Your work focuses on ethnic and racial disparities in obesity. Why is it important that we study obesity in the first place? What are the medical and social implications of being obese?
So obesity, or higher weight, is associated with some of the major chronic diseases, so, for example, diabetes, and importantly, cardiovascular disease, which is the largest contributor to death and morbidity here in the United States and also nation wide. Addressing obesity and its important determinants, like diet and physical activity, is incredibly important for the wellbeing of our population as a whole.
The Sightlines data shows that blacks are the least likely to have a healthy BMI, followed by Hispanics. What are some of the most significant factors driving the ethnic and racial disparities in obesity? What are some of the challenges unique to each of these groups?
Sure. So there are some pretty marked disparities inn obesity across the life course, so from childhood all the way through older adulthood in obesity across racial-ethnic lines, and also across socioeconomic status. The determinants of those disparities are, as you might imagine, multifactorial. I like to categorize them, at least for myself, as thinking about individual level factors, family or peer level factors, neighborhood factors, and then larger society or policy level factors. And obviously they’re not distinct in those categories either. There’s interplay and confounding effects across those levels of determinants. In our society, at least, we tend to think about the individual level factors first. I think most people’s brains gravitate towards this personal responsibility. It’s the personal choices that people make that lead them to have an unhealthy weight or an unhealthy lifestyle. And while certainly we all have choice when it comes to diet and physical activity, I think those individual level factors play a role. It’s important to think about how those are influenced by outer levels of influence. Let’s look at each level. At the individual level, we do have information on level of knowledge that people have about diet and physical activity and potentially how that might impact the choices they make as it relates to their weight or as it relates to diet, physical activity, even sleep, as we’re learning. Also different levels of stress and different lifestyle factors that people have that have been shown to be associated with obesity. I think often times one of the strongest predictors of obesity in childhood is soda consumption, and that’s a good example of an individual level determinant. But then of course, children don’t decide to drink soda by themselves. So its important to look at family level next. People are influenced by their families and also by their peers and that kind of changes over their life course, with a really important influence from family at the beginning, and an increasing influence from peers as we age. There was some really interesting data that came out of the Framingham study showing that obesity was contagious. So, they did a social network analysis and showed that you’re more likely to be obese if your peers are obese. You’re also more likely to be obese if your family members are obese. And of course that carries with it a family component—a genetic as well as an environmental impact. And of course, from peers we think that it’s a shared environment, but also maybe shared values and behaviors. So, then moving outwards, I think we get into some of the influences that we could potentially impact through policy changes, such as neighborhood influences. If you attend a school where you’re not allowed to have soda on campus, you are less likely to be obese than if you go to a school where there’s easy soda access, for example. If you live in neighborhood that has easy access to fast food or a lot of access to fast food, you’re more likely to be obese than if you live in a neighborhood that doesn’t have those types of food outlets. If you live in a neighborhood that’s more walkable, we hope that you will be out being more physically active than if you don’t. So, there’s neighborhood and community level influences for your diet and physical activity, and I keep adding on sleep and stress and some of the other factors that we think probably play a role in your weight status. And then we think about some of those social or political factors that also have an influence. We haven’t talked about some of the more social determinants of health, like income inequality or racism or historical trauma or some of these factors that may be subconsciously influencing the choices that people are able to make or the opportunities they have in life that may influence their weight status. And then, of course, there’s policies like we’ve heard a lot about this election, like soda taxes and other policies that influence how easy it is for us to access healthy foods versus less healthy foods. We know that energy dense, nutrient poor foods are much cheaper than, for example, fresh fruits and vegetables, and that has to do with a lot of food pricing policies we have in the United States as well as agricultural policies. Those can influence our weight status as well. So, you can kind of see that each of those layers influences the one next to it, and makes it kind of an exciting area to study—but also really challenging.
You stated that “incorporation of the upstream determinants of health in collaboration with communities is the key to addressing health equity in the US.” Can you expand on that statement?
While its really hard to do in practice and often not supported by the type of research funding that we have available to us, gong as upstream as possible, in other words, trying to look at what those root causes of health disparities are, especially when you’re including the communities that you’re studying in that type of research, has a lot of promise. I can just give an example. A local urban American Indian community here in the Bay Area was really interested in addressing diabetes and obesity in their community. They had done some work around diabetes prevention already and had been quite successful, but time and time again, kept butting up against this concept that they called historical trauma, so this idea that there’s an intergenerational transfer of life experiences that have happened to a population. And they felt that historical trauma promoted the development of obesity and diabetes as well as hindered their strategies for prevention. So, to them, that was one of the root causes that was influencing poor diet and physical activity choices and increasing the likelihood that people would be obese or diabetic. We went about together, as a group, in partnership coming up with strategies that would address historical trauma and help folks to make healthier lifestyle changes. Historical trauma is definitely one of those examples of a very upstream cause, and for some people it can even be hard to see the tie between something that happened 7 generations ago and choices that I’m making today. But at least in the American Indian culture, that was very much how they viewed the problem in their community. You know, I think that in other communities, for example, in Latino communities, looking at the effects of acculturated stress. What happens when they move here? An example from a project we worked on in the Salinas Valley with farm worker population is that for for families who risk their lives, basically, to come here to make a better life for their family, and then they’re able to access foods that they never had access to at home because of food insecurity, it’s pretty powerful to want to give your children everything you never had, especially when you suffered so much to do that. Getting McDonalds or getting certain junk foods that have a high societal price to you can be really compelling. And then for someone to say, you need to eat traditional foods—like rice and beans and tortillas are really healthy—that can be a little bit difficult for someone who’s been through that. No outside intervention or policy that’s not developed in partnership with the community is really going to have resonance, I don’t think. It has to be something that’s developed from the ground up with the community input, so that people are more likely to take advantage.
What sort of policy interventions do you believe will be most effective in reducing obesity disparities, as well as obesity rates in general?
It’s a hard question, but at the very core it’s an easy question. So any policies that can reduce the cost of healthy foods and reduce the costs of being active in our communities are policies that are going to help address obesity. In my mind, we need to have a dual approach. We need to make the healthiest choice the easiest choice. And we need to work with individuals to help them take advantage of that. For a long time, there were two camps of people working on the more individual level and people working more on the environmental or policy level. And I think really, at this point, we need to work hand in hand. In many of our communities, more than 50% of the population is already obese. We need to help them to undo some of the patterns that have developed and we need to help our younger people always know that a healthier choice is available and the best choice. We have some good examples from smoking cessation. But essentially any policy, whether it’s a soda tax or it’s changing the wick coupon so that there are more healthy foods, being able to use food stamps at farmer’s markets, any of those that increase access to healthy foods will be good polices. Likewise, for physical activity, anything we can do to increase active transport, to make our communities more attractive for walking, and to make workplaces more supportive of being physically active, will be policies that will help us. Unfortunately, I don’t think there’s one policy—that would be the easiest—but it’s going to take a whole shift in our policy making to include that in all of our strategies.
How do you think information technology can be used to combat obesity?
So we use information technology in multiple ways. So starting down at the individual level, some of the strategies that we know that are most helpful in changing behavior have to do with monitoring your behavior. So, you can imagine that behaviors you’re not aware of are harder to change. Increasing your awareness of your physical activity and your dietary choices can be really powerful in helping you to make changes, and information technology is great for that. I mean, it’s in everyone’s phone now how many steps you’re taking a day and there’s a gazillion different applications out there that you can use to monitor your dietary intake or track whatever it is you want to do. I think, at the individual level, those can be really helpful. I think as we move to those outer layers of influence, information technology can also be really great for making changes in our environment and our policies. For example, ways that you can document your neighborhood or how polices are influencing what you eat and how active you are can be used to communicate with policy makers more effectively. As researchers, we like to think that our data will convince people to make better polices to improve health, ad sometimes it’s that personal story or bringing something alive for a policy maker that can motivate them to change their minds or develop a policy or promote a policy. Information technology can be really powerful for that. Even to use an example from my own life—in our town you can use an app to report anything that is wrong with the streets or is influencing your ability to walk your child to school or whatever it is, then policy makers can get that, or the city can get that, and make changes right away. That’s just an easy example, but you can also do that on a bigger scale, potentially.
This question takes a step back and looks at how we assess obesity in the first place. Is BMI a good measure of obesity or weight status in general?
So, body mass index is a good measure of obesity, but not a perfect measure of obesity. What we really care about when it comes to weight is the adiposity that people are carrying on their body. We think that physiologically that’s what leads to diseases. It’s not the weight we’re so concerned about, its really the diseases that the weight is influencing or promoting—so diabetes, cardiovascular disease, certain cancers, and things like that. There of course are some societal effects directly associated with obesity, but in terms of physical and mental health, it’s not so much the weight but what it leads to. That being said, when it comes to satisfying populations for risk for those diseases, or when it comes to doing large scale screenings, we’ve compared body mass index to other measures of adiposity, so for example, waist circumference, or a skin fold thickness, these different rations, waist to hip ratio, things like that, and at the end of the day, body mass index is either better or as good as some of those other measures, and its much easier to do accurately on a larger population. Although we’ve tried other measures when it comes to obesity research, I think we come back to body mass index pretty frequently. Of course there are much more accurate ways to measure adiposity using DEXA or using underwater weighing, for example, but it’s just not practical when it comes to large public health efforts. I think the long and short of it is body mass index is imperfect, but good enough.
Can you talk a little bit about your career development award from the American Heart Association? What does a family-based approach entail?
I think that we have done quite a bit as a field when it comes to childhood obesity and when it comes to adult obesity, and I think we still really have a gap in how to address obesity in adolescents. It’s a really important group to work with, because the activity and dietary patterns you lay down in adolescence tend to persist to adulthood more so than they do during childhood, and also the weights status you are when you are an adolescent is a self image you carry with you developmentally all through life. You know, it’s a time of change, and I think people view it as a really challenging time, as adolescents are becoming more independent from their families and relying more on their peers. It’s a time of transition before many go off to college and get jobs. So, while I see that as a challenge, I also see it as an incredible opportunity. When you’re in that time of a transition, you have an opportunity to make healthier patterns and hopefully make those maintained and sustained over your life course. That being said, I still think we haven’t quite figured out how to do it. The funding from the American Heart Association helped us to pilot a family based approach. This was actually on middle school adolescents, so trying to get middle school adolescents, before they start high school, to set down those healthy patterns. During middle school is when we see an incredible decrease in physical activity. Children tend to be quite active and actually meet Physical Activity Guidelines for Americans more often than adolescents do. Once they get to adolescence, the proportion of kids who are engaging in the recommended 60 minutes of physical activity a day goes dramatically down. During that time period, we pilot tested a family based intervention where we did an in-person intervention at a community health center—a youth center, actually—and we worked with the adolescents by themselves and the parents by themselves, and then had a joint session. And that kind of mirrored what we heard from adolescents, of how much feedback from parents they wanted. They do want to do things on their own and with peers, but at the same time an 11-14 year-old depends on their parents a lot, to get everywhere, for food, for all sorts of things, and developmentally are still influenced probably more by their parents than by their peers. So we are still analyzing this data, but really the point of it was to see if we could even get adolescents to change behavior, get parents to increase their knowledge during that time period, and then come together and have kind of a role model family meal that could be an example of what they could do at home. Another fun activity we did as part of that intervention was to let the adolescents, during each session, plan a portion of a family party. Adolescents voiced that they really wanted to have a say in their family life, and they were getting older, and they wanted to have more responsibility. The parents had to let them plan a party—pick the food, pick the entertainment, pick everything. Then they hosted the party at the end. And they had some guidelines—it had to be healthy, and there had to be some physical activity, and things like that. The parents were just invited. That was kind of fun for them to get to take charge of something, and do some cooking. And since then we’ve done an additional project, a pilot project with older teens, so the 14-18 year old group, and they wanted nothing to do with their parents. They wanted their parents to bring them—it’d be fine if their parents listened about something—but they wanted to be only by themselves for the session. And the biggest motivator it seemed like for them –in terms of coming to the intervention—was the peer relationships that they made. The people that made friends in the group came back every time without fail and looked forward to it, even though it was a Saturday morning in the summer. Kids who didn’t click with a anyone else, it wasn’t for them. So, that peer component was the most important I would say.