Eden contained perfect food that would have sustained the perfect man and he would not have died had he remained in Eden, unless Jehovah had put him to death in some direct manner.

But God drove him out of Eden, took him away from the perfect food, caused him to gather his food from among the thorns and thistles and from other imperfect elements of the earth that were found outside of Eden; and in this condition he continued to sicken and to die until at the end of the period of 930 years he was dead.
[48]A kind and loving parent sometimes inflicts punishment upon a child because the child has violated a rule.

The parent punishes the child not because he loves to see the child suffer, but for the good of the child, in order that it might be disciplined and might learn the proper lessons.

If the child always did good and never did evil it would not merit nor receive any punishment from a loving parent.

One of the chief purposes of Jehovah in dealing with mankind in the manner he does deal with them is that humankind might be disciplined and learn the lessons of good and the effect of doing wrong, and thus learn to appreciate the love of the heavenly Father.
[49]When God sentenced our first parents to death and drove them out of Eden, he had in mind and had already planned for their future blessing, as we will see upon a further examination of his plan.