Author Interview: Sonja Yokum
Associate Scientist at the Oregon Research Institute

What are the main findings of the study?

In the present study, we tested whether global and regional brain volumes correlated with Body Mass Index (BMI) and increases in BMI over 1-year follow-up in young females.

The findings demonstrate overall differences in both white matter (WM) and gray matter (GM) depending upon BMI, with obese subjects showing greater global brain atrophy.

The findings also suggest that elevated weight is associated with high WM volumes in regions previously found to be involved in food reward.

Importantly, low GM volumes in regions implicated in inhibitory control were related to future weight gain.
The data are interpreted to suggest that abnormalities in GM in brain areas associated with inhibitory control increase the risk for weight gain and that abnormalities in WM appear to be secondary to the weight gain.

Were any of the findings unexpected?

The results converge with findings of previous studies in middle-aged obese adults, suggesting that obesity (even at a relatively young age) is related to volumetric brain differences.

What should clinicians and patients take away from this study?

The relations between BMI and GM/WM volumes are complex and further consideration of other variables (e.g., medical conditions and genetics) is warranted.

However, while the specific mechanisms underlying these volumetric differences remain to be investigated, our findings have important public health implications, because they suggest that regional and global brain volume abnormalities are related to BMI and increases in BMI at a relatively young age, potentially resulting in greater risk for future declines in cognition or other brain functions.

What recommendations do you have for future research as a result of your study?

In the current study we were not able to test the effect of change in BMI on brain volume, as we did not have repeat scans for these subjects at 1-year follow-up. Future studies should test bi-directional relations between BMI and region brain volume via a prospective repeated-measure design.

Citation:

Relation of regional gray and white matter volumes to current BMI and future increases in BMI: a prospective MRI study

Yokum S, Ng J, Stice E.

Oregon Research Institute, Eugene, OR, USA.
Int J Obes (Lond). 2012 May;36(5):656-64. doi: 10.1038/ijo.2011.175.
Epub 2011 Sep 6.

Author Interview: Jennifer Lundgren, PhD, FAED

Associate Professor and Chair
Department of Psychology
University of Missouri-Kansas City
5030 Cherry Street, Rm 321 Kansas City, MO 64110

What are the main findings of the study?

We examined the prevalence and familial patterns of night eating syndrome (NES) in families enrolled in the Québec Adipose and Lifestyle InvesTigation in Youth (QUALITY) study.  Families (one child, mother, and father for whom at least one parent was obese or had abdominal obesity) completed the Night Eating Questionnaire (NEQ) as part of this longitudinal study on the development of metabolic disease in children at risk for obesity.

We found that full threshold NES was rare: 0% of children, 0.5% of mothers, and 0.3% of fathers met criteria.  Symptoms of NES, however, were more common.  Among all participants, the most common symptoms were sleep and mood disturbance.  There some disagreement between child report and parent report of child behavior for sleep disturbance; 32% of children reported sleep disturbance, whereas only 14% of parents reported that their child had sleep disturbance.

When statistically controlling for age, sex, and body mass (BMI kg/m²), the night eating questionnaire scores of spouses were not significantly correlated, but mothers’ scores were significantly correlated with the scores of both sons and daughters.

Finally, we conducted a heritability analysis of night eating questionnaire scores; when controlling for age, sex, and BMI, the heritability was low but statistically significant at 0.24.

Were any of the findings unexpected?

The prevalence of NES in mothers and fathers was surprisingly low given that NES is more common in obese individuals (at least one parent had to be obese for inclusion in the study).  Even when examining the two core features of evening hyperphagia (consumption of ≥ 25% of total daily food intake after the evening meal) and nocturnal ingestions of food, the prevalence of these symptoms is low compared to previous studies.

What should clinicians and patients take away from this study?

Clinicians who assess and treat obesity and related conditions should routinely assess for night eating behavior and potential distress or impairment in functioning that it might cause.  They should also be cognizant that night eating syndrome runs in families, so if a parent reports difficulty with night eating, his/her child may be at increased risk as the child ages, particularly if the child is overweight or reports sleep difficulty.

What recommendations do you have for future research as a result of your study?

We are following this sample over time and future reports will examine the stability of NES in children and adults, as well as address questions about the development of NES, especially among children whose parents report difficulty with night eating behavior.

Future research should continue to examine the familial aggregation of NES and further explore genetic, environmental, and the interaction of such factors in the development of NES.

Citation:

Prevalence and Familial Patterns of Night Eating in the Québec Adipose and Lifestyle InvesTigation in Youth (QUALITY) Study.

Lundgren JD, Drapeau V, Allison KC, Gallant A, Tremblay A,

Obesity (Silver Spring). 2012 Apr 3. doi: 10.1038/oby.2012.80

The Weight of the Nation documentary series and public awareness campaign by the cable network HBO, launching this week, features National Institutes of Health research showing how obesity affects the country’s health and how interventions can turn the tide against obesity and its complications.

The network, in consultation with NIH and other major health organizations, developed four documentaries focused on obesity. The project also includes a three-part HBO Family series for kids, 12 short features, a social media campaign, and a nationwide community-based campaign to mobilize action to move the country to a healthier weight.

The films feature several NIH-funded clinical studies that have formed the basis of scientific evidence on the causes and consequences of being overweight or obese, including the Diabetes Prevention Program (DPP), Coronary Artery Risk Development in Young Adults (CARDIA) study, and Bogalusa Heart Study. The DPP found that even moderate weight loss can help prevent type 2 diabetes. The CARDIA study measures changes in coronary heart disease risk factors. The Bogalusa Heart Study examines how cardiovascular disease develops over time.

“If we don’t take the obesity epidemic seriously as individuals and as a nation, we will pay a serious price,” said NIH Director Francis S. Collins, M.D., Ph.D., who appears in all of the main documentaries in the series. “It’s going to take diverse and rigorous research to understand the causes of obesity and to identify interventions that work in the real world. The results from federally funded research, as seen in these documentaries, can help to prevent and treat obesity and its complications.”

More than one-third of adults in the United States and nearly 17 percent of the nation’s children are obese, which increases their chances of developing many health problems, including type 2 diabetes, heart disease, high blood pressure, stroke, fatty liver disease, and some cancers. In 2008, the nation’s obesity-related medical costs were an estimated $147 billion.

In fiscal year 2011, NIH funding for obesity research totaled $830 million. The 2011 Strategic Plan for NIH Obesity Research highlights the crucial role of research in efforts to reduce obesity, emphasizing moving science from laboratories to clinical trials to practical solutions. The plan is designed to help target efforts and resources in areas most likely to help people.

Results from NIH-funded obesity-related research include:

• Finding effective lifestyle changes that can be implemented in communities to reduce weight, lower risk factors for heart disease, and prevent or delay type 2 diabetes
• Finding new targets and pathways for prevention and treatment of obesity, including the role of sleep, and how bacteria in the intestine may have an impact on obesity
• Finding that exposure in the womb to maternal obesity or diabetes may increase the risk of obesity or diabetes in offspring, suggesting a critical period for intervention
• Investigating genetic factors contributing to obesity and its complications.

To keep moving forward in the quest to prevent, treat, and reduce obesity and its complications, NIH funds obesity-related clinical trials around the country, including on the NIH campus in Bethesda, Md. To find trials in your area and how to enroll, visit NIH’s Clinical Research Trials and You website at www.nih.gov/health/clinicaltrials. NIH also supports public education and awareness programs to combat obesity and its complications, including We Can! (Ways to Enhance Children’s Activity & Nutrition), the Weight-control Information Network and the National Diabetes Education Program.

The documentaries were produced by HBO Documentary Films and the Institute of Medicine, in association with NIH and the Centers for Disease Control and Prevention, and in partnership with the Michael & Susan Dell Foundation and Kaiser Permanente Foundation.

Community screenings of the four-part documentary series are taking place now. The series debuts on HBO on May 14 and 15, with two films airing back-to-back each night. On May 16, the first of three films in The Weight of the Nation for Kids airs on HBO Family. The films will stream free on www.HBO.com  , and may be provided for free by some television carriers.

For more information, go to www.nih.gov/health/NIHandweightofthenation.

Author Interview: Nicholas P. Greene, Ph.D.
Cardiovascular Research Center
University of Virginia

What are the main findings of your study?

The purpose of our study was to investigate the therapeutic benefits of single bout exercise and exercise training on measures of blood lipids and lipoproteins in overweight and obese men and women.  Although others have reported beneficial changes in blood lipids in response to a single session of exercise (Crouse et al., Journal of Applied Physiology, 1997), we observed only minimal influence of a single bout of exercise on these measures in either men or women.  However, when we examined the data following 12 weeks of exercise training we saw, as reported in other populations, an increase in HDL-cholesterol in overweight and obese men.

Also corresponding to previous reports we observed no significant effects of exercise training on total HDL-cholesterol in women.  However, the intriguing part of these findings was that while no change in total HDL-cholesterol was observed in women, they did show a change in HDL subfractions which favored enhanced reverse cholesterol transport and thereby a more athero-protective HDL profile.

We have previously shown the efficacy of a novel form of exercise, the aquatic treadmill, to improve aerobic fitness and body composition in this population (Greene et al., Medicine & Science in Sports & Exercise, 2010).

Therefore, we also had subjects perform training using either a conventional land treadmill or the aquatic-based treadmill and observed that these beneficial changes in cholesterol occurred equally regardless of the mode of exercise training.  Finally, we saw these beneficial effects despite only minimal weight loss in our population, providing further evidence that exercise can provide therapeutic benefits without the need for dramatic weight loss.

Were any of the findings unexpected?

While many of our findings were expected, we did not necessarily expect to see the shift in HDL subfractions which occurred in our sample of women.  These data represent a novel means by which cardiovascular risk may be reduced by exercise in women and support the need for a more detailed analysis of blood cholesterols to evaluate the efficacy of any therapeutic intervention designed to improve such health parameters.

What should clinicians and patients take away from this study? 

Exercise training can positively impact health outcomes, particularly blood cholesterols, without the need for dramatic weight loss in overweight and obese adults, and that these effects are seen with multiple modalities of aerobic exercise.  Additionally, basic cholesterol panels may not be enough to understand the full efficacy of a therapeutic regimen and should be expanded to include cholesterol subfractions to fully elucidate the efficacy of such regimens.

What recommendations do you have for future research as a result of your study? 

Future research should be conducted to see under what conditions a single bout of exercise may alter blood cholesterols in overweight and obese men and women, as the single bouts used in our study appear to have been insufficient.

Also, research should be conducted to better understand the mechanisms by which the gender differences seen in our study occur.

Citation:

Acute Exercise and Training Alter Blood Lipid and Lipoprotein Profiles Differently in Overweight and Obese Men and Women

Nicholas P. Greene, Steven E. Martin and Stephen F. Crouse
Obesity (16 March 2012) | doi:10.1038/oby.2012.65

Author Interview: Donald A. Williamson, Ph.D.

Pennington Biomedical Research Center

What are the main findings of the study?

A school-based obesity prevention program that modified the school environment to promote healthy eating, increased physical activity, and decreased sedentary behavior was effective for reducing body fat in boys and attenuating body fat gain in girls. Students in grades 4 to 6 at the beginning of the three year study participated in the cluster randomized controlled trial. Students were all from rural communities of Louisiana, USA.

Were any of the findings unexpected?

A secondary prevention approach that used classroom instruction and an internet-based program was combined with the environmental program and its effects were contrasted with a control group and the environmental program alone. We found that this secondary prevention program did not enhance the obesity prevention effects of the environmental program. This finding was unexpected.

What should clinicians and patients take away from this study?

The study found that the environmental program had modest effects on body fat in boys and girls from rural communities. Most participants were African-American and poor. This finding is important for several reasons. The environmental program is relatively inexpensive, especially in comparison to clinical treatment and more intensive programs such as the secondary prevention program that was tested in the study. The environmental program had broad effects on changes in body fat, nutrition, physical activity, and sedentary behavior. These effects were observed in an underserved population, mostly poor rural children, and it was effective for a range of children including obese and non-obese, boys and girls, and white and African-American children. The breadth of the effects should be understood within the context of relatively small effects on adiposity and health behaviors of the entire study cohort. These small population effects should be regarded as one tool in the fight against childhood obesity, but should not be viewed as a replacement for clinical treatment of children who are already significantly overweight.

What recommendations do you have for future research as a result of your study?

The potential costs and health consequences of the childhood obesity epidemic have been well documented. Thus, finding a solution to this problem is vital to the health of modern societies. The findings of this study, in combination with the findings from other relatively long-term school-based obesity prevention studies, suggest that school-based obesity prevention can be effective if the intervention is implemented over a period lasting several academic years.

The results, however, must be anticipated with realistic expectations: the effects on adiposity and health behaviors will be modest and will be insufficient to manage the health risks associated with overweight and obese status that is already present. This observation suggests that a comprehensive solution to the childhood obesity epidemic should be multi-tiered, offering primary prevention as a first-line defense and clinical treatment or secondary prevention as an option for children who are already overweight or obese. Future research should test the efficacy of such multi-tiered approaches to find the most effective and least costly solution to the childhood obesity epidemic.

Citation and Abstract:

Effect of an Environmental School-Based Obesity Prevention Program on Changes in Body Fat and Body Weight: A Randomized Trial.

Williamson DA, Champagne CM, Harsha DW, Han H, Martin CK, Newton Jr RL,
Sothern MS, Stewart TM, Webber LS, Ryan DH.

1] Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA [2] Department of Psychology, Louisiana State University, Baton Rouge, Louisiana, USA.Obesity (Silver Spring). 2012 Mar 8. doi: 10.1038/oby.2012.60. [Epub ahead of print]

Abstract

This study tested the efficacy of two school-based programs for prevention of body weight/fat gain in comparison to a control group, in all participants and in overweight children.

The Louisiana (LA) Health study utilized a longitudinal, cluster randomized three-arm controlled design, with 28 months of follow-up. Children (N = 2,060; mean age = 10.5 years, SD = 1.2) from rural communities in grades 4-6 participated in the study. Seventeen school clusters (mean = 123 children/cluster) were randomly assigned to one of three prevention arms: (i) primary prevention (PP), an environmental modification (EM) program, (ii) primary + secondary prevention (PP+SP), the environmental program with an added classroom and internet education component, or (iii) control (C).

Primary outcomes were changes in percent body fat and BMI z scores. Secondary outcomes were changes in behaviors related to energy balance. Comparisons of PP, PP+SP, and C on changes in body fat and BMI z scores found no differences. PP and PP+SP study arms were combined to create an EM arm. Relative to C, EM decreased body fat for boys (-1.7 ± 0.38% vs. -0.14 ± 0.69%) and attenuated fat gain for girls (2.9 ± 0.22% vs. 3.93 ± 0.37%), but standardized effect sizes were relatively small (<0.30).

In conclusion, this school-based EM programs had modest beneficial effects on changes in percent body fat. Addition of a classroom/internet program to the environmental program did not enhance weight/fat gain prevention, but did impact physical activity and social support in overweight children.

“Now more than ever, it is important that the care of patients undergoing bariatric surgical procedures be consistent with current evidence and best practices,” says Editor-in-Chief Kristin L. Seidl, PhD, RN, Director of Outcomes for Nursing and Patient Care Services, University of Maryland Medical Center. “As clinical research advances and the knowledge base expands, healthcare providers will be challenged to continuously integrate new knowledge into practice. Bariatric Nursing and Surgical Patient Care is committed to disseminating the most up-to-date information available in order to assist all members of the multidisciplinary team.”

Author Interview: Nicholas P. Greene, Ph.D.
Cardiovascular Research Center University of Virginia

What are the main findings of the study? 

The purpose of our study was to investigate the therapeutic benefits of single bout exercise and exercise training on measures of blood lipids and lipoproteins in overweight and obese men and women.

Although others have reported beneficial changes in blood lipids in response to a single session of exercise (Crouse et al., Journal of Applied Physiology, 1997), we observed only minimal influence of a single bout of exercise on these measures in either men or women.  However, when we examined the data following 12 weeks of exercise training we saw, as reported in other populations, an increase in HDL-cholesterol in overweight and obese men.  Also corresponding to previous reports we observed no significant effects of exercise training on total HDL-cholesterol in women.

However, the intriguing part of these findings was that while no change in total HDL-cholesterol was observed in women, they did show a change in HDL subfractions which favored enhanced reverse cholesterol transport and thereby a more athero-protective HDL profile.

We have previously shown the efficacy of a novel form of exercise, the aquatic treadmill, to improve aerobic fitness and body composition in this population (Greene et al., Medicine & Science in Sports & Exercie, 2010).

Therefore, we also had subjects perform training using either a conventional land treadmill or the aquatic-based treadmill and observed that these beneficial changes in cholesterol occurred equally regardless of the mode of exercise training.

Finally, we saw these beneficial effects despite only minimal weight loss in our population, providing further evidence that exercise can provide therapeutic benefits without the need for dramatic weight loss.

Were any of the findings unexpected? 

While many of our findings were expected, we did not necessarily expect to see the shift in HDL subfractions which occurred in our sample of women.

These data represent a novel means by which cardiovascular risk may be reduced by exercise in women and support the need for a more detailed analysis of blood cholesterols to evaluate the efficacy of any therapeutic intervention designed to improve such health parameters.

What should clinicians and patients take away from this study?

Exercise training can positively impact health outcomes, particularly blood cholesterols, without the need for dramatic weight loss in overweight and obese adults, and that these effects are seen with multiple modalities of aerobic exercise.

Additionally, basic cholesterol panels may not be enough to understand the full efficacy of a therapeutic regimen and should be expanded to include cholesterol subfractions to fully elucidate the efficacy of such regimens.

What recommendations do you have for future research as a result of your study?

Future research should be conducted to see under what conditions a single bout of exercise may alter blood cholesterols in overweight and obese men and women, as the single bouts used in our study appear to have been insufficient.

Also, research should be conducted to better understand the mechanisms by which the gender differences seen in our study occur.

Citation:

Acute Exercise and Training Alter Blood Lipid and Lipoprotein Profiles Differently in Overweight and Obese Men and Women

Nicholas P. Greene, Steven E. Martin and Stephen F. Crouse
Obesity (2012) doi:10.1038/oby.2012.65

Authors’ Interview: Janet Latner, Daria Ebneter, and Kerry O’Brien 

Janet D. Latner, Ph.D.
Department of Psychology
University of Hawaii at Manoa
2530 Dole Street, Sakamaki C400
Honolulu, HI 96822

What are the main findings of the study?

Young men and women were asked to read vignettes describing a woman who had either lost weight (70 pounds/32 kilograms) or had remained weight stable, and who was either currently obese or currently thin.

Participants were then asked their opinions about this woman, such as how much they found her attractive.

Surprisingly, currently thin women were viewed differently depending on their weight history.  Those who had been obese in the past were perceived as less attractive than those who had always been thin, despite having identical height and weight.  Participants were also questioned about their dislike of obese people in general.

After reading about women who had lost weight, participants expressed greater bias against obese people than after reading about women who had remained weight stable – regardless of whether the weight-stable woman was thin or obese.

In other words, our negative attitudes towards obese persons may be increased when we are shown that body weight is easily controllable.

Were any of the findings unexpected?

Prejudice against obese people is widespread and harmful. Many obese people are trying to lose weight to escape the painful discrimination and bias they frequently encounter.  However, our findings suggest that weight loss actually does not erase the stigma faced by obese people.

What should clinicians and patients take away from this study?

Our findings suggest that even after weight loss, obese people may not ever escape the stigma of obesity.

This “residual stigma” might explain the lower-than-expected earnings and occupational attainment by women who were previously, but no longer, overweight.

This study also suggests that descriptions of weight loss, such as those often promoted in the media, may significantly worsen obesity stigma.

What recommendations do you have for future research as a result of your study?

It is conceivable that in real-world settings, residual stigma might be even worse, for example, for an individual whose family, friends, and colleagues, have long known her and potentially stigmatized her as an obese individual.

Prospective studies, including both quantitative and qualitative investigations, are needed to explore the stigmatizing experiences of individuals who have lost weight.

Citation:

Residual Obesity Stigma: An Experimental Investigation of Bias Against Obese and Lean Targets Differing in Weight-Loss History

Janet D. Latner, Daria S. Ebneter and Kerry S. O’Brien
Obesity (7 March 2012) | doi:10.1038/oby.2012.55

Diet-Induced Weight Loss in Overweight or Obese Women and Changes in High-Density Lipoprotein Levels and Function

Author Interview: Richard O. Cannon, III, MD

National Heart, Lung, and Blood Institute, NIH Bethesda, Maryland

In the study published online March 15 by the journalObesity, Sacheck and colleagues examined the association between weight status and fitness levels by assessing student performance on five fitness tests. Regardless of their weight, students were classified as “fit” if they passed all five tests and “underfit” if they failed one or more tests.

The assessments taken between 2004 and 2007 coincided with a city-wide weight and fitness intervention that prompted improvements to gymnasiums, promotion of physical activities outside of school, professional development for physical education teachers and issuing “Health and Fitness report cards” to parents. The 2,793 students in the study participated in bi-weekly school gym classes plus a daily recess, and annual assessments of their BMI and physical fitness.

“Of the 1,069 students who were initially obese or overweight, 17% achieved a healthy weight within the one to four year study period compared with 6.3% of students who began the study at a healthy weight and became obese or overweight.” said Jennifer M. Sacheck, Ph.D., senior author and an assistant professor at the Friedman School. “It is encouraging to see any kind of reversal in unhealthy weight patterns, considering Centers for Disease Control statistics indicate child and adolescent obesity rates rose approximately 13% between 1980 and 2008.”

Within the four-year study period, 27% of the 1,882 students who were underfit at baseline became fit.

“Obese and overweight girls who achieved fitness were almost five times as likely, and obese and overweight boys were two and a half times as likely, to reach a healthy weight than those who stayed underfit,” said first author Adela Hruby, a Ph.D. candidate at the Friedman School. “It turns out that maintaining fitness is beneficial, too. We observed that obese and overweight girls and boys who both started and ended the study being fit were more likely to have a healthy weight by the end of the study.”
Staying fit also benefitted healthy weight boys and girls; they were more likely to maintain their weight than those students who declined from fit to underfit over the course of the study.

Maintaining or achieving a healthy weight appeared to be most closely associated with cardiorespiratory fitness, which was assessed by the students’ performance in a 20-yard shuttle run (a 6-minute, back-and-forth run between two markers). Incremental improvement in cardiorespiratory fitness was associated with achieving a healthy weight in children who were obese or overweight at baseline and with weight maintenance in healthy weight students who were fit at baseline.

Sacheck noted additional research is needed to explain the current results. “Because ours is an observational study using just annual measures, it is unclear whether students who became fit did so before they lost weight or whether they lost weight before they became fit,” she said. “Long-term intervention trials that assess both fitness and nutrition could provide more data to determine the role of improved fitness in weight loss.”

A range of options exist for increasing child fitness. “Federal guidelines call for at least 60 minutes of moderate to vigorous exercise per day and most of that should fall into the category of cardiorespiratory fitness that builds the capacity of the heart and lungs, such as soccer or dancing,” Sacheck said. “In addition to organized sports, school recesses or walking to school counts toward that one-hour goal. Parents can help by being active with their kids and limiting time spent watching TV or playing video games.”

The authors propose schools as leading advocates for physical activity programming and policies, such as in-school fitness testing. “Although data on childhood fitness and health outcomes is still evolving, there is a body of research showing relationships between the two in adults, such as reduced risk for cardiovascular disease and diabetes. If studies continue to show the same for children, there is an even stronger case for fitness testing in schools where large groups of children can have access to such an evaluation.”

This study was funded by grants from the American Heart Association. Student data collection was funded by a United States Department of Education Physical Education Program (PEP) grant to the Cambridge Public Schools.

Hruby A, Chomitz VR, Arsenault LN, Must A, Economos CD, McGowan RA, and Sacheck JS. Predicting Maintenance or Achievement of Healthy Weight in Children: The Impact of Changes in Physical Fitness. Obesity, March 15, 2012; doi:10.1038/oby.2012.13.