Answer – There is plenty of good science, and more is coming all the time to support the paleo/Primal/low-carb. And the science behind the low-fat paradigm has been unequivocally shown to be bad science.
We’re all aware of the anecdotal evidence; I write about it all the time on my blogs. The Primal diet and lifestyle helped me lose 80 pounds and maintain going on 8 years now. Going more keto lost me an additional 10 pounds. But don’t take my word for it.
Below are two links to Mark Sisson’s blog. He calls his diet “Primal” but it’s essentially paleo, though he advocates dairy for those who can eat it without digestive issues and fatty meats, not just lean.
Additionally, Chris Kresser and Dominic D’Agostino are scientists that post good reference material and do some ground-breaking research.