Pop quiz: Which has more protein per calorie, beef or broccoli? Yep. Broccoli. This green bodybuilding machine has 15.5 percent more protein per calorie than beef.

Animal protein has been linked with a higher risk of death for all cause mortality, CVD, and cancer (JAMA, 9/20/2016). Animal protein causes good stuff and bad stuff to grow really fast, while plant protein causes good stuff to grow, without the harmful side effects. The upper limit for protein intake should be 10% of calories. Spinach, garlic, black beans, oatmeal and garbanzo beans are excellent sources of plant protein.

Here’s the simple truth: Plants have protein, they have plenty of it, and it’s 100 percent healthy. Since you have a choice, why not choose the healthiest option? As Dr. Walter Willett, chair of Harvard’s Department of Nutrition, recommends: “Pick the best protein packages by emphasizing plant sources of protein rather than animal sources.”

Some of the information, and the graphic above are from Rip Esselstyn’s excellent book, The Engine 2 Diet.