Mark Sisson's 'Closed Loop' Theory of Metabolic Efficiency

Mark Sisson sits down with his co-author Brad Kearns to discuss the topic of metabolic efficiency and why he thinks he doesn't eat all that much for someone of his size and activity level.

In Mark's recent "What I Eat In A Day" video, many people commented on how little Mark actually eats in a day. This video is a bit of a followup and addresses why he thinks that is.

[traceyshearer]

I do 20/4 IF and have never felt better. I don't tell most people because they look at you like your crazy. I exercise early and don't eat till 12-1pm. I think the body thrives on this system. I sleep better, my menopausal hot sweats have all but disappeared and I have no aches or pains. Life is good thanks to people like you guys👍❤

[joannekerr]

I often spend hours a day watching videos on paleo-primal-keto-carnivore subjects ... and then I come here and get ONE 10 minute video with Brad and/or Mark that changes my life.
I am intrigued by the 'closed loop' body system that you have begun to talk about lately and would love to hear much more about it.
Thank you both.

[ashleywessel]

Wow, you can really tell he has learned so much from years of trial and error, and is speaking from experience. What he talks about makes so much sense, as I reflect it it my own experiences and struggles. I so appreciate and am inspired by this man

[audrey]

Hey Mark and Brad! I have been following you for years and you have changed my life forever. At 52 I am healthier than ever! Thank-you 😊

[christinawoodard]

I lost 20 lbs in 8 weeks. I am now 13.5lbs away from my goal, healed my gut of colitis and borderline Crohn’s. I have always had some kind IBS even as a child. My liver enzymes have come down after yo-yoing in my blood work. THANK YOU MARK SISSON. you saved me from a 700$ medication a month med to suppress my immune system. There is always hope you guys.

[NHBob]

62 years old here, I discovered keto about 16 years ago from my then doctor Cate Shanahan when she was a physician here in New Hampshire. About a month ago I added in time restricted feeding IF with a strict 3 meals a day, no snacking. I'm 135 lbs, 5'11 small boned. I exercise every day 30 to 45 minutes of calisthenics or power yoga, plus time on my bicycle (with a trainer attached for foul weather). Breakfast is always three free range eggs over easy with about 2 oz. hard Italian cheese, then lunch is 3 slices of Swiss cheese and 2 slices of Turkey with Primal Kitchen mayo and maybe a small serving of fermented sauerkraut. Dinner will be some kind of meat like burger, steak, chicken, fish, or other seafood, some kind of green vegetable or salad. The salad gets the Primal Kitchen Caesar. A couple oz. of 90% dark chocolate to finish dinner off. A few times a week I will have a glass or 2 of wine at dinner, or 1 beer. 20 to 30 grams of carbs total for the day. I push those carbs to only dinner time so I have only 1 insulin event each day. This keeps my energy level high and constant throughout the day, and my mood very calm and stable.

[jameschesterton]

Mark is a great speaker, very interesting and articulate.

[stephikarolyi]

Mark and Brian's talks are always a treat.

[erikjanse]

Very interesting theory. First time I hear someone talking about increased temperature during the night to burn extra calories. I am experiencing the same!

[anitas]

This is great and not many discuss this at all - we just don’t need all that much to eat, especially if there’s body fat to use.

[djustice]

I can’t think Mark enough for sharing his knowledge. I’ve been following his advice for sometime now and I feel better now than I have in many many years. Also at age 49 I’m looking pretty damn good thanks Mark!

[MikeKilo]

I’ve been eating OMAD ketovore and intermittent fasting for some time now and it’s the only way for me! This man speaks the truth!

[justinmckenzie]

This video right here, folks. This is how it's done. There are countless videos on YouTube describing keto, weight loss, etc., but this one sums up the winning strategy perfectly. I lost 100 pounds long before I even discovered Mark Sisson or this video, but I'm here to say that this clip perfectly describes what worked for me. As Mark said, it's about being able to "access stored body fat on a regular basis." He hit the nail on the head at the 4:14 mark. I think it's inaccurate to call keto a "high fat" diet because that seems to imply the necessity of eating a lot of fat. Rather, it's a lifestyle of adequate protein to maintain muscle mass, and adequate good fats to feel satisfied. It's "high fat" only in the sense that you are eating more fat than protein. And you can have some low-glycemic vegetables if you'd like, and a little bit of low-glycemic fruit as well (i.e. berries). When you do all this, you end up with a ~2000 calorie lifestyle, low levels of glycogen and glucose, and a body ready to tap into fat every day. You can go from being fat, to being skinny fat. Then if you tweak this lifestyle a little bit and start lifting weights, I think you can get on a path to looking like the bodybuilders of the 50s, 60s and 70s (muscular and lean). I would think this would require more protein, lifting weights, and possibly replenishing the glycogen storage before a workout, while keeping everything else the same. Any thoughts?

[stevenfrew]

I have been on a low calorie diet for the past year and eating pretty much a similar diet to what you explain in your video. During this time I lost a lot of weight and body fat feel great However, I have been told that living on a low calorie intake is bad for your metabolism and I have been concerned that I am doing damage to myself. After watching this video I am happy that I can continue on the same path without fear and the whole "closed loop" makes sense. Thank you Mark and Brad for this video.

[alexanderturl]

Again…legit guy, great info, and lives the life he teaches.
My only problem is not mentioning how integral TRT is to maintaining his great body composition at this age.

[anthonyvitale]

I was just talking about this earlier at the gym!!! I can’t understand how I can push my body everyday running 5miles, boxing, S&C, 35-45 in the sauna & not be super hungry. Yesterday I wasn’t very hungry. I don’t eat usually until 2-3pm. I train fasted always have. Maybe my body is using food from the last day or so?? Because at some point in the week I will totally smash food. But sometimes I’m shocked with how little food I need. Assuming I need to eat more considering the training. I do focus on a balance of protein & fats & carbs. I love broccoli & kale. Idk maybe I’m metabolically flexible!!!

[melindawiens]

🌺 So incredibly true. I could not lose an extra 20 pounds for 10 years that had accumulated.
I now IF and have 2 low carb nutritionally dense meals and I am losing weight, have tons of energy and I’m enjoying my food. Love this way of eating.

[harackmw]

I tried 2 months of no carbs. I started to lose weight, but I couldn't function. The gut aches I had made me want to double over in pain, and I had to give it up. People kept saying it would eventually go away, but it didn't. Going to have to try and meet the plan half-way I think with some healthy carbs.

[rjreddenbaker]

Turned strict carnivore 4 months ago for health and weight loss reasons and it's exceeded expectations so far in several areas including weight loss, mental clarity, energy level, carb addiction control, and most importantly what it has taught me about WHY I eat. I got the Audible version of "2 meals a day" yesterday and really enjoyed the first hour or so I heard. I do want to be able to include some non meat things here and there, because I am doing this to have more quality time with my family, and for better or worse, we live in a culture centered around eating. I'm not going to exclude myself from the celebrations I did all this to be around for by missing out on things like having a drink with my daughter on her upcoming 21st b-day, or future wedding, or one of my wife's prize winning choc chip cookies once or twice a year with my girls while just watching a movie at home. Quality of life and food are important. For me it really boils down to treating processed foods and sugar like what they are - Very tasty poison. Eat a little, very infrequently, and most will be just fine. Make it a lifestyle choice - and you will get metabolic disease. Fortunately for most, if we stay at it, and are diligent and purposeful, we will feel better and get metabolically healthy and live long and prosper.

[leewood]

Love this stuff. transformational and liberating.