It takes about an hour to digest most of a meal, so that is the time Dr. Pressman says to wait after a meal. It also takes about a 1/2 to digest a glass of ozonated water, so that's the time Dr. Pressman say to drink ozonated water before a meal. All day is silly of your Dr. to say. My wife would be daed if she had followed that advise.
Take Care,
Gaylen