(Before we discuss the first diet, let's describe the first man and woman.)
Q: How did the first man on earth come into existence?
A: "The Lord God formed man from the dust of the ground and breathe into his nostrils
the breath of life, and the man became a living being."
Genesis 2:7 NIV
Q: How did the first woman on earth come into existence?
A: "...God caused the man to fall into a deep sleep; ...took one of the man's ribs and
close up the place with flesh. Then the Lord God made a woman..."
Genesis 2: 21,22 NIV
Q: What were their names and, what did they look like?
A: "As Adam came forth from the hand of his creator, he was of noble height,
and of beautiful symmetry. He was more than twice as tall as men now living
upon the earth, and was well proportioned. His features were perfect and
beautiful. His complexion was neither white, nor sallow, but ruddy, glowing
with the rich tint of health. Eve was not quite as tall as Adam. Her head
reached a little above his shoulders. She too was noble - perfect in symmetry
and very beautiful. All the organs and faculties of [their] beings were egually
developed and harmoniously balanced."
Ellen White, Spiritual Gifts, Vol. 3, p34
Q: What was their main source of food God provided for them?
A: "And the Lord God made all kinds of trees grow out of the ground - trees that
were pleasing to the eye and good for food. In the middle of the garden [of Eden]
were the tree of life and the tree of the knowledge of good and evil. [God said]
'You are free to eat from any tree in the garden; but you must not eat from the
tree of the knowledge of good and evil...'"
Genesis 2: 9,16,17 NIV
Q: So, what was the type of food God gave them to eat?
A: "Then God said, 'I give you every seed-bearing plant on the face of the whole
earth and every tree that has fruit with seed in it. They will be yours for food.'"
Genesis 1:29 NIV
Q: Exactly what were some of these seed-bearing foods?
A: "The fruit was very large and of differnt colors; some nearly black, some
purple, red, pink and light green. This beautiful and luxuriant growth of
fruit upon the branches of the vine was called grapes. Fruit from the tree
of life looked like apples of gold and silver."
Ellen White, Story of Redemption, pgs. 21,22
Q: What was another source of their food, and why?
A: "She took [fruit from the forbidden tree of knowlegde of good and evil] and ate it.
She also gave some to her husband ...and he ate it. [God said] 'curse is the ground
because of you; through painful toil you will eat of it all the days of your life...you
will eat the plants of the field.'"
Genesis 3: 6,17,18 NIV
So, what constitutes the first diet? Fruits or anything a tree brings forth and, plants (vegetation/food) from the field.
In closing,"In order to know what are the best foods, we must study God's original plan for man's diet. He who created man and who understands his needs appointed Adam [and Eve] their food. God gave our first parents the food He designed that the race should eat. Grains, fruits, nuts and vegetables constitute the diet chosen for us by our Creator.[This diet]...impart a strength, a power of endurance and vigor of intellect. Again and again I have been shown that God is bringing His people back to His original design..." (underline mine)
Ellen White, Counsels on Diet and Foods, p.81,82