Identical twins reveal what happened when one of them went vegan and the other didn’t

It's a common saying - 'you are what you eat' - but just how true is it?

A set of identical twins decided to test it out when one of them went vegan and the other didn’t.

Twins Carolyn Sideco and Rosalyn Moorhouse joined forces with Stanford Medicine and other researchers in a study to see how quickly a vegan diet can improve cardiovascular well-being, with the experiment being captured in a four-part documentary series for Netflix aptly titled You Are What You Eat.

During the eight-week experiment, Carolyn, alongside 21 others from sets of twins, was put on a strict vegan diet while Rosalyn remained on an omnivore diet. Both diets were designed to be health-conscious, emphasising whole foods and minimising added sugar and processed foods.

For the first four weeks, participants were provided with 21 meals per week, provided by a meal delivery service, and for the remainder of the study, they prepared their own meals with help and guidance from a registered dietician.

Identical twins Carolyn and Rosalyn took part in an experiment to test the impact of a vegan diet on our health (Netflix)

By choosing identical twins to participate in the study, researchers were able to minimise the influence of genetics, lifestyle, and upbringing on the results, and isolate the impact of diet itself on our heart health. And the results were pretty impressive.

The study found substantial improvements within the first four weeks of adopting a vegan diet. Participants following the vegan diet saw significant reductions in their LDL-C (low-density lipoprotein cholesterol or 'bad cholesterol') levels, insulin levels and body weight - all of which play a crucial role in our cardiovascular health.

By the end of the eight weeks, LDL-C levels had decreased to 95.5 mg/dL for vegans and 116.1 mg/dL for omnivores (the optimal LDL-C level is less than 100 mg/dL).

Followers of the vegan diet also exhibited a 20 percent reduction in their fasting insulin levels and lost an average of 4.2 pounds in weight.

The study found that a vegan diet can reduce your LDL-C levels, insulin levels and weight (Getty Stock Images)

Dr. Christoper Gardner, the study's senior author, acknowledges that going strictly vegan can be difficult for a lot of people to adopt and maintain, but he recommends that we all incorporate more plant-based foods into our diets to reap the cardiovascular benefits.

And that's exactly what Carolyn and Rosalyn have done.

Since the experiment came to an end, Carolyn has returned to eating an omnivore diet but both twins have increased the number of plant-based meals they regularly consume.

You Are What You Eat is available to watch on Netflix now.