get angry at myself , even though I 'm aware that I am in good shape . But what do feelings have to do with numbers ? Most women know that it is possible to immediately gain 15 pounds by eating one pint of Ben & Jerry 's . And when it comes to your butt -LRB- which can enlarge six sizes in the wrong pair of jeans -RRB- , the rules of physics no longer apply . Oprah.com : Start loving the way you look We need a better way to quantify these fluctuations -- a formula that goes beyond your BMI and calculates the feel of overweight . So I propose the personal body image index -LRB- PBII -RRB- . The general idea is as follows : • Start with your weight . • Subtract seven pounds if you have just worked out . • Add five if you 've single-handedly finished a plate of guacamole and chips ; four for macaroni and cheese ; six for death-by-chocolate cake . • Subtract 10 pounds if people nearby are fatter than you . • If you 're wearing black pants , subtract two ; if in a bathing suit
-LRB- OPRAH.com -RRB- -- One portion of macaroni and cheese . One slice of chocolate cake . One pair of svelte black pants . Do some very simple , if highly emotional , addition and subtraction , and you arrive at a whole new way to see yourself . The first documented instance of my distorted body image is an entry in my fourth-grade journal . `` I just ate three cookies , '' it says . `` I feel fat . '' There is no way that I actually was ; my jeans , although dorky , fit just fine . Nevertheless , the disconnect grew worse as puberty approached -- especially in eighth grade , when the body mass index -LRB- BMI -RRB- entered my life . This is a formula that tells you whether you need to drop pounds -- and while it 's generally reliable , it does n't take body composition into account . At 5 ' 4 '' and 140 pounds , I 'm close to the overweight category , but that 's only because I 've got heavy bones and a sprinter 's thighs . Every time I calculate my BMI , I