In plain language, base your diet on garden vegetables, especially greens, lean meats, nuts and seeds, little starch, and no sugar. That’s about as simple as we can get. Many have observed that keeping your grocery cart to the perimeter of the grocery store while avoiding the aisles is a great way to protect your health. Food is perishable. The stuff with long shelf life is all suspect. If you follow these simple guidelines you will benefit from nearly all that can be achieved through nutrition.
Modern diets are ill suited for our genetic composition. Evolution has not kept pace with advances in agriculture and food processing resulting in a plague of health problems for modern man. Coronary heart disease, diabetes, cancer, osteoporosis, obesity and psychological dysfunction have all been scientifically linked to a diet too high in refined or processed carbohydrate. Search “Google” for Paleolithic nutrition, or diet. The return is extensive, compelling, and fascinating. The Caveman model is perfectly consistent with the CrossFit prescription.
Excessive consumption of high-glycemic carbohydrates is the primary culprit in nutritionally caused health problems. High glycemic carbohydrates are those that raise blood sugar too rapidly. They include rice, bread, candy, potato, sweets, sodas, and most processed carbohydrates. Processing can include bleaching, baking, grinding, and refining. Processing of carbohydrates greatly increases their glycemic index, a measure of their propensity to elevate blood sugar.
The problem with high-glycemic carbohydrates is that they give an inordinate insulin response. Insulin is an essential hormone for life, yet acute, chronic elevation of insulin leads to hyperinsulinism, which has been positively linked to obesity, elevated cholesterol levels, blood pressure, mood dysfunction and a Pandora’s box of disease and disability. Research “hyperinsulinism” on the Internet. There’s a gold mine of information pertinent to your health available there. The CrossFit prescription is a low-glycemic diet and consequently severely blunts the insulin response.
Current research strongly supports the link between caloric restriction and an increased life expectancy. The incidence of cancers and heart disease sharply decline with a diet that is carefully limited in controlling caloric intake. “Caloric Restriction” is another fruitful area for Internet search. The CrossFit prescription is consistent with this research.
The CrossFit prescription allows a reduced caloric intake and yet still provides ample nutrition for rigorous activity.
A theoretical hierarchy exists for the development of an athlete. It starts with nutrition and moves to metabolic conditioning, weightlifting, and finally sport. This hierarchy largely reflects foundational dependence, skill, and to some degree, time ordering of development. The logical flow is from molecular foundations, cardiovascular sufficiency, body control, external object control, and ultimately mastery and application. This model has greatest utility in analyzing athletes’ shortcomings or difficulties.
We don’t deliberately order these components but nature will. If you have a deficiency at any level of “the pyramid” the components above will suffer.
-Greg Glassman, What is Fitness?