The other day some coworkers and I were discussing just how popular kale has become and I decided to do a little digging to see whether Americans are eating kale as much as they're talking about eating kale. The easiest way to answer this is with a massive research study looking at a representative sample of Americans and their kale consumption habits. I decided to spend 20 minutes Googling and try to answer the question.
Search trends definitely indicate rising popularity - it's now right up there with broccoli:
But kale consumption lagged other vegetables significantly (at least in 2012):
At this point I realized per lb consumption is a bad way to compare leafy greens and other, heavier vegetables and went looking for something better. I found a Washington Post article that used another method called "disappearance" which is "imports plus production minus imports." This method (and the article) indicates kale was much more popular in the 1990s, which suggests we're probably not eating more.
However, a commenter pointed out an interesting finding from the Sacramento Bee that "Before this boom in popularity, the biggest U.S. kale buyer was Pizza Hut, which used the dark green variety to decorate its salad bars." This may indicate that previous spikes were garnish-based vs consumption based.
What all this means is that while the average Americans' "kale conversation" is probably increasing faster than their "kale consumption," consumption has likely increased pretty significantly. It could be that the surge in conversation is a leading indicator for actual consumption - especially if you've seen just how much people are influenced by opinion leaders in the media or their own social circle.