What about bring in a body fat % scale and hopping on it? Take a quick measure and then down a glass of water. Repeat. Then just point out the obvious - are you suddenly fatter? No. So why put so much emphasis on something that isn't accurate?
Take out a gossip rag and find a scrawny celebrity and compare them to someone who looks healthier (ie Jennifer Garner, Jessica Biel pre-muscle loss), etc). Ask her which looks stronger, healthier, and hotter? Who looks frail, timid, and/or like a pre-pubescent boy?
Can she see their weights? No. Would she rather focus on losing a ton of weight or would she rather focus on feeling and looking stronger, fitter, and more confident?
I honestly wish someone had said those things to me. I was that girl when I was 13. Except I wasn't telling this to a trainer, I was telling this to the weightloss counselor at diet meeting. And I was at the "ideal" bmi for my height
