It goes back a lot further than that. The moment we started tinning food and making long life carbohydrates the equation completely changed. They take so much l

It goes back a lot further than that. The moment we started tinning food and making long life carbohydrates the equation completely changed. They take so much less energy to digest than their counterparts but its even deeper. Have a read into the difference in flour making over the past century and how industrial processes and wheat variants have gone hand in hand to remove all the fiber from bread. We have been adjusting our food to increase calory density and reduce the cost of digestion for thousands of years but it really accelerated in the past 120. A Kilo Calory is the energy extracted in burning it, our body doesn't burn fuel it chemically converts it into different substances, the processes are so different since one conserves mass and the other does not. It is a terrible measure given plant fibre burns well and produces lots of energy and hence has lots of calories but plant fibre generally goes right through us since we can't digest a lot of it. The entire thing is a bit rotten from a science point of view. Reducing how much we eat sort of works, for some people, changing to more natural foods works for others, changing to fats and protein exclusively for others etc etc. Few studies show the majority of people loosing fat long term. All this to me points to the fact we don't have this figured out at all yet.