How the Netflix Documentary “You Are What You Eat” Helps Bring Awareness to the Importance of DEXA Scans
by DEXA SCAN Boston
With the excitement around lifestyle changes, a Netflix docuseries, You Are What You Eat, has taken off in popularity. This series follows 4 sets of identical twins participating in a larger study overseen by Christopher D. Gardner, a professor at Stanford University.
The Study
In this study, 22 sets of twins were randomly assigned to either a healthy vegan or healthy omnivore diet. This diet was then followed over the course of 8 weeks. During the first 4 weeks pre-planned food was delivered to participants to facilitate the initial diet change. However, for the last 4 weeks the twins were instructed to cook on their own, staying within the parameters of their assigned diet. Each diet was also coupled with fitness training to maximize the health benefits for each participant.
Throughout the show, the twins highlight the different challenges and successes of their experience. For example, giving up cheese was particularly challenging for one twin as it was such a favorite food of his that the twins were often called the ‘cheese brothers’. However, he tried several vegan alternatives and was surprised by the similarity in taste and pleasure. While adding a touch of humor, following their story emphasizes the power of lifestyle changes in the lives of real people.
Why Select Twins for the Study Design?
The purpose of this study was to determine the pros and cons of an omnivore versus vegan diet on different metrics of health. In particular, this study wanted to evaluate the effects of these diets on body composition, the biological clock, microbiome, and the brain. Since these areas of health can be influenced by genetics, identical twins were chosen to limit this influence in the results. Specifically, since identical twins share 100% of their DNA, any observed differences between twins is a result of their environment, including the differences in the nutritional plans each one undertook over the 8 weeks. A very cool study design to disentangle nature vs. nurture!
Evaluating Results
(*Note: Some Spoilers Below!)
The main outcomes from this study demonstrated several benefits to a vegan diet. The twins assigned to the vegan diet had a more diverse gut microbiome, lower levels of LDL cholesterol, and lower levels of TMAO (a compound that causes inflammation). One of the most interesting results was that they also had increased telomere length compared to the twins that followed the omnivore diet. Telomere length is used as an indicator of biological age, so this implies the twins that followed the vegan diet are actually biologically younger than the twins that followed the omnivore diet!
One test featured was the DEXA scan, the gold standard for assessing body composition. This test was performed at both the beginning and end of the study. The results of these scans were very interesting, showing that most of the twins following the omnivore diet gained muscle, more so than the twins following the vegan diet. However, all of the twins following the vegan diet lowered their visceral fat. This is a significant measure of health because visceral fat is the dangerous fat surrounding your organs that increases the risk of developing several chronic illnesses. Overall, the findings of this study indicate that lifestyle changes can impact body composition and general health in just a few short weeks.
Benefits of the DEXA Scan
Body mass index (BMI) is a commonly used yet outdated way to evaluate health. The concept of BMI, which is the ratio of body weight to squared height, first came about in the 1800s. BMI is not the most accurate indication of health because it does not consider the proportion of fat and muscle in an individual’s total mass. For example, athletes are often classified as obese using BMI as a result of having a high amount of lean mass.
However, the good news is that a new technology called the DEXA scan has emerged as a more efficient tool that is also safe and non-invasive. The scan works by taking X-rays using very low levels of radiation to differentiate between fat, bones, and muscle. This allows the DEXA scan to provide an analysis of percent fat, percent muscle, visceral fat, and bone density. All this information is incredibly valuable to making lifestyle changes and getting a more accurate picture of overall health. If you’re looking to make a lifestyle change like the twins in You Are What You Eat, a DEXA scan is a great first step to kickstart your health journey!