This section is from the book "Health Without Medicine. A Treatise On The Laws Of The Human System", by Larkin B. Coles. Also available from Amazon: Philosophy Of Health.
Next to our obligations to God, are our obligations to ourselves. If we are under obligation to treat our Creator right, we are also, next to him, under obligation to treat ourselves right. The second table of the moral law, comprehended in this, "Thou shalt love thy neighbor as thyself," implies the preŽxistence of the law of self-love; and the law of self-love involves the obligation of self-protection. What right have we TO abuse, or even to neglect, ourselves? To do that which will injure our constitution or health, is sinful in the sight of Heaven. To transgress physical law is transgressing God's law; for be is as truly the Author of physical law, as he is the Author of the moral law. Whoever, therefore, violates the laws of life and health, sins against God as truly as though he break the ten commandments. Every man is therefore under moral obligation to obey those laws; and whoever dares violate them will find "The way of transgressors is hard."
The moral sense of community is exceedingly obtuse on this subject. With the great majority, appetite is the only law which governs; and in spite of all that can be said, it will probably continue to be so: and those who choose to have it so, must bear the consequences. But some may possibly be induced to examine their obligations and responsibilities in the case. Where is the consistency of being governed by principle instead of appetite, in regard to the demands of the moral law, and yet let appetite rule instead of principle in regard to physical law? for, as before stated, when we violate physical law, we do truly violate moral obligation. Whoever will let appetite govern in one thing, is in a fair way to let it govern in all things. Whoever, through appetite, will allow himself to eat too much or too often, is very likely to give license to all other appetites and passions in proportion to their strength and activity.