Eat in due season, for strength, and not for drunkenness! Ecclesiastes 10:17.
(TDG 340.1)
Eat at regular periods. By wrong habits of eating, you are preparing yourself for future suffering. It is not always safe to comply with invitations to meals, even though given by your brethren and friends, who wish to lavish upon you many kinds of food. You know that you can eat two or three kinds of food at a meal without injury to your digestive organs.
(TDG 340.2)
When you are invited out to a meal, shun the many varieties of food that those who have invited you set before you. This you must do if you would be a faithful sentinel. When food is placed before us, which, if eaten, would cause the digestive organs hours of hard work, we must not, if we eat this food, blame those who set it before us for the result. God expects us to decide for ourselves to eat that food only which will not cause suffering to the digestive organs....
(TDG 340.3)
Often the different kinds of food placed in the stomach do not agree, and fermentation is the result. This is the cause of many stomach difficulties. Eat at regular hours, and eat wholesome food. Do not place in the stomach too great a variety of food at one meal.
(TDG 340.4)
I dare not say to you or to anyone else, You must eat only two meals a day. But I do say that too much food should not be placed in the stomach at one time, for when this is done, the stomach has no chance to do its work properly. For some, three meals a day are better than two.
(TDG 340.5)
For thirty years, I have taken only two meals a day, and I have not eaten between meals. I know for my own part that two meals can be so arranged as to be perfectly convenient. Yet no one is to make his own case a criterion for others. Each one should study carefully the organism of his body, that he may know how to deal intelligently with the body, and that he may be sure that intemperance in eating is not destroying the vital forces of the system. Each one should know for himself how to care properly for the machinery of the body, for no one else can do this for him.—Letter 324, November 27, 1905, to Elder W. W. Simpson, an evangelist in Los Angeles, California.
(TDG 340.6)