ST. PAUL (AP) -- A Minnesota surgeon has written a new diet book that calls for counting cups instead of calories.

Dr. Nick Meyer wrote the book, "The Proportion Fit Diet: Count Cups, Not Calories" after looking for ways to lose weight himself.

He says limiting how many cups of food he eats instead of counting calories helped him lose 18 pounds.

His book offers a formula for calculating how many cups a person should limit himself or herself to in order to lose weight.

The equation is based on a person's body-mass index.

Meyer specializes in hand surgery as an orthopedic surgeon at St. Croix Orthopaedics in Stillwater.