The main proximate cause of increase in human weight over the last few decades is over-eating - other factors like decreased energy need due to less active lifestyle seem at best secondary if relevant at all. The big question is what misregulates homeostatic system controlling food intake towards higher calorie consumption?
The most common accepted answer is some sort of superstimulus theory - modern food is so tasty people find it irresistible. This seems backwards to me in its basic assumption - almost any "traditional" food seems to taste better than almost any "modern" food.
It is as easy to construct the opposite theory of tastiness set point - tastiness is some estimate of nutritional value of food - more nutritious food should taste better than less nutritious food. So according to the theory - if you eat very tasty food, your appetite thinks it's highly nutritious, and demands less of it; and if you eat bland tasteless food - your appetite underestimates its nutritious content and demands too much of it.
It's not even obvious that your appetite is "wrong" - if you need certain amount of nutritionally balanced food, and all you can gets is nutritionally balanced food with a lot of added sugar - the best thing is eating more and getting all the micro-nutrients needed in spite of excess calories. Maybe it is not confused at all, just doing its best in a bad situation, and prioritizes evolutionarily common threat of too little micronutrients over evolutionarily less common threat of excess calories.
As some extra evidence - it's a fact that poor people with narrower choice of food are more obese than rich people with wider choice of food. If everyone buys the tastier food they can afford, superstimulus theory says rich should be more obese, setpoint theory says poor should be more obese.
Is there any way in which setpoint theory is more wrong than superstimulus theory?
Using sugar for human consumption is, in a sense, quite wasteful.
I claim, that given sugar, using it for human consumption is one of the least wasteful things to do with it.
This is still inefficient compared to other means of using the same sunlight.
In the future, if there is an option between powering organic people with sugarcane-produced sugar and powering cybernetic people with solar cells, and we can choose to be either organic or cybernetic, then your argument will be valid—assuming there are no other options, which is silly. For right now, people need food. Converting sunlight into other forms of energy in other ways is fine and good, but personally, I would also like to keep growing food for me and my brethren.
though again this is only sugar-to-mechanical efficiency.
This is a big caveat. A typical person burns much more energy maintaining homeostasis than they do in moving. Following that, brain activity is the second-largest energy sink. While athletes can quadruple their caloric requirements (indicating that mechanical energy can become the largest drain on energy), I think calculating energy conversion with your example is suspect.
Okay, now I think I see the source of our miscommunication: you're assuming humans have an important use in addition to manufacturing products, while I wasn't.
Related to: Babies and Bunnies: A Caution About Evo-Psych, Superstimuli and the Collapse of Western Civilization.
The main proximate cause of increase in human weight over the last few decades is over-eating - other factors like decreased energy need due to less active lifestyle seem at best secondary if relevant at all. The big question is what misregulates homeostatic system controlling food intake towards higher calorie consumption?
The most common accepted answer is some sort of superstimulus theory - modern food is so tasty people find it irresistible. This seems backwards to me in its basic assumption - almost any "traditional" food seems to taste better than almost any "modern" food.
It is as easy to construct the opposite theory of tastiness set point - tastiness is some estimate of nutritional value of food - more nutritious food should taste better than less nutritious food. So according to the theory - if you eat very tasty food, your appetite thinks it's highly nutritious, and demands less of it; and if you eat bland tasteless food - your appetite underestimates its nutritious content and demands too much of it.
It's not even obvious that your appetite is "wrong" - if you need certain amount of nutritionally balanced food, and all you can gets is nutritionally balanced food with a lot of added sugar - the best thing is eating more and getting all the micro-nutrients needed in spite of excess calories. Maybe it is not confused at all, just doing its best in a bad situation, and prioritizes evolutionarily common threat of too little micronutrients over evolutionarily less common threat of excess calories.
As some extra evidence - it's a fact that poor people with narrower choice of food are more obese than rich people with wider choice of food. If everyone buys the tastier food they can afford, superstimulus theory says rich should be more obese, setpoint theory says poor should be more obese.
Is there any way in which setpoint theory is more wrong than superstimulus theory?