It’s obviously not something that’s meant to be taken literally; if it was, this blogger would be a cheese sandwich.
But there is an obvious, common sense correlation between what we feed our bodies with and how we act and feel, which is what the phrase is intended to express.
So where does it come from?
It has often been mistakenly attributed to one of the ancient Chinese sages such as Confucius or Lao-Tze. But it was actually coined in 1826 by Anthelme Brillat-Savarin, a brilliant lawyer, politician and authority on food, who wrote: “Dis-moi ce que tu manges, je te dirai ce que tu es.” [“Tell me what you eat and I will tell you what you are.”]
Brillat-Savarin was years ahead of his time. He was one of the first to identify sugar and processed white flour as potential causes of obesity. One wonders how he would feel now, if he knew that an extremely rich, creamy French cheese and a heavy cake filled with whipped cream and doused in rum would later be named in his honour.
Perhaps surprisingly, the first known instance of the phrase in English was in an advertisement for beef, which appeared in American newspapers in the 1920s.
“Ninety per cent of the diseases known to man are caused by cheap foodstuffs,” it read. “You are what you eat.” This may have inspired another pioneering nutritionist, Victor Lindlahr, to use the phrase as the title for a massively successful book that he published in 1942.
The theories of people like Brillat-Savarin and Lindlahr, which state that diet has a direct and massive effect on human health, are now regarded as blindingly obvious. How strange to think that they were seen as controversial, revolutionary, even subversive when they first came up with them!