Brethren and sisters must not be sick upon the encampment. If they clothe themselves properly in the chill of morning and night, and are particular to vary their clothing according to the changing weather, so as to preserve proper circulation, and strictly observe regularity in sleeping and in eating of simple food, taking nothing between meals, they need not be sick. They may be well during the meeting, their minds may be clear and able to appreciate the truth, and they may return to their homes refreshed in body and spirit. Those who have been engaged in hard labor from day to day now cease their exercise; therefore they should not eat their average amount of food. If they do, their stomachs will be overtaxed. We wish to have the brain power especially vigorous at these meetings and in the most healthy condition to hear the truth, appreciate it, and retain it, that all may practice it after their return from the meeting. If the stomach is burdened with too much food, even of a simple…
"What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God’s."
While not a direct quote, the EGW passage's emphasis on caring for the body through proper diet, rest, and clothing to maintain health and mental clarity echoes the sentiment of 1 Corinthians 6:19-20, which states that our bodies are temples of the Holy Spirit and should be used to glorify God.