Harvard Public Health Magazine

A Weighty Challenge

Pritzker scholarship winners fight the obesity epidemic from many angles

At the Harvard School of Public Health, up-and-coming young researchers are getting the training they’ll need to tackle this emerging epidemic. This year, three doctoral students became the first at HSPH to receive generous financial support through scholarships established by Harvard College alumna Penny Pritzker ‘81, and her husband, Bryan Traubert. The fellowships are part of the Donald and Sue Pritzker Nutrition and Fitness Initiative, funded in 2006 with a $5 million pledge from the couple in honor of Pritzker’s parents. In addition to providing a total of $1 million for students working in disciplines related to preventing obesity and its associated diseases, the Initiative will endow a new junior professorship at HSPH in obesity and metabolic syndrome research. It is also supporting the nationwide evaluation of a childhood exercise and nutrition program piloted at YMCAs in 20 cities (for details on the YMCA partnership, click here).

Here, the first three Donald and Sue Pritzker Scholars share their research interests and their passion for public health.

 

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Take the stairs: Developing exercise habits for healthy hearts and minds

“If research is the best way I can contribute, great. But I would also like to apply that research to influence policy or interventions that promote health and fitness.” —Pritzker Scholar Jacob Sattelmair, ScD ‘11

As U.S. primary and secondary schools wrestle with the time demands of increased standardized testing, physical education (PE) classes are often among the first programs to hit the chopping block. But with childhood obesity levels skyrocketing across all demographic boundaries, it’s crucial that kids be encouraged to develop lasting exercise habits.

Jacob Sattelmair, a doctoral student in epidemiology, thinks it’s time for a PE renaissance. It’s impractical to expect children and adolescents to schedule the recommended hour a day of moderate to vigorous exercise on their own, Sattelmair asserted in a draft paper he wrote last year in collaboration with John Ratey, an associate clinical professor of psychiatry at Harvard Medical School. However, there is no national standard for physical education classes, and Illinois is currently the only state requiring daily PE. Government mandated and funded daily PE is the best way to ensure that all kids get the body and brain-boosting benefits of regular physical activity, Sattelmair believes.

PE for life

According to Sattelmair, who is 25, schools need a new model for quality PE. “The old way, the kids who are the most fit to begin with are the ones who get to play. Everyone else gets marginalized,” he says.

He’s encouraged by the work of PE4life, a Kansas City-based non-profit. The organization has developed a daily PE program that emphasizes personal fitness goals over competition. Preliminary data from its nine pilot schools in the South and Midwest show that students’ grades and behavior are improving, Sattelmair says, although the results have not yet been measured against control schools.

Growing up in rural Rochester, Mass., Sattelmair learned early on that exercise made him feel better. “I was more relaxed, had a better mood, and related better to others,” he says. He found the scientific backing for that conviction in his studies of neurobiology at Harvard College, and of the science and medicine of athletic performance at the University of Oxford, in England, where he earned his master’s degree. He rowed competitively at both schools.
At Oxford, Sattelmair wrote his thesis on the effects of exercise on the brain. As he learned about the positive impact of physical activity on cognition, depression, anxiety, and stress, Sattlemair’s interests shifted to public health promotion, he says.

Fork in the road

Next year, Sattelmair plans to explore the relationship between exercise and cardiovascular disease risk. For now, he’s wrapping up his coursework and exploring various health promoting sideline projects, such as helping a friend design a videogame played on an exercise bike. Over the summer, he helped organize a workplace wellness conference as an intern with the World Health Organization.

“Apart from his academic smarts, I believe Jake has the intellectual curiosity, initiative, and drive to succeed,” says his advisor, I-Min Lee, associate professor of epidemiology at HSPH.

Though it’s too soon to say what direction he’ll take, Sattelmair wants to stay in public health. “If research is the best way I can contribute, great. But I would also like to apply that research to influence policy or interventions that promote health and fitness,” he says. “Maybe a little of both.”

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Keeping it off: Understanding the biology of gastric bypass surgery

“When you lose weight, your metabolism slows down. But that doesn’t happen after gastric bypass. I really want to understand why.”
—Pritzker Scholar Ida Hatoum, ScD ‘09

Given the vast array of diet plans, exercise options, and “miracle” weight-loss pills available today, why is it still so hard for people to lose weight and keep it off?

Ida Hatoum, a doctoral student in nutrition and epidemiology, wants to get to the bottom of a phenomenon she’s been witnessing all her life. She grew up in Framingham, Mass., watching her mom struggle with her weight while her dad ate whatever he wanted. “They say that 90 percent of people who lose weight are going to gain it back. I don’t think it’s because people are weak or lazy. I think there’s something biological going on,” says Hatoum, 26.

Predicting weight loss

She’s at the start of a thesis project that may generate some new insight. In collaboration with scientists at the Massachusetts General Hospital Weight Center, where she works as a research assistant, Hatoum is analyzing genetic data and medical records from 1,000 obese patients who had gastric bypass surgery between 1999-2007. She hopes to identify genetic markers that can predict how much weight patients will lose following the surgery.
In a gastric bypass operation, which is recommended only for obese patients with a body mass index (BMI*) of around 40 or higher, the stomach is surgically reduced in size. Then, its connection to the small intestine is re-routed to bypass the duodenum, the site where food is broken down. This bypass restricts the amount of calories and nutrients that can be absorbed. Research suggests the surgery may also have an effect on hormones—-possibly those that stimulate appetite or control the metabolic rate, says Hatoum.

Following the surgery, patients lose 60 percent of their weight in excess of their healthy BMI, on average. Most also see their weight-related health problems, such as type 2 diabetes, sleep apnea, and hypertension, improve or go away, according to a study published in the Journal of the American Medical Association in 2004. But the amount of weight lost is highly variable. A genetic predictor would help doctors and patients better assess whether the surgery’s risks—and the substantial changes in eating patterns required to adapt to an altered digestive system—are worth it.
Understanding the biological mechanisms behind the surgery would also have important implications for the study of obesity, Hatoum says. “When you lose weight, your metabolism slows down. You’re trying to conserve energy because your body thinks it’s starving. But that doesn’t happen after gastric bypass. I really want to understand why.”

Sparked by biology

Hatoum’s perspective on her obesity research evolved from experience. As an undergraduate at Boston University, she studied the media’s effect on body image in men. Her subsequent stints as an intern at a children’s weight-loss camp in England, and as a volunteer working on pregnancy prevention programs in schools, pointed her towards a career in public health. In 2003, she began a master’s program at HSPH in the Department of Society, Human Development, and Health, where she studied social policy issues related to obesity and was inspired by a biology class.

“I’m driven by the question of why people gain weight and, more so, why they can’t lose weight. I think there’s an answer. I don’t think that I’ll find it on my own, but I’d like to contribute,” she says.

Her advisor, Eric Rimm, associate professor of nutrition and epidemiology at HSPH, is in her corner. “Ida’s final doctoral thesis will encompass research in biological mechanisms of disease as well as population studies of obesity and related co-morbidities. This linking of basic science and large-scale research in humans may well define what all public health research will be like in the future.”

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Stretched to the limit: Exploring the role of fat cells in metabolic disease

“I really enjoyed the work and felt like I was skilled at it. And when those two things come together, you shouldn’t ignore them.” —Pritzker Scholar Meg Gregor, PhD ‘10

Meg Gregor is growing fat cells in a dish and stressing them out. It’s all part of a typical day’s work in the laboratory of her advisor, Gökhan Hotamisligil, the James Stevens Simmons Professor of Genetics and Metabolism at HSPH. Hotamisligil is pioneering research on obesity’s impact on metabolic diseases, including type 2 diabetes and cardiovascular disease, and the doctoral student is happy to be contributing.

“The research is really intriguing to me because it involves the whole body,” Gregor says. “You focus on what fat cells do, but you also study how fat is affecting the liver or how the brain is affecting your weight.”

Gregor has felt at home in a lab ever since she first stepped into one as a biology undergraduate at Hope College, in Michigan. “I really enjoyed the work and felt like I was skilled at it. And when those two things come together, you shouldn’t ignore them,” she says. A semester abroad in the Dominican Republic, where she shadowed doctors in an urban hospital, opened her eyes to public health.

Asking big questions

After graduation, Gregor worked as a technician at the Van Andel Research Institute in Grand Rapids, Michigan, for four years. There she studied the molecular basis of cancer under distinguished oncologist George Vande Woude, who encouraged her to continue developing as a scientist. At HSPH, where she is working towards a PhD in biological sciences, Gregor, 30, studied under Hotamisligil and became intrigued by metabolic research as it applies to obesity.
Hotamisligil and his colleagues have greatly advanced scientists’ understanding of the biological processes at work in fat cells. Once thought to be mere storehouses for excess energy, fat cells are in fact active players in the system controlling metabolism, the chemical process that converts food into energy. But fat cells can only take so much stress. As Hotamisligil has shown, those of an obese person are stretched to the limit. When faced with additional stresses such as a bombardment of excess nutrients, one of the cell’s chief operating systems, the endoplasmic reticulum (ER), reacts with a stress response that can lead to insulin resistance. This precursor to type 2 diabetes interferes with the body’s ability to process glucose.

New treatment pathways

Gregor’s thesis focuses on how the ER orchestrates fat-cell function. She is also studying the pathways that ignite inflammation in response to the rush of nutrients—a process that scientists now suspect lays the grounds for metabolic disease. Her work has so far generated promising indications that these molecular processes are critical to the health of fat cells, and that it is also possible to enhance their capacity with chemicals that can make the cells more resilient. If these concepts apply to humans (an idea she plans to test), they could open up new possibilities for treating metabolic disease.

“It has been a great joy to work with Meg on this extremely exciting and equally challenging project,” Hotamisligil says. “In general, I like graduate students in the lab to tackle big questions with strong applications to critical health problems. This approach has suited Meg very well; it drives her intellectually and stokes her passion.” 

Amy Roeder is the development communications coordinator for the Office for Resource Development at HSPH.