Jocelyn, seeing that you've been a member for about a month, I really doubt that you've gotten under the skin of many members here. You haven't seen the efforts, the hardship, the energy, the questions, the dedication, the so-close-to-give-up-but-still-keep-goings, the positive attitudes, the MANY success of this place.
Coming out saying that we pretty much all are doing it wrong, is probably not the right way to get people's attention.
Instead, you should befriend people, inspire, help, and use your knowledge to help people to the place where they really want to be.
Simply throwing a "you're all doing it wrong" statement followed by a lot of math (simple or not - I understand what you are saying and I am not saying you are significantly wrong) is simply not gonna win anyone over. It's a wasted effort, if you ask me.
As a personal trainer, you should already know that all people are different, we have different reasons to lose weight and we have different reasons that we are overweight. It doesn't always just come down to numbers. I hope you understand this when you're with your clients.
"Losing weight is never about eating as little as possible"
"You wouldn't worry so much about what others think of you if you realized how seldom they do.
― Eleanor Roosevelt
"Do. Or do not. There is no trying."
- Master Yoda.
From October 4th 2010 to April 3rd 2012 I lost half my body weight - 80 kilos/170 lbs. Since then, I have had two cosmetic surgeries to remove excess skin. I have now quadrupled my strength, gained several kilos in muscle mass, and today I focus on building muscle, optimizing my diet, and living healthy. I am stronger, healthier, thinner, happier!