The Zoe METHOD Trial Has Finally Been Released!

Zoe’s 4 year trial, the METHOD (measuring efficacy through outcomes of diet) study was finally completed and released earlier this week.

So what did it show us? Or better yet, what didn’t it show us…?

For those of you have been living under a rock, Zoe is arguably the largest personalised nutrition company that promises to help their consumers lose weight, feel better and improve overall health based on their scientific and evidence based approach.

Through stool testing and wearing a CGM (continuous glucose monitor) Zoe can use the data to make informed decisions about what you should or shouldn’t be eating.

So what did they do in this trial?

They took a group of people and randomly split them into two groups. 1 group was told that they would be getting the Zoe program (the test group), the other was just given a leaflet with generic nutrition advice (the control group).

Whilst it was randomised, there was a lack of ‘blinding’ - which meant that the test group knew they would be getting the ‘fancy’ Zoe program, whereas the other group was handed a leaflet, with generic NHS healthy eating guidelines, information that they probably would’ve seen hundreds and hundreds of times.

This creates something called a ‘performance bias’ where motivation and general perspective/outlook can be impacted.

Already a great experiment eh..?

Furthermore, the test group was given regular follow up appointments with the Zoe team for support, guidance and coaching on nutrition habits which then resulted in the test group having to log their foods on a daily basis.

If you’ve ever had to log into a food diary for a dietician/nutritionist/coach to review, you’ll know that it can have a profound impact on your eating behaviour because you knew it was going to be reviewed and critiqued..

Maybe you’ll skip dessert for a few days or perhaps not log in the few biscuits you’ve had…something called the ‘Hawthorne effect’.

Finally, the test group were also provided with frequent interactive lessons on nutrition - how to eat healthily etc.

So in general, lots of accountability, support and coaching compared to the control group.

The results?

Very mild improvements on serum triglyceride levels (1 of their primary outcomes) and no improvement in serum LDL cholesterol (their 2nd primary outcome).

There were other improvements seen such as body weight, waist circumference but it was very mild.

(They also did not track the amount of exercise that both groups did).

So overall, a very poorly executed trial, which they are now using the results to market to the general public as their ‘evidence backed science’ which helps their consumers get results.

I’m no scientist myself, but it certainly doesn’t feel like a fair trial that proves that personalising the diet based off microbiome testing & CGM data is what led to their mild results..