Answer:
Our lifestyles changed. People have started eating more fast food or ready meals and do not get enough exercise. 20 to 50 years ago, tips like putting down your fork in between bites or drinking water in between every bite, etc. was the norm and was encourage by many people. It would have been very easy for someone back then to get carried away with weight loss. A great example would be the book Stick Figure by Lori Gottleib.