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Hungry for Something New

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“One way or another, I am going to get this message across. Mother Nature intended for us to eat Mother Nature’s produce.” - Dr. William McCarthy

WALK INTO DR. WILLIAM MCCARTHY’S OFFICE and you’re surrounded by posters, magnet messages and hand-painted mobiles featuring fresh fruits and vegetables. The four fruits and vegetable soup McCarthy brings to the office each day occupy a prominent spot on his desk. And if that’s not enough, the adjunct professor in FSPH’s Department of Health Policy and Management makes a daily sartorial statement, with fruits and vegetables adorning most of his ties.

“Dr. McCarthy’s devotion to promoting the consumption of fresh fruits and vegetables is difficult to miss,” says Dr. Lillian Gelberg, a close colleague who serves as professor in the Fielding School and David Geffen School of Medicine at UCLA. “He is passionate about improving the health of vulnerable populations, and his career has focused on developing interventions to support making the ‘right choice the easy choice’ by creating healthier households, schools, workplaces and neighborhoods.”

Over the course of dozens of studies and program evaluations designed to shed light on how to effectively encourage healthy eating among at-risk populations, McCarthy has adhered to a simple premise. “Human nutrition is optimized when our environments make it easy for us to eat the quantity of minimally processed plant foods that our forebears consumed 1,000 years ago,” he says. “And environments lacking in physical-activity opportunities and convenient access to minimally processed fruits and vegetables make it difficult to sustain a healthy appetite for water-rich, fiber-rich plant foods.”

McCarthy’s zeal for creating surroundings conducive to healthier eating emanates from two professional epiphanies. The first came when, as a graduate student studying social psychology in the late 1970s, he learned that two of his siblings had taken up smoking. “I was shocked,” he recalls. “We had solemnly agreed as preteens never to smoke, so their reversal of attitude toward smoking when they became adolescents piqued my intellectual curiosity.”

His pursuit of possible reasons for youth smoking onset prompted McCarthy to apply his interest in environmental influences on behavior to the burgeoning field of health psychology. He conducted wide-ranging studies to identify effective strategies for persuading members of targeted populations not to smoke. McCarthy also served as chief evaluator of California’s tobacco-use education efforts in the state’s public middle and high schools for 11 years.

In the late 1980s, he found himself again challenged by unexpected behavior change. In 1989, the first year after California voters passed Proposition 99’s 25-cents-per-pack tax on cigarettes, researchers reported a decline of more than 10 percent in smoking statewide. Because Proposition 99 tax revenues had not yet accumulated and were unavailable to fund any tobacco control education in 1989, the first-year decline was attributable mostly to the increased expense of the habit. “I should have become an economist if I really wanted to reduce tobacco use,” McCarthy quips. “Despite all of the anti-tobacco education in previous years, we had been getting only 1 percent reductions per year.”

For McCarthy, the lesson was that health education goes only so far if people are surrounded by unhealthy options. “We have communities that are ‘food swamps’ — everything is calorie-rich, nutrient-poor and processed,” he says. “In my professional lifetime the percentage of adult Americans who are overweight or obese has more than doubled. That’s obviously not because of any change in genetics; it’s our environment.”

Through his work, McCarthy is increasingly convinced that the best way to fight obesity is to promote healthier food choices rather than simply urging people to reduce the calories consumed from their usual food choices. His recent projects include a six-session program offering instruction in urban agriculture to East Los Angeles residents, as a practical strategy to offset a less-than-optimal food environment. He also worked with the Los Angeles Unified School District (LAUSD) in its efforts to provide healthier foods to its students. In 2011, LAUSD began offering more wholesome items, especially fruits, vegetables, whole grains, and a range of healthy ethnic foods. “Given that children consume up to half of their daily nutrients in school, school food service departments can powerfully influence students’ liking for healthier foods,” McCarthy said, adding that it can take 8-12 tastings for children to overcome their initial dislike of a new vegetable. McCarthy has become a proponent of providing garden-fresh produce to schoolchildren. “Every elementary school should have a garden,” he says. “Gardening should be part of the curriculum for both educational and health reasons.”

McCarthy has found his beliefs about the weight control benefits of healthier food choices strengthened by the emerging research on the gut microbiota — the trillions of microorganisms that inhabit the intestine and exert considerable influence on health and disease. “These studies are explaining some of the conundrums in our field, such as why low-income populations, which suffer food insecurity, are at greater risk of obesity than populations with everyday access to food,” McCarthy says. “The gut microbiome research suggests that the quality of what one eats is an important influence on satiety. People who need to economize when it comes to food choices buy low-cost foods that are fiber-poor and calorie-rich, and because the lack of fiber reaching the gut microbiota depresses satiety signaling, it also means they need more calories to feel satisfied than people with diets high in fruits and vegetables.”

From a societal perspective, McCarthy argues, the short-term costs associated with fostering environments that promote physical activity and fresh fruit and vegetable consumption are more than offset by the longer-term benefits of improved health and quality of life. “Unfortunately, short-term horizons are leading to policies that contribute to avoidable disease and premature deaths,” he says. “Academic researchers have a responsibility to point out the long-term avoidable costs associated with these decisions.”

McCarthy doesn’t shy away from making that case. “One way or another, either from my mouth or visually through my ties, I am going to get this message across,” he says. “Mother Nature intended for us to eat Mother Nature’s produce.”