Big Fat Keto Lies: Introduction

The last thing the world needs is another keto diet book.



Welcome to Big Fat Keto Lies!

This book is a tour of the most prevalent keto and low-carb myths and misconceptions and my learnings gleaned through my quest for nutritional enlightenment in ‘Ketoland’. 

Like many others, I was once a loyal keto disciple, following the latest keto diet gurus during my early quest for nutritional enlightenment.

I could quote chapter and verse from the latest best-selling keto bible.  But what I couldn’t do, no matter how religiously I kept the faith, was lose weight—much less fat—or improve my blood glucose and other critical biomarkers.

What I don’t want to be with Big Fat Keto Lies is another false prophet that people blindly follow. Instead, I hope to take the role of shepherd and tutor, guiding you—just as I did myself, my family, and now thousands of Optimisers in our Optimising Nutrition community—by exposing the big fat keto lies that I once believed but have unlearned on my journey.   

The story of how ‘low-carb’ morphed into ‘keto’ is a classic example of the ‘if a little is good, more must be better’ mentality that we often fall victim to.  

But ‘keto-bashing’ isn’t the purpose of Big Fat Keto Lies.  Only a fool would attempt to completely discredit a way of eating that has helped so many. 

There are numerous benefits from a lower-carbohydrate diet that enables to avoid the hyperpalatable, processed, and nutrient-poor combination of fat and carbs that drives us to now eat more than ever!

Sadly, I fear that many of the invaluable aspects of a lower-carb diet will be lost when the trend dies and keto becomes another dietary fad and a ‘thing of the past’. 

My goal with Big Fat Keto Lies is to help you leverage the many benefits of a lower-carb way of eating by exposing, correcting, and clarifying keto beliefs that have proven to be counterproductive and even dangerous when taken to extremes.

The nutritional framework detailed in this book will empower you with awareness to be a fiercely objective consumer, deputised to ferret out half-baked truths and outright lies in any social, electronic, digital, or print media that crosses your path.

While many of you may have already acquired these detective skills, the majority of ‘Ketonians’ have not (yet!).  Sadly, it’s often the most devout keto true believers that often end up with the least optimal results.  The injustice comes down to splinter groups, subcultures, and closed-minded communities postulating their “one true way”.”

It is no wonder that confusion is rife, and inflammatory online arguments continue to spark like wildfire.  However, these e-wars have ironically boosted the popularity of these keto half-truths because ‘controversy gets clicks’.

We now have endless bastardised versions of keto. A leaky revival tent has taken the place of the core benefits of a lower-carb diet.

Objections to Big Fat Keto Lies

Since Big Fat Keto Lies was initially released, several readers have pushed back, claiming that many keto advocates now already agree with the “12 lies”. 

This is partly true, and some of the keto gurus have quietly backed away from some of the lies.  A few brave and noble leaders have publicly renounced their previously held beliefs.

But confusion will prevail until a united council of keto gurus admits to their faithful disciples that ‘these are the truths we once believed but have now been proven false’. 

You can either:

  • hold your breath, waiting for the hierarchy to release an updated ‘official’ version of the keto gospel and recant the errors of the past, or
  • you can get busy reading to understand how you can optimise your diet to suit your unique goals and context.

I’ve organised the chapters of Big Fat Keto Lies around 12 of the most rampant keto ‘commandments’ that tend to cause the most confusion and failure. 

  • Keto Lie #1:  ‘Optimal ketosis’ is a goal. More ketones are better.
  • Keto Lie #2:  You have to be ‘in ketosis’ to burn fat.
  • Keto Lie #3:  You should eat more fat to burn more body fat.
  • Keto Lie #4:  Protein should be avoided due to gluconeogenesis.
  • Keto Lie #5:  Fat is a ‘free food’ because it doesn’t elicit an insulin response.
  • Keto Lie #6:  Food quality is not important. It’s all about insulin and avoiding carbs.
  • Keto Lie #7:  Fasting for longer is better.
  • Keto Lie #8:  ‘Insulin toxicity’ is enemy No. 1.
  • Keto Lie #9:  Calories don’t count.
  • Keto Lie #10:  Stable blood sugars will lead to fat loss.
  • Keto Lie #11:  You should ‘eat fat to satiety’ to lose body fat.
  • Keto Lie #12:  If in doubt, keep calm and keto on.

Charitable readers might consider these ‘half facts/half fictions’ as no more than a dozen innocuous, misguided, and misconstrued ‘little white lies.’

But diligently following these ‘commandments’ often leads one to fail to achieve their health goals of reducing body fat, achieving healthy blood sugar levels, or optimising their metabolic health.  

Those gullible enough to ‘go keto’ based solely on what they have ‘learned’ through social media, podcasts, or by ‘eavesdropping’ on the endless arguments on Facebook, Twitter, Instagram, and TikTok put themselves at risk of endangering their own health.

Similar to how the commercial diet industry profits by pedalling its wares to desperate dieters, the charming and persuasive ‘snake oil’ front men and women hawk their pseudo ‘keto’ vendibles to consumers desperate to hand over their hard-earned cash for that elusive ‘magic pill’.

In an attempt to cut through the noise, I have taken a data-driven approach to identify factors like satiety, nutrient density, and healthy blood glucose levels that make any diet work.

Once you understand these fundamental principles of nutrition, you will be able to identify extremes like chasing higher ketones, more fat, and the extremes of plant vs animals in your diet that are not only irrelevant but counterproductive and often dangerous if taken too far.

When you examine each “lie” through the lens of Nutritional Optimisation, you’ll find clarity, a basic understanding of keto mechanics, answers to frequently asked questions, and practical action steps to take when—or if—you discover your keto beliefs no longer serve you.

Who Am I?

My name is Marty Kendall.

I live in Brisbane, Australia.

I’m not a doctor.

I’m an engineer.

I have a family history of obesity and diabetes. I was always the ‘fat kid’.

My family was primarily vegetarian for religious reasons, so I ate plenty of processed grains and fake meat way before it was popular. 

I am married to my wife Monica, who happens to have Type-1 Diabetes

My quest to understand nutrition, diabetes, insulin and optimal blood sugar management began in 2002 when we started dreaming of having kids. We wanted to avoid the scary array of complications that often accompany high blood sugars during pregnancy

We now happily have two robust, healthy teenagers!  

By experimenting with different dietary modifications, we have managed to halve Monica’s daily insulin requirements. The adventure has also changed us.

As an engineer, I think in numbers, charts, and systems.

What you’re reading is not a typical diet book. Big Fat Keto Lies lays out the logic of how various health and nutrition parameters interact.

Having access to several large and unique datasets allowed me to test various nutrition theories for myself. I wanted to identify the shared themes that make all diets work and eliminate the ‘magical thinking’ and belief—not to mention the ethical and commercial bias—that is so common in nutrition and other ‘soft’ fields.

Through my excursions and explorations of nutrition-focused literature, data, analysis, and research, I collected some unique insights that I can’t wait to share with you.

I hope these insights will keep you from stumbling headlong into the pitfalls and potholes (and rabbit holes, too) that swallow up too many folks travelling down their road to nutritional enlightenment.

Insights from Type-1 Diabetes

I spend a lot my day watching Moni’s continuous glucose meter (CGM) trace as I fine-tune her closed-loop insulin pump system to optimise her blood sugars. I’ll admit, I’m obsessively fascinated by this! 

I want to understand how I can empower Monica to optimise control of her diabetes, manage my health, and set an example for our kids.

I have used my analysis skills to crunch the numbers to give Monica the best chance at a long, healthy, and vibrant life.  It’s super satisfying to see her now living with a non-diabetic HbA1c of 5.1% with around 30 units of insulin per day, compared to an HbA1c greater than 7% and 50-60 units per day that she started with.

I consider this an honour because I have learned so much about the various factors that affect insulin and blood sugar.  People with Type-1 Diabetes give us fascinating quantitative insight into how our bodies respond to the food we eat. 

I have also learned that it is critical to understand the difference between someone with Type-1 Diabetes and the 98.5% of us with fully functioning pancreases.  

Sadly, the majority of the keto doctors have lost sight of this and fail to consider the factors like body fat levels and other variables unrelated to food that influence basal insulin requirements and the critical difference between exogenous (injected) insulin and endogenous insulin (produced by your body).

The techniques that help people with Type-1 Diabetes stabilise their insulin and blood sugars do not necessarily lead to optimal health and fat loss for the rest of us.

Despite what we believe, most of us can’t turn off our pancreas to stop producing insulin regardless of what we eat. Unfortunately, this critical subtlety seems to be lost or ignored by many low-carb and keto-savvy leaders, gurus, and doctors. 

What is Agnostic Nutrition?

In days gone by, humans interpreted things they didn’t understand as mysterious or magical. We formed religions and cult-worshipped the sun, earth, fire, thunder, and rain as deities that gave us nourishment and sustained us. 

In modern times, we abandoned many of the old deities as we gained more insight into the elements of nature. Empirical data and a deeper scientific understanding have since filled many of our knowledge gaps. 

While we have gained a deeper understanding of the external world and universe, many of the things that occur inside our bodies are still a mystery to us.

We may no longer attribute natural phenomena to the interventions of the gods, but that hasn’t stopped many of us from ascribing near ‘magical’ or ‘supernatural’ powers to diets.

While nutrition is still an evolving science, it is still a science with finite principles and not a matter of religious belief or debate.  While commercial interests and religious perspectives have heavily influenced the conversation around nutrition, I believe nutrition science needs to be agnostic.  There must be fundamental principles that apply to all humans. 

Context is critical. To make progress towards your destination, you need to understand where you are now and where you want to go.  My aim in this book is to highlight the most powerful levers in nutrition and show you how they can be applied to various contexts for different people with different goals.

Endogenous Ketosis for Health and Fat Loss vs Therapeutic Ketosis

Nutrition is not a ‘ ‘one-size-fits-all’ solution.  To ensure you get the desired outcome on a ketogenic diet, it is critical to understand the difference between:

  • a ketogenic diet designed for optimal health, weight loss, and diabetes reversal to achieve endogenous ketosis when fat is released from your body stores to be used for energy, and
  • a therapeutic ketogenic diet is designed to manage epilepsy, Parkinson’s, dementia, and Alzheimer’s disease, where ketone levels are derived from dietary fat or exogenous ketone supplements

Simply ‘going keto’ by adding more fat or chasing higher ketones may not get you closer to your goal of improved metabolic health.  In fact, it could lead you further away from your goal if you don’t tailor your nutritional approach to your current context and intentions.

Optimising Nutrition

In January 2015, I started sharing my observations on and was overwhelmed by the responses.  In addition to writing articles, I spent a lot of time analysing people’s food logs to create recommendations that helped them move towards more optimal nutrition. 

Three years ago, Alex Zotov contacted me out of the blue. He offered to partner with me to develop a suite of tools that would help automate and scale Nutritional Optimisation to help more people.

Alex is a programmer with a background in neuroscience and app creation for doctors and researchers that are user-friendly.  After gaining weight after his professional tennis career, he was also on a quest to solve the puzzle of nutrition quantitatively. 

Over the past three years, we have helped people apply the insights from our analysis by developing the Nutrient Optimiser

We have run numerous Masterclasses and have seen some radical results in people who have implemented our systemised approach to personalised nutrition by managing the metrics that matter.

In an effort to bring Nutritional Optimisation to the masses, we have continued to refine our data-driven approach to nutrition to make it as simple as possible for people to get the results they want. 

Most recently, we developed Data-Driven Fasting, which leverages your blood sugars to guide your fat-loss journey.  The response and results have been phenomenal!     

Ironically, after five years of trying to teach people to optimise what they eat, it seems that more people have more interest in not eating rather than learning how to eat well. However, the best results always occur when the two are paired together. 

Why Am I Doing This?

This book aims to summarise the critical lessons and ah-ha moments that I have learned by writing hundreds of articles and working with thousands of people in the Macros Masterclass, Micros Masterclass, and the Data-Driven Fasting Challenge

This is the book that I wish someone had handed to me when we started this journey. It includes:

  • the most valuable lessons I’ve learned,
  • things I once believed but have found were wrong and had to unlearn, and,
  • simple action steps that will save you time and avoid confusion on your journey. 

I would also like to remind you that I’m not a doctor. I’m an engineer.  I just love numbers, graphs, and interpreting data.  

I have devoted every available moment I have had over the past seven years or so to analysing, researching, and writing on nutrition and how we can fine-tune our food choices to align with our goals.  

Please judge what you read on its merits and with an open mind.  It’s not always the most qualified people who have the ‘Eureka’ moments.  More often, it’s the people with personal motivation who come to a topic unblinkered by traditional education, who see things with fresh eyes. 

Sadly, we often get it wrong when we try to apply our ‘understanding’ of science and biochemistry to human metabolism.  We get caught up in a single magical mechanism and often miss the forest for the trees. 

To get the most effective results with the least effort, we need to step back and look at the big picture to see if it aligns with reality for most people most of the time. 

Who Is This Book For?

This book has been written for a range of different audiences.

  • For people who have been following a ‘keto’ or low-carb way of eating and may not be seeing the results they hoped for:
    • This book will help them fine-tune their current eating methods to ensure they continue to move towards their goals.
  • For people managing diabetes (either Type-1 or Type-2)
    • This book will help them understand how the food they eat affects their blood sugar and insulin and how to modify their diet to improve their results.
  • For people interested in nutrition who just want to learn to eat better:

What Is ‘Optimal Metabolic Health’ and Why Is It Important?

Health and nutrition can be confusing and overwhelming.  There are lots of tests, technologies and things we can measure. However, you only need to apply the basics to move towards improved metabolic health and see results.

In this book, you will see the term ‘optimal metabolic health’ repeatedly. It’s worth defining so you know what I’m trying to help you achieve.

As my good friend and Optimising Nutrition advisor Dr Ted Naiman likes to say, pretty much anything that makes you leaner and more robust makes you healthier.  This is not merely a matter of being lighter, but instead having less body fat and more strength and lean muscle mass. 

We’re always looking for easy hacks and shortcuts to look and feel better. We can manage symptoms and markers with drugs and bio hacks, but they do not fix the problem and only give you better test results. 

But, managing symptoms and test results don’t always make you healthier.  Some common examples of symptom management include:

  • injected (exogenous) insulin or avoidance of carbs to achieve stable blood sugars, so we look like we are lean and metabolically healthy,
  • exogenous ketones or refined dietary fat to increase blood ketones, so we look like we are losing weight in an energy deficit, 
  • supplementation with vitamin D or melatonin so we look like we are young, healthy, sleep well, get adequate sun exposure, and have a well-calibrated circadian rhythm, and
  • statins to reduce cholesterol, so our blood cholesterol levels conform to what we believe are healthy values, and so on.

We Are Overfed but Undernourished

These days, our food system is awash with cheap energy.  We are overfed but undernourished.  Thanks to fossil-fuel-based fertilisers, industrial agriculture and food processing, we have won the war against hunger and conquered food security issues we were trying to solve half a century ago. 

Today, our modern food system makes it easier than ever to get energy.  But getting the essential nutrients like vitamins, minerals, essential fatty acids, and amino acids that we really need to thrive are much harder to come by. 

Nutrient-poor, low-satiety foods drive us to eat more than we need in search of the nutrients our bodies require for optimal health.  Unfortunately, this quickly leads to energy toxicity or excessive amounts of energy in our bloodstream as high blood glucose, ketones, free fatty acids, and body fat.  This energy toxicity, driven by our modern food environment, is the root cause of common modern diseases like obesity, Type-2 Diabetes, heart disease, autoimmunity and cancer. 

To improve our metabolic health, we must make more informed food choices that will enable us to get the nutrients we need without consuming excess energy.  

Rather than merely using more willpower, which usually leads to hunger, failure, guilt and rebound binging, we need to make smarter food choices that satisfy our bodies.  Fundamentally, we need to find a way to give our bodies the nutrients they need without excess energy. 

Sadly, a dwindling minority of us are considered metabolically healthy.  While we all don’t need to identify as super-fit bodybuilders, most of us would benefit from having less fat and more strength and lean body mass. 

It’s not just about being lighter, but having less body fat and more muscle to ensure we are resilient as we age. 

With just a tape measure, bioimpedance scale, and blood glucose meter, you can track your metabolic health at home and keep track of measurements like:

  • body fat,
  • lean mass and muscle,
  • waist:height ratio, and
  • fasting blood sugar.

You May Be a Unique Snowflake…  But You’re Probably Not  

You may be a unique snowflake.  However, I would be surprised if what you read here doesn’t work for you if you apply the basic principles. 

In this book, I offer my summary of the research that I have found most useful alongside my analysis of many large data sets.  Together, this information shows what helps most people to manage their blood sugars, insulin, satiety, and body fat and move toward optimal metabolic health.

Over the years of riding the keto wave, I made numerous mistakes and believed in things espoused by ‘gurus’ that I later found didn’t stack up.  I would love it if you could avoid the potholes and dead ends on the road to nutritional enlightenment. I would also love it if the low-carb and keto communities listened, so they could continue to grow and help more people.  

I have been banging this drum for a while now. The articles on Optimising Nutrition have had 4.2 million views from 2.3 million people worldwide. 

Many have listened. Some have not. But I have tried. You will read here the highlights of my disagreements and opportunities for refinement of the theories that form the foundation of our current understanding of low-carb and keto science. 

Unfortunately, most of the studies showing the benefits of keto and low-carb have been on epilepsy, cancer, or from people wanting to market some magical supplement. General health studies on a low-carb lifestyle have sadly been far and few.

This book is intended for people interested in using low-carb or keto to reach health goals of reversing diabetes, losing body fat, and optimising health and resiliency.

I hope my insights will provide some clarity to help people escape the tsunami of metabolic disease already crashing down upon us. If we don’t keep learning and moving forward, the consequences are ominous!

Common Misconceptions About ‘Keto’

There have been many keto beliefs that have sprung up that we have later found to be incorrect. Over the past six years, I have spent a lot of time discussing these at length, analysing data to test these beliefs, and writing numerous blog posts sharing my learnings. 

I put out a survey in the Optimising Nutrition Facebook Group to see what people thought I should cover in a book to address the most common areas of confusion. 

As you can see from the survey results below, there was surprising enthusiasm and a long list of topics. These are some of the most common questions that have caused the most confusion and debate.  I have endeavoured to address and add some clarity throughout the remainder of this book.

Get your copy of Big Fat Keto Lies

I hope you’ve enjoyed this excerpt from Big Fat Keto Lies. You can get your copy of the full book here.


7 thoughts on “Big Fat Keto Lies: Introduction”

  1. thanks for checking out the introduction to the book Bill. the words bioavaile/bioavailability featre 21 times in the full book. I laso had a good chat recently on the Carnivore Cast about bioavailability. (see

    • Hi, Marty. Sorry to appear to be a pain but you really should check your spelling before you push ‘send’. I’d like to have confidence in the writer’s ability to spell before I buy his/her book.

      • Appologies for the Australian/British spelling. I’m an Aussie. Let me know if you find anything specific. I’ve had a number of people proof it, including a professional scientific editor.

  2. It sounds like Jimmy Moore could use a copy of your book–many of these myths are/were being pushed by him and his podcast guests.

  3. Hi Marty, what is your take on pufa fats and keto? Some of the mainstream guys have notices, that keto could be good somehow after years of downplaying, but only if you do it on margarine, nuts etc pufa-6 and fish oil based fats. E.g. old but small short study on skinny students

    Superficially, it all looks good, sugar/starch resistriction makes first its magic (and overly omega-6 intake messes things up):
    – keto is stronger, which suddenly is a Good Thing
    – glucose drops more -must be good (see sensitivity)
    – insulin drops a bit more
    – triglys drop more (less vldl sent out?)
    – only hdl does not “improve” as much (let’s leave ldl aside)

    All in all, in comparison to starvation fast (this must be transiently natural), everything goes a bit to other direction. Insulin sensitivity remains and improves!, strange, you keep signaling when you like to spare the little glucose for brain and red blood cells…?

  4. Good question! I suppose I don’t see elevated ketones as an end goal for the majority of people. (i.e. unless you are using it for the management of epilepsy, dementia, Parkinson, Alzheimer’s etc.

    I mentioned this study in chapter #11 of the book:

    As an aside, an interesting study looked at the response to 70% fat diets with high levels of polyunsaturated fats vs saturated fats (see Differential metabolic effects of saturated versus polyunsaturated fats in ketogenic diets). Participants saw more elevated blood ketones, lower glucose and better insulin resistance on the diet that provided more fat from polyunsaturated fats compared to saturated fats. According to Dr Tommy Wood, it appears that polyunsaturated fats allow us to eat more and put on more body fat before we exceed our Personal Fat Threshold and become insulin resistant. A ketogenic diet consisting of less saturated fat and more polyunsaturated fat may be useful if your goal is simply to maximise ketone levels for therapeutic purposes. However, it may not be ideal for body composition or long-term health.
    A diet with less unsaturated fat may help to raise our Personal Fat Threshold so we don’t become insulin resistant and develop Type 2 Diabetes as quickly. However, the satiety analysis indicates that unsaturated fats may also drive us to consume more energy from refined fat that will cause us to gain fat more quickly and reach our Personal Fat Threshold in a similar time.

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