I recently wrote about the interesting and fun book The 9-inch Plate "Diet" where we learn about the cultural factors influencing the increase in the amount of food we consume.
Today I learned (thanks to Adam Engst) about a Cornell University study that found that recipes in The Joy of Cooking have similarly increased in calorie count over the previous decades. One tidbit from the study is that a meal for 4 people in 1986 would have been for 7 people in 1936. Egads.