Like the saying goes, the only constant is change. We may resist it all we want, but Time and its inevitable evolution of everything in its path is unaffected by our attempts to stop it. The resulting trajectory of humanity's nascent ascent appears to be positioning itself to sweep us into progressive new times, especially where our food choices are concerned, as nearly 7 billion people are now standing on the little scraps of land that we share with some 55 billion rather large animals raised for food each year. (As another famous saying goes: This town ain't big enough for the both of us.) So, beef (and all factory-farmed meat) may be going from rib-eye to relic as we transition to a greener world… literally—as in leafy, green vegetables.

Environmentalists cite meat production as one of the biggest contributors to global warming, and the USDA's new food pyramid (MyPlate) suggests the healthiest choice is making vegetables and fruit the biggest part of every meal by reducing consumption of animal proteins. Kale is far more nutritious than other leafy greens, but these seven reasons why it is such an important futurefood may just surprise you.

1. Anti-inflammatory: Inflammation is the number one cause of arthritis, heart disease and a number of autoimmune diseases, and is triggered by the consumption of animal products. Kale is an incredibly effective anti-inflammatory food, potentially preventing and even reversing these illnesses.

2. Iron: Despite the myth that vegetarians are anemic, the number of non-vegetarians with iron-deficiencies is on the rise. Per calorie, kale has more iron than beef.

3. Calcium: Dairy and beef both contain calcium, but the U.S. still has some of the highest rates of bone loss and osteoporosis in the world. Kale contains more calcium per calorie than milk (90 grams per serving) and is also better absorbed by the body than dairy.

4. Fiber: Like protein, fiber is a macronutrient, which means we need it every day. But many Americans don't eat nearly enough and the deficiency is linked to heart disease, digestive disorders and cancer. Protein-rich foods, like meat, contain little to no fiber. One serving of kale not only contains 5 percent of the recommended daily intake of fiber, but it also provides 2 grams of protein.

5. Omega fatty acids: Essential Omega fats play an important role in our health, unlike the saturated fats in meat. A serving of kale contains 121 mg of omega-3 fatty acids and 92.4 mg of omega-6 fatty acids.

6. Immunity:Superbugs and bacteria are a serious risk to our health. Many of these come as a result of factory farm meat, eggs and dairy products. Kale is an incredibly rich source of immune-boosting carotenoid and flavanoid antioxidants including vitamins A and C.

7. Sustainable: Kale grows to maturity in 55 to 60 days versus a cow raised for beef for an average of 18-24 months. Kale can grow in most climates and is relatively easy and low impact to grow at home or on a farm. To raise one pound of beef requires 16 pounds of grain, 11 times as much fossil fuel and more than 2,400 gallons of water.

Want to eat more Kale? Try Rod Rotondi's delicious kale salad recipe, Hale Kale Salad. Enjoy.

Keep in touch with Jill on Twitter @jillettinger

Sources:

http://www.peta.org/issues/animals-used-for-food/meat-wastes-natural-resources.aspx

http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2461/2

http://www.irondisorders.org/iron-deficiency-anemia

http://www.ellenskitchen.com/faqs/calcium.html

Image: Steven Jackson Photography