Diet, not declining physical activity, may be the primary cause of the obesity epidemic in

Well SupportedIncreased energy intake, driven by diet, is estimated to be 10 times more significant than reduced energy expenditure in causing obesity.

Well SupportedIn developed nations, individuals burn more calories primarily due to larger body size, not increased physical activity.

Partially SupportedDiet quality, particularly the proportion of ultraprocessed foods, strongly correlates with higher body fat, independent of age, sex, or activity level.

Partially SupportedThe obesity epidemic in developed countries may be primarily caused by diet rather than declining physical activity.