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Obesity is Not a Disease of Sloth and Gluttony

By Caitlin Dow, PhD

The most recent data from the CDC indicates that approximately 35% of American adults have obesity (1). In order to reduce obesity prevalence, a popular notion is that people with obesity just need to “eat less and move more.” Indeed, many public health programs use this concept as their primary approach for combating obesity. While eating less and moving more may help prevent obesity or result in successful, sustained weight loss in individuals who are simply overweight (but not yet obese), ongoing research indicates that these simple lifestyle changes will do very little in the face of prolonged obesity (2).

If you look at any weight loss study, you will most assuredly find the same results, regardless of study design. The first six months are generally characterized by substantial weight loss, followed by sustained weight regain, resulting in a final weight that is negligibly lower and potentially higher than the starting weight . This “checkmark effect” or weight loss recidivism that has been reported nearly ubiquitously across diet and exercise-based weight loss trials (3) indicates that lifestyle interventions are generally not successful modalities for treating obesity.

Based on a rudimentary understanding of metabolism, the calories in/out approach should work for weight loss and weight loss maintenance. So why doesn’t it work for so many people? The answer lies in the complex network linking the environment, genetic predisposition to obesity, as well as metabolic and physiological changes. A large body of literature indicates that the brain’s reward systems are significantly dysregulated in individuals with obesity (4). In an environment that supports ease of access to highly palatable foods, the pleasurable effects of consuming said foods can override homeostatic control of intake. While some people are able to regulate intake despite the high palatability of these foods, a number of genetic mutations in the brain’s reward systems may result in overeating and obesity in many people. Furthermore, the hypersensitive reward systems that often lead to obesity can become insensitive once a state of obesity is attained. In effect, this leads to overeating to receive the same pleasure from the same foods. These dysregulated reward systems are coupled with preadipocyte expansion into mature adipocytes, allowing for increased fat storage. While this isn’t the entire story, this should shed some light on the complex interactions of dysregulated internal systems that foster the metabolic abnormalities that result in obesity. Importantly though, these impairments are typically only demonstrated once obesity has been introduced and sustained (3).

As for weight loss, when caloric restriction is initiated, the body triggers a number of systems to prevent starvation. From an evolutionary perspective, this makes sense as food sources were often unpredictable and the body adapted to conserve energy – the “feast and famine” principle. However, for most of us living in industrialized nations, famine is rare and feast is common, limiting the need for this once very necessary adaptation (though the body has not evolved to recognize the abundance of calories in our modern food supply). When we try to induce weight loss via caloric restriction, the body will reduce its resting metabolic rate to counter these advances (5). This supports the “set point theory” – the idea that the body will defend its highest-sustained weight. In fact, as weight loss increases, the drive to restore the highest bodyweight only increases (6). It’s like when you’re pulling on your dog’s leash to get him into the vet and he plants his feet firmly and resists with all his might. Ultimately his strength pulls him out of his collar and sends him running in the opposite direction. Except here we’re talking about the human body and it’s not nearly as comical.

All of these biological adaptations that introduce, sustain, and defend obesity explain why weight loss and its maintenance is so exhaustingly difficult for so many people. As Ochner and colleagues suggest, most individuals who had obesity but lost weight simply have “obesity in remission and are biologically very different from individuals of the same age, sex, and body weight who never had obesity.” As a hypothetical scenario, imagine you are comparing two people: they weigh the same, but person A had obesity and has lost weight whereas person B has never lost weight. Person A will have to burn up to 300 calories more (or consume 300 calories fewer) than person B to maintain that weight (2). This underscores the idea that weight regain is not simply an issue of willpower and weakness.

What we need more of are studies evaluating multiple approaches to weight loss (surgeries, medications, likely in combination with lifestyle changes). What we need less of is bias from people without obesity, the media, and even healthcare providers. Indeed, “the mere recommendation to avoid calorically dense foods might be no more effective for the typical patient seeking weight reduction than would be a recommendation to avoid sharp objects for someone bleeding profusely” (2). We also need better obesity prevention approaches because, clearly, it’s biologically more feasible to prevent weight gain than to lose weight and keep it off.

References

1.Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of childhood and adults obesity in the United States, 2011-2012. JAMA. 2014;311(8):806-814. doi:10.1001/jama.2014.732.

2.Ochner CN, Tsai AG, Kushner RF, Wadden TA. Treating obesity seriously: when recommendations for lifestyle change confront biological adaptations. Lancet Diabetes Endocrinol. 2015:

3.Ochner CN, Barrios DM, Lee CD, Pi-Sunyer FX. Biological mechanisms that promote weight regain following weight loss in obese humans. Physiol Behav. 2013:120:106-13. doi: 10.1016/j.physbeh.2013.07.009.

4.Kenny JP. Reward mechanisms in obesity: new insights and future directions. Neuron. 2011:69(4):664-79. doi:10.1016/j.neuron.2011.02.016

5.Grattan BJ, Connolly-Schoonen J. Addressing Weight Loss Recidivism: A Clinical Focus on Metabolic Rate and the Psychological Aspects of Obesity. ISNR Obesity. 2012. doi:10.5402/2012/567530

6.Rosenbaum M, Leibel RL. Adaptive thermogenesis in humans. Int J Obes.2010:34:S47-55. doi:10.1038/ijo.2010.184

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Health Literacy and Implications in Nutrition Care

By Mayra Sofia Crespo Bellido

“I drink tea of guanábana leaves when I can’t make it to my chemotherapy sessions. Did you know Miss, that eating guanábana is just as good as 10 chemotherapy sessions?” I was shocked when a patient shared this piece of information with me during a nutritional assessment interview. Luckily, my preceptor stepped in and educated the patient and his spouse on the risks of completely substituting traditional medicine with alternative treatments that are not evidence-based. He argued with my professor. In that moment it sunk in how dangerous health illiteracy can be.

Health literacy has been defined as “the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions.” It involves different factors such as: health knowledge, listening, speaking, arithmetical, writing, and reading skills, and cultural competencies of health professionals as well as other systemic factors.

According to the National Center for Education Statistics, nearly 9 out of 10 adults may lack the skills needed to manage their health and prevent disease. Nearly 14% of adults (30 million people) have ‘below basic’ health literacy. These adults were more likely to report their health as poor (42%) and are more likely to lack health insurance (28%) than adults with Proficient health literacy. These patients are more likely not to vocalize their concerns and questions as well as being less active participants in their care because of the stigma associated with being health illiterate. Being health illiterate is a stronger predictor of health than socioeconomic status, education, ethnicity, or race.

Nutrition professionals in all areas face health illiteracy on a day-to-day basis. During my dietetic internship training, I have a difficult time gathering accurate information from patients during the nutritional assessment in the clinical setting, particularly when assigned a high patient load. That initial interaction may be somewhat compromised by the fact that most patients do not know how to express nutritional concerns and time is too constricted to dig deep into the answers provided. Same goes to other areas of practice: nutrition researchers dealing with tailoring informed consent forms to the level of health literacy of their population of interest or foodservice managers explaining to their employees the reasons to follow HACCP procedures to ensure food safety. Even public health nutrition professionals may face it while trying to advocate in favor of measures such as the taxation of sugar-sweetened beverages.

Healthy People 2020 includes the specific objective to increase health literacy under the topic of Health Communication and Health Information Technology. In this era health and nutrition information is produced and distributed by individuals and organizations with various agendas. It is critical that people have the skills to navigate this sea of information without feeling overwhelmed by nutrition confusion. Guiding people through this process and giving them strategies to find and understand accurate food and nutrition information could allow for a new sense of empowerment that could position dietitians, nutritionists and other nutrition professionals as the go-to source in these matters for people who have put their trust elsewhere to get the information.

The World Health Organization has determined improving health literacy has implications in a greater scope than individual decision-making processes with the following quote:
“[…] Health Literacy goes beyond a narrow concept of health education and individual behavior-oriented communication, and addresses the environmental, political and social factors that determine health. Health education, in this more comprehensive understanding, aims to influence not only individual lifestyle decisions, but also raises awareness of the determinants of health, and encourages individual and collective actions which may lead to a modification of these determinants. Health education is achieved therefore, through methods that go beyond information diffusion and entail interaction, participation and critical analysis. Such health education leads to health literacy, leading to personal and social benefit, such as by enabling effective community action, and by contributing to the development of social capital.”
Such an impact could guide the food and nutrition policy measures that are needed to ensure the population’s health by activism that intends to change social determinants of health. Wow!

There is a vast amount of literature in health literacy, yet there is still some room for improvement in the scope of practice. Public health and community nutrition professionals could make use of the health care system’s shift from acute care towards preventive care and health promotion to justify projects that improve basic health literacy skills. Helping people understand the purpose of health and nutrition behavior change, increasing self-efficacy and helping individuals make decisions accordingly is vital.

References
Department of Health and Human Services (US), Office of Disease Prevention and Health Promotion. Health literacy online: A guide to writing and designing easy-to-use health web sites.

Health Communication and Health Information Technology- https://www.healthypeople.gov/2020/topics-objectives/topic/health-communication-and-health-information-technology

Health literacy and health behaviour- http://www.who.int/healthpromotion/about/en/

Carbone E., Zoellener, J. (2012) Nutrition and Health Literacy: A Systematic Review to Inform Nutrition Research and Practice. J Acad Nutr Diet. doi: 10.1016/j.jada.2011.08.042

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Food Security in Puerto Rico: Vulnerable Food Supply

By Mayra S. Crespo Bellido

In 1942, Dr. Lydia J. Roberts was asked by Dr. M. L. Wilson of the US Food and Nutrition Board to visit Puerto Rico under the pretenses that “there was a problem in [the island], which ordinarily imported much of its food.” After all, the island only produced 65% of the food the habitants needed, 35% was being imported at the time. Dr. Roberts was assigned to study the food and nutrition situation in order to report back to Washington, DC. Out of her collaboration with the University of Puerto Rico as a visiting professor, a clear picture of the living situation for the islanders during the 1940s was portrayed in her book Patterns of Living in Puerto Rican Families. This classic one-of-a-kind report depicts explicitly the poor health conditions and severe food insecurity in most households, mostly due to lack of educational and monetary resources. During this period infectious diseases were ranked #1 among the most common causes of mortality for all ages.

In the 21st century, a changing landscape of health problems troubles Puerto Rico. Following nutrition transition patterns of developing countries, the leading causes of death of our time are all from complications of chronic conditions associated with the increasing prevalence of obesity in the island. In 2013, 35% of Puerto Ricans living in the island benefited from the Nutrition Assistance Program, and the majority of the population benefits from other programs such as WIC and Child Nutrition Programs. Nonetheless, Puerto Rico deals with serious food security issues as the island produces only 17.65% of the food it consumes, importing 82% from over 10 different countries.

According to the Food and Agriculture Organization (FAO), food security exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food which meets their dietary needs and food preferences for an active and healthy life. The four dimensions of food security as defined by the FAO are: food availability, food access, proper utilization and stability. A recent study established that food security is not distributed equally as people living in rural areas of the island are disproportionately affected unemployment rate, greater proportion of habitants below the poverty level and lower education levels all of which may create barriers to food access and proper utilization. However for the Puerto Rican population it becomes a little more complicated than that.

Dr. Myrna Comas, Puerto Rico Secretary of Agriculture, has made it her lifework to bring awareness of the vulnerability of the food chain supply in Puerto Rico. As stated by Dr. Comas, the high dependence on imported foodstuff, constant decreases in local agricultural production, the fact that there is only one functioning seaport that receives all merchandise imported, the great distances food has to travel to get to the island, and a lack of policy to ensure food security are some of the many reasons the food chain supply to the island is susceptible to external influences. Some identified risk factors that could interfere with the supply of food are: global climate change, food and water contamination, reduction of terrains devoted to agriculture in the island, accidents, and free trade agreements, among others.

Under the direction of Dr. Comas, the Puerto Rico Department of Agriculture has systematically addressed these issues for the past couple of years. Part of this plan to counterattack the risk of having a food crisis includes an educational campaign to bring awareness to the matter of food security, and initiatives to conserve agricultural lands and to promote local agricultural production of staple foods. There is evidently a long way to go until this matter is resolved. Hopefully with increased knowledge and understanding of the repercussions of letting this problem remain unaddressed will encourage the proper authorities to create local and international food policy that avoids an impending food crisis in the island.

References
Rosario-Mejías, M, Dávila-Román, A. (2012). Distribución geográfica de la seguridad alimentaria en Puerto Rico, 2005-2009. CIDE Digital 3(1-2), 109-118.

http://academic.uprm.edu/mcomas/HTMLobj-159/tesis.pdf

http://www.elnuevodia.com/expuestopuertoricoaunacrisisalimentaria-1717099.html

http://puertorico.media.indypgh.org/uploads/2012/01/bolet_n__13_enero_2012.pdf

http://jp.pr.gov/Portal_JP/Portals/0/Publicaciones/PublicacionesHistoricasOnline/Compendio%20de%20Estadisticas%20Sociales%20-%201988-2.pdf

http://www.fao.org/focus/e/obesity/obes2.htm

https://www.cfda.gov/index?s=program&mode=form&tab=core&id=3050f5bc0ed98a93fcc273237e0dd0cd

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.