I came to the startling realization the other day that the shape of our bodies and the shape of our packaging has undergone an alarmingly parallel transformation over the past 50 years or so ...
Using soda as an example, let's first consider the 8-ounce bottle of Coke. This is one serving size of carbonated goodness, served up ice-cold in a glass bottle that -- once empty -- was returned to the bottler, who would carefully wash, sanitize, and refill the container. People took good care of these bottles (the fact that there was a small monetary incentive to do so certainly didn't hurt!) and, on average, bottlers were able to reuse the glass packages 25-30 times before the paint would start to fade and they were forced to take the bottles out of circulation. People also took better care of themselves back then; they kept portion sizes in check and put forth a little extra effort to keep themselves in circulation (so to speak).
By comparison, the 20-ounce bottle of Dr. Pepper on the left crams two and a half servings into it's shapeless plastic packaging, and -- despite the serving size on the label -- we generally pour all of that sweet, sugary liquid down our gullets in a single sitting, transferring the contents of the bulging container into our bulging bellies. Then we carelessly discard the single-use containers, thinking little of the cost, energy, and oil it takes to create a new container for yet another super-sized serving of soda. If we're lucky, the plastic bottles will be recycled, but this doesn't often happen.
Think about it -- the small, svelte, and shapely bottle of Coke could swap clothes with Barbie ... the big, bulging bottle of Dr. Pepper would be resigned to covering up in a flowing, shapeless mumu. Guess the phrase "you are what you eat" should extend to beverages, too!