Tofu: 2 ounces (about 1/4 cup) = 1 Protein

Tempeh: 1/4 cup = 1 Protein

Soy nuts: 1/4 cup = 1 Protein plus one Extra

Edamame: 1/3 cup = 1 Protein

Miso paste: 2 tablespoons = 1 Protein

Soy milk (non-fat): 1 cup = 1 Dairy

What about soy foods not listed? First, decide if the item is basically Protein (most soy products count as Proteins), Dairy (if it's soymilk fortified with calcium), or Vegetable (for example, green soybeans). Next, look at the label to determine caloric content, and compare to the ranges below to figure out portion size.

1 Protein = 45-80 calories

1 Vegetable = 10-40 calories

1 Dairy = 90-120 calories

1 Extra = 30-70 calories

For example, suppose you buy a small bag of soy nuts at the store for a snack and the label reads:
Soybeans prepared with sunflower oil
Serving size: 1/4 cup
Calories: 140 (calories from fat = 60)

This tells you that 1/4 cup of soy nuts contain 1 Extra (the 60 calories from fat), plus 80 additional calories, which can be considered as 1 Protein. So a 1/4 cup serving of soy nuts counts as 1 Protein plus 1 Extra.