There is a nice presentation here explaining the issue of
Calories, Energy Balance, Thermodynamics & Weight Loss

If you just want to skim through the slides used in the presentation or have full screen versions available as the presentation proceeds you can download the slides here

Towards the end of the talk Zoe mentions Barry Groves who believes.
You should eat what you are designed to eat This link leads to another slide presentation that speaks for itself.
If you want to hear Barry Groves talk that goes with these slides then it's probably this one