Introducing the PREDICT 2 Study
I am less than 48 hours away. 48 hours away from beginning my participation in a study that will potentially provide insight into how my body metabolizes food. Not how people my age/gender/race tend to metabolize food, but how my body uniquely metabolizes food.
This study is riding the wave of personalized nutrition that’s been surging through the scientific community for the last decade. Because as scientists learn more and more about nutrition and the digestive system, the clearer it becomes that metabolism is a deeply personal experience.
Imagine this. Instead of following the latest popular diet (i.e. gluten-free, paleo, keto, intermittent fasting), people have the opportunity to take a test to identify their unique responses to different foods. For example, a gluten-free diet may work for some (Celiac disease, gluten intolerance), while for others there might be something else in wheat products that’s causing them discomfort. In theory, this test could identify what “something else” is.
The study is called PREDICT 2, and it involves following a schedule of eating pre-prepared meals and providing blood, saliva, and stool samples for analysis. “PREDICT” stands for “Personalized Responses to Dietary Composition Trial,” and I’ll talk more about the study, its sponsor (a commercial company, Zoe Global Limited), and the collaborators involved (Stanford University, Massachusetts General Hospital, King’s College London, and Tufts University) in more detail later this week. I’ll also be blogging about PREDICT 1, a two-week study that measured physiological responses to specific foods. Researchers showcased preliminary results from PREDICT 1 at the American Society of Nutrition conference early in summer 2019.
The study will take place over 12 days: one set-up day, 10 study days, and one follow-up visit to a clinic where I’ll have blood samples taken. I received my study pack in the mail two days ago, and it contained all of the items I’ll need throughout the study, including the standardized meals.
On some days, I’ll have standardized breakfast and lunch meals that I’ll eat. Depending on the day and the samples I need to provide, I’ll need to wait 2-4 hours after each standardized meal before eating again. I can drink water, coffee, and tea during these times, but they recommend that I drink about the same amount of caffeine that I normally do every day.
I’ll log all of my non-standardized eating and drinking activity in a mobile app I downloaded on my phone. If you’ve ever used My Fitness Pal to track calories and nutrients you’ve consumed through food, the app as very similar to that.
On the set-up day, I’ll use materials I received in the study pack to collect a stool sample. This sample allows scientists to analyze the diversity of my microbiome, which is key to understanding my body’s unique response to certain nutrients in food. I’ll also collect a saliva sample on the set-up day, which provides the study team with samples of my DNA. The study team describes that DNA samples enable them to “identify certain genetic characteristics that have been previously associated with [my] responses to foods that [they] will measure during the study.”
On some days, I’ll provide blood samples at specific times before and after meals. From these samples, study scientists can learn about how my blood fat levels change throughout the day and before and after specific meals. The study team describes blood fat levels as a “key metabolic indicator and one of the two main sources of energy in your body,” with blood sugar, or blood glucose, being the other main source of energy.
To measure blood glucose, I’ll be wearing a blood glucose monitor* throughout the study. I activate the monitor myself on the set-up day, about 16 hours before the first study day. The monitor takes this time to calibrate.
*This glucose monitor is FDA-approved for use in the management of diabetes but not for evaluating blood sugar levels in non-diabetic contexts, including this study
In addition to the glucose monitor, I will also be wearing an activity tracker on my nondominant wrist throughout the study to measure my physical activity and sleep levels. This tracker is very similar to FitBit technology.
After the 10 study days, I will visit a Quest Diagnostics Patient Service Center to provide a blood sample. The study team requires that I do this within one week of the tenth study day and before 11:00am so the samples can be shipped and processed at a central lab the following day.
All of the sample analysis relies on knowing exactly what I consumed to elicit certain physiological responses. Thus, it’s crucial that I follow the food and drink schedule as closely as possible, eating and drinking standardized meals and drinks when scheduled and carefully recording my food and drink consumption at all other times.
I am not getting paid to do this study, but I am pretty pumped about getting my results back. The study team is hoping for 1,000 participants, so potentially you could be involved too! A few months after the study, I will be contacted by the study team to discuss my results. If I want them to, they can also share the results with my primary care physician. Essentially, I’m hoping for information on my personal physiological response to components of different foods and how those responses compare to common responses to food.
While the insights gleaned from this study will likely help build an algorithm for predicting individual responses to food, the informed consent form states: “the predictive value of this research is not yet proven and it is unknown whether you will benefit from the information”
Over the next couple of days, I’ll be posting regular updates about the study as well as providing background information about the people and science involved. I’m really excited (as nerdy as it sounds) to participate in a study that’s doing awesome things for science by learning how different people respond to different foods and what factors account for those differences. I hope people will ask questions about my experiences and be inspired to participate in meaningful studies like this in the future!
Note: While the PREDICT 2 study team encourages participants to share information about the study, the statements made in this blog post and future blog posts are based on my own research and sets of opinions.