Personalized nutrition apps could provide valuable data to people trying to eat healthier, though more research must be done to show effectiveness.
As a type 2 diabetic, Michael Snyder has long been interested in how blood sugar levels vary from one person to another in response to the same food, and whether a more personalized approach to nutrition could help tackle the rapidly cascading levels of diabetes and obesity in much of the western world.
Eight years ago, Snyder, who directs the Center for Genomics and Personalized Medicine at Stanford University, decided to put his theories to the test. In the 2000s continuous glucose monitoring, or CGM, had begun to revolutionize the lives of diabetics, both type 1 and type 2. Using spherical sensors which sit on the upper arm or abdomen – with tiny wires that pierce the skin – the technology allowed patients to gain real-time updates on their blood sugar levels, transmitted directly to their phone.
It gave Snyder an idea for his research at Stanford. Applying the same technology to a group of apparently healthy people, and looking for ‘spikes’ or sudden surges in blood sugar known as hyperglycemia, could provide a means of observing how their bodies reacted to an array of foods.
“We discovered that different foods spike people differently,” he says. “Some people spike to pasta, others to bread, others to bananas, and so on. It’s very personalized and our feeling was that building programs around these devices could be extremely powerful for better managing people’s glucose.”
Unbeknown to Snyder at the time, thousands of miles away, a group of Israeli scientists at the Weizmann Institute of Science were doing exactly the same experiments. In 2015, they published a landmark paper which used CGM to track the blood sugar levels of 800 people over several days, showing that the biological response to identical foods can vary wildly. Like Snyder, they theorized that giving people a greater understanding of their own glucose responses, so they spend more time in the normal range, may reduce the prevalence of type 2 diabetes.
The commercial potential of such apps is clear, but the underlying science continues to generate intriguing findings.
“At the moment 33 percent of the U.S. population is pre-diabetic, and 70 percent of those pre-diabetics will become diabetic,” says Snyder. “Those numbers are going up, so it’s pretty clear we need to do something about it.”
Fast forward to 2022,and both teams have converted their ideas into subscription-based dietary apps which use artificial intelligence to offer data-informed nutritional and lifestyle recommendations. Snyder’s spinoff, January AI, combines CGM information with heart rate, sleep, and activity data to advise on foods to avoid and the best times to exercise. DayTwo–a start-up which utilizes the findings of Weizmann Institute of Science–obtains microbiome information by sequencing stool samples, and combines this with blood glucose data to rate ‘good’ and ‘bad’ foods for a particular person.
“CGMs can be used to devise personalized diets,” says Eran Elinav, an immunology professor and microbiota researcher at the Weizmann Institute of Science in addition to serving as a scientific consultant for DayTwo. “However, this process can be cumbersome. Therefore, in our lab we created an algorithm, based on data acquired from a big cohort of people, which can accurately predict post-meal glucose responses on a personal basis.”
The commercial potential of such apps is clear. DayTwo, who market their product to corporate employers and health insurers rather than individual consumers, recently raised $37 million in funding. But the underlying science continues to generate intriguing findings.
Last year, Elinav and colleagues published a study on 225 individuals with pre-diabetes which found that they achieved better blood sugar control when they followed a personalized diet based on DayTwo’s recommendations, compared to a Mediterranean diet. The journal Cell just released a new paper from Snyder’s group which shows that different types of fibre benefit people in different ways.
“The idea is you hear different fibres are good for you,” says Snyder. “But if you look at fibres they’re all over the map—it’s like saying all animals are the same. The responses are very individual. For a lot of people [a type of fibre called] arabinoxylan clearly reduced cholesterol while the fibre inulin had no effect. But in some people, it was the complete opposite.”
Eight years ago, Stanford's Michael Snyder began studying how continuous glucose monitors could be used by patients to gain real-time updates on their blood sugar levels, transmitted directly to their phone.
The Snyder Lab, Stanford Medicine
Because of studies like these, interest in precision nutrition approaches has exploded in recent years. In January, the National Institutes of Health announced that they are spending $170 million on a five year, multi-center initiative which aims to develop algorithms based on a whole range of data sources from blood sugar to sleep, exercise, stress, microbiome and even genomic information which can help predict which diets are most suitable for a particular individual.
“There's so many different factors which influence what you put into your mouth but also what happens to different types of nutrients and how that ultimately affects your health, which means you can’t have a one-size-fits-all set of nutritional guidelines for everyone,” says Bruce Y. Lee, professor of health policy and management at the City University of New York Graduate School of Public Health.
With the falling costs of genomic sequencing, other precision nutrition clinical trials are choosing to look at whether our genomes alone can yield key information about what our diets should look like, an emerging field of research known as nutrigenomics.
The ASPIRE-DNA clinical trial at Imperial College London is aiming to see whether particular genetic variants can be used to classify individuals into two groups, those who are more glucose sensitive to fat and those who are more sensitive to carbohydrates. By following a tailored diet based on these sensitivities, the trial aims to see whether it can prevent people with pre-diabetes from developing the disease.
But while much hope is riding on these trials, even precision nutrition advocates caution that the field remains in the very earliest of stages. Lars-Oliver Klotz, professor of nutrigenomics at Friedrich-Schiller-University in Jena, Germany, says that while the overall goal is to identify means of avoiding nutrition-related diseases, genomic data alone is unlikely to be sufficient to prevent obesity and type 2 diabetes.
“Genome data is rather simple to acquire these days as sequencing techniques have dramatically advanced in recent years,” he says. “However, the predictive value of just genome sequencing is too low in the case of obesity and prediabetes.”
Others say that while genomic data can yield useful information in terms of how different people metabolize different types of fat and specific nutrients such as B vitamins, there is a need for more research before it can be utilized in an algorithm for making dietary recommendations.
“I think it’s a little early,” says Eileen Gibney, a professor at University College Dublin. “We’ve identified a limited number of gene-nutrient interactions so far, but we need more randomized control trials of people with different genetic profiles on the same diet, to see whether they respond differently, and if that can be explained by their genetic differences.”
Some start-ups have already come unstuck for promising too much, or pushing recommendations which are not based on scientifically rigorous trials. The world of precision nutrition apps was dubbed a ‘Wild West’ by some commentators after the founders of uBiome – a start-up which offered nutritional recommendations based on information obtained from sequencing stool samples –were charged with fraud last year. The weight-loss app Noom, which was valued at $3.7 billion in May 2021, has been criticized on Twitter by a number of users who claimed that its recommendations have led to them developed eating disorders.
With precision nutrition apps marketing their technology at healthy individuals, question marks have also been raised about the value which can be gained through non-diabetics monitoring their blood sugar through CGM. While some small studies have found that wearing a CGM can make overweight or obese individuals more motivated to exercise, there is still a lack of conclusive evidence showing that this translates to improved health.
However, independent researchers remain intrigued by the technology, and say that the wealth of data generated through such apps could be used to help further stratify the different types of people who become at risk of developing type 2 diabetes.
“CGM not only enables a longer sampling time for capturing glucose levels, but will also capture lifestyle factors,” says Robert Wagner, a diabetes researcher at University Hospital Düsseldorf. “It is probable that it can be used to identify many clusters of prediabetic metabolism and predict the risk of diabetes and its complications, but maybe also specific cardiometabolic risk constellations. However, we still don’t know which forms of diabetes can be prevented by such approaches and how feasible and long-lasting such self-feedback dietary modifications are.”
Snyder himself has now been wearing a CGM for eight years, and he credits the insights it provides with helping him to manage his own diabetes. “My CGM still gives me novel insights into what foods and behaviors affect my glucose levels,” he says.
He is now looking to run clinical trials with his group at Stanford to see whether following a precision nutrition approach based on CGM and microbiome data, combined with other health information, can be used to reverse signs of pre-diabetes. If it proves successful, January AI may look to incorporate microbiome data in future.
“Ultimately, what I want to do is be able take people’s poop samples, maybe a blood draw, and say, ‘Alright, based on these parameters, this is what I think is going to spike you,’ and then have a CGM to test that out,” he says. “Getting very predictive about this, so right from the get go, you can have people better manage their health and then use the glucose monitor to help follow that.”
A patient getting examined at health startup Forward.
What if going to the doctor's office could be … nice?
If you didn't have to wait for your appointment, but were ushered right in; if your medical data was all collated and easily searchable on an iPhone app; if a remote scribe took notes while you spoke with your doctor so you could make eye contact with them; if your doctor didn't seem horribly rushed.
Would you go to the doctor to get help staying healthy, rather than just to stop being sick?
Would that change the way you thought about your health? Would you go to the doctor to get help staying healthy, rather than just to stop being sick? And would that, in the long run, be much better for you?
Those are the animating questions for Forward, a healthcare startup devoted to preventive care. Led by founder Adrian Aoun, formerly of Google/Sidewalk labs, Forward opened its first office in San Francisco in 2016 and has since expanded to Los Angeles, Orange County, New York, and Washington, D.C., with a San Diego location opening soon.
It's been described as the "Apple Store of doctor's offices," which in some ways is a reaction to Forward's vibe: Patients have described the offices as having blonde wood, minimalist design, sparkling water on tap — and lots of high-tech gadgets, like the full-body scanner that replaces the standard scale and stethoscope.
The interior of a Forward office.
(Courtesy Forward)
The more crucial difference, though, is its model of care. Forward doesn't take insurance. Instead, patients, or "members," pay a flat $149 per month, along the lines of a subscription service like Netflix or a gym membership. That fee covers visits, messaging with medical staff through the Forward app, the use of a wearable (like a Fitbit or a sleep tracker) if the physician recommends it, plus any bloodwork or diagnostic tests run in the on-site labs. (The company declined to disclose how many people have signed up for memberships.)
Predictability is Forward's other significant, distinguishing feature: No surprise co-pays, or extra charges showing up on a billing statement months later. Everything is wrapped up in the $149 membership fee, unless the physician recommends visiting an outside specialist.
That caveat isn't a small one. It's important to note that Forward is in no way meant to replace standard health insurance. The service is strictly focused on preventive care, so it wouldn't be much use in case of an emergency; it's meant to help people, as far as is possible, avoid that emergency at all.
Ani Okkasian's family recently went through such an emergency. Her 62-year-old father, an active and seemingly healthy man living with diabetes, had been feeling unwell for a while, but struggled to receive constructive follow-up or tests from his doctor. It finally emerged that his liver was severely damaged, and he suffered a stroke — the risk of which can be elevated by liver disease. He seemed to deteriorate completely within mere weeks, Okkasian said, and in January he passed away.
"He was someone who'd go to the doctor regularly and listen to what they said and follow it," Okkasian said. "I shouldn't have had to bury my father at 62. I still believe to my core that his death could have been avoided if the primary care was adequate."
"I could tell that the people who designed [Forward] had lost someone to the legacy system; it was so streamlined and so much clearer."
Okkasian began researching, looking for a better alternative, and discovered Forward. Founder Aoun lost his grandfather to a heart attack; his brother's heart attack at age 31 was the impetus to start Forward.
"I could tell that that was the genesis," Okkasian said. "Having just lost someone, and having had to deal with different aspects of the healthcare industry — how complicated and convoluted that all is — I could tell that the people who designed [Forward] had lost someone to the legacy system; it was so streamlined and so much clearer."
So Who Is Forward For?
The Affordable Care Act mandates that evidence-based preventive care must be covered by insurers without any cost to the patient. Today, 30 million Americans are still living without health insurance; but for most of the population, cost shouldn't prevent access to standard, preventive care, says Benjamin Sommers, a physician and professor at the Harvard T.H. Chan School of Public Health who has studied the effect of the ACA on preventive care access.
For Okkasian and her family, it wasn't a lack of access to primary care that was at issue; it was the quality of that primary care. In 2019, that's probably true for a lot of people.
"How come all other industries have been disturbed except the medical industry?" Okkasian asked. "It's disturbing the most people. We're so advanced in so many ways, but when it comes to the healthcare system, we're not prioritizing the wellness of a person."
Is Forward the answer? Well, probably not for everyone. Its office are only in a handful of cities, and there are limits to how scalable it would be; it's unavoidable that the $149 per month charge restricts access for a lot of people. Those who have insurance through their employer might have a flexible spending account (FSA) that would cover some or all of the membership fee, and Forward has said that 15 percent of their early members came from underserved communities and were offered free plans; but for many others, that's just an unworkable extra cost.
Sommers also sounded a dubious note about a maximalist attitude toward data collection.
"Even though some patients may think that 'more is always better' — more testing, more screening, etc. — this isn't true," he said. "Some types of cancer screening, ovarian cancer screening for instance, are actually harmful or of no benefit, because studies have shown that they don't improve survival or health outcomes, but can lead to unnecessary testing, pain, false positives, anxiety, and other side effects.
"It's really great for people who are in good health, looking to make it better."
"I'm generally skeptical of efforts to charge people more to get 'extra testing' that isn't currently supported by the medical evidence," he added.
But relatively healthy people who want to take a more active approach to their health — or people who have frequent testing needs, like those using the HIV-prevention drug PrEP, and want to avoid co-pays — might benefit from the on-demand, low-friction experience that Forward offers.
"It's really great for people who are in good health, looking to make it better," Okkasian said. "Your experience is simplified to a point where you feel empowered, not scared."
