Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God. 1 Corinthians 10:31. RC 151.1
The character of the food and the manner in which it is eaten exert a powerful influence on the health. Many ... have never made a determined effort to control the appetite, or to observe proper rules in regard to eating. Some eat too much at their meals, and some eat between meals whenever the temptation is presented. RC 151.2
The need of carefulness in habits of diet should be impressed on the minds of all.... I appeal to all to refuse to eat those things that will injure the health. Thus they can serve the Lord by sacrifice. RC 151.3
Those who obey the laws of health will give time and thought to the needs of the body and to the laws of digestion. And they will be rewarded by clearness of thought and strength of mind. On the other hand it is possible for one to spoil his Christian experience by abuse of the stomach. Those things that derange the digestion have a benumbing influence on the finer feelings of the heart.... Every habit that injures the health reacts upon the mind. That time is well spent which is directed to the establishment and preservation of sound physical and mental health. Firm, quiet nerves and a healthy circulation help men to follow right principles and to listen to the promptings of conscience.... RC 151.4
The brain is the citadel of the being. Wrong physical habits affect the brain, and prevent the attainment of ... good mental discipline. Unless the youth are versed in the science of how to care for the body as well as for the mind, they will not be successful students. Study is not the principal cause of breakdown of the mental powers. The main cause is improper diet, irregular meals, a lack of physical exercise, and careless inattention in other respects to the laws of health. When we do all that we can to preserve the health, then we can ask God in faith to bless our efforts.... RC 151.5
The youth should be taught that they are not at liberty to do as they please with their lives. God will not hold guiltless those who treat lightly His precious gifts. Men should realize that the greater their endowment of strength, of talent, of means, or of opportunities, the more heavily should the burden of God's work rest upon them, and the more they should do for Him. The youth who are trained to believe that life is a sacred trust will hesitate to plunge into the vortex of dissipation and crime that swallows up so many promising young men of this age.—Counsels to Parents, Teachers, and Students, 297-300. RC 151.6
Mental and moral power is dependent upon the physical health.—Mind, Character, and Personality 1:61. RC 151.7