One of the reasons CrossFit tends to produce excellent physiques in both men and women is that it forces you to do everything. You’re lifting heavy, sprinting, going long and slow sometimes, going short and intense. You’re tapping into every energy system and stimulating anabolic pathways. It’s a recipe for fat loss and muscle gain.
If you eat enough to support your activity levels, that is.
Historically, that’s been the big knock against paleo by CrossFitters: It’s too satiating a diet. The food you eat is so nutrient-dense that you end up eating fewer calories than you need to maintain the activity. What makes paleo so great for weight loss—inadvertent calorie reduction—makes it tough for CrossFit.
One argument is that this is exactly the point. CrossFit is too demanding, and if you can’t keep it up on a paleo diet—arguably the diet to which our bodies are best adapted—there’s something wrong with the training. Maybe so. Maybe CrossFit does ask too much of you. But that’s what humans do. We push boundaries. We seek new heights. We elevate and innovate. It’s what built this civilization, and it’s what drives people to endure great physical discomfort in the gym, on the field, or on the track.
Criticize it all you want, but it’s not going anywhere. I’m glad for that. Breaking boundaries is kinda what makes us great.
But it can be intense. Research indicates  that the average CrossFit WOD burns about 20 calories per minute (for men) and 12.5 calories per minute (for women).
Calories burned don’t provide the whole story. Replacing energy expended is one thing. Building new tissue is another. While a slogging jog around the block burns calories, it triggers an insignificant amount of muscle protein synthesis. To increase protein demands, you need to lift something .
A CrossFit workout burns calories and it increases muscle protein synthesis—two conditions that increase calorie requirements.
Where does the Primal Blueprint eating plan fit in? How can it account for the increased energy demands of CrossFit?
On paper, I think everyone understands the potential for going Primal while a CrossFitter.
You eat more calories and micronutrients. Whereas a typical gym rat might have a post-workout shake with waxy maize, egg whites, and skim milk, a Primal post workout meal might include baked potato, seared sockeye salmon, and a glass of whole milk. Similar calories counts, vastly differently nutrient profiles. Those extra nutrients will assist in performance and recovery.
But you have to eat them.
How Can You Make Sure to Eat Enough on Primal?
Breakfast sets the stage for optimal eating the rest of the day. Now, I’ll often skip breakfast, but I’m not trying to support a CF schedule. I’m not trying to gain weight. Skipping breakfast is skipping a great opportunity put more food in your body.
If you are a dedicated early morning class participant, you can work out fasted but make sure you eat enough the night before and be sure to eat breakfast soon after, even if you aren’t famished. These workouts can a suppress appetite for a few hours. While that’s great if you are looking to lose fat, to reach peak performance and aid in recovery you need to eat.
This flies in the face of my usual advice to savor your food, linger at the table, and make a meal a drawn-out event. There are times and places for that kind of eating, but it’s not conducive to getting enough calories. Studies show that people who eat breakfast faster get hungrier sooner , an effect not mediated by changes to appetite hormones. It just happens. Go with it.
Eat Calories First, Micronutrients Second
Prioritize the foods that provide the most calories, then eat the lighter fare. Don’t eat a cup of steamed spinach, for example, then your steak and sweet potatoes. The spinach has satiety-inducing compounds but very few calories ; many low-calorie, high-nutrient plant foods are similar in this respect.
Eat More Carbs
Low-carb, high-fat dieting is probably the most effective way to inadvertently reduce calories. That is, people eating that way just tend to eat less food without trying. Eat more Primal sources of carbs should increase your appetite—or at least stop suppressing it—and allow you to excel in your training. Since your carb requirements have gone up doing CrossFit , this shouldn’t be a problem.
Add Fat to Your Food
Gram for gram, fat contains the most calories of all the macronutrients. I’d advise adding nutrient-dense fat sources  to your meals, like egg yolks , grass-fed butter , bone marrow , cheese , avocados  (and their oil ), olives  (and their oil ), and nuts /seeds .
Make Sure You’re Not Actually Strict Paleo
Primal is far more flexible than strict paleo, allowing calorie-dense foods like dairy , white rice , white potatoes , and even legumes . We also promote the consumption of fatty meats, which are higher in calories than the leaner meats promoted by the earliest versions of paleo.
Get Fish Sauce
Real fish sauce —the stuff made by fermenting salted fish—is a potent source of glutamate, the flavor-enhancing amino acid also found in MSG. Glutamate is a powerful amino acid, despite its bad reputation. You can use it to teach picky eaters to like novel foods . You can add it to almost any savory food to boost the umami flavor and enhance the entire eating experience. And it can help increase appetite and improve digestion .
Before you enact those changes, first make sure you truly do need more calories. There are some tell-tale signs that you’re not getting enough calories, beyond the typical ones like poor performance and harder recovery. (You can consider using a TDEE calculator if you feel you need to. There are a lot of them out there these days. Eat to Perform  is one that caters to CrossFitting, and it’s free.)
Signs You Need to Take in More Calories
Female Athlete Triad
Female CrossFitters are at risk for the dreaded “female athlete triad.” When women combine heavy, intense training with undereating, they may develop the “female athlete triad “: disordered eating (ultra low calories), osteoporosis, amenorrhea. If all that sounds extreme, it is but it isn’t; the triad is shockingly common among adolescent and young adult female athletes.
Also, the triad exists on a spectrum. You may not be breaking hips and losing your fertility outright, but you could be weakening your bones and skipping periods. These are all warning signs.
Male athletes are at risk, too. Not for the missing periods, but for the other stuff .
Slower Recovery from Sprains and Pulls
It’s common knowledge that undereating impairs your ability to bounce back from workouts. Extreme low calorie intake also inhibits collagen synthesis , a crucial step toward healing connective tissue after a strain.
Calorie restriction lowers testosterone , sexual impulses, and attraction to otherwise fetching females (albeit rodent females). Human calorie-restricted males also have lower testosterone . This tanks your ability to recover from exercise, let alone actively make gains. And remember, women need testosterone to make gains , too.
While we sleep, If we’re trying to maintain a heavy CrossFit schedule while undereating, our stress hormones will be high, our blood sugar will be all over the place, and our liver glycogen will be low. Our livers are supposed to release glycogen as needed to keep blood sugar stable while we sleep. If they don’t have enough glycogen, your body releases stress hormones to convert protein into glucose. That shot of adrenaline solves the blood sugar issue, but it also tends to wake you up, or at least disturb the quality of your sleep.
Fat Gain, Especially in the Belly
When your calories get too low, cortisol – one of the main stress hormones – goes up . Chronic elevation of cortisol , as you probably know, is strongly associated with abdominal fat.
If any of those symptoms check out, and you do need to eat more calories, Primal is a great way to make it work.
Thanks for reading, everyone. Take care and stay tuned for the rest of the series.