This is just too good to quote any of it. You'll just have to go read the whole thing, as Peter — the very smart UK veterinarian — ridicules the "calories in / calories out" oversimplification.

Stephan has commentary, and Mark, looking great at 54, has prescient insights into exactly what Peter is talking about.

Read it all. Then, consider being of some help to your family and friends who've suffered too long under the Diet Delusion. You very well might save their life.