Whats the total daily intake (calories, grams of fat, protein) that a person nee!

Whats the total daily intake (calories, grams of fat, protein) that a person needs to survive and be healthy?

AND how long can someone go if they are far beneath that total before they begin to suffer physical problems do to the lack of proper nutrition?
What kind of Physical problems?
Are they repairable problems?

like.... say supposing someone usually has 1000-1600 calories a day (mostly liquids) and no more than 6-9g fat per day (except occasionally) and does this for a period of years.
(*Like, most times (half the month) only 1200 cal tops, 3-5g fat daily; but (the other half month) maybe has 1400 and 6-9g fat... and their fat intake only ever goes above 9g when they eat out or have pizza or somthing). and protein varies between 5-12g daily; depending. and they've done this for years.....
That person would still be healthy because they are still technically consuming food and some kind of calories and fat, correct? or is that incorrect?
what should the daily intake be in order to be healthy? and would there be physical problems that could occur because of this type of diet?

2 weeks ago
... okay, this a SERIOUS question..... (thought i should say that as some of my questions arent serious, or supposed to be taken seriously...)

Just pretending such a person existed (and praying that they don't)....

The body needs fuel to keep it healthy. It needs calcuium to make the bones strong, it needs protein to fuel the muscles to help you move, it needs carbohydrates to keep your heart beating, to give you memory and concentration, to control your mood, and to burn fat (a body can't burn fat unless it has carbs in it, just like a fire needs wood).

The long term impact of such a horrifically inadequate diet like the one you describe, include:

- reduced or removed monthly cycles. This prevents calcium from entering the bones causing brittleness and also seriously restricts a body from becoming pregnant in the long term.

- reduced concentration and an increased likelihood of depression due to the lack of carbs.

- severe iron deficiency which causes tiredness and lethargy.

- poor heart function. The body needs fat (sorry but it's a fact) because the muscles and organs are made of some part fat. Removing fat from the diet means your organs and muscles aren't functioning well.

- shockingly decreased immune system which means a higher amount of illness which the body will struggle to overcome.

- poor body image. The person who sustains this type of diet isn't a happy person. Most likely they're obsessive, reclusive, and really, quite boring to be around. Someone who loves life, loves themself, is far more enjoyable to be around that someone who's always going on about their food intake.

But surely, someone wouldn't really be so foolish to keep to such a foolish diet?