New Thoughts about Causes, Prevention, and Treatment of Childhood Obesity

Journal Articles & Websites

David Allison

Willette AA, Bendlin BB, Colman RJ, et al. Calorie restriction reduces the influence of glucoregulatory dysfunction on regional brain volume in aged rhesus monkeys. Diabetes 2012;61(5):1036–1042.

Tajeu GS, Sen B, Allison DB, et al. Misuse of odds ratios in obesity literature: an empirical analysis of published studies. Obesity 2012.

Berentzen TL, Ängquist L, Kotronen A, et al. Waist circumference adjusted for body mass index and intra-abdominal fat mass. PLoS ONE 2012;7(2):e32213.

Mandana Arabi

The Sackler Institute for Nutrition Science

Arabi M, Frongillo EA, Avula R, et al. Infant and young child feeding in developing countries. Child Dev. 2012;83(1):32–45.

Mangasaryan N, Arabi M, Schultink W. Revisiting the concept of growth monitoring and its possible role in community-based nutrition programs. Food Nutr. Bull. 2011;32(1):42–53.

Diane Craft

Active Play Books: A site that connects parents and teachers to resources about fun physical activities for children. Visit the website for information on books, DVDs, and workshops and to view videos of some of the activities.

Lauren Hale

Magee L, Hale L. Longitudinal associations between sleep duration and subsequent weight gain: A systematic review. Sleep Med. Rev. 2012;16(3):231–241.

Martin A, Barajas RG, Brooks-Gunn J, et al. Parenting services may be an opportunity for improving bedtime routines among at-risk preschoolers. Behav. Sleep Med. 2011;9(4):237–242.

Hale L, Berger LM. Sleep duration and childhood obesity: moving from research to practice. Sleep 2011;34(9):1153–1154.

Kathleen Hallinan

PE4 Life

Fun 2B Fit

Budde H, Brunelli A, Machado S, et al. Intermittent maximal exercise improves attentional performance only in physically active students. Arch. Med. Res. 2012;43(2):125–131.

McManus AM, Masters RSW, Laukkanen RMT, et al. Using heart-rate feedback to increase physical activity in children. Prev. Med. 2008;47(4):402–408.

John Jakicic

Faith MS, Van Horn L, Appel LJ, et al. Evaluating parents and adult caregivers as "agents of change" for treating obese children: evidence for parent behavior change strategies and research gaps: a scientific statement from the American Heart Association. Circulation 2012;125(9):1186–1207.

Jakicic JM, Davis KK. Obesity and physical activity. Psychiatr. Clin. North Am. 2011;34(4):829–840.

Hergenroeder AL, Brach JS, Otto AD, et al. The influence of body mass index on self-report and performance-based measures of physical function in adult women. Cardiopulm. Phys. Ther. J. 2011;22(3):11–20.

Janine Jurkowski

Ramos BM, Jurkowski J, Gonzalez BA, et al. Latina women: health and healthcare disparities. Soc. Work Public Health 2010;25(3):258–271.

Rimmer JH, Riley B, Wang E, et al. Physical activity participation among persons with disabilities: barriers and facilitators. Am. J. Prev. Med. 2004;26(5):419–425.

Lopez-Class M, Jurkowski J. The limits of self-management: community and health care system barriers among Latinos with diabetes. J. Hum. Behav. Soc. Environ. 2010;20(6):808–826.

Omry Koren

Larsson E, Tremaroli V, Lee YS, et al. Analysis of gut microbial regulation of host gene expression along the length of the gut and regulation of gut microbial ecology through MyD88. Gut 2011.

Ran-Ressler RR, Khailova L, Arganbright KM, et al. Branched chain fatty acids reduce the incidence of necrotizing enterocolitis and alter gastrointestinal microbial ecology in a neonatal rat model. PLoS ONE 2011;6(12):e29032.

Vaishnava S, Yamamoto M, Severson KM, et al. The antibacterial lectin RegIIIgamma promotes the spatial segregation of microbiota and host in the intestine. Science 2011;334(6053):255–258.

John Kral

Coplan JD, Abdallah CG, Mathew SJ, et al. Metabolic syndrome and neurometabolic asymmetry of hippocampus in adult bonnet monkeys. Physiol. Behav. 2011;103(5):535–539.

Dhariwal L, Kral JG. Offspring outcomes after maternal BPD: euphenics for the epidemic? Surgery for obesity and related diseases. J. Am. Soc. Bariatric. Surg. 2011.

Kral JG, Otterbeck P, Touza MG. Preventing and treating the accelerated ageing of obesity. Maturitas 2010;66(3):223–230.

David Levitsky

Levitsky DA, Pacanowski CR. Free will and the obesity epidemic. Public Health Nutr. 2011:1–16.

Levitsky DA, Garay J, Nausbaum M, et al. Monitoring weight daily blocks the freshman weight gain: a model for combating the epidemic of obesity. Int. J. Obes. (Lond). 2006;30(6):1003–1010.

Speakman JR, Levitsky DA, Allison DB, et al. Set points, settling points and some alternative models: theoretical options to understand how genes and environments combine to regulate body adiposity. Dis. Model Mech. 2011;4(6):733–745.

Christine Olson

Gantner LA, Olson CM. Evaluation of public health professionals' capacity to implement environmental changes supportive of healthy weight. Eval. Program Plann. 2012;35(3):407–416.

Lipsky LM, Strawderman MS, Olson CM. Maternal weight change between 1 and 2 years postpartum: the importance of 1 year weight retention. Obesity 2012.

Paul KH, Graham ML, Olson CM. The web of risk factors for excessive gestational weight gain in low income women. Matern. Child Health J. 2012.

Kathleen Rasmussen

Frith AL, Naved RT, Persson LA, et al. Early participation in a prenatal food supplementation program ameliorates the negative association of food insecurity with quality of maternal-infant interaction. J. Nutr. 2012.

Rasmussen KM, Abrams B. Gestational weight gain and later maternal health: are they related? Am. J. Clin. Nutr. 2011;93(6):1186–1187.

Rasmussen KM, Geraghty SR. The quiet revolution: breastfeeding transformed with the use of breast pumps. Am. J. Public Health 2011;101(8):1356–1359.

Jesse Roth

Roth J. Evolutionary speculation about tuberculosis and the metabolic and inflammatory processes of obesity. JAMA 2009;301(24):2586–2588.

Roth J, Qiang X, Marbán SL, Redelt H, Lowell BC. The obesity pandemic: where have we been and where are we going? Obes. Res. 2004;12 Suppl 2:88S–101S.

Susan Terwilliger

Terwilliger SH, Gueldner SH, Bronstein L. A preliminary evaluation of the well-being picture scale—children's version (WPS-CV) in a sample of fourth and fifth graders. Nurs. Sci. Q. 2012;25(2):160–166.

Terwilliger SH. Early access to health care services through a rural school-based health center. J. Sch. Health 1994;64(7):284–289.

Sponsors

Presented by

Conference Sponsors

This conference is sponsored by the Conversations in the Disciplines Program of the State University of New York.

SUNY Upstate Medical University

Universal Hospital Services

Guthrie Health

Broome County Health Department

Lourdes Hospital

Clinical Science and Engineering Research Center (CSERC)

It's no secret that, globally speaking, people are getting fatter. Whether measured directly, by average body mass index of a population or by the prevalence of overweight, or indirectly, by the incidence of chronic conditions such as type 2 diabetes and cardiovascular disease, the world is clearly in the midst of an obesity pandemic. While the overall trend is troubling, perhaps the most disturbing facet of this evolving public health disaster is the rise in childhood obesity. Left untreated, overweight and obese children may face a lifetime of social stigmatization, weight-related health problems, and physical limitations.

On April 27–28, 2012, a diverse group of researchers, physicians, teachers, and other professionals at the front lines of the childhood obesity epidemic met in Binghamton, NY to discuss the problem. An equally diverse audience of more than 200 attendees listened to the presentations and participated in a series of highly interactive panel discussions and breakout sessions covering all aspects of childhood obesity.

Binghamton, a small city in one of the poorest and most rural parts of New York state, provided an appropriate venue. Citing a recent Gallup poll that identified the town as the second-most obese city in the U.S., conference co-director Allison Alden of Binghamton University's Center for Applied Community Research and Development said, "That's not something that Binghamton would like to be known for."

After an overview by Jesse Roth of Albert Einstein College of Medicine, who discussed mounting evidence that the complications of obesity stem largely from a chronic inflammatory state induced by excess fat, David Allison of the University of Alabama at Birmingham delivered an enlightening keynote presentation dispensing with many of the common myths and legends surrounding weight control. Roth and Allison then joined other speakers on a panel that tackled a wide range of related subjects, from the utility of body mass index (BMI) as a measure of obesity to the role of exercise in combating the problem.

A series of speakers then took up separate aspects of childhood obesity. Susan Terwilliger of Binghamton University presented a model for the social ecology of weight gain, Janine Jurkowski from the University at Albany placed the phenomenon into the context of health equity, especially in rural areas, and Kathleen Hallinan, a physician at Guthrie Medical Center, described a physical activity program she and her colleagues have implemented in Corning, NY, another rural community affected by obesity. Christine Olson and Kathleen Rasmussen, both of Cornell University, talked about the effects of obesity on pregnant women and on nursing infants, Lauren Hale of Stony Brook University covered the importance of sleep in combating weight gain, and John Kral of SUNY Downstate Medical Center described the effects of bariatric surgery on pregnancy outcomes.

The second day of the conference began with a keynote address by Mandana Arabi from the Sackler Institute for Nutrition Science about the global scope of the obesity pandemic. In a cruel twist, many developing countries are now combating problems of undernutrition and overnutrition simultaneously. Omry Koren of Cornell University then talked about the correlation between weight gain and gut microbial ecology. John Jakicic of the University of Pittsburgh and Diane Craft of SUNY Cortland covered interventions to increase children's physical activity at the school and preschool levels, respectively. Finally, David Levitsky of Cornell University highlighted the controversial but surprisingly effective technique of daily weighing to encourage weight maintenance.

Between the major presentations, conference attendees participated in lively panel discussions and breakout sessions that ranged from the best ways to approach parents about their children's obesity to the effects of urban planning on activity levels. While nobody has yet discovered a miracle cure for childhood obesity, the conference provided a deep and broad discussion of the topic and helped the group identify which strategies are most likely to work.

Speakers:
Jesse Roth, Albert Einstein College of Medicine, Yeshiva University
David Allison, University of Alabama at Birmingham

Panel moderator:
John Kral, SUNY Downstate Medical Center

Highlights

• Excess body fat stimulates a chronic inflammatory state.
• Exercise may reduce the sequellae of obesity even without causing weight loss.
• Many widely accepted "truths" about obesity are either wrong or unproven.
• Body mass index (BMI) is a widely used but minimally useful measure of obesity.

Fat in the fire: Inflammation for good and bad

Jesse Roth of Albert Einstein College of Medicine began his overview of the conference topic by reminding the audience that there's nothing funny about fat. "We need to abolish the link between obesity and comedy," he said. Despite the rising toll of type 2 diabetes, cardiovascular disease, arthritis, and other debilitating comorbidities of obesity, many entertainers continue to use fat characters as the butts of jokes.

Switching from the social to the biological problem of obesity, Roth gave a brisk review of evolutionary history, from the emergence of single-celled life about 3.5 billion years ago to the rise of multicellular organisms and eventually of mammals, including humans. Life, for virtually all of that time, has been dominated by competition for scarce nutrients and survival of infectious diseases, selective pressures that forced humans to evolve elaborate mechanisms to ward off starvation and to fight microbes. The modern food environment, however, presents a vast glut of easy calories and a virtual absence of many previously common infections, a situation for which our bodies are woefully unprepared.

As a result, many people now consume more calories than they burn, and their bodies dutifully pack the surplus into fat. This excess fat then stimulates a chronic inflammatory state, leading to insulin resistance, elevated blood pressure, and a panoply of dangerous chronic diseases that reduce quality of life as well as causing disability and a shortened lifespan (or "shortgevity"). "It's really inflammation and its complications that we're worried about," said Roth.

Fat's inflammatory effects may have helped previous generations of humans deal with chronic infectious diseases such as tuberculosis, which was essentially untreatable before the mid-20th century. Indeed, the traditional therapy for tuberculosis was to overfeed patients and to keep them sedentary, precisely the conditions that lead to obesity and metabolic syndrome. The resulting inflammation probably helped fight the infection. Without such infections, though, modern humans are getting the sanitarium's side-effects without its benefits.

Underscoring the importance of inflammation, Roth pointed to data showing that the anti-inflammatory effects of moderate exercise can ward off many of obesity's chronic effects, even without reducing BMI. "Exercise has multiple mechanisms by which it's improving body health," said Roth, adding that "there are a lot of allies that we have that we can call upon to help us improve the inflammatory situation."

Big lies: Myths about obesity

David Allison of the University of Alabama at Birmingham took the podium next for a keynote presentation, delivering a bracing dose of skepticism to much of the conventional wisdom about obesity. First, he addressed one of the field's most frequently stated "findings": that people are getting fatter because they are consuming more energy than they expend. "It's a mathematical truism that the change in body energy stored is a function of the change in energy in minus the change in energy out, but to offer that as an explanation for obesity ... is vacuously true; it's just a restatement," said Allison, adding that "perhaps we know less [about obesity] than we think."

Beyond being uninformative, such a restatement of the energy balance equation may also be misleading. Allison cited several studies showing that reducing available food or increasing exercise levels doesn't reliably reduce body weights in humans or in other animals. "Biological systems adapt, it's difficult to predict what any intervention is going to do a priori," said Allison.

Other findings reiterate the limitations of a simple energy imbalance model. For example, domestic pets and city rats have gained weight over the last 50 years, alongside the rise in human obesity, but nobody knows why. Even laboratory mice fed strictly controlled diets in the U.S. National Toxicology Laboratory have, as a population, put on weight over the years.

Feral rats in Baltimore are getting heavier. (Image courtesy of David Allison)

Allison also dissected several myths about obesity, common beliefs which have either been disproven or which lack sufficient evidence. Researchers have known for several years that people with the most ambitious goals for weight loss tend to do best at it, but dieticians and doctors still advise patients to set modest goals. The well-known "freshman 15," the alleged 15-pound weight gain caused by attending one's first year at a university, has also been revealed as a myth; the actual average gain is substantially less, and it also affects young adults who don't go to college.

Some myths remain central to efforts to prevent and treat obesity, despite contradictory evidence. Allison and his colleagues performed a literature review in 2010 that found no statistically significant evidence that reducing soda pop consumption had any effect on children's weight, but policymakers still campaign against sugar-sweetened drinks. Meanwhile, other researchers have found that people who consume breakfast, a meal nutritionists have long promoted, were no less likely to be obese than non-breakfast-eaters.

In response, Allison advocates taking a fresh look at factors that could be driving the obesity pandemic. The average American BMI rose slowly from 1960-1975, then began to climb sharply. Over the same period, air-conditioning use, sedentary jobs, and numerous other potential fattening factors also rose. By casting a broader net and keeping an open mind, researchers and policymakers could test and deploy more rational solutions.

Refining metrics of overweight and obesity

After the initial presentations, John Kral of SUNY Downstate Medical Center moderated a panel discussion on the challenge of defining overweight and obesity. On its face, it seems like a simple problem: people who weigh more than they should are overweight, and those who weigh a lot more are obese. But how much should people weigh, and where is the line between moderately overweight and obese?

The standard measure of healthy weight is the body mass index (BMI), the ratio of weight over the square of height. People with a BMI over 25 are considered overweight, and those with a BMI over 30 are obese. However, panelists broadly agreed that BMI is a blunt instrument. "I think that at each level, body mass index is a good first approximation of where we want to go, but ... we should be more sophisticated about it and we should think about making finer interpretations," said Roth.

One major problem with BMI is that it doesn't distinguish between different types of fat. People with excess visceral fat, which correlates with poor health, fall into the same category as those with excess subcutaneous fat, which is much less dangerous and can even be healthy in some populations. BMI is particularly problematic in children. Early obesity often reverses spontaneously, so a high BMI for a pre-adolescent child may be no cause for concern, whereas an overweight adolescent could be headed for lifelong trouble.

Panelists also talked about potential interventions. Evidence for dieting and exercise, the standard approach to treating obesity, is spotty. Both strategies seem to work well in the short term, but as dieters know all too well, the weight tends to come back over time. Other tactics may be both simpler and more effective. As Allison explained, "with pretty good confidence we can say getting kids to have less screen time ... actually seems to be not only an effective but also a cost-effective way" to reduce obesity.

Speakers:
Susan Terwilliger, Binghamton University
Janine Jurkowski, University at Albany
Kathleen Hallinan, Guthrie Medical Center

Local Service Provider Panel:
Moderator: Mary McFadden, Broome County Health Department
Panelists: Tarik Abdelazim, formerly of the City of Binghamton
Mark D. Bowers, New York State Department of Transportation
Nancy Coddington, WSKG
Ray Denniston, Broome-Tioga Boards of Cooperative Educational Services (BOCES)
Jenny English, Stay Healthy Kids Club, Universal Hospital Services
Patricia Fell, Stay Healthy Kids Club, Universal Hospital Services
David Garbarino, New York State Athletic Administrators Association
Robin Mosher, Lourdes Physician Network
Scott Reigle, Binghamton Metropolitan Transportation Study
Jackie Stapleton, WSKG
Julie M. Tucker, Broome-Tioga Boards of Cooperative Educational Services (BOCES)
Lisa A. Vroman, DePaul Pediatrics

Highlights

• Childhood obesity stems from and affects the larger context of a child's family and community.
• Poverty is one of the biggest risk factors for obesity.
• A renewed focus on physical fitness and home economics classes may improve children's health.
• Community organizations can help encourage healthier lifestyles in a wide range of settings.

Community influence on childhood obesity

Susan Terwilliger, one of the conference's co-organizers and a clinical professor in Binghamton University's School of Nursing, views childhood obesity from a perspective that is both local and holistic. Working in the communities near Binghamton, she observed that "the population I work with [is] extremely rural ... and tends to be isolated." The area also tends to have an alarmingly high rate of childhood obesity.

Childhood obesity stems from a complex ecosystem of interactions around the child. (Image courtesy of Susan Terwilliger)

Though the statistics are clear, Terwilliger emphasized that both the causes and effects are complex. "These problems have consequences way beyond the physiological, we have consequences to the emotional, spiritual, cognitive, and sociocultural development of the child, and we need to look at the whole picture," she said.

Researchers who have taken this "ecological approach" have identified three major predictors of childhood obesity: dietary patterns, physical activity, and sedentary behaviors such as TV watching. Terwilliger emphasized that these factors are part of a large ecosystem of family, school, and social ties that surround a child.

In an effort to shift the balance of that ecosystem, Terwilliger and her colleagues worked with local communities to implement a physical activity program for children. The program provided extra after-school classes in various physical activities and provided transportation to and from the classes. Though the children's BMIs did not change during the course of the short, four-month experiment, participants and their parents were highly enthusiastic about the program, citing benefits such as a sense of belonging and an alternative to more negative activities such as gang membership. Terwilliger argued that those types of ancillary benefits underscore the need for a broader analysis of such programs, beyond any effects they have on BMI.

Social determinants & health inequity

Janine Jurkowski of University at Albany also works with families in rural New York, but with an emphasis on health inequity, or how imbalances in money, power, and resources influence the health of communities and individuals. "We're talking about things that are not always talked about in child obesity research, but they impact everyone's lives at some level," said Jurkowski.

Indeed, social determinants such as family income and community resources affect everything from childhood development to educational attainment and access to health services, and in the U.S., child obesity disproportionately affects those at the bottom of the socioeconomic ladder.

In a study in rural Rensselaer County, New York, Jurkowski and her colleagues took a family ecological approach similar to Terwilliger's. The study used a combination of activity monitors, diet interviews, parent surveys, and observational research to promote child wellness and to reduce the risk of obesity among families in the Head Start preschool program. In contrast to many such studies, the investigators allowed an advisory panel made up of community members and local parents to make many of the key research decisions. "If we want to work with families, we need to treat them like they know what they're talking about, because they do, whether or not we agree with all their choices," said Jurkowski.

The advisory panel identified job training requirements, unsafe neighborhoods, and access to childcare as major factors that reduced parents' ability to provide healthy environments. In response, Jurkowski's team is seeking to provide social support networks and help to the parents to improve their children's nutrition and activity levels.

Gym class 2.0: The future of Physical Education

Kathleen Hallinan, a physician in Corning, New York, works at the front lines of the obesity epidemic. "Most of my day is spent taking care of complications of obesity ... diabetes, high blood pressure, high cholesterol," said Hallinan, whose patients' problems are often the grown-up results of excess weight in childhood.

Figure shows percentage of students in healthy fitness zone for schools using the PE4 Life program, versus controls. (Image courtesy of Kathleen Hallinan)

Hoping to attack the problem on a larger scale, she and her colleagues began working with a local YMCA on a "Healthy Kids Day," which later expanded into a broader initiative that now includes health insurers and local employers. This coalition is now implementing three major programs to combat obesity through local schools.

The "PE4 Life" program, originally developed by physical education teacher Phil Lawler in Illinois, focuses on overhauling traditional gym classes. Instead of teaching the usual team sports, PE4 Life programs equip children with heart rate monitors and have them participate in individual sports that they will be able to pursue throughout their lives. The program has claimed impressive results not only in overall student health, but also in seemingly unrelated measures such as higher academic test scores and lower detention rates. "Kids are squirrely, and they need to exercise, and this is good for them," said Hallinan.

Meanwhile, the "Fun 2B Fit" program focuses on food, teaching second through fourth graders about new foods and how to make them. The children liked most of the healthy dishes and encouraged their parents to start serving them, with a single exception: "the only thing they really didn't like across the board was hummus," said Hallinan. In another food-related program, Hallinan's group is promoting a "5-2-1-0" formula, for five servings of fruit and vegetables, two hours or less of "screen time," at least one hour of physical activity, and zero sodas each day.

Fighting fat on all fronts: Interventions to counter obesity

After the morning talks, conference attendees could choose from a series of breakout sessions on different aspects of childhood obesity. These small group meetings provided intimate, highly interactive venues for researchers, physicians, nurses, teachers, and others to share ideas and to discuss the best practices for tackling the problem. In the "Teaching Children about Obesity" session, for example, Hallinan led a brainstorming exercise on ways to promote healthier lifestyles. Participants agreed that simple messages, repetition, and a focus on educating entire families and communities are the most successful strategies. Other sessions covered the distinction between obesity prevention and treatment, the issue of commercial influence on children, and ways to set goals for community change.

After lunch, a panel of local service providers gave short presentations about a diverse set of interventions. Nancy Coddington and Jackie Stapleton discussed an educational campaign by WSKG, the local Public Broadcasting Service affiliate, promoting healthy eating and exercise. School officials Julie Tucker and Ray Denniston of Broome-Tioga Board of Cooperative Educational Services presented their efforts to reform school lunch menus, and Jenny English, a registered nurse coordinating the Stay Healthy Kids Club, and Patricia Fell, director of community health services at Stay Healthy, described three programs aimed at increasing children's physical activity at home. "People in general are not aware that kids need 60 minutes of physical activity per day," said English, adding that programs such as hers can help get that message across.

David Garbarino, a physical education teacher and administrator, showed the results of an audit of New York schools' physical fitness programs, which revealed that only 10 of more than 700 schools met the state's own minimal requirements for physical activity. Garbarino and his colleagues implemented the "Patriots in Motion" program to remedy that problem.

Finally, urban planners Tarik Abelazim, Mark Bowers, Caroline Quidort, and Scott Reigle discussed their efforts to overhaul the built environment to promote more physical activity, and Lisa Broman and Robin Mosher described an effort to improve childhood obesity treatment in a major physician network.

Speakers:
Christine Olson, Cornell University
Kathleen Rasmussen, Cornell University
Lauren Hale, Stony Brook University
John Kral, SUNY Downstate Medical Center

Highlights

• Excessive weight gain during pregnancy predisposes the developing fetus to obesity.
• Limiting weight gain in pregnancy may not help much for mothers who were already overweight pre-pregnancy.
• Insufficient sleep correlates with both obesity and poverty, but the relationship is complex.
• Women who undergo bariatric surgery before pregnancy lower the risk that their children will be obese as infants and as children.

Eating for too many: The effects of maternal malnutrition

Christine Olson of Cornell University began the afternoon presentations with a review of the research on maternal nutrition and childhood obesity. In the 1990s, David Barker of the University of Southampton found that men with the lowest birth weights had the highest death rates from ischemic heart disease later in life. Barker's hypothesis, that gestational undernutrition sets a baby on a course for later obesity, has since garnered support from many other studies.

Researchers have found that maternal overnutrition also predisposes children to obesity, underscoring the idea that fetal epigenetic changes—heritable alterations in gene expression patterns that are not directly related to genome sequence—can have profound effects on child development.

Olson and her colleagues studied obesity among pregnant women who attended the Bassett Healthcare clinic in Cooperstown, New York between 1994 and 2003. They found that overall, 41% of the women gained excessive weight during pregnancy. The problem was worse for women who were already overweight, though: "72% of those women gained more than the recommended weight during pregnancy," said Olson.

Excessive gestational weight gain is very common. (Image courtesy of Christine Olson)

Fortunately, an intervention program that involved healthy dieting seems to have helped. In the highest-risk group—low-income women—the researchers saw a 60% reduction in excessive gestational weight gain, in line with similar intervention studies elsewhere. However, the program seems to have had no effect on higher-income women, a finding that Olson thinks may stem from modern dieting culture: "Most higher-income women today have been on ... a diet four different times in their lives." For these women, childbearing may provide a convenient excuse to ignore the diet and pack on a few extra pounds with the intention of losing the weight later.

A formula for obesity: The effects of maternal weight

Kathleen Rasmussen of Cornell University also discussed the effects of maternal weight on children's subsequent development. While epigenetic studies have provided some tantalizing clues about the phenomenon, Rasmussen pointed out that the problem of weight gain in children is not simply a question of prenatal programming. For example, obese mothers are also likely to terminate breastfeeding earlier, and their babies may have altered feeding habits at weaning.

Cultural and family factors affect the child's weight as well, particularly in the child's transitions from breastfeeding to formula and then to solid foods. "In the U.S., this means parents put too much formula in the bottle, and then insist that the baby finish it," said Rasmussen, citing one example.

In a study at Bassett Hospital in Cooperstown, Rasmussen and her colleagues enrolled more than 2,000 pregnant women and found that babies born to obese mothers were 250 grams heavier on average than those born to normal-weight mothers. Other studies have shown that this difference stems largely from the mothers' pre-pregnancy weight, not from their weight gain during pregnancy. "That means [that] if we can get moms to change their weight gain, we're not going to change the playing field dramatically. It will be better, but it's not going to make the basic problem go away, and that's that our women are too heavy," said Rasmussen.

To address the problem, Rasmussen advocates promoting healthier weights for women of childbearing age, urging only moderate weight gain in pregnancy, making breastfeeding more socially acceptable in public and private settings, and educating parents about how to feed infants and young children.

Heavy sleepers: Sleep deprivation & obesity

Lauren Hale of Stony Brook University shifted the topic to sleep problems, which scientists are increasingly seeing as a major correlate of obesity. "Everybody knows there's an obesity epidemic, but what people don't know about is there's a [sleeplessness] epidemic too," said Hale. Teenagers, for example, should sleep at least nine hours per night, but 90% of them don't reach that goal, a shortcoming that has far-reaching impacts on quality of life, cognitive functioning, public safety, and learning.

Indeed, in 2006 the U.S. Institute of Medicine identified the cumulative effects of sleep loss and sleep disorders as an unrecognized public health problem. The Centers for Disease Control did not have a category for these problems in their "Healthy People" standards until their most recent revision in 2010.

Hale and her colleagues view sleep as an issue of social disparity; people with less education, minorities, and the poor sleep less than the educated, white, and wealthy. This massive national sleep debt also correlates strongly with obesity in many populations, but the correlation is complex. "There [are] some interesting, unexpected associations which give credence to this idea that context matters, it's not just all a biological phenomenon," said Hale.

That complexity has frustrated simple interventions. In a trial that tried to improve sleep hygiene, or habits that promote healthy sleep, in infants by decreasing stimulation close to bedtime, the intervention had no apparent effect. In response, Hale advocates taking a broader approach and focusing on improving overall living conditions and personal empowerment. "This is the way that we can work together to improve sleep, obesity, and healthy development," she said.

Cutting the fat: The implications of bariatric surgery

John Kral of SUNY Downstate Medical Center delivered the day's last major talk, presenting his team's data on women who became pregnant after having weight-loss surgery. From 1998 to 2005, there was an eightfold increase in the number of bariatric surgeries performed worldwide. Bariatric procedures modify the digestive tract to promote weight loss. Kral and his colleagues decided to study pregnancy outcomes in women who had had a bariatric procedure called a bilio-pancreatic diversion duodenal switch (BPD-DS). The procedure reduces gastric capacity and lipid absorption, and increases the speed with which liquid empties from the stomach and glucose leaves the body. It also resolves type 2 diabetes almost immediately, by mechanisms that are not entirely clear.

Bariatric surgery re-routes the digestive tract to promote weight loss and to resolve metabolic syndrome. (Image courtesy of John Kral)

In a large cohort of women between 18 and 50 years old, Kral and his colleagues found infant obesity rates of 27% in pregnancies that occurred before the surgery, but only 10% in those that occurred afterward. The investigators were concerned about what would happen to these children later in life, though. A famous historical study of children born during the Dutch famine of 1944–1945 revealed that nutritional deprivation in certain stages of pregnancy correlates strongly with obesity later in the child's life. Would bariatric surgery have the same effect?

Apparently not. Looking at the same children at age 7, Kral's study found 37% of those born after their mother's surgery were overweight or obese, compared to 60% of those born before the surgery and 38% of the general population of 7-year-olds. "That vicious cycle [of obesity] has been broken by the fact that the moms had this rather drastic type of surgery," said Kral.

Another round of breakout sessions followed the day's talks. In the session on the built environment, a small but enthusiastic group of urban planners bemoaned the inconsistency of data on the specific effects of urban design on obesity, but the animated discussion soon turned to the numerous well-documented benefits of such features as bike trails, accessible mass transit, and walkable neighborhoods. The group concluded that these changes were probably worthwhile whether they improve the population's average BMI or not. Other breakout sessions covered the methods for evaluating intervention programs, strategies for educating the public about proper weight gain during pregnancy, and ways to help communities promote healthier eating and exercise habits.

Speakers:
Mandana Arabi, The Sackler Institute for Nutrition Science
Omry Koren, Cornell University
John Jakicic, University of Pittsburgh
Diane Craft, SUNY Cortland
David Levitsky, Cornell University

Highlights

• Many countries are now confronting a dual burden of malnutrition and obesity.
• School-based interventions should strive for lifestyle changes affecting both weight and fitness.
• Simple, inexpensive games can teach preschoolers movement skills and can encourage a lifetime of healthy activity.
• Daily weighing is highly effective in promoting weight maintenance.

It's a big world after all: The global obesity epidemic

Mandana Arabi of the Sackler Institute for Nutrition Science at the New York Academy of Sciences kicked off the conference's second day with a keynote presentation on the global obesity pandemic. Though commonly considered a problem of prosperity, obesity is in fact tragically common in poor countries. Many nations that are still struggling with malnutrition and food insecurity are also seeing rising rates of obesity, a double burden that may stem in part from foreign food aid programs. "Sometimes we even wonder, the way these programs are built, if we are contributing to the trend moving towards overweight and obesity," said Arabi.

An estimated one billion adults are overweight and 300 million are obese worldwide, and public health experts expect those numbers to rise to 1.5 billion overweight individuals by 2015. The cost of that extra poundage is astonishing, with 2.6 million people a year now dying from complications of obesity. Besides diabetes and heart disease, excess body fat also contributes to rising rates of cancer, stroke, and chronic respiratory diseases.

Overweight prevalence and number affected in developing countries. (Image courtesy of Mandana Arabi)

The problem is not evenly distributed. Graphing various health indicators on a series of maps, Arabi demonstrated that Africa and South America are among the hardest-hit regions. "These are countries that already are dealing with issues of child malnutrition ... even having high levels of infant mortality, and at the same time they have high burdens of diabetes," said Arabi. Countries have also varied in their progress against this seemingly contradictory burden. Acute and chronic malnutrition are declining across Asia and Latin America, but are still climbing in Africa.

Developed countries have largely conquered undernutrition, but have had rising rates of overweight and obesity since 1974. At the same time, the global diet has changed, with a decrease in starch and a rise in refined sugar consumption just about everywhere. The fat content of meals also increased from 20% to 40% in the past few decades, while meat consumption has skyrocketed in the developing world. Meanwhile, fruit and vegetable production in many regions is now insufficient to meet dietary recommendations for the populations of these regions.

In response, the World Health Organization recently developed a global strategy on diet, physical activity, and health, addressing multiple levels of causes and solutions. "We shouldn't really be thinking linearly when we're addressing obesity," said Arabi, adding that the epidemic "is not really down to laziness or overeating, but that our biology has stepped out of kilter with society."

Omry Koren of Cornell University spoke next, presenting unpublished data on one aspect of that out-of-kilter biology. Koren and his colleagues have found that the collection of microbial species in the human gut varies dramatically between normal-weight and obese subjects and also changes during the course of pregnancy, suggesting another mechanism that may contribute to multi-generational obesity.

The bus stops here: Increasing children's physical activity

John Jakicic of the University of Pittsburgh shifted the discussion back to school-age children, surveying several efforts to increase physical activity and to improve nutrition in this population. Acknowledging that the societal problem of obesity is more complex than a simple energy balance equation, Jakicic pointed out that changing that balance is nonetheless part of the solution. "From an intervention perspective, the question is how do we manipulate energy expenditure ... [and] how effective are those [interventions] in actually regulating body weight?" he asked.

Physical activity is the most variable component of energy expenditure for most people, so it's no surprise that most interventions have focused on getting subjects to move more. Unfortunately, some of the most obvious strategies haven't worked very well. Citing studies that tried to intensify schools' physical education classes and improve school lunches, Jakicic pointed out that neither approach had much effect on students' body weights. "So unless we find a way to expand the amount of activity a child can get in a school ... only focusing on schools to fix this problem is not correct," he said.

Jakicic advocates simultaneously increasing children's physical activity outside the school. Efforts to promote walking to school instead of being driven, for example, can apparently decrease obesity and increase physical fitness. "What this tells me is ... when I try to focus on children, especially those who are obese, I need to focus on both fitness and body weight," said Jakicic.

A is for active: Preschool physical activities in childcare settings

Diane Craft of SUNY Cortland has been taking a similar tack with preschool children, who are often enrolled in home-based and center-based childcare programs which lack the equipment, the funds, and the specially trained staff to lead children in structured physical activities. "Regrettably the social policies in our country are that those who care for our youngest children during a very, very important stage of their development are paid very poorly," said Craft.

To encourage these childcare programs to provide more physical activity, Craft and her colleague developed Active Play!, a program that offers training to childcare providers in leading simple and fun physical activities. Crucially, none of the activities require advanced equipment or facilities. In one activity, for example, a teacher suspends a sheet across the room like a tennis net, and scatters socks on the floor on both sides. Children on each side try to throw the socks to the other side.

Such seemingly rudimentary activities can teach profoundly important skills. After showing a video clip of children playing the sock game, Craft described how young toddlers first throw in an immature fashion, using only their arms. With practice, they will learn to use their legs and core muscles, helping them master fundamental movement skills. She also illustrated how physical activities can incorporate practice in academic concepts such as counting and recognizing letters.

Self-monitoring as intervention

David Levitsky of Cornell University and his colleagues have been working with subjects at the opposite end of the educational pipeline: college students. Levitsky began with data identifying the starting point of the obesity epidemic, which began somewhat abruptly in 1980 and which primarily involved people in the 18–35-year-old age range who were already heavy adding excessive weight. To interrupt this pattern, Levitsky decided to try a deceptively simple technology: the bathroom scale.

In an initial study, Levitsky and his colleagues distributed digital scales to 52 women in their first year of college, and had them weigh themselves daily and submit the data. The subjects gained no weight during the 12-week study, compared to the usual 2 kilograms that female students normally gain during that time. A subsequent study of a separate group of students the following year found the same result.

Figure shows the results of the Fall 2002 weight control study. (Image courtesy of David Levitsky)

Because the researchers had not provided any dieting or exercise advice, they surveyed the students afterward, and discovered that they had employed a wide range of strategies, from skipping dessert to exercising more, to maintain their weight whenever they saw it rising. "The point is, there is not one formula that worked for everybody. For some people, some ways of changing are more viable than others," said Levitsky.

The investigators are now setting up a similar study in obese adolescents, who will weigh themselves daily and who will receive a small financial incentive for keeping their weight within a narrow range. Because the subjects in that study are still growing, keeping their weight constant should cause their BMI to decrease.

Another round of breakout sessions followed the talks, allowing attendees to discuss such issues as the major gaps in obesity research, some ways to change social norms to promote healthy lifestyles, the challenges of funding limitations, and some ways to collaborate to change the community factors that promote obesity. A poster session concurrent with the conference allowed another diverse group of researchers to interact extensively as well. While the global obesity pandemic is still far from being solved, the meeting revealed a vibrant and active set of collaborations that seem poised to help combat it.