The popular conception of a gene is “a weird collection of DNA and chromosomes and other stuff that determines whether or not you’re going to get this type of cancer, how long you’ll live, and if you’ll get a coronary bypass at some point in your life.” There’s this idea that genes are immutable, that they represent a sort of cosmic destiny for an individual. But, aside from some heritable traits like eye and hair color or the number of fingers on your hands and feet, genes are actually programmable. They “express” themselves in different ways according to information gathered from our environment, our food, and our behaviors. They “turn on” or “turn off” in response to these environmental signals. Thus, though you might have “the gene for type 2 diabetes” – which is really just a genetic proclivity towards the disease, not a sentence – providing the right environmental signals will prevent the gene from ever turning on.
How we eat, exercise, sleep, interact with our social circles, stress, and spend time outdoors (plus tons of other environmental signals) determines how our genes express themselves; how our genes express themselves in turn determines our level of health. Genetic predisposition is not your destiny.

Food is the single most important factor in body composition. You can exercise all you want but as long as you’re eating garbage, and too much of it, you won’t get very far. For that reason, any real attempt to modify your body composition has to begin by addressing what you put in your mouth. I like to start with the quality of the food you eat. I don’t discount the importance of quantity, mind you, but I do find that honing in on the quality of the food is more crucial and effective. Case in point: 2000 calories of fast food will have a very different effect on your body composition, satiety, and nutrient intake than 2000 calories of grass-fed meat, wild fish, and produce grown in rich, fertile, nutrient-dense soil. The fast food won’t be as satiating, nor as nutrient-dense, as the real food, so you’ll likely be compelled to eat more of it. The fast food will primarily include trans- and polyunsaturated fats, sugary sauces, refined grains, and poor quality meat, which will promote insulin resistance and the storage of body fat while inhibiting fat burning. Eating Primal food, rich in animals, plants, and healthy fat, on the other hand, will normalize insulin sensitivity, thereby allowing fat burning. In effect, quality will determine quantity; you’ll eat less spontaneously when you eat healthy Primal foods. Quality paired with proper quantity will in turn determine your body composition.
Sleep matters, exercise helps, stress has an effect, but how you eat – what you eat and how much you eat – is the prime determinant of your body composition.

Despite their exalted position in the Conventional hierarchy of healthy foods, grains are completely and utterly unnecessary. And yes, that even goes for whole grains. I mean, what’s so great about them, anyway? What unique nutrients do they provide? If you want fiber, eat vegetables. If you want antioxidants, eat colorful produce. If you want carbs, eat fruits and tubers. Humans got along fairly well without wide scale grain agriculture for many thousands of years, and there’s no real reason to buy in today, especially when you consider the grain antinutrients like gluten that impair digestion, reduce mineral absorption, and damage the intestinal lining. What is it, then, that necessitates 10-12 servings of whole grains a day? It’s madness. Besides, for all the supposed health benefits that the grain-obsessed like to say are supported with tons of studies, this just isn’t the case when you look a little deeper. Those studies invariably compare whole grains to refined grains, and in that case, the whole grain will generally win out. I’d suspect that if you compared a whole grain-based diet to a grain-free Primal way of eating, you’d get very different results. Unfortunately, that study hasn’t been done.
There’s nothing good in grains that you can’t get elsewhere, and plenty bad that you won’t find elsewhere. Don’t eat ‘em.

Another popular health canard is that dietary saturated fat and cholesterol are horrible, evil things that seek only to clog our arteries, thicken our blood, and pad our waistlines. That’s crazy, of course. Fat, especially saturated fat, and dietary cholesterol are important building blocks for sex hormones like testosterone. Saturated fat helps us absorb nutrients from our food. Saturated fat is inherently the most stable fat, able to withstand heat and light stress without oxidizing, and it’s incredibly satiating. Cholesterol is crucial in the creation of vitamin D from sun exposure. And contrary to popular belief and the protestations of “experts,” neither saturated fat nor dietary cholesterol have been linked to an increased risk of cardiovascular disease. Sugar, refined PUFA oils, trans-fats? Those are the real enemies. Oh, and consider this: every successful diet is actually a high-fat diet. When you lose weight, whether it’s through low-carb Primal or high-carb vegan, you are consuming ample amounts of highly saturated animal fat. The only thing is that this animal fat is coming off your body, but it’s still saturated animal fat just the same.
A diet rich in animal fat and cholesterol is not just safe, it’s downright healthy.

Exercise is healthy. Exercise is necessary for lasting wellness. Exercise builds muscle and exerts beneficial effects on hormone expression and function. Exercise gets you strong, gets you fit, and keeps you young. I like exercise; I do some form of it every single day, and I recommend that you do the same. But exercise alone is highly ineffective for weight management. For it to truly help manage your weight, exercise must be paired with a healthy eating plan, adequate sleep, effective stress management, ample sun exposure, and healthy amounts of social contact with friends, family, and loved ones. Sure, some people take exercise to the extreme, training for hours and hours on end, all in the quest to burn a few hundred more calories, to “make up for” those donuts at breakfast, to eradicate those love handles. And if you go long enough and hard enough, yeah, you’ll “burn calories.” But at what cost? Exercise is a stressor, after all. Maintained at a chronic, extreme pace and frequency, exercise becomes a chronic stressor that does more harm than good. It makes you hungry. It increases systemic and local inflammation. It depresses your immune system. It fatigues you, leading to less activity throughout the day. You’ll eventually and inevitably burn out unless you eat a massive amount of calories to make up for all that you’ve lost, and, at that point, you’re back at square one.
You can’t out-exercise a bad diet and poor lifestyle.

Study after study shows that the key to optimal health, aging, and fitness is muscle strength and mass. The more lean mass we have, the better we’re able to handle what life can dish out, whether it’s carrying groceries, playing with our kids, saving our own lives in a life-or-death situation, or engaging in the time-tested essential activity known as love-making. Luckily for those of us who relish our free time, the most effective, most efficient ways to build and maintain lean mass are through intense strength and sprint training. Twice a week, spend 15-40 minutes lifting heavy things using functional, full-body compound movements – squats, pullups, pushups, planks – and once every 7-10 days, spend 10-20 minutes doing 8-10 all out sprints. If you don’t want to move heavy weights, you don’t have to; bodyweight exercises are plenty of stimulus for most people. And if you’re not ready to run sprints on a track, plenty of lower-impact alternatives exist, like cycling, swimming, rowing, or even uphill sprints.