... that generations need to be taught to cook appropriate - and often cheaper - foods in order to provide better quality calories ...
There is no such thing as a "better quality calorie". A calorie is a calorie is a calorie.
A calorie is the amount of heat required to raise the temperature of one gram of water by one degree Celsius. When used in terms of nutrition a "calorie" is actually a kilocalorie - 1,000 calories. The body uses calorific food in order to produce the energy required to enable muscles to work and to provide the background energy needed to keep the various physiological systems working. The more work your body and musculature does, the more calories it needs. The body also needs other types of nutrient such as proteins, vitamins and minerals.
Calories are packaged very conveniently in carbohydrates which many of the plants we eat produce in prodigious quantities. Another problem is that many of the foods we like to eat - like chocolate - contain lots and lots and lots of calories. However, if you consume too many calories the body does not excrete the unused calories it stores them for future use - as fat.
Obesity has nothing to with the "quality" of calorie simply the quantity.