Genetics also effect your extraction efficiency. If a person consumes 1000 kilocalories of food as measured with a bomb calorie meter some individuals might get 4184 kilojoules of system input and some might only get 2000 kilojoules of system input.

This does however not in anyway point to some proposition where obesity is not caused by food overconsumption. It does however showcase that genes have effects that increases the statistical likelihood for some people with certain genetics to become obese. And that the threshold for food overconsumption for an individual will depend on the individuals genes. But that is not a bold new statement, another example would be that a large human will require more energy to live, their food overconsumption threshold will be at a higher energy value.