“Personalized nutrition” has been one of the microbiome economy’s biggest promises and shakiest claims. So when ZOE — the company co-founded by epidemiologist Tim Spector — ran a proper randomized controlled trial, it was a real test of whether the idea holds up.

The METHOD trial (published in Nature Medicine, 2024) randomized 347 US adults aged 41–70 to one of two arms: an 18-week app-guided personalized dietary program — tuned to each person’s food responses, post-meal glucose and triglyceride spikes, microbiome and health history — or standard US dietary guidance.

The personalized arm significantly reduced blood triglycerides (a pre-specified primary outcome). That’s a genuine, peer-reviewed signal that individualizing diet can beat generic advice on a hard cardiometabolic marker.

Read the fine print

It was also modest and caveated. The trial was funded by ZOE. The other primary outcome — LDL cholesterol — showed no significant difference. And only the intervention group logged food in real time, inviting the critique that some benefit came from the act of self-monitoring rather than the personalization itself.

The verdict isn’t “personalization is magic.” It’s “personalization is real, measurable, and smaller than the marketing.”

Sources

  1. Bermingham et al., ZOE METHOD randomized controlled trial, Nature Medicine (2024)
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