In this conversation, Gary Taubes argues that much of modern nutrition science is built on weak, self-reinforcing assumptions—especially the idea that obesity is caused by overeating. He describes this as circular reasoning: weight gain is taken as proof of excess calorie intake, rather than something that needs to be explained. Because nutrition studies are difficult to tightly control, these assumptions often go untested, allowing flawed ideas to persist.

Taubes also highlights how funding, incentives, and institutional bias shape which hypotheses get studied and which are ignored. Earlier research that focused on metabolic regulation—particularly the role of hormones like insulin—was largely sidelined in favor of simpler calorie-based explanations. From this perspective, obesity and metabolic disease may be driven less by conscious overeating and more by how the body partitions and uses energy, with appetite and intake acting as downstream effects.