How conscious are our food choices?

Eating and body weight are less related to free will than you might think.

What we put on our dinner plates is the result of conscious choices, right?

I didn’t appreciate this was a question until I started researching a book about why we eat. Sure, innumerable processes in our bodies are regulated, involuntary — from the beating of our hearts to our immune responses. But, like many people, I thought that eating was not one of them. Diet gurus have long told us that what we eat (or don’t) and how much weight we gain (or lose) are totally the product of free will.

As it turns out, diet culture is once again wrong. The science is once again way more interesting. Over the last 30 years, researchers have discovered regulatory systems that shape what and how many calories we eat, and also how much fat we store. These systems, influenced by our genes and environments, are largely involuntary.

So how can eating be driven by unconscious choices while obesity rates have sky-rocketed? In other words: how can something that’s biologically regulated also change so much?

Dr. Stephen O'Rahilly, one of the Cambridge University researchers who helped unpick how all this works, used a great analogy when I put the question to him. As a species, humans are now much taller than we were 100 years ago. Height is highly heritable and population-level increases in height are unquestionably linked to changes in nutritional availability. This means “genetics determine where you are on [the normal] distribution. And then environment shifts the whole distribution.”

When it comes to height, “nobody seems to think that it’s difficult keeping these two ideas in their head at the same time,” he added. Yet the idea that weight can also be the product of biological regulation is far less intuitive for many of us.

Since the new-ish diabetes and obesity drugs (such as Ozempic and Wegovy) tap into these regulatory systems, it seemed like a great moment to look at how the systems were discovered, how they work, and why it’s hard for people to accept eating as an involuntary behavior. I wrote about all of this in the New York Times today. You can read the article here.

Thanks for reading and as always, feel free to reach out.

All the best,

Julia

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