NATURE SUFFICIENT means real, authentic, whole, complete, perfect, just-right, on-mark, no more no less—just, in Christ. It is the state of being, hearing, and hearkening to His Voice in all one does and says—being mightily changed by Christ—receiving in us His sufficient Divine nature—having no disposition to do evil, but to do good continually. It is to be truly... set free.

The nature, or Divine design of our existence is such that only One course is sufficient for the fulfillment of the Divine measure of our creation.

Full relief from the impact and stress of the natural man comes through Christ. To be changed from the natural man to nature sufficient we are utterly reliant upon Christ, who alone is sufficient to make up partakers of the Divine nature or being nature sufficient or complete or perfect... even as our Father in Heaven is perfect. 

Our nature or the object and design of our existence is to become as Christ is and receive fullness of Joy as He has. This Divine nature or fulfillment of the measure of our creation is possible because...  

2 Peter 1:4
Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.

2 Corinthians 3:5
Not that we are sufficient of ourselves to think any thing as of ourselves; but our sufficiency is of God;

Ether 12: 27
And if men come unto me I will show unto them their weakness. I give unto men weakness that they may be humble; and my grace is sufficient for all men that humble themselves before me; for if they humble themselves before me, and have faith in me, then will I make weak things become strong unto them.

Moroni 10:32
Yea, come unto Christ, and be perfected in him, and deny yourselves of all ungodliness; and if ye shall deny yourselves of all ungodliness, and love God with all your might, mind and strength, then is his grace sufficient for you, that by his grace ye may be perfect in Christ; and if by the grace of God ye are perfect in Christ, ye can in nowise deny the power of God.

D&C 89: 10-11
Wholesome herbs (fruits & veggies) God hath ordained for the constitution, nature, and use of man—in the season thereof (fresh or raw).

Gen 1: 28
And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it:

Gen 1: 29
And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat.

Mark 12: 30
And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength.

Matt 5: 37
But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil. This simply means that we are, as the Spirit of God directs, to be truly honest—real authentic whole. Any other posture or word is pretense or us relying upon ourselves or posturing in fear—which is not edifying and not of God. Such taketh the name of God in vain. We do not keeping our covenant Divine nature as a prince or princess of God and who we truly are. We are left without integrity and live with internal conflict and stress. We are to learn from such (know evil), not live with such. Anything more or less than authentic honesty damns us in our progress. From such we are to repent that we may enjoy stress free form and function—in Christ. This is the great secret of life—though it is not a secret.

Matt 5: 48 
Be ye therefore perfect, even as your Father which is in heaven is perfect.

Nature sufficient simply means to be... of God—perfect in Christ.