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: March, 2017
Mar 19, 2017

If you're concerned about your cholesterol, or confused about what to do, this episode is for you. In this episode, I list the four key factors that control blood cholesterol levels and outline the simplest dietary or lifestyle changes we can make to have the biggest impact.

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.

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

00:33 Cliff notes; 09:22 Targeting the low-hanging fruit; 11:50  The total-to-HDL-C ratio as a fingerprint of low LDL receptor activity; 13:20  Other markers such as particle size, particle count, and ApoB as fingerprints of low LDL receptor activity; 16:30  The four factors that control the LDL receptor; 18:50  Intracellular free cholesterol (effects of dietary fiber, cholestyramine, statins, and polyunsaturated fatty acids or PUFAs); 20:37  Thyroid hormone (effects of micornutrients, body fat, and carbohydrate intake); 23:50  Insulin (via PCSK9, effects of the fasting-feeding cycle and carbohydrate intake); 27:00  Inflammation (via PCSK9, effects of acute infection and chronic inflammation); 29:15  Practical approaches to maximizing LDL receptor activity; 29:22  Nutrient-dense whole food diets; 34:00  Thyroid disorder; 37:15   Adrenal stress, circadian stress, inflammatory stress; 39:05  Insulin resistance, body composition, and fatty liver disease; 42:00  Weight loss will improve insulin sensitivity, and for many a low-carb diet is a tool to achieve that, but in an insulin-sensitive person, carbohydrate stimulation of insulin has a powerful beneficial effect on LDL receptor activity; 46:20  Inflammation and PCSK9; 47:00  C-Reactive Protein levels, body composition, diet quality, and exercise; 49:25  Replacing fat with carbohydrate.


Mar 11, 2017

In this episode, I explain how to come up with a good question, obtain the background information you need, find research, obtain full texts, organize them, read the different sections of a paper to get the right kind of value out of it, and critically analyze the study design. If you're a beginner, this is really designed for you. If you're more advanced, you'll enjoy the specific examples I give of problems interpreting research studies.

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.

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

0:06:15  How to develop a good question; 0:09:30  How to use pubmed and Google Scholar; 0:11:50  Why and how to use MeSH terms (medical subject headings); 0:16:50  5 ways to get full-texts for free that are totally legal; 0:24:35  How Sci-Hub will facilitate the technological evolution of research distribution and the Spotify-ication of the science publication industry; 0:32:45  How to organize science papers to prevent wasted time and frustration later; 0:34:40  Reference management software; 0:36:35  The anatomy of a science paper; how you should approach each section and what you can learn from it; 0:46:45  Peer review makes discussions within papers more objective; how a scathing peer review from six years ago continues to influence how I teach hormesis today; 0:55:30  Acquiring background information with textbooks; 0:57:35  Specific textbook recommendations; 1:05:15  What you need to do before developing your own point of view; 1:10:30  Strengths and limitations of different study designs; 1:13:47  Observational versus experimental studies and the tradeoffs of context, size, and duration with strength of cause-and-effect inferences; 1:16:50  The central role of randomization in experimental studies; 1:19:20  Randomization needs a high sample size to be effective; 1:21:07  Example: Finnish Mental Hospital Study; 1:22:50  Example: LA Veterans Administration Hospital Study; 1:25:50  Regression to the mean; how a study can show something to be true when it’s completely false; change-from-baseline data versus differences-between-groups data; 1:35:45  The need for a control group: Atkins and methylglyoxal study as an example 1:37:35  Compared to what? Picking the right control group; 1:41:50  The generalizability tradeoff: in vitro and in vivo, animal and human, sex, race, and other population differences; 1:46:47  Contextual patterns determine outcome 1:47:50  Thailand zinc/vitamin A study as an example of nutrient interactions; 1:56:20  Do your homework, assume good faith, ask questions.

Mar 4, 2017

Do you want beautiful, flawless, radiantly healthy skin? Want to stay healthy during cold season? Want to eat that bagel without your blood sugar spiking through the roof? Then it's time to think about zinc.

Zinc is critical to every aspect of our biology, but the first things to go when we run low are our skin health, our immune system, and our glucose tolerance. Zinc, moreover, is critical to antioxidant defense, so should be considered broadly protective against all of the degenerative diseases that occur with aging.

Wait, are you too young to care about aging? No problem. You at least want healthy skin, great sex, or a lean physique, so listen up.

Zinc-rich foods are harder to come by then you'd think. Nutritional databases can be wildly inaccurate if you don't adjust for inhibitors of zinc absorption in natural foods. And zinc supplements can be valuable, but they're not a panacea. In fact, used wrongly, they can quickly induce a deficiency of copper and other minerals that are just as critical to your health. 

The show notes can be found at They contain recommendations for specific 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'll find all of the following and more: 

0:00:35 Cliff Notes; 11:40 The discovery of zinc deficiency on diets of whole wheat bread with small amounts of milk and potatoes, a quarter pound of clay, and no meat: dry skin, hypogonadism, lack of secondary sex characteristics, short stature, frequent infections; 17:25 The biochemical and physiological roles of zinc; 19:00 structural roles of zinc, with an emphasis on zinc finger motifs; interactions with vitamins A and D, thyroid hormone, adrenal hormones, and sex hormones 24:07 Catalytic roles of zinc, including the RNA polymerases that make it necessary for the production of every single thing in the body; 26:30 Interactions with vitamin A, from transport via retinol-binding protein (RBP) through activation by alcohol dehydrogenases to retinal and retinoic acid through creating vision via rhodopsin and regulating gene transcription via DNA-binding of the retinoic acid receptor; 29:20 Regulatory roles of zinc 32:25 Zinc and oxidative stress (necessity for hydrogen peroxide production in the thyroid gland and immune phagocytes, zinc release from zinc-thiolate clusters; protective effects of metallothionein exchanging zinc for other metals; negative effects of uncoupling of endothelial nitric oxide synthase [eNOS] on blood vessel function and oxidative stress; 42:45 Regulation at the cellular level (metallothionein, MT; ZIP and ZnT transporters) 44:20 Regulation of metallothionein (metal transcription factor-1 [MTF-1] through the metal response element [MRE] controlled primarily by zinc but also heavy metals, antioxidant response element [ARE] via Nrf1 and Nrf2, which provides regulation by oxidative stress and copper, glucocorticoid response element [GRE] which provides regulation by adrenal hormones and inflammation; 53:40 What happens when we eat zinc (effects of phyate, amino acids, calcium, organic acids, and iron) 1:01:00 Plasma zinc and the exchangeable zinc pool 1:06:00 Factors that affect plasma zinc status (variation according to meals, diurnal variation, stress, inflammation, menstruation) 1:10:25 Causes and effects of deficiency 1:14:20 Variations in soil zinc; 1:15:40 Balance of animal protein and phytate in the diet 1:19:00 Causes and effects of toxicity (especially with respect to copper deficiency) 1:27:20 What is the best marker of zinc status? 1:29:45 Plasma zinc as a marker of zinc nutritional status; 1:37:00 Copper deficiency markers as the most sensitive markers of zinc excess 1:38:10 Dietary strategies (animal foods, especially oysters, red meat, and cheese; soaking, sprouting, and fermenting to neutralize phytate) 1:40:35 Zinc supplementation on a plant-based diet (especially relevant to vegan diets but also to vegetarian diets) 1:42:25 Supplementation of zinc (what form? Citrate, acetate, gluconate, picolinate, oxide? What dose? When to take it?) 1:44:35  Recommendations for timing of diet and supplements across the day for best absorption 1:47:00 Wrapping up