Does the carbohydrate-insulin model correctly reverse the causal direction of the energy balance model, so that hormonally driven fat storage causes overeating rather than overeating causing fat storage?

The mainstream energy balance model treats a caloric surplus as the cause of fat gain. The carbohydrate-insulin model, argued most fully by David Ludwig and colleagues in a 2021 American Journal of Clinical Nutrition paper, proposes the reverse: that a shift in substrate partitioning toward fat storage, driven by the insulin response to dietary carbohydrate, itself creates the positive energy balance rather than following from it. Kevin Hall and other researchers have published data its authors say falsifies the carbohydrate-insulin model, proponents disagree that the tests were decisive, and systematic reviews have not found the long-term weight-loss advantage for low-carbohydrate diets the model would predict.