A life sustaining food bar.

Is there such a thing? Something that wouldnt leave a person malnutritious or make you sick?

I believe it’s called “a potato” but I’m sure someone more knowledgeable than myself will correct me in due course.

Plumpy’nut is a food used to treat severe malnutrition.

You may be looking for Nutraloaf

We’ve had a few separate threads on someone a simple, catchall, food that meets all nutritional needs. In at least one of them, I suggested cold cereal and milk. Anyway, you’ve changed the meme to be a bar rather than another food, but still … we’ve done this before. It is trivial to vitamin-mineral-amino acid fortify a food product with sufficient calories, but no one wants to eat the same thing for a very long period of time.

Human Chow!

And People Kibble!

http://boards.straightdope.com/sdmb/showthread.php?threadid=53966&perpage=50

There was a reality TV show named Solitary which only fed the contestants a hard, flavorless nutrient bar for basically the duration of filming (except as a reward in a few situations). Unfortunately, I don’t know how long filming was, so it’s unclear how long they survived on it and whether they could have continued on healthily for a prolonged period of time.

Surprised nobody has mentioned Soylent Green yet.