Big Fat Keto Lies: Introduction

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 from my quest for nutritional enlightenment in ‘Ketoland’. 

Over the years, there have been many variations on low-carbohydrate diets, each with their unique theories and beliefs.  More recently, ‘keto’ has thrived thanks to the power of podcasts, YouTube, conferences and social media. 

‘Keto’ is now a broad umbrella term that can mean a lot of different things to different people.  Much like religious sects, new groups splinter and spawn where there is any slight disagreement. 

We now have endless versions of keto, with numerous subcultures and closed communities, where people can celebrate their own version as they follow their preferred guru who speaks ‘the truth’.  Then, when they all come together for conferences or online summits, they all have conflicting messages. It’s no wonder there is so much confusion and so many arguments online (which ironically, likely boost the popularity of keto, because controversy gets clicks)!

I have been fortunate to have access to some unique and large datasets that have enabled me to test the various theories and claims.  I wanted to identify the common themes that make all diets work while eliminating the ‘magical thinking’ that is common in nutrition and other areas where the science is not yet settled. 

Through my journey, I have gained some unique insights that I can’t wait to share with you!   But rather than just ‘keto bashing’, I want to empower you to differentiate fact from fiction so you will be more able to recognise the counterfeit and half-truths, no matter how strongly a particular group believes them.  

You will be able to leverage the many benefits of low-carb and keto while avoiding the beliefs that, when taken to the extremes, often become counterproductive and even dangerous. 

I hope the insights from my journey will help you avoid the pitfalls and potholes that many find themselves stuck in on the road to nutritional enlightenment. 

Note: This post is the first chapter of my new book, Big Fat Keto Lies, which will be available here for a limited time. To read it all now, you can get the full book here.

The twelve lies

I have organised the chapters of this book around 12 “lies”.  Rather than intentional lies, you could see these as half-truths or misguided beliefs, that when taken to the extreme, will lead you away from optimal health. 

  • Keto Lie #1:  ‘Optimal ketosis’ is a goal and 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 fat
  • Keto Lie #4:  Protein should be avoided because of 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 #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

If you’ve spent any time researching low carb or keto diets, you may have come across some of all of these.  Different groups hold some or many of these as their core tenants.  However, you may have also come across plenty of arguments around these beliefs and why they are not necessarily true.  Unfortunately, the arguments on Twitter and Instagram often add to the confusion. 

My goal here is to examine each of these lies through the lens of Nutritional Optimisation to provide some clarity, give you a deeper understanding of what is happening.  I also want to give you practical action steps that you can apply and give you the knowledge to troubleshoot your diet if/when you find these beliefs are no longer serving 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. 

Growing up, my family was mostly vegetarian for religious reasons, so I ate plenty of processed grains and fake meat (before it was popular).  I am married to 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 occur with high blood sugars during pregnancy.  Happily, we now have two robust teenagers who are thriving.  

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 integrative systems.   What you are about to read is not your typical diet book.  I have tried to lay out the logic of how I think the various parameters in health and nutrition interact and which levels you can pull to most effectively get the results you need. 

Insights from Type 1 Diabetes

I still spend a lot of the day watching Moni’s continuous glucose meter (CGM) trace as I try to fine-tune her closed-loop insulin pump system to optimise her blood sugars.  I want to understand how I can empower her to optimise control of her diabetes as well as manage my health and set an example for our kids. 

I find it fascinating to see all the things that affect blood sugar and insulin.  I have used my analysis to crunch the numbers to better understand how to give Monica the best chance at a long, healthy and vibrant life.  

People with Type 1 Diabetes give us a fascinating quantitative insight into how our bodies respond to the food we eat.  But I have also learned that it is critical to understand the difference between someone with Type 1 Diabetes and the 99.99% of us who have a fully functioning pancreas. 

The techniques that work to 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.  The vast majority 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 on many of the low-carb and keto thought leaders, gurus and even doctors. 

Agnostic nutrition

In days gone by, humans saw things that they didn’t understand as mysterious or magical.  We formed religions and worshipped deities (like the sun, earth, fire, thunder and rain) that gave us nourishment and sustained us.  In modern times, we have moved on from many of these deities as we gained more knowledge about the sun, rain, thunder, fire etc.  Empirical data and a deeper scientific understanding have filled in many of our knowledge gaps. 

But, while we have gained a deeper understanding of the external world and universe, many of the things that occur inside our body are still a mystery to us.  Rather than worshipping mystical deities in an attempt to explain natural phenomena, many of us still give special names to, put our faith in and ascribe near-magical or supernatural power to diets.

While nutrition is still an evolving science, it is still a science, not a matter of religious belief or debate.  Although commercial interests and religious beliefs have heavily influenced the conversation around nutrition, I believe nutrition science needs to be agnostic.  There must be some simple fundamental principles. 

But context is always critical.  To make progress towards your destination, you need to understand where you are now and where you want to get to.  My aim in this book is to highlight the most powerful levers in nutrition and how they can be applied in a range of contexts for people with different goals.

Endogenous ketosis for health and fat loss vs therapeutic ketosis

Nutrition is not a ‘one size fits all’ solution.  When it comes to ‘ketogenic diets’, to ensure you get the desired outcome, it is critical to understand the difference between:

  • a ketogenic diet designed for health, weight loss and diabetes reversal to achieve endogenous ketosis (i.e. when fat is released from your body stores), and
  • a therapeutic ketogenic diet designed for the management of epilepsy, Parkinson’s, dementia and Alzheimer’s disease, where ketone levels are driven from external sources  (i.e. dietary fat from the food eaten). 

Simply ‘going keto’ 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 goals.

Optimising Nutrition

In 2015, I started sharing my observations on and was overwhelmed by the response. 

In addition to the articles, I spent a lot of time analysing people’s food logs to create food and meal recommendations to help them move towards more optimal nutrition.  Then Alex Zotov offered to partner with me to develop a suite of tools that would help automate and scale the process of Nutritional Optimisation to make it scalable so we could help more people.   

Over the past couple of years, we have helped people apply the insights from our analysis by developing the Nutrient Optimiser.  We have run numerous Nutritional Optimisation Masterclasses and have seen some radical results as we guide people to implement our systematised approach.  We have continued to refine our data-driven approach to nutrition to try to make it as simple as possible for people to get the results they want. 

More recently, I developed Data-Driven Fasting, which leverages your blood sugars to guide your fat loss journey.  The response, and the results it has produced, have been phenomenal!  It seems that most people are more interested in not eating rather than learning to eat well.  But the best results always occur when the two are paired together. 

Why am I doing this?

My goal with this book is to summarise the key lessons learned and ‘ah-ha’ moments that I have had after writing hundreds of articles and working with thousands of people in the Nutritional Optimisation 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 useful 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. 

Just reminding you that I’m not a doctor:  I just love numbers, graphs and interpreting data.  I have devoted every spare moment I have had over the past 5 years to analyse, research and write 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 miss the forest for the trees.  We need to step back to look at the big picture to see if it aligns with reality for most people most of the time. 

Who is this book for?

I created this book with a range of different audiences in mind.

  • For people who have been following a ‘keto’ or low carb way of eating for more than a few months and may not be getting the continued results, this book will help them fine-tune current way of eating to ensure they continue to move toward their goal.
  • For people who are managing diabetes (either Type 1 or Type 2), it 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 who are interested in nutrition and just want to learn to eat better, this book will give you some fresh insights about how to view nutrition through the lens of Nutritional Optimisation.

What is ‘optimal metabolic health’ and why is it important?

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

In this book, you will see the term ‘optimal metabolic health’ used repeatedly, so 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 says, pretty much anything that makes you leaner makes you healthier.   This is not simply a matter of being lighter, but rather having less body fat with more strength and lean muscle mass. 

We’re always looking for hacks and shortcuts to look and feel better.  We can manage symptoms and markers with drugs and hacks, but they only give you better test results.  But managing symptoms and test results don’t always make you healthier. 

Some common forms 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, sleeps well, has good circadian rhythm and gets adequate sun exposure), and
  • statins to reduce cholesterol (so our blood cholesterol levels conform to what we believe are healthy values), and so on.

These days, our food system is awash with cheap energy.  We are overfed but undernourished.  We’ve won the war against hunger and conquered food security issues that we were trying to solve half a century ago. 

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

Nutrient poor, low satiety food drives us to eat more than we need to get the nutrients our bodies need for optimal health.  This quickly leads to energy toxicity (i.e. excessive amounts of energy in our bloodstream as high levels of glucose, ketones and free fatty as well as our body fat), which is the root cause of the majority of our modern diseases (e.g. obesity, Type 2 Diabetes, heart disease, etc.). 

The way to improve our metabolic health is to make more informed food choices that will enable us to get the nutrients we need without having to consume excess energy.  But rather than merely using more willpower (which usually leads to hunger, failure, guilt and rebound binging), we need to make smarter food choices that leave our body satisfied. 

Sadly, only a small minority of us are defined as metabolically healthy.  Although we don’t need to all become super-fit bodybuilders, most of us would benefit from having a little less fat and a little more strength and lean body mass.  It’s not just about being lighter, but rather having less body fat and more muscle to ensure we are resilient, especially as we age. 

Some simple measurements that you can use to track your progress on your journey towards metabolic health at home (using a tape measure, bioimpedance scales and a blood glucose meter) include:

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

You may be a unique snowflake, but…

You may be a unique snowflake, but what I offer here is my summary of the research that I have found most useful, paired with my analysis of a number of large data sets, to show what works for most people to help them manage their blood sugars, insulin, satiety, and body fat and thus move toward optimal metabolic health.  I would be surprised if what you read here doesn’t work for you if you are willing to apply it. 

Over the years of riding the keto wave, I have made plenty of mistakes and believed many things, which 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 will also love it if the low-carb and keto communities listen so they can continue to grow, become stronger and help more people.  

I have been banging this drum for a while.  The articles on Optimising Nutrition have had 4.2 million views, from 2.3 million people from all over the world.  Many have listened.  Some have not.  But I have tried.  What you will read here are 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 research into the benefits of keto and low carb has been done for people with epilepsy, cancer or by people wanting to market some magical supplement.  This book is aimed at the vast majority of people who are interested in low carb or keto because they want to reverse their diabetes, lose body fat and achieve more optimal metabolic health and more reliance to whatever comes your way. 

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

Get your copy of Big Fat Keto Lies

I hope you’ve enjoyed the introduction to Big Fat Keto Lies.

You can get your copy of the full (207 pages, 45k words) book here.

What people are saying about Big Fat Keto Lies

Marty Kendall enjoys one of the highest vantage points in the entire nutritional landscape.

Thanks to an open mind and a keen eye for seeing patterns in data, Marty has managed to entirely reverse engineer eating.

In his book, ‘Big Fat Keto Lies’, Marty sifts through the quagmire of diet religion and deftly plucks all of the essential gems out of a huge pile of unhelpful dietary dogma.

Ted Naiman MD

Marty, this book is brilliant!  This is my message to the world also! 

You continue to inform people with honest and accurate information and self-experimentation.  We are all learning together.  Thank you for your contributions. 

Nutrient density is where it’s at, and I agree entirely that each person needs to figure out their own carbohydrate tolerance. 

Professor Mark Cucuzzella MD FAAFP

Professor West Virginia University School of Medicine

WVU Centre for Diabetes and Metabolic Health

There are many myths and misconceptions on low carb and ketogenic diets.  Learning how to do the diet correctly from the beginning will make a big difference, especially on your medium to long term results and health.

Keto can be a great tool to improve your health, but more so if done correctly from the start.  In his book, Marty does an excellent job at reviewing, correcting and explaining in an easy to understand way, the most prevalent myths in the low carb/keto community.

Luis Villaseñor

Nutritionist, SFN

Ketogains Founder

Big Fat Keto Lies is a must-read for anyone who has stalled on their path to health and optimal weight. Data-driven engineer Marty Kendall unpacks the common keto dietary conventions that typically cause people to fail in the long-term.

Marty, through easy to follow discussions, explains the often neglected but importance of focusing on dense foods to control appetite – beyond simply looking at macros and calories.

If optimizing your health and nutrition is your goal, you will not be disappointed.

Jeffry Gerber, MD

Family Physician, Denver’s Diet Doctor

Denver Colorado, USA

Every popular diet contains some truth and, as time goes on, ever greater outlandish, hyperbolic and inaccurate claims.

Marty Kendall does a superb job at dispelling the many myths of the keto diet that have grown up over the past few years but offers us a legitimate solution based upon tens of thousands of his analysis of many large data sets.

Big Fat Keto Lies is an essential read for anyone wanting to step out of all pop culture diet trends and embrace a truly agnostic form of nutrition for health.

Aimee Gallo

Vibrance Nutrition

Certified Nutritionist

Master’s in Nutrition and Functional Medicine  

If your goal is to healthfully lose body fat using the most up to date nutrition science and don’t know where to start, I highly recommend Big Fat Keto Lies, by Marty Kendall.

As a Harvard-trained radiation oncologist, integrative oncologist and functional medicine practitioner, I have spent nearly two decades counselling patients on the importance of reducing body fat and insulin resistance. During this time, I have witnessed countless patients try unsuccessfully to lose weight or maintain their weight loss using the latest “weight loss diets” (including the popular ketogenic diet and intermittent fasting). Once you read Big Fat Keto Lies, you will understand why these approaches, often don’t work.

Marty explains in a very approachable manner, the reasons why people are biologically programmed to fail on most weight-loss diets or calorie restriction. In Big Fat Keto Lies, you will also learn practical, effective, healthful and sustainable approaches to fat loss that are simple to understand and implement. I will be recommending this book for all of my patients who want to optimize their metabolic health, lose body fat and improve their anticancer biological terrain.

            Dr Brian Lawenda, MD

Medical Director, Northwest Cancer Clinic

National Director of Integrative Oncology and Cancer Survivorship

GenesisCare, Kennewick, WA

Marty is the best.  Like a watchmaker who understands every little cog in and wheel of nutrition.

            Cian Foley


Get the book!

Get your copy of Big Fat Keto Lies.

To kickstart your journey towards optimal get your free program and one of 70+ food lists personalised just for you!  

Marty Kendall

  • Bill Robinson says:

    …and yet you still seem to ignore bioavailability…
    But go ahead and take down my comment as you usually do.

  • Wenchypoo says:

    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.

  • JR says:

    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…?

  • Marty Kendall says:

    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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