Why Metabolic Flexibility is the best method to lose weight and stay lean!

That’s me foam rolling. These days I don’t work out quite as much and instead focus more on stretching and regeneration!

For as long as I’ve been in the fitness industry, I’ve been told that you should never go longer than a few hours without eating. And boy did I abide by that rule, turning me into one of those folks who could never go more than a few hours before becoming “hangry.” Hangry is a term that combines the words hungry and angry, meaning you become angry because you’re hungry when your blood sugar crashes a couple of hours after eating something. I was constantly snacking so I was always “well-fueled.” Because I also used to work out very hard average 5/week, I never really gained weight. I loved my carbs so much that I didn’t even want to consider cutting them a little. I’d rather work out like a maniac to stay lean. If I wanted to lose weight, I either counted (and cut) calories and/or worked out extra hard. Never did I consider my carb-intake.

I believe this was the biggest mistake I ever made when it comes to fitness and well-being in general.

With the exception of people who have medical conditions and have to follow a certain diet, the only people who should follow this high carb/medium protein-approach to fitness are those who are ONLY looking to add muscle and are extremely active every day. Think professional athlete (who tend to already have a low body fat percentage).

Most people don’t fit this profile. Most people tend to have too much body fat and many of them also have okay muscle mass (though adding some muscle is still usually a good idea, especially if you don’t have much muscle mass). Very few people want to actually lose muscle, though they exist.

Most people love carbs. Who can blame them? Carbs are delicious, which is why people tend to eat too many of them and get fat. America and, increasingly, the rest of the industrialized world, are getting fatter and fatter, not to mention unhealthier. The answer to this problem used to be to follow a ketogenic diet. I like to call it “going keto.” Going keto means you’ll eat very few carbs, medium amounts of protein and lots of saturated as well as unsaturated fats. According to registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women’s Hospital, the focus on a true keto diet is to eat way more fat than protein. (Atkins and Paleo are modifications of the ketogenic diet, allowing you to eat more protein.) I, like lots of other people, simply don’t want to live a life this strict when it comes to carbs. We still want to be fit and lean and feel great all the time, though. The common-sense solution is to become metabolically flexible.

Using the Metabolic Flexibility approach makes it easy for you to lose weight AND then stay lean. It will also likely cure many of your health issues, especially ones related to moods. Mood swings used to be my middle name.


It’s your ability to switch between burning carbs and fat to fuel your body to live your life, as well as to exercise. If you’re very metabolically flexible, you will have no problem going back and forth. You’re likely the kind of person who can eat whatever they want and never gain weight. If not, you’re one of those people who gain a couple of pounds after having dessert just once. The good news is, you don’t have to be this way. You too can become metabolically flexible, and I’ll tell you how later in the article. For some people making the switch will be easier than for others. It all depends on your current fitness levels and also on your genes. If you’re someone who’s been working out like a fiend most of your life, especially lately, it will probably happen in a week or so. Having practiced Intermittent Fasting will also make the switch easier.


In addition to easily losing body fat–which is what the vast majority of people mean when they say they want to lose weight–and staying lean, being metabolically flexible encourages you to always live like that. You don’t ever have to go on a hard-core diet (like going keto requires). Do I need to remind you that you’ll most likely gain back the lost weight and then some if you severely restrict carbs for a couple of weeks? Such a waste of time! If you’ve been living strictly on a keto diet, it will also be difficult for you to use carbs for fuel. In other words, you’ll likely gain body fat when you do eat that one dessert again because now your body is trained to use fat for fuel, not carbs. Plus, going keto will often make you feel tired and irritable. And when you work out hard, your muscles feel depleted and weak (because they are). Who needs that? Certainly not a performance athlete. If you want to run fast in a 5 or 10 K, DO NOT GO KETO. Low-carb diets are far more conducive to steady-state exercise like light biking or walking/light jog. Also, if you’re looking to ADD muscle to your body, do not go Keto. Low-carb diets are best for people who want to MAINTAIN their current muscle mass (like me; I have enough muscle.). You may have to go Keto for 7-21 days in order to become more fat-adapted, however. By fat-adapted, I mean able to easily switch to use your stored body fat instead of using carbs all the time. Which brings us to how to become metabolically flexible:


  1. EXERCISE. Like I already mentioned, if you’re someone who has always exercised a lot, switching from metabolic inflexibility to metabolic flexibility will be easier. That’s why I put exercise as the first thing you need to do. Walk a lot, do a lot of strength-training and intervals every now and then. According to Mark Sisson’s Guide to Metabolic Flexibility: ” Between improved insulin sensitivity, restored fat burning, and more (and better) mitochondria, exercise is the first thing you should be doing to regain metabolic flexibility.” Always get exercise!
  2. INTERMITTENT FASTING. Intermittent fasting is when you eat only within a certain amount of time every day, though it can also be that you’re not eating for a day or two each week. Check out my detailed Guide to Intermittent Fasting here. The most common approach is to go 16 hours without eating, and then eat normally in the next 8 hours. That’s called the 16:8, which is what I do, but I try to do 17:7 or even 18:6 whenever I can, as you burn more body fat the longer you fast.
  3. GO KETO. According to Mark Sisson, my new health guru, this is the fastest way to become metabolically flexible. Check out his awesome blog here (For some reason I can’t include his M F guide in my list of references below.) It’s especially effective for people who are very metabolically inflexible and sedentary. My recommendation is that you at least add a 45-60 min walk most days of the week to speed up the process. Also, if you choose going strict keto to become more fat-adapted (metabolically flexible) and you work out a lot, do about 90 grams of carbs/day. Only someone who’s very sedentary, has lots of body fat, and perhaps is pre-diabetic needs to go below 30 grams/day to get into ketosis. Experiment with carb amounts to see what works best for your activity levels.
  4. INCLUDE FOODS/SUPPLEMENTS THAT PROMOTE MF. Take magnesium supplements daily, eat things like very dark chocolate and colorful produce, and take/eat Omega-3 fat-rich foods like fatty fish.


  1. You no longer get hangry.
  2. Your energy levels stay consistent throughout the day.
  3. You’re no longer ravenous when you wake up.
  4. You can easily skip a meal without feeling bad in any way.
  5. You don’t feel the urge to snack.
  6. You no longer have mood swings.
  7. You can lose weight–body fat– fairly easily!

Remember, while you can enjoy life and eat carbs when you are metabolically flexible, it does NOT mean you can two pounds of chocolate cake a day. You will gain weight and feel like crap if you do;)










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