohydrates, ‘keto’, by definition, has an identity problem that is sadly causing many people to worsen their metabolic health, insulin resistance, obesity and diabetes. 

I would dearly love to see the ‘optimal ketone chart’ retracted.  I think it is potentially dangerous advice and leads many people, including myself, to worse metabolic health. 

I published a blog post on this topic back in July 2015 that has received nearly 383,638 views.  I’ve also left plenty of comments on the Virta Facebook Page, sharing my insights.  Sadly, most of them were deleted.  

I have spoken to Steve Phinney, Jimmy Moore and a number of other ‘keto gurus’ about this.  But sadly, a large industry has built up around ‘keto’ believing that elevated ketones are an end goal and the secret to achieving optimal health, so the Titanic is probably not about to turn around any time soon.

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2 thoughts on “Keto Lie #1: ‘Optimal ketosis’ is a goal. More ketones are better. The lie that started the keto movement.”

  1. …and to think that all it took to turn the MLM world into a pile of sand is a wee thing called a pandemic…

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