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A Closer Look: State-Specific Prevalence of Childhood Obesity Defies National Trends

By Jonelle Agurs, ASN Intern

According to the National Health and Nutrition Examination Survey (NHANES), national reports indicate a steady increase in childhood obesity levels, in preschoolers up to four years of age. However, state-specific studies of data retrieved from the Pediatric Nutrition Surveillance System (PedNSS) tell a slightly different story: in 2011, nineteen U.S. states/territories reported a drop in obesity prevalence among low-income preschoolers up to 2.6%, with the greatest decline observed in the Virgin Islands. Although national obesity levels among this age group still range from 9.2-17.9%, we must acknowledge the sporadic, yet significant lapse in prevalence rates of this medical condition from state-to-state.

Childhood obesity is associated with a variety of physical complications, such as high blood pressure, diabetes, and asthma, which in turn, contribute to mental health setbacks that affect a child’s self-esteem and motivation to perform daily tasks. Obese preschoolers are five times as likely to become obese adults, as compared to their non-obese peers, and low-income households are particularly vulnerable to chronic obesity – inexpensive fast food options, that boast great taste, but have little nutritional value, are disproportionately marketed in low-income, minority communities. Using cross-promotion marketing tactics, 71% of food products use third-party licensed characters to appeal to adolescent audiences, but less than 20% meet nutritional guidelines set for children. A public health intervention at this impressionable stage of a child’s life is crucial in ensuring better health habits for a lifetime.

So, why do some states show significant improvements in obesity levels? It is most likely because these state and county agencies play a unique role in the success of their communities – a role that involves everyone from the enthusiastic teacher in a child’s preschool class, to the soccer coach in charge of physical education after school, to the local grocer who provides fresh fruits and vegetables for the community. Local and state initiatives, aimed to implement healthier food and recreational options for the communities they serve, have aligned their WIC programs with the Dietary Guidelines for Americans, which gives nutritional recommendations for consumers at every level.

In my home state of Maryland, for example, county health departments have already begun to equip families and healthcare providers with strategies to manage and prevent obesity in pediatric clients. In 2013, the Montgomery County Government initiated Be Active Montgomery! – a series of summer fitness events, in partner with Montgomery County schools, that promote physical fitness and family community building. In 2014, the Howard County Health Department in Columbia, MD issued a Childhood Obesity Prevention Toolkit to educate families on how to encourage healthy dietary/physical habits at home, and they also provided website access to a WIC Vendor Locator that would assist families in finding stores in their communities. I believe that local strategies such as these have contributed to the decrease in low-income pediatric obesity rates in Maryland from 2008-2011, despite the steady population increase.

Childhood obesity in America is one of those issues that is entangled in a web of possible causes. Food deserts in low-income communities promote consumption of quick-and-easy, fatty meal solutions. Highway expansion results in more vehicles per capita and an increase in traffic safety concerns for parents whose children walk and bike around the neighborhood. Public transportation, however useful, proves inconvenient for expectant, single mothers, who are incapable of transporting loads of groceries to their homes. All in all, the solution to the obesity epidemic in America may seem elusive; however health professionals should approach the situation with a modicum of hope that children will be our nation’s saving grace. Regardless of personal opinion, if the movers and shakers of this country made every effort to, literally, think of the children, perhaps we can redesign our environmental and socioeconomic constructs as a nation, to afford every child access to a proper community that promotes healthy living.

Hot Topics in Obesity will be discussed on Friday, December 5 during the fourth annual Advances and Controversies in Clinical Nutrition conference. Dr. William H. Dietz, Director of Redstone Global Center for Prevention and Wellness at GWU in Washington, DC, will give an address “What Explains the Reported Declines in Childhood Obesity?” Dr. Rebecca Puhl will address obesity and weight-related stigma during the same session. Read an interview with her.

The conference runs December 4-6 at the Gaylord National Resort & Convention Center in National Harbor, MD, and features a dynamic program with topics ranging from dietary supplements to nutrition and cancer. To learn more about this year’s conference, please visit the website.

References
1. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6231a4.htm
2. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1449228/
3. http://www.apa.org/pi/families/resources/newsletter/2012/07/childhood-obesity.aspx
4. http://www.ncbi.nlm.nih.gov/pubmed/19719889
5. http://journals.cambridge.org/download.php?file=%2FPHN%2FPHN13_03%2FS1368980009991339a.pdf&code=f5a13f391d3239a1ff41ae708a1ef5e1
6. http://www.howardcountymd.gov/displayprimary.aspx?id=4294969221
7. http://www.montgomerycountymd.gov/rec/bam/index.html
8. http://assets.thehcn.net/content/sites/montgomery/Final_Draft_Obesity_Action_P

Nutrition Research: Revisiting our Foci

By Kevin Klatt

A few weeks ago, I had the pleasure of reading Allyson West and Marie Caudill’s Research and Practice Innovations paper in the Journal of the Academy of Nutrition and Dietetics, entitled “Applied Choline-Omics: Lessons from Human Metabolic Studies for the Integration of Genomics Research into Nutrition Practice” (1). The publication elegantly describes how integrating metabolomic, transcriptomic and genetic/epigenetic approaches into traditional controlled feeding studies can help refine the Dietary Reference Intakes, and elucidate the mechanisms by which choline and folate contribute to overall health.

Referencing the Nutrition Research Priorities established by the American Society for Nutrition (ASN) in 2013 (2), we can clearly see that the approaches described by West and Caudill fall in line with ASN’s thinking on how to advance the field of nutritional sciences. The Nutrition Research Priorities report specifically highlights furthering our understanding of nutrition and health by pursuing –omics research to understand individual responses to nutrients. For me, it was encouraging to see these kinds of advanced techniques and their clinical applications representing the field of research in a major clinical nutrition journal.

Fast-forwarding to this past week, I found myself staring at headlines inflaming the conversation around the newest low-carbohydrate/low-fat research, published in the reputable Annals of Internal Medicine (3). The publication is a randomized trial that ultimately concludes “the low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet”. Being in such a high profile journal and funded by the NIH, one would expect this publication to add some significant perspective to our understanding of energy balance and disease progression, two areas also highlighted in the 2013 Nutrition Research Priorities report. Unfortunately, upon reading the paper, one is quickly underwhelmed by the lackluster weight loss over 12 months, the poor accuracy of the dietary recall data, the lack of any information about diet quality, the use of imprecise measurement techniques, and the authors’ failure to discuss alternative conclusion, beyond just the low-carbohydrate component of the diet. I have specifically detailed the limitations of this trial elsewhere.

As I finished reading the study, West and Caudill’s ‘Choline-omics’ paper came to mind, and I couldn’t help but feel frustrated: why are we still funding these overly reductionist paradigms of low-carb vs low-fat, when much more integrative and informative approaches are being taken? To quote the 2013 Nutrition Research Priorities report on the topic of energy balance:
“A systems approach is preferable because the standard experimental approach of varying one factor at a time has accomplished little to address the population-wide problem of energy imbalance.”
Yet here we are, still trying (and failing) to vary only one factor, and publishing it in a premier journal for physicians. Is this how we want to represent nutrition research?

I further sat and thought about this trial: even at the outset, given the design, and the quality of the proposed data to be collected, what could this have added to our knowledge of nutrition? The trial states that its goal was to conduct a randomized trial to compare low-carb versus low-fat diets on body weight and CVD risk factors in a diverse population without comorbidities. Beyond the overly reductionist paradigm of low-carb/fat, the study design is questionable in that “neither diet included a specific calorie or energy goal.” Ultimately, the trial tested whether a macronutrient goal, coupled with education and a meal replacement bar would spontaneously lead individuals to lose weight, in a diverse population without comorbid conditions. Not surprisingly, after being sent into an environment with highly palatable, minimally nutritious high carbohydrate/ high calorie foods, the low-carbohydrate group fared better. Is this substantially improving our understanding of nutrition and energy balance? If there’s any theme that holds true with weight loss and disease risk reduction, it’s that choosing a well-planned, reduced energy diet which an individual can adhere to is most important (4,5,6,7). Given the failure to reach recommended fiber intakes and minimal weight loss seen in this trial, nothing about the previous statement appears to change.

Even worse than the limited information to be gained from this kind of trial is the media reporting and subsequent public response to this research. The public’s perception of nutrition recommendations isn’t that great, as acknowledged in what I would argue is the most pertinent point of the Nutrition Research Priorities report:
“Perhaps the greatest barrier to advancing the connections between food and health is the variability in individual responses to diet; it is also the origin of public skepticism to acceptance of dietary advice….”
If individual variability spurs public skepticism, we should seek to explain that variability. One only needs to look to the original 1980’s Dietary Guidelines for Americans (4) to see that we’ve known that there is individual variation in weight gain/loss and in biomarker response to diets high/low in fat. Yet here we are, 3 decades later, and we’re conducting trials that do nothing to further isolate and understand the factors that contribute to this variation. However, what we are doing is deepening this public skepticism, as history shows us the controversial topic of low-carb vs. low-fat undoubtedly garners a lot of press.

Don’t get me wrong, research that attempts to understand individual variation in response to food and nutrients is being done, but, despite being identified as a major priority, it does not appear to be so. It’s truly a shame to be in this field and see examples of researchers employing the most cutting edge techniques to answer pressing questions, only to be overshadowed by overly simplistic paradigms that incite more sentiment than they do advance science. It is essential that scientists, and more importantly funding agencies, are aware of the field’s established research priorities, so that we can stop asking the uninformative questions that tantalize a public controversy and start generating truly substantial evidence, which fosters public trust in recommendations. These established Nutrition Research Priorities can be found in full here.

References:
1. http://www.ncbi.nlm.nih.gov/pubmed/24529976
2. http://www.ncbi.nlm.nih.gov/pubmed/23784071
3. http://annals.org/article.aspx?articleid=1900694
4. http://www.health.gov/dietaryguidelines/1980thin.pdf
5. http://www.nejm.org/doi/full/10.1056/NEJMoa022207
6. http://www.nejm.org/doi/full/10.1056/NEJMoa0804748
7. http://jama.jamanetwork.com/article.aspx?articleid=200094
8. http://www.health.gov/dietaryguidelines/1980thin.pdf

EB 2014: The Underappreciated Role of Intestinal Fat Storage

By Colby Vorland, Student Blogger

Could a “fatty intestine” be related to insulin resistance and energy balance? These and other provocative questions were addressed by Dr. Elizabeth Parks during ASN’s Scientific Sessions in San Diego. Organized by the Energy and Macronutrient Metabolism Research Interest Section, Dr. Parks gave a seminar titled, “Going with your gut: Individual responses in dietary fat absorption.”

Dr. Parks’ research often focuses on the cephalic phase of digestion – or the early physiological response before food is even ingested. She presented a story that led her to her current path: Teff and Engelman demonstrated in 1996 with a sham feeding model that taste has an important effect on glucose metabolism and, in 2002, Robertson and colleagues published data showing that, compared to a high fat meal, consuming a high carbohydrate meal at night resulted in better glucose tolerance in the morning. Concurrently, they demonstrated a high fat meal at night yields a better fat tolerance the following day. These data suggest that there is some adaptive priming occurring and that, as Dr. Parks put it, “you best metabolize what you’ve just eaten.” She noted that we need to better match the challenge test with the eating pattern of interest.

In 2003, Robertson and colleagues published the results of an experiment in 10 healthy participants scheduled for an endoscopy who were fed a high fat meal, then 5 hours later were fed 50 grams of fat with either 38 grams of glucose or water. The participants who consumed the glucose along with the fat in the second meal showed less lipid in the jejunum. In other words, some dietary fat was stored in the intestine from a meal and its release was accelerated when glucose in combination with fat was consumed. Since then, Dr. Parks and others have shown that simply tasting fat without ingesting it, or just consuming carbohydrate, can cause an early rise in chylomicron secretion and blood triglyceride levels. This means that the intestine stores some of the fat from previous meals; in fact, Parks estimates that ⅕ to ¼ of the fat in your meal is stored in the intestine for at least 16 hours, and it is released in response to taste. Their data also suggests that body fat is negatively correlated with the amount of fat coming from the intestine and entering the blood at a subsequent meal. If intestinal fat stores serve a regulatory function to control energy balance (by releasing in response to taste), this raises the possibility that the mechanism that controls how much is release is perturbed.

Parks then discussed research supporting that we can taste fat. As further evidence, they have scoured literature for kinetic data and devised a mathematical model to show that rate of release of fat from the gut is consistent with the idea that this physiological response is due to our ability to taste fat. She also noted that chylomicrons may be supported in the absence of dietary fat by fatty acids in circulation entering the enterocyte, being packaged into chylomicrons, and secreted. Some data suggest that high free fatty acids increase the contribution from plasma to chylomicrons.

Dr. Parks has also been asking: does the rate of fat absorption impact health? Dr. Jennifer Lambert and Parks have unpublished data showing that the time-course of triglyceride absorption between people can vary substantially – about 1 to 4 hours. She showed graphs of the fat absorption curves of individual participants, and the patterns were often variable, emphasizing that much remains to be understood about why this occurs. Finally, she showed that stratifying by an early or late absorption peak revealed differences in participants in each group. For example, participants with an early peak tended to be more insulin resistant than those with a later peak.

Dr. Parks has been innovative in her use of stable isotopes for exploring lipid metabolism in health and disease. Clearly the intestine is an underappreciated tissue in fat storage and we are just on the cusp of understanding the role in which it mediates health and energy balance.