Mr. Smith was terribly overweight, so his doctor put him on a diet.

"I want you to eat regularly for 2 days, then skip a day, and repeat this procedure for 2 weeks. The next time I see you, you'll have lost 5 pounds."

When Mr. Smith returned, he had lost nearly 20 pounds.  "Why, that's amazing!" the doctor said, "Did you follow my instructions?"

Mr. Smith nodded. "I'll tell you though, I thought I was going to drop dead by the end of that 3rd day."

"From hunger, you mean?"

"No, from skipping!"