Office of Research & Development

Obesity

More than 35 percent of American adults are obese, and about 17 percent of children are obese. This translates to more than 78 million adults and 12.5 million children. More than 7 in 10 Veterans who receive VA care are either overweight or obese.

Obesity is a risk factor for heart disease, type 2 diabetes (once known as adult-onset or non-insulin-dependent diabetes), stroke, and some types of cancer. In particular, diabetes and obesity have become a very prevalent combination.

Metabolic syndrome is the name for a group of risk factors that raises the risk of heart disease and other health problems, such as diabetes and stroke. A large waistline, high triglyceride levels, low HDL (good) cholesterol levels, high blood pressure, and high fasting blood sugar all increase the likelihood of developing these diseases.

VA research on obesity looks at the biological processes of weight gain and weight loss. Our researchers compare the safety and effectiveness of obesity treatments, and work to find ways to help Veterans keep from gaining weight—for example, through exercise and healthy eating.

VA researchers' efforts work hand in hand with VA's MOVE! program, a national weight-management and exercise initiative designed and coordinated by VA's National Center for Health Promotion and Disease Prevention.

VA researchers are also part of the Minnesota Obesity Center, a nutrition and obesity research center funded by the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health. Other partners in the effort are the University of Minnesota, the Mayo Clinic, Hennepin County Medical Center, and HealthPartners Research Foundation.

Selected Milestones and Major Events

Selected Milestones and Major Events for obesity research

Selected Major Accomplishments

  • Establishing a relationship between the production of the hormone ghrelin and gastric bypass surgery
  • Showing that gastric banding leads to a reduction of diabetes symptoms
  • Adapting existing materials on exercise to help spinal-cord-injured Veterans exercise safely and lose weight
  • Finding that bariatric surgery in older males does not significantly decrease death rates

Overview

In the past 20 years, there has been a dramatic increase in obesity in the United States. More than one-third of adults and 17 percent of children and adolescents are obese. Conditions relating to being unhealthily fat include heart disease, stroke, type 2 diabetes, and certain types of cancer.

Overweight and obesity are terms used for ranges of weight that are greater than what is considered healthy. A body mass index (BMI) of 25.0 to 29.9 is considered overweight, and a BMI of 30.0 and above is considered obese. (BMI is a number calculated from a person's weight and height. Here is a link that helps you calculate your own BMI.)

VA estimates that more than 165,000 Veterans who receive their health care from VA have a BMI of more than 40, which indicates a serious condition called morbid obesity. Morbid obesity can interfere with basic physical functions and increase the risk of developing obesity-related conditions.

The basic cause of overweight and obesity is an imbalance between the calories a person consumes and those he or she expends. Many factors can contribute to this imbalance. However, the rapid increase in overweight and obesity in both the general population and among Veterans over the last several decades suggests that environmental and behavioral influences may now play a greater role than genetics.

In 1999, scientists discovered that the hormone ghrelin may be the signal that makes people feel like eating. The concentration of ghrelin in a person's blood rises quickly right before a meal, and falls once food is eaten.

In 2002, researchers from the VA Puget Sound Health Care System and the University of Washington in Seattle reported that obese people who followed a six-month diet program and lost a significant amount of weight showed greatly increased ghrelin concentrations in their blood. This alteration in their body's functioning, and the hunger pains that follow, contributed to post-diet weight gain.

Gastric bypass surgery helps people lose weight by changing how their stomachs and small intestines handle the food they eat. The team found that in people who had undergone gastric bypass surgery, ghrelin in the blood had plummeted from normal concentrations and didn't fluctuate before or after meals—in contrast to the findings in the diet group. This suggests that the surgery disrupts the stomach's normal ghrelin secretion.

Other studies are in conflict, however, on whether ghrelin levels return to close to normal in gastric bypass patients in the long run, once weight loss has stabilized. European researchers not affiliated with VA have found that sleeve gastrectomies, which involve the removal of part of the stomach, reduce ghrelin levels by an average of 60 percent, and that those levels remain lower five years after surgery.

Diabetes and obesity

One of the main risk factors for type 2 diabetes is obesity. VA investigators and others have found that sustained weight loss leads to major benefits for those with, or at risk for, type 2 diabetes and many other health problems.

Type 2 diabetes affects nearly 20 percent of Veterans who use the VA health care system, or more than 1 million Veterans. VA is working to decrease the incidence of both diabetes and obesity among Veterans (see our Diabetes page), and to improve care for Veterans with diabetes who are overweight or obese.

Researchers at the VA San Diego Health Care System completed a study in 2012 that found gastric banding, another type of obesity surgery, nearly always improves or eliminates diabetes symptoms. The researchers followed 66 people with type 2 diabetes who had undergone gastric banding surgery.

Before the banding, all required daily medication for their diabetes. After two years, 48.5 percent had no symptoms of diabetes. Another 47 percent saw their symptoms improve, and only 4.5 percent saw no change in their diabetes status.

Those who saw no change were more likely to have had diabetes for a longer time before the procedure, and were also likely to have lost less weight over the two-year time period following the surgery.

Spinal cord injury and obesity

Nearly 66 percent of VA's patients with spinal cord injuries and disorders are either overweight or obese. In 2011, a team led by researchers at VA's Puget Sound Health Care System adapted materials on weight management and physical activity on the VA MOVE! program's website, to make them helpful to Veterans with spinal cord injuries. They also developed new materials on their own.

The researchers modified 22 existing pamphlets by including wheelchair fitness activities and photographs, providing safety tips for wheelchair users, and offering other ideas to help spinal cord injured patients perform physical activity safely. They also developed five new pamphlets.

Weight loss studies

VA MOVE! programs throughout the nation offer a series of classes, including both exercises and nutrition information, to help Veterans develop weight management skills. VA researchers at the Sioux Falls, S.D., VA medical center recently studied weight-loss outcomes among 120 Veterans to see if these classes are helpful when participants are at locations other than where the classes are taught.

Half of the Veterans in the study took part in a series of 12 weekly MOVE! classes through videoconferencing. The MOVE! participants lost weight, while the control group, which took neither video nor in-person classes, gained weight.

The average weight difference between the groups was about 12 pounds, and the MOVE! participants kept their weight off a year after their weight was first measured.

Bariatric surgery is the general term for all surgical procedures designed to address obesity. These surgeries are considered the most effective way for severely obese patients to achieve weight loss.

Researchers conducting a VA study published in 2012 found, however, that the department's costs to treat surgical patients three years after bariatric surgery were similar to its costs to treat Veterans who did not have this kind of surgery. Obesity-associated health expenses are very high, and are disproportionately higher for morbidly obese patients.

Previous studies had found that health care expenditures decreased after bariatric surgery, two to five years after the procedure took place—but these studies examined outcomes in younger, primarily white, and female populations. This study focused on older men, at lest 17 percent of whom were minorities.

The team, from VA's Center for Health Services Research in Primary Care in Durham, N.C., used VA's electronic health records system and data from the VA Surgical Quality Improvement Program (VASQIP) to review the medical records and VA claims data of 847 Veterans who had had bariatric surgery between 2000 and 2006 at one of 12 VA medical centers. Their records were compared to 847 obese Veterans who had not had the surgery.

The authors believe that, despite the costs, bariatric surgery is still a valuable option for treating extremely obese patients, because of the undeniable health benefits of the surgery, which include a strong evidence of significant reduction in body weight, comorbid conditions (diseases that occur at the same time as others), and improved quality of life.

They are currently observing patients who have undergone bariatric surgery and those who have not over a 10-year period to compare weight change, long-term survival, and costs related to the surgery. A previous study by the same team, published in 2011, found that bariatric surgery in older males was not significantly associated with a decrease in rates of death.

Recently completed studies

In 2013, VA researchers at the Hines VA Medical Center in Chicago published the results of a study on whether a personal digital assistant (PDA) can help Veterans lose weight. The researchers looked at Veterans with a BMI between 25 and 40 who had been dealing with chronic pain for at least six months.

Half of the Veterans in the study were given a PDA on which they recorded food intake, physical activity, weight, mood, and pain intensity. This group also received telephone support every other week for six months. Weight loss among the group using PDS was greater than that in the control group at three months, six months, nine months, and a year.

According to the team, self-monitoring of diet and physical activity is associated with weight loss success, and can be performed conveniently using handheld devices.

Another study published in 2013 by researchers with the San Francisco VA Medical Center found high rates of overweight and obesity among a relatively young group of Iraq and Afghanistan Veterans—and that obesity rates where highest among those with posttraumatic stress disorder (PTSD) or depression.

The researchers did a retrospective analysis of nearly 500,000 Veterans' health records, and found that 75 percent of Iraq and Afghanistan Veterans were either overweight or obese at their first encounter with VA health care. Most of their BMI's remained stable over a three-year period; some who were overweight or obese continued to gain weight; and fewer who were obese lost weight.

They also found that Veterans with PTSD and depression in particular were at the greatest risk of being either obese without losing weight or obese and continuing to gain weight.

Ongoing studies

At the Durham VA Medical Center, William Yancy Jr., MD, MPH, has performed a number of trials investigating the effects of various dietary and weight loss approaches on body weight, cardiovascular risk, and diabetes. Among the findings he and his team have previously reported on is a 2010 study that indicates that a low-carbohydrate diet is better at lowering blood pressure than the weight loss drug orlistat together with a low-fat diet.

Dr. Yancy is currently the principal investigator of a VA-funded study that is investigating the impact of diet preference on weight loss success. Other ongoing studies by VA researchers include:

  • Examining an innovative approach to weight loss, called ASPIRE, that involves phone-based weight management and coaching and a simplified diet;
  • Looking at the possibility of providing MOVE! Instruction to Veterans with serious mental illness by using a computerized, web-based version of the program;
  • Developing partnerships with Veterans groups to provide MOVE! instructions at locations, such as service organization posts, that are more convenient to
  • Working to understand the molecular basis of adipogenesis—a process in which fat cells are produced and turned over. This research is integrating genomic knowledge to identify steps that may be manipulated to affect several genes that are impaired by obesity and its related complications; and
  • Studying ways that plasma fatty acids, which are at higher levels in people who are obese, regulate production of a lipid metabolite that causes inflammation that affects insulin resistance, the first step along the way to type 2 diabetes, atherosclerosis (the buildup of plaque in the arteries), and cancers that occur at higher rates in obese patients. (Lipid metabolism is the process by which fatty acids are stored in the human body.)

More on our Website

Extra weight: No protection against broken bones, as once thought. VA Research news feature.

Weight-loss surgery: Does it save health-care costs in the long run? VA Research news feature.

Bison edges beef in nutrition study, VA Research Currents, Summer 2013

Obesity no hindrance to heartburn drugs, VA Research Currents, March-April 2013

VA Research virtual media roundtable: diabetes/obesity

Selected Scientific Articles by our Researchers

Plasma ghrelin levels after diet-induced weight loss or gastric bypass surgery. Cummings DE, Weigle DS, Frayo RS, Breen PA, Ma MK, Dellinger EP, Purnell JQ. The increase in the plasma ghrelin level with diet-induced weight loss is consistent with the hypothesis that ghrelin has a role in the long-term regulation of body weight. Gastric bypass is associated with markedly suppressed ghrelin levels, possibly contributing to the weight-reducing effect of the procedure. N Engl J Med, 2002 May 23;346(21):1623-30.

A randomized trial of a low-carbohydrate diet vs orlistat plus a low-fat diet for weight loss . Yancy WS Jr, Westman EC, McDuffie JR, Grambow SC, Jeffreys AS, Bolton J, Chalecki A, Oddone EZ. In a sample of medical outpatients, a low-carbohydrate, ketogenic diet led to similar improvements as orlistat therapy combined with a low-fat diet for weight, serum lipid, and glycemic parameters and was more effective for lowering blood pressure. Arch Intern Med. 2010 Jan 25;170(2):136-46

Survival among high-risk patients after bariatric surgery . Maciejewski ML, Livingston EH, Smith VA, Kavee AL, Kahwati LC, Henderson WG, Arterburn DE. In propensity score-adjusted analyses of older severely obese patients with high baseline mortality in Veterans Affairs medical centers, the use of bariatric surgery compared with usual care was not associated with decreased mortality during a mean 6.7 years of follow-up. JAMA. 2011 Jun 15;305(23):2419-26.

Health expenditures among high-risk patients after gastric bypass and matched controls. Maciejewski ML, Livingston EH, Smith VA, Kahwati LC, Henderson WG, Arterburn DE. Based on analyses of a cohort of predominantly older men, bariatric surgery does not appear to be associated with reduced health care expenditures 3 years after the procedure. Arch Surg. 2012 Jul;147(7):633-40.

Effect of early weight loss on type 2 diabetes mellitus after 2 years of gastric banding. Edelman S, Bhoyrul S, Billy H, Cornell C, Okerson T. Shorter duration of type 2 diabetes mellitus and greater percent excess weight loss were associated with an increased likelihood of remission or improvement in diabetic status through gastric banding after 2 years. Gastric banding is a potential adjunctive treatment for obese patients with diabetes. Postgrad Med. 2012 Nov;124(6):73-81.

Integrating technology into standard weight loss treatment: A randomized controlled trial. Spring B, Duncan JM, Hedeker D. The addition of a PDA and telephone coaching can enhance short-term weight loss in combination with an existing system of care. JAMA Intern Med. Jan 28, 2013;173(2):105-111.

The effectiveness of telemedicine for weight management in the MOVE! program. Ahrendt AD, Kattelmann KK, Rector TS, Maddox DA. Videoconferencing is an effective method to provide the MOVE! Weight Management Program to Veterans. J Rural Health, 2014 Winter;30(1):113-9.

The relationship between body mass index and mental health among Iraq and Afghanistan veterans. Maguen S, Madden E, Cohen B, Bertenthal D, Neylan T, Talbot L, Grunfeld C, Seal K. The growing number of overweight or obese returning veterans is a concerning problem for clinicians who work with these patients. J Gen Intern Med, 2013 Jul;28 Suppl 2:S563-70.

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