Maybe the biggest split that I’m aware of, or that I think is the most important, is the difference between mainstream “CICO” thought and “Fuel Partitioning.”
The CICO people call their model EBM, or Energy Balance Model. If you say that energy balance is a simplification and not a very useful dieting tool, they get mad at you. How could you possibly think the Energy Balance Model was about balancing energy?! C’mon, man! (Yes, this literally happened to me. Also, according to a serious nutrition scientist, no serious nutrition scientists believes in CICO and that’s a straw man argument.)
This split was perfectly illustrated a few years ago in a debate between mainstream nutrition scientist Stephan Guyenet and nutrition writer Gary Taubes of Good Calories, Bad Calories fame.
The debate was held on the Joe Rogan podcast and it was a perfect example of the dysfunctional discourse in the nutrition space. It mainly consisted of both contenders accusing the other of acting in bad-faith, misrepresenting The Science, and general dishonesty. There was yelling.