[jqm]

All food may have protein, but all food does not have essential amino acids (which cannot be made by your body) in the quantities required to maintain health. This is why non-meat eaters must be sure to add certain foods (or certain combination of foods) to their diet if they want to stay healthy. Not bagging on vegetarianism, but the idea you can get sufficient protein by just eating any old plant is.... wrong. And animal protein is a far easier and certain way to get essential amino acids. This from a guy who was a vegetarian for a number of years.

[noondip]

> All food may have protein, but all food does not have essential amino acids (which cannot be made by your body) in the quantities required to maintain health.

> the idea you can get sufficient protein by just eating any old plant is.... wrong.

You're quite mistaken. If what you say were true, a warning of it would be clearly made by medical and nutritional authorities. Alas, no respectable organization says it, precisely because it's a myth. You can easily search on Google to find evidence which contradicts your post. Here are just the first two results I found when looking at potatoes as an example:

> The high nutritive value of potato protein can be understood when its composition is compared with that of whole wheat (Table 2). Apart from histidine, it contains substantially more of all the essential amino-acids ; this superiority is particularly striking for lysine, the amount present being similar to that in a typical animal protein.

https://www.ncbi.nlm.nih.gov/pubmed/13536266

> For a 120 pound adult, five potatoes (960 calories) supply over 100% of the recommended intake for all essential amino acids.

> It's pretty difficult for an adult to eat a plant-based, vegetarian diet that doesn't provide all EAAs, as long as caloric needs are met.

> Finally - The pool of AAs that our body uses to manufacture its own proteins isn't limited by what we eat. Normal daily turnover of our cells provides a substantial pool from which to draw amino acids. Bacteria that line our colon also manufacture AAs, including EAAs, that we can utilize.

> It is a misconception that plants provide "incomplete protein", regardless of what Ms. Lappe advanced in her 1971 book, "Diet For A Small Planet."

http://fanaticcook.blogspot.com/2008/04/if-all-you-ate-were-...

[jqm]

for a 120 pound adult....

But I weigh over 200 pounds. So 9+ potatoes a day from me to get all the essential amino acids. That's a pretty high starch to protein ratio and would be nearly my whole intake in calories to get a bare minimum of amino acids. Essentials aside, is that enough protein? Also at that point I would have fulfilled my daily requirement of calories but be still be short vitamins A, K, E, calcium, selenium, fatty acids and who knows what else.

That aside, potatoes are one plant. I don't dispute you can eat certain plants or combinations of plants to get all essential amino acids. To restate "the idea you can get sufficient protein by eating just any old plant is... wrong". It is. You'd be in serious nutrition trouble if you tried to live on just broccoli or lettuce. You have to carefully balance your diet as a healthy vegetarian and it is far easier just to add some animal protein.

For the record I still eat a "mostly" vegetarian diet. But not completely. And I feel a lot better and have more energy than when I did ate a full vegetarian diet.