The popular story of how low-carb diets work goes something like this: Reducing your carbohydrate in...
Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...Tell Me More
For this week’s edition of Dear Mark, I’m answering three questions from readers. First, is the reduced protein efficiency in older adults due to inactivity, or is it something inherent to the aging process, or both? Second, how does a person know if they’ve actually “earned” any carbs? Does everyone on a keto diet earn carbs by virtue of exercising, or is there more to it? And finally, how can a hardgainer with a packed schedule all week long and limited gym time maintain what little muscle mass he’s managed to gain?
Let’s find out:Read More
For today’s edition of Dear Mark, I’m answering a couple of questions from the comment sections of the last couple weeks. First, it’s been established that fasting and exercise both raise growth hormone. What about fasted exercise—does that have an even stronger effect? And what about continuing to fast after your fasted workout? Then, I discuss the inevitability (or not) of wear and tear on the arteries from blood flow-induced shear stress. Is shear stress “bad,” or do certain factors make it worse?
Let’s dig in.Read More
For today’s edition of Dear Mark, I’m answering three questions. First, can LDL actually infiltrate the arteries, or is there more to the story? Malcolm Kendrick says there’s more to the story, so I dig into some literature to see if they corroborate his position. Second, is New Zealand farmed salmon good to eat? And finally, what should you do about elevated ferritin levels—and why else might they be elevated if not because of your iron?
Let’s go:Read More
Last week’s post on iron levels got a big response and garnered a ton of questions from you guys. Today, I’m going to clarify a few things and answer as many questions as I can. First, do iron and ferritin levels mean different things for men and women? If so, how do those differences manifest? What about premenopausal women vs postmenopausal women? Second, what do we make of the fact that ferritin is also increased in times of inflammation? Is there a way to distinguish between elevated ferritin caused by inflammation and elevated ferritin caused by high iron? Third, is desiccated liver a good option for liver haters? And finally, I share some exciting plague news.Read More
For this week’s Dear Mark, I’m answering a question from a reader about a topic I thought I’d covered (so did they) already. A quick look through the archives (hey, I can’t remember absolutely everything I ever wrote) showed that I had not, so here we go. It’s all about whether fermented foods—sauerkrauts, kimchis, pickles, yogurts, and any other food that has been acted upon by probiotic bacteria—make eating meat healthier and more enjoyable. From the start, I suspected that they do, but I had to confirm it in the scientific literature.
Let’s find out:Read More
For today’s edition of Dear Mark, I’m answering one eternal question: How do the Hadza tribespeople of Northern Tanzania eat so much honey and maintain their trim figures and pristine metabolic health? Are they eating keto whenever they’re not eating honey? Are they running hill sprints to burn through glycogen stores and improve their insulin sensitivity? Are they trading mongongo nuts for Metformin? Or is there something unique about honey that makes it different than sugar?
But before I get to the question, it’s a brand new year.Read More
For today’s edition of Dear Mark, I’m answering a bunch of questions from comment sections. First, did I get AMPK and mTOR mixed up in a recent post? Yes. Second, I give a warning for those who wish to add ginger to their broth. Third, is it a problem that we can’t accurately measure autophagy? Fourth, how does coffee with coconut oil affect a fast? Fifth, is there a way to make mayonnaise with extra B12 and metformin? Actually, kinda. Sixth, should you feel awkward about proposing hypotheses or presenting scientific evidence to your doctor? No.
Let’s go:Read More
For today’s edition of Dear Mark, I’m answering a few questions from readers. First, the diabetes drug metformin looks like a “wonder” drug, even (or especially) for non-diabetics. Are there any known side effects? Is there anything we should watch out for?
Second, I address some of the concerns and criticisms shared in response to the Kraft Heinz announcement post.Read More
Last week, Craig Emmerich graced us with a great post on the oxidative priority of various dietary fuel sources, namely fats, carbohydrates, and protein.
If you haven’t had the chance to read through Craig’s post, definitely do. The visuals really drive home the point of fuel priority. Visuals appeal to me. They have a way of sticking with you, and there’s a power in recalling them when you’re making daily choices.
Today, I’m going through and answering some of the questions you folks had in the comment board.Read More
Yesterday, I linked to a study showing that the beneficial effects of high levels of cardiorespiratory fitness—the kind you build with cardio/endurance training, HIIT, and sprints—have no upper limit. At first glance, this study appears to bust the “myth” of chronic cardio and the U-shaped curve of endurance training and prove that the more you train, the longer you’ll live. This appears to run counter to some of my central claims—that too much mid-to-high intensity endurance exercise leads to burnout, health issues, and diminishing returns.
A commenter wrote a great comment that got me wondering:Read More