Q: How much protein does an active 40-something woman need each day?
A: Less than you might think. For an average-weight woman, the Institute of Medicine recommends 46 grams of protein per day. If you'd like to know the exact amount you require, multiply your body weight in pounds by 0.36. As a practical matter, there's no need to add up protein grams. So long as you're eating a variety of beans, grains, vegetables, and fruits, you'll get adequate protein.
Related: Getting Enough Protein
Beans are especially protein-rich, with around 8 grams in a 1/2-cup serving. Including soybeans and soy foods such as tempeh and tofu in your diet will contribute a great deal toward meeting your protein needs. If you're pregnant or nursing, your protein requirement goes up to 71 grams per day. But that is still achievable with a plant-based diet. Extra protein likely comes with the extra calories you're consuming. If your well-meaning husband arrives home with protein powders and a pound of beef liver, you might gently remind him that, although you're eating for two, one of you is very small.