I agree, it is indeed fun to look at the old advertising and see the social impact and what we clearly know now as false statements made by industries like the sugar industry.
The World War 2 era had a number of interesting developments as a result of the war. Some of the television advertising was promoting TV dinners as a means for convenience. Remember that women were being asked to participate in the war effort and prior to that it was more or less assumed that men go to work and women stay home and spend time in the kitchen. So, they targeted women with the TV dinner advertising.
The next thing that was interesting about WW2 was “Active Dry Yeast”. We needed to feed a lot of soldiers, and the invention of fast rising yeast helped us produce bread at a new unheard-of pace. So, the whole idea of eating sourdough bread, which takes time (but preprocesses the grain by both yeast and bacteria processes) got thrown by the wayside. That preprocessing is missing today, and one can speculate it may be one factor contributing to the widespread GI issues we have today, Celiac, etc.