Greg Hickey, Ironman triathlete, former trainer and pro baseball playerOriginal author Let’s make fun of this question. I’ll give you the macronutrient breakdowns (carbohydrates, proteins and fats) of four foods and tell me which one you would choose as a protein source. Food A (100 g) 63.2 g of carbohydrates, 21.3 g of protein, 0.9 g fat (74.0% carbohydrate, 24.9% protein, 0.1% fat) Food B (100 g) 23.2 g of carbohydrates, 58.4 g of protein, 9.3 g of fat (25.5% carbohydrate, 64.2% protein, 10.2% fat) Food C (100 g) 21.9 g of carbohydrates, 7.8 g of protein, 3.1 g of fat (66 , 8% of carbohydrates, 23.7% of proteins, 9.5% of fats) Food D (100 g) 0 g of carbohydrates, 23.1 g of protein, 1.2 g of fat (0% of carbohydrates, 95.1% protein, 4.9% fat) Of these four foods, I would choose food B and food D. Food B has more total protein, but if I wanted less carbohydrates and / or fat, I would consider food D. But for proteins, I would choose both foods B and D compared to foods A and C. Food A has more protein t otali compared to food C, but I would consider food C if I wanted a lower percentage of carbohydrates.So what are these mysterious foods? Black beans.B chlorella.C Halo Top vanilla ice cream.D breast chicken. Based on this data, I would say that chlorella is a great source of protein that most people do not recognize. In fact, along with spirulina, chlorella is the most dense protein food I know. Chlorella and spirulina are just algae. You can buy them dried, both in powder and in compressed tablets. At the same time, I don’t consider ice cream or black beans (or any other type of non-soy beans) as an excellent source of protein. I wouldn’t eat ice cream for proteins (even an ice cream with higher proteins like Halo Top). And black beans have a similar macronutrient profile. So, if you want a large source of protein that is relatively unknown and is actually primarily a protein, try chlorella and spirulina. And for other sources of protein that most people don’t recognize, see the Complete Guide to Sustainable Proteins.