Mastering Nutrition

Hi, I'm Chris Masterjohn and I have a PhD in Nutritional Sciences. I am an entrepreneur in all things fitness, health, and nutrition. In this show I combine my scientific expertise with my out-of-the-box thinking to translate complex science into new, practical ideas that you can use to help yourself on your journey to vibrant health. This show will allow you to master the science of nutrition and apply it to your own life like a pro.
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Mastering Nutrition



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Now displaying: February, 2017
Feb 18, 2017

Selenium is critically essential to the defense against oxidative stress and to thyroid hormone metabolism. Soil concentrations cause so much variability in the selenium content of foods that any two of us could be eating the same diet and one of us could have too little selenium and the other too much. That makes it essential to understand how to measure and manage our nutritional status. In episode 35, I continue the series on managing nutritional status by teaching you how to do just that.

The show notes for this episode are found at They contain recommendations about foods and supplements.

This episode is brought to you by Kettle and Fire Bone Broth. Use the link to get $10 off your first order.

This episode is also brought to you by US Wellness Meats. Head to and enter "Chris" at checkout to get 15% off your order as long as the final price is over $75 and you order fewer than 40 pounds of meat. You can use "Chris" to get the same discount twice.

In this episode, you will find all of the following and more: 0:00:34  Introducing the new name, Mastering Nutrition; 0:01:00 Cliff Notes; 0:10:55  My story with selenium deficiency: white spots in fingernails and frequent colds; 0:14:14  Soil variation plays a major role in selenium deficiency and toxicity; 0:18:40  Biological roles of selenium (antioxidant protection, immunity, thyroid health, through glutathione peroxidases and thyroid deiodinases, control of protein function through thioredoxin reductase, other poorly understood roles); 0:29:00  Signs of deficiency (vulnerability to viral infection and other infection, hepatic cirrhosis, white fingernails that can fall out, cardiac insufficiency and enlargement of the heart with fibrosis and necrosis as occurs in Keshan disease, increased vulnerability to vitamin E deficiency, iron overload, and toxin exposure) 0:39:45 Signs of toxicity (hepatic cirrhosis, white spots and streaks in brittle fingernails, loss of hair and nails, additional signs in acute toxicity from mistakes in supplement manufacture); 0:43:45  Optimizing between deficiency and toxicity: Hashimoto's thyroiditis and cancer; 0:49:00  Different forms of selenium in plant and animal foods; 0:49:38  How selenomethionine from plants is metabolized to selenocysteine; 0:55:10  How selenocysteine from animal foods enters as selenocysteine; 0:55:30  How selenocysteine is converted to selenide for incorporation into selenoproteins; 0:56:25  How inorganic selenite and selenate are converted to selenide using glutathione; 1:01:46  Markers of nutritional status (selenoprotein P, glutathione peroxidase, selenium concentration of various body tissues with an emphasis on plasma and serum but including other blood fractions, hair, and nails) 1:12:53 Ideal ranges of markers; 1:16:42  Dietary requirements and how to meet them with food (organ meats and offal, seafood, Brazil nuts, bioavailability issues in seafood, mushrooms, and cruciferous vegetables); 1:26:45 Why methyl-selenocysteine is not a substitute for selenocysteine and why selenomethionine is the best currently available option for a supplement; 1:28:13  The proper dose of a supplement; 1:35:07  Things we will learn in the future: implications of needing methylation to both utilize enough selenium and detoxify excess; interactions with glutathione and antioxidant system; selenoprotein P becoming commercially available to health care practitioners and individuals; the rise of novel markers as we learn more about the poorly understood selenoproteins 1:37:10  Wrapping Up

Feb 16, 2017

This is a quick note to let you know that I changed the name of the show from "The Daily Lipid" to "Mastering Nutrition" and to explain why I did it.

Feb 10, 2017

Stephan Guyenet made a book! The Hungry Brain is available now, and in episode 34, Stephan and I talk all about it.

Stephan is a long-time friend and colleague. He has a PhD in neuroscience, and studies the role of the brain in controlling the food we eat and the other behaviors we engage in that affect our body composition and risk of obesity. His book lays out how the brain makes these decisions and what we can do to outsmart these deeply rooted instincts in today's challenging environment.

We begin by talking about what makes us fat, why we are now fatter than ever, why our environment affects some of us so much more strongly than others, and what we can do about it on both an individual and societal level. Then we move on to the book: what you can get out of reading it, why Stephan decided to write it, and the process he used during the three years of research, writing, and publication. In the last part, I get Stephan's advice for people who want to follow a similar career path, and ask Stephan how he sees his career evolving now that he's left academia but has stayed so intimately involved with science.

You can find the shownotes for this episode at

This episode is brought to you by US Wellness Meats. Head to and enter "Chris" at checkout to get 15% off your order as long as the final price is over $75 and you order fewer than 40 pounds of meat. You can use "Chris" to get the same discount twice.

This episode is also brought to you by Kettle and Fire Bone Broth. Use the link to get $10 off your first order.

In this episode you will find all of the following and more:

0:35 Introduction, Stephan’s bio, overview of the interview; 1:00 Why do we get fat and why are we fatter than ever before? 13:00 Teasing apart increased food intake from decreased physical activity; 15:53 If the Hadza (hunter-gatherers in Tanzania) don’t have higher energy expenditure than we do, why are they so lean? 19:03 Food reward hit our society after a long decline in physical activity; what happens when high food reward hits a society where physical activity remains high? 22:25 What is the most fattening diet in the world? 28:15 Are effort costs more powerful than exercise? 33:52 The effect of the “built environment,” the effort costs of exercise and the cultural honor we bestow on convenience; 35:17 If our environment has become so obesogenic, how come so many of us are lean? 39:23 In Nutrition and Physical Degeneration, Weston A. Price took hundreds of photos of people all over the globe who ate themselves into very ill health with diets rich in refined flour and refined sugar, yet none of them are fat. Why not? 43:03 What are the most impactful things we can do as individuals to maintain healthy body composition? 46:50 What are the most impactful things we can do as a society to encourage healthy body composition?
48:56 The risks of food taxes and similar political tools, and the risks of inaction.

51:09 Who should read Stephan’s book, “The Hungry Brain,” and what does he hope they’ll get out of it?

53:26 How did he decide to write “The Hungry Brain,” and why did he find the concept so compelling and book-worthy? 55:20 That the brain regulates body fatness seems obvious in retrospect. What hid its obviousness for so long? 59:56 How receptive are nutrition scientists to the food behavior concepts being studied by neuroscientists?

1:02:35 How researching this topic in such depth caused Stephan to recalibrate the evidence and understanding he needs before he would be willing to challenge the perspectives of experts.

1:05:27 A day in the life of writing The Hungry Brain; 1:06:35 How Stephan got experts to talk to him; 1:09:15 How Stephan made the decision to leave academia from his postdoc to write a book rather than pursuing a tenure-track faculty position, and how he sees his career path evolving; 1:12:53 If someone were to follow in Stephan’s footsteps and write a scientifically rigorous book for a general audience, what do they need to lay the foundations for success? Audience building, funding and frugality, time for writing, pitching a proposal, illustrations, keeping the gears of the publishing gears turning, publicity; 1:16:30 How much time did Stephan spend on this? 1:18:15 Managing a book advance 1:19:38 The surprising hurdles of self-employment: will Stephan keep jumping them, or get a job? 

1:20:00 Wrapping up: where people can find the book, where people can find Stephan’s other work.

Stephan has given us all so much for free over so many years. Let's all buy his book!

Feb 3, 2017

In episode 33, we continue the series on assessing and managing nutritional status. This time we talk about copper. Copper deficiency can cause anemia that is very difficult to tell apart from iron-deficiency anemia, osteoporosis, histamine intolerance, high cholesterol, and a variety of mental effects resulting from neurotransmitter imbalances. Serum copper and ceruloplasmin are excellent tools for assessing nutritional status, but are confounded by inflammation, birth control, menopausal status, and hormone replacement therapy, making it necessary to look at the diet, lifestyle, digestive problems, and other factors that make copper deficiency plausible. 

I discuss how to protect yourself from the small risk of copper in your drinking water, and why I think many claims about excess copper outside the context of frank toxicity are misleading.

Everything converges on the practical questions of what to do in these situations.

You can find the show notes to this episode at

This episode is brought to you by Kettle and Fire Bone Broth. Use the link to get $10 off your first order.

This episode is also brought to you by US Wellness Meats. Head to and enter "Chris" at checkout to get 15% off your order as long as the final price is over $75 and you order fewer than 40 pounds of meat. You can use "Chris" to get the same discount twice.

In this episode, you will find all of the following and more:

0.00.35 Cliff Notes; 0.10:25 A case of copper deficiency? 0.14.00 Biochemical and physiological roles of copper (monoamine and diamine oxidases, MAO and DAO, lysyl oxidase, dopamine hydroxylase/beta-monooxygenase, peptidylglycine alpha-amidating monooxygenase, cytochrome C oxidase, superoxide dismutase, ceruloplasmin, hephaestin, metabolism of histamine, tyramine, polyamines, serotonin, norepinephrine, dopamine, conversion of dopamine to adrenaline, production of neuropeptides such as oxytocin, vasopressin, gastrin, neuropeptide Y, cholecystokinin, collagen synthesis, energy production, prevention of osteoporosis and neutropenia, immune support, cholesterol metabolism, antioxidant defense, mental health, and much more); 0:18:55 Copper's intimate relationship with iron; 0:30:10 What is the best marker of copper status (covers copper in serum, plasma, red and white blood cells, and platelets, ceruloplasmin, and other copper-dependent enzymes); 0:33:38 Effect of inflammation on ceruloplasmin; 0:35:10 Effect of estrogen on ceruloplasmin; 0:43:18 Causes of deficiency  0:43:50 How much copper do we need? 0:43:45 Best food sources; 0:48:30 Variation within food sources according to soil; 0:51:00 Zinc supplementation; 0:51:53 Digestive problems (SIBO, Celiac, antacids, proton pump inhibitors, PPIs, gastric bypass); 1:00:52 How to treat deficiency; 1:02:01 Which form of copper to use (oxide, sulfate, glycinate, etc)? 1:04:10 Toxicity: copper-mediated oxidative stress; 1:05:22 Wilson's Disease; 1:08:15 Infants and copper absorption; 1:11:00 Contribution of water to toxicity; 1:16:50 One case of supplement megadosing leading to liver failure; 1:17:30 Toxicity claims based on serum Cu or serum ZN/CU ratio are not reliable; 1:20:50 Summing up