Doctor put her on a diet

My girlfriend was slightly overweight.

So, our Doctor put her on a diet.

He said to her that she had to eat regularly for 2 days, skip a day and repeat that procedure for 3 weeks and that when he sees her next time, she should have lost at least seven pounds.

When she returned 3 weeks later, she had lost 18 pounds.

“That’s amazing”, said the doctor, “Did you follow my instructions?”

My girlfriend replied, “Yes but I tell you what, I thought that third day was going to kill me.”

“From hunger?” asked the Doctor.

“No, from skipping!” replied my girlfriend.