Our Protein Sample Menus show that you can get more than enough protein on a vegetarian diet, eating a wide variety of fresh whole foods every day. Each day's menus combine foods for complete protein - without even thinking about it.
These menus aren't necessarily what you should eat. They're based on an average 40 yr old, 140 lb woman, who needs 2000 calories per day and 47 grams of protein, and her 42 yr old, 160 lb husband, who needs 59 grams of protein daily. Personally, I've never met this couple!
According to Western nutrition, we should consume 1/3 of our body weight or .36 grams of protein per lb of body weight. That doesn't hold up on close examination. Theoretically, a 6'2” 250 lb man would need 80 grams of protein a day - which could only be true if he's a tri-athlete.
An active rapidly growing seven year old could need more protein than a full size sedentary adult. And contrary to what we've been told, athletes don't need a lot more protein than regular people. They do need more complex carbohydrates for energy to support all that physical activity.
Plus, our bodies tend to adapt to the food that's available. In non-Western countries, like the third world, for most people the idea of consuming all those calories and that much protein is a joke. Two thirds that much food and half the variety is a luxury. Add the fact that 25% of Americans are obese, and you begin to sense that maybe we eat too much!
And here's the Veggie Catch-22: According to nutritional science, ideally we should get 10 - 15% of calories from protein, 15 - 30% from fat, and 55 - 70% from carbohydrates. The sample menu pie charts show that fat is on the high side, carbs and protein on the low side.
If you reduce the fat in those meals, you reduce the calories, but also the good fats which your body needs. And if you increase or decrease the protein or carbs, you might get more or less of everything than you need.
The fact is that in a vegetarian diet, it's impossible to compartmentalize or analyze fat, carbs and protein. Grains, legumes, and even veggies & fruit are a mixture of all three, plus vitamins, minerals, essential fatty acids, and fiber.
Many factors determine how many calories and how much protein you really need: age, size, growth, activity level, digestion, metabolism, body type, genetics, culture, geography.
The quality of your diet also matters. E.G. organic vs non-organic; fresh vs canned or frozen; home-made vs processed; local vs shipped from CA 2 weeks ago.
So, keep your eye on the big picture when it comes to nutrition. Pay attention to your own situation, and don't get hung up on calories and grams of protein. Let your body and your good sense be your guides.