Mark's Daily Apple is the go-to destination to learn how to lead a healthy Primal life in this hectic modern world. A completely irreverent, bold take on the latest in health, diet, fitness and supplement news. Daily health tips and breaking information. Recipes, fitness and health coaching.
To the average person, the idea of elite athletes skipping meals sounds like pure madness. Athletes are fine-tuned, well-oiled machines. Machines need fuel. You don’t see race car drivers running on empty to “promote training adaptations” in their vehicles. No, high performance requires high energy reserves.
Athletes need to eat, and eat well. Right?
But humans aren’t machines. We’re biological. The car doesn’t respond to training stress, but we do. We adapt, grow, recover, and build new capabilities in response to the stress we endure. You expose yourself to a ton of stress, recover from that stress, and end up stronger/fitter/faster on net. That’s training. And sometimes, high stress is exactly what we need to progress—a few heavy sets of squats, some rounds on the Airdyne, a killer CrossFit workout—as long as you can recover from it. A major modulator of our stress is the amount of food we have coming in. At least in theory, exercising in a fasted state could provoke a powerful adaptive response that athletes would find helpful.
So, does it stack up? What exactly can intermittent fasting offer athletes?
Benefits Of Fasting For Athletes
Increases In Growth Hormone
Growth hormone helps spur, well, growth. It improves immune function. It builds muscle, bone, and cartilage. Kids are swimming in the stuff, and they heal like Wolverine. Older adults who inject it enjoy improved wound healing and workout recovery. That’s why it’s a banned substance in professional athletics, and it’s why natural ways to augment growth hormone secretion can be very helpful to athletes of all stripes.
Fasting increases growth hormone, most likely as a way to limit harmful tissue degeneration and preserve muscle; so does exercise. Once or twice a week, I like to fast after workouts to extend and expand the GH release. That’s a slightly more extreme version of post-workout carb abstention, but it’s the same idea: withholding food and forcing your body to adapt. This increases growth hormone (important for fat burning and cellular repair) and speeds up fat adaptation.
Improvement Of Metabolic Flexibility
In experienced male lifters (5-year history of 3-5 days/week training upper and lower body, drawn from advertisements placed in bodybuilding gyms), fasting for 16 hours a day and eating for 8 increased metabolic flexibility.
Metabolic flexibility is the ease with which a person is able to switch between sources of energy—from carbs to fat and back again. For the average person interested in health and longevity, maintaining metabolic flexibility is an important way to live a healthy life. For an athlete interested in performance, health, and longevity, metabolic flexibility is absolutely essential.
If you’re metabolically flexible, you can burn fat for longer before switching over to carbs. You can burn carbs when you actually need them, right away. And afterwards, you can switch back into passive fat-burning mode to keep unnecessary carb cravings and insulin low and improve recovery.
Reduction Of Inflammation
To attain the training effect, an athlete must incur a big blast of inflammation (from the exercise) and then recover from that inflammation. Blunting the initial inflammatory response with drugs and even mega-doses of vitamins will impair the training effect. You can also reduce the training effect by training too soon after a workout, thereby stacking inflammation.
You need the inflammation, but you also need the inflammation to subside. Both sides of the coin matter. What fasting does is improve your natural ability to dampen inflammation. You get the big inflammatory response of a tough workout.
This is where a fasted workout can really shine. When you’re fasted, you’re in a state of very low inflammation. And then you introduce the workout, and inflammation spikes. It’s a big response, a heightened response—and you must adapt to it. Oscillating between fasting, training, and feeding lets you hit those extremes, those margins where peak performance occurs.
Maintenance Of Energy Expenditure
There’s something revitalizing about going without food for a decent period of time and then feasting. You could spend the week restricting calories each day or use fasting to arrive at the same weekly caloric load and the effects will be different. Chronic calorie restriction enervates. Intermittent calorie restriction peppered with intermittent feasting energizes.
For an athlete, chronic calorie restriction spells doom. They need energy. They need to be able to expend energy when they need it. Luckily, studies show that intermittent fasting is one way to “reduce calories” without reducing energy expenditure. Perhaps the main reason is that IF doesn’t necessarily lower calories; it just changes when you get them. In the bodybuilder study, the athletes in both the fasting and the control groups ate about the same number of calories. But only the fasting group lost a lot of body fat, and they did this without suffering a drop in energy expenditure. Pretty cool stuff.
That said, you can overdo it. Too much fasting for too long will depress energy expenditure, as would happen with any kind of chronic calorie reduction. It’s just that fasting seems to stave off the drop in energy longer than other forms of “dieting,” especially if you maintain your calorie intake.
Concerns About Fasting For Athletes
May Reduce Testosterone
In the bodybuilder study, the group with the 8-hour eating window experienced a drop in testosterone. As T is essential for muscle protein synthesis, performance, strength, and general vitality, this could be problematic for athletes (particularly male ones). Despite the drop in testosterone, though, they still gained lean mass, lost fat, and got stronger—so it may not be practically relevant.
May Be Hard To Get Enough Calories To Gain Muscle or Recover
Athletes do need more fuel than the average person. A big draw of fasting for weight loss is that it makes it easier to reduce calories by erecting illusionary barriers that we nonetheless adhere to. If you only have an 8-hour eating window, you can’t eat outside of it. If you’re “fasting today,” you simply can’t eat. It makes things really simple for people who otherwise have trouble limiting food intake.
The flip-side is that it can make eating enough calories difficult, especially for athletes who do need more fuel than the average person. In a recent study, lifters who ate inside a 4-hour eating window had a 650 calorie daily deficit, lost a little bit of body fat but failed to gain any lean mass, while the control group—who ate more calories and protein—did gain lean mass. The fasting group simply wasn’t able to eat enough food or protein. Despite that, the 4-hour eating window group still gained upper and lower body strength, and they didn’t lose muscle mass. I suspect they could have gotten great results with a few hundred more calories of protein.
As is the case with every study that attempts to collate the individual experiences and results of hundreds of humans into “trends” and “averages,” there’s a wide variety of personal responses to fasting among athletes. The name of the game is experimentation—you have to see what works for you. This week I’ll give some specific recommendations for specific types of athletes, as well as my own experiences utilizing fasting in the pursuit of better physical performance.
For now, though, how has fasting worked for you and your athletic pursuits? Does it seem to help or hinder?
Asparagus has always been one of my favorite vegetables. With great fiber content and a unique taste, it’s a go-to for my Primal and keto meals. Another plus: it’s simple to prepare. That said, however, it does take a bit of precision. The best way I’ve found to prepare asparagus is roasting, and nothing beats the tanginess of lemon to complement its taste. Serve it up with some flavorful chicken or salmon for a full Primal and keto-friendly dinner.
The light taste of fish is often overpowered by heavy sauces. We’ve found marinades to be a great alternative. Some healthy oil means they hold up better to the heat of baking or grilling as well. A quintessential summer flavor for said marinade? Cilantro lime of course! And we’ve got the marinade ready-made, to boot…. We’ve complemented this quick delicacy with fresh green beans, garnished with red pepper, red onion and some cilantro for an easy and tasty dinner pairing.
Additional cilantro, minced red onion and avocado, to garnish
Soak a cedar plank in water for 2 hours. While the plank is soaking, preheat the oven to 375 ºFahrenheit.
Toss the green beans, red pepper, garlic, avocado oil, red wine vinegar, and a pinch of salt and pepper together. Lay the mixture out on a parchment-covered sheet pan. Roast for 15 minutes, then flip the vegetables over with a spatula. Roast until the green beans and are well roasted and top with minced onion and cilantro.
Fire up your grill. The fish will need to cook over indirect heat. Take the cedar plank out of the water and place on a paper towel. Place the plank on the grill for 2 minutes. Flip the plank over and place the fish portions on top of the plank and spoon and remaining marinade over the top. Cover the lid and cook for about 15 minutes, or until the fish is firm and opaque. The cooking time may vary slightly depending on the thickness and size of the portions of fish. Top with chopped cilantro, minced onion and avocado slices and serve alongside the green beans.
Nutrition Information (4 oz. cod and 1/3 of green beans):
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The bracelet that shocks you if you eat too much junk food.
“When we bought our tiny shed, an 8x4metre box, half that size downstairs, we boxed what all we had and after a year donated what we hadn’t dragged out. We didn’t have much, now we have less and we love it. In 6 months we’ll be mortgage free at 47 and 53, permaculture based on an acre of off grid ocean paradise. Because we down sized and constantly checked in with need vs want. Life got simpler, easier and more fun. Now we choose. I recommend giving the Jones’ a wave but not trying to keep up with them.”
Fudge is the stuff of nostalgia. The fact is, however, it’s just a memory for most of us because of the high sugar content and unhealthy ingredients of typical recipes. But not this one…
This tempting keto fudge is just as creamy as you remember it, but with almost zero carbs and a boost of collagen as well as healthy fats, this recipe is a keto dream. And with the goodness of Nuttzo keto butter, it’s got a satisfying crispy crunch. Keto living just got more delicious.
One of the biggest challenges on the keto diet is curbing your cravings for carbs.
We’re used to filling up on bready things to feel satiated, so it makes sense that we reach for a sandwich when we’re low on energy. Going keto typically means that you need to give these foods up, but luckily, it is possible to whip up keto-approved loafs, rolls, and more that cut carbs while delivering the same chewy crumb you crave.
This recipe list has everything from fluffy almond flour sandwich bread to low-carb and keto-friendly snacks, like buttery garlic bread. On the sweeter side, there’s moist zucchini bread dripping with gooey, sugar-free dark chocolate, or a quick and easy blender batter blueberry-studded sweet loaf.
Sate your bread cravings with these keto-friendly recipes, and cut the carbs while doing it.
You spend your days reading this and other health blogs, communing with Primal and keto folks on social media, staying abreast of the nutrition literature, arguing about arcane metabolic minutiae on forums, counting your linoleic acid intake, and you forget that most people don’t know 2% of what you know about diet.
So, when you hear people criticize keto, don’t get exasperated (even if the criticisms are silly). Be ready to respond. And hey, not all criticisms are unfounded. In many cases, wrangling with them will only make you more honest and informed about your diet. Let’s look at some of the more astute keto critiques….
1) Your Brain Needs Glucose, How Do You Even Think?
This isn’t so much wrong as incomplete. Yes, the brain famously needs glucose—but not as much as we’re lead to believe. Once you’re keto-adapted, ketones can provide most of the brain’s energy needs. At max ketone production and adaptation, you’ll still need about 30 grams of glucose for your brain.
Your liver can make about 150 grams of carbohydrates a day from gluconeogenesis, so even if you don’t eat any carbs at all (and you can definitely eat carbs on keto) you’ll still be able to manufacture the requisite 30 grams of glucose.
2) Don’t You Need Carbs for Energy?
The beauty of keto (and low-carb eating in general) is that it leads to low insulin—both fasting and post-prandial (after meals). When your insulin is low, you’re able to access your stored body fat and liberate it to be burned for energy. Since even the leanest among us carry pounds of body fat, that means you have tens of thousands of calories of clean-burning energy available for liberation at any time.
Once you’re keto-adapted, you’ll most likely find that you have steadier energy than before.
3) How Do You Get Fiber?
Actually, there are plenty of ways to obtain fiber on a ketogenic diet. Many of the best sources of prebiotic fiber—the kind that feed and nourish the good gut bacteria living in your digestive tract—are fairly low in digestible carbohydrates and mesh well with keto. For example:
Green bananas (Yes, a green banana is mostly resistant starch, which your body cannot digest.)
Almonds and pistachios
Plenty of fiber in those.
4) How Do You Exercise Without Carbs?
There are two primary energy systems used during exercise: aerobic and anaerobic. Aerobic energy relies on fat; anaerobic relies on glucose. The better you are at burning fat, the more work you can do while remaining aerobic. This preserves stored glucose (glycogen) for more intense efforts, increasing your overall energy efficiency. Particularly for endurance training, being keto-adapted allows you to utilize greater amounts of stored body fat for energy and reserve glycogen for when you really need it.
And besides, if you do engage in glycolytic, glucose-intensive training, you can always cycle carbs in and around your workout sessions. Your insulin-sensitive muscles will suck up any glucose you consume as glycogen without affecting your insulin levels or your ability to generate ketones and burn fat.
5) Doesn’t All That Fat Give You Heart Disease?
The vast majority of studies placing people on low-carb, high-fat or ketogenic diets find that markers of heart health improve rather than decline.
In obese adults with type 2 diabetes, a ketogenic diet improved blood lipids and boosted fat loss compared to a low-calorie diet.
In lean, healthy adults without any weight to lose (and who didn’t lose any weight during the course of the diet), total cholesterol went up from 159 to 208 mg/dL and triglycerides fell from 107 to 79 mg/dL. A lipophobic doc might freak out at the rise in TC, but given that the triglycerides dropped, I bet the change reflects a rise in HDL and an overall positive, at worst-neutral effect.
Now, do some people see classically-deleterious changes to their blood lipids? Sure. Anything can happen. We’re all different. I talk more about keto and cholesterol effects here. But the weight of evidence shows that becoming fat-adapted through a keto diet is better for your heart health than not.
6) You’re Just Losing Water Weight, Not Fat
Here’s the truth:
Yes, when you go keto and start shedding glycogen from your liver and your muscles, you lose a lot of water. That’s because every gram of glycogen is stored with 3-4 grams of water. Burn the glycogen and you lose the water along with it.
But this glycogen-and-water loss is a prerequisite for losing “real” weight. It’s a harbinger for fat loss. Once the glycogen runs low, that’s when you start getting into deep ketosis and developing the ability to burn massive amounts of body fat for energy.
7) I Heard the Keto Diet Kills Your Gut Bacteria
Ah, yes, I remember that study. They either fed people a varied diet of fruits, vegetables, grains, legumes, and other foods—or a diet of lunch meat and cheese. Turns out the lunch meat and cheese “keto diet” was bad for the gut biome, increasing gut bacteria linked to obesity and metabolic problems and decreasing gut bacteria linked to health. Of course it was.
A keto diet doesn’t have to consist of bologna and American cheese slices. In fact, it shouldn’t. As I explained in the fiber section, a well-formulated ketogenic diet is full of prebiotic fiber, non-starchy vegetables, and even low-sugar fruit that provide plenty of nourishment for your healthy gut bacteria. What these studies and media stories attack is a caricature of keto, a diet full of processed meat and low quality cheese. They aren’t relevant for someone following a Primal keto diet.
8) Keto Isn’t Sustainable
Well, what do you mean by sustainable?
If you’re talking about the “restrictiveness” of the diet at a personal level, that depends. Sure, you can’t go keto and continue eating Pop Tarts and donuts for breakfast, heaping bowls of pasta for lunch, and fast food burgers (with the bun, at least) and fries with a shake for dinner. But you can eat eggs, bacon, and blackberries for breakfast. You can eat a Big Ass Salad full of a dozen different species of vegetables for lunch. And you can have a ribeye with buttered broccoli for dinner with a glass of wine. I don’t know about you, but that’s a pretty damn sustainable way to eat in my book.
If you’re talking about the environment, and worrying about farting cows or whatever, the evidence is quickly accumulating that properly-raised and managed grazing livestock can sequester more carbon than they emit, revitalize (and even de-desertify) grasslands, and produce more calories-per-unit-of-input than conventional pasture-raising. A large portion of the world’s surface isn’t even suitable for growing crops and is better used for grazing animals. The environmental sustainability of meat-eating is still an open question, but the popular conception of “meat bad, grains good” is completely incorrect and incomplete.
What other keto criticisms have you encountered in the wild? Leave them down below, and thanks for stopping in today, everyone.
For today’s edition of Dear Mark, I’m answering three questions. First, what’s the deal with the new Harvard study claiming that eating more red meat increases the death rate? Does it actually prove this? Second, how about the one claiming that reduced carb diets also increase death? Should you worry? And finally, why do I recommend eating locally farmed farmer’s market produce, even if it isn’t organic?
What’s your take on this Harvard study? www.hsph.harvard.edu/news/press-releases/increasing-red-meat-consumption-linked-with-higher-risk-of-premature-death/
“those who increased their daily servings of red meat over an eight-year period were more likely to die during the subsequent eight years”
It’s total nonsense with very little applicability to MDA readers.
Red meat eaters were more likely to be smokers.
Red meat eaters weighed more.
What else did people change as they added or removed red meat from their diets over the eight years?
The study doesn’t say much.
What we know:
Those who ate more red meat as time wore on also ate more calories per day—roughly 400 more. Those who ate less red meat as time wore on tended to reduce their overall calorie intake.
Those who ate more red meat as time wore on also gained more weight.
The simplistic urge is to assign blame for these changes to the increase in red meat, since that’s what the study is studying and that’s what they keep mentioning throughout the paper. But there are a million other variables that could have caused it, that likely did cause it, because that’s how cause-and-effect works in this world. Or rather, causes-and-effect.
And remember: this wasn’t an interventional study where one group was told to avoid red meat and one group was told to eat more red meat. This was data pulled from two different studies done decades ago, gathered by asking people what they ate on a typical day and then following up with them at a late date to see who died, who got cancer, who gained weight. It wasn’t explicitly about red meat. So, this is a mishmash of remembrances of what some people think they might have eaten, and the researchers from today’s particular paper homed in on the red meat and tuned out everything else.
This isn’t about individual people. These are abstract numbers.
One of the more interesting notes in the discussion section of the paper was this line:
Unprocessed meat consumption was only associated with mortality in the U.S. populations, but not in European or Asian populations.
I’ll be revisiting that line in the near future. For now, though, any ideas what could be going on?
Mark, do low-carb diets increase all-cause mortality? Hearing from lots of people about this latest one…
This is another piece of nonsense. Instead of studying legitimate low-carb diets like keto, Atkins, or basic Primal Blueprint, it separated people into four tiers of “low-carb” intake.
Tier one got 66% of their energy from carbohydrates.
Tier two got 57% of energy from carbohydrates.
Tier three got 49% of energy from carbohydrates.
Tier four—the one with the highest mortality risk—got 39% of energy from carbohydrates.
Now, I could probably hit “send” and stop the post right now. I mean, that about says it all. In what world is 39% of calories from carbohydrates a low-carb diet? How is that the “lowest-carb” diet? Pure madness.
The study also didn’t discuss diet quality. What kind of fats, carbs, and protein are these people eating? What exactly are they omitting and including? How’s their omega-3 intake? They eating mostly chicken, mostly beef, or plants?
All we know, in addition to their macronutrient ratios, is that people in the “low-carb”/39% carb group:
Smoked the second most.
Ate the least saturated fat.
Drank the most alcohol.
Exercised the least.
Really what this study is saying is that eating the high-fat, high-carb Standard American Diet will increase your mortality. This is no surprise.
As I’ve said before, you should pick a macronutrient—fat or carbs—to focus on and go with it. Sure, Michael Phelps could eat 10k calories of McDonald’s and maintain optimal performance, body comp, and health because he’s burning through it all, but you’re not him and you’re not training at an Olympic level for five hours a day. Trying to hang out in no-man’s land where you’re kinda high-carb, kinda high-fat is a bad idea for most people. You could make a 39% carb diet “better” by going with Perfect Health Diet principles, sticking to healthy Primal sources of starches and fats, but that doesn’t work for everyone.
You mentioned going to Farmers Markets every week. I would love someone to explain to me the push for buying local and going to Farmers Markets. Every time I hear them mentioned I cringe a little. I certainly understand buying local, and I agree with that, IF the fruits and vegetables are organic. Usually they are not, so I stay away from local and avoid the toxins/pesticides.
I can only assume that those who buy local don’t mind the pesticides, and if they juice, drinking a glass of chemicals.
What am I missing here? I would love to buy local, but sadly it’s rarely organic. I’d rather buy non-local organic.
Have you ever talked to the supposedly non-organic farmers?
In my experience, the vast majority of vendors at the farmers markets are using organic methods even if they aren’t certified. Reason being, organic certification is quite stringent to attain. It’s a multi-year process.
They have to go chemical-free for years. If they’re at year three of the conversion to organic, they can’t advertise “organic” but for all intents and purposes they’re there.
It costs money. Farming is a hard way to make a living. Going legit might represent a big chunk of cash that they can’t quite justify at the moment.
Go to a market, and go frequently. Get to know the people there. Look the farmer in the eyes and ask how they grow. The majority of the ones I’ve met are doing things right. They’re small operations. They’ve got their kids pitching in and helping out. They’re using man/womanpower and precision and know-how. They aren’t flying crop dusters to carpet bomb the entire field with chemicals.
Another (big) advantage of local produce is the freshness. Fruit and vegetables that travel fifty miles after being picked the day before are a world of difference from produce picked last week and shipped halfway across the country (let alone world sometimes).
That’s it for today, folks. If you have any questions or comments about today’s questions and answers, write in down below.
The last couple weeks I’ve grilled up some great Primal+keto meat dishes: steak and marinated chicken. But I’m a big believer in above ground, non-starchy vegetables for a Primal and keto diet. One of the things I love about this recipe is that it shows how vegetables—even cooked ones—never need to be a bland afterthought. These mixed peppers and onions are flavorful all on their own, but the seasonings and dressings turn this into a great side that will hold its own against any meat dish.
Chicken salad is a classic and a frequent sight at summer potlucks and luncheons. But the PUFA oils and high carb breads it usually comes with put a damper on what should be a good thing. Thankfully, this recipe offers a healthy re-do that satisfies a paleo, Primal, and keto standard—not to mention appetite.
Next time you cook up a chicken dinner, prepare a bit extra to put together this easy dish. It makes for a perfect workday lunch or fast weeknight meal.
Time in the Kitchen: 20 minutes (not counting chicken cook time)
2 lb. boneless, skinless chicken breast or thigh meat, cooked & shredded