Myths and Facts: Obesity

Some blame it on our sedentary lifestyles and “American”- sized menus. Others claim calorie-laden carbs, sugary snacks and nutrient-deficient processed foods are the leading culprits. Food additives, artificial sweeteners and even antibiotics have also been linked to America’s growing girth, but the reality is that whatever the reasons are for the upward climb of our collective body mass index (BMI), America as a whole has become overwhelmingly obese.

According to the Centers for Disease Control and Prevention, more than one-third of American adults are classified as obese.¹ Obesity is linked to more than 60 chronic diseases,² including heart disease, stroke, type 2 diabetes and certain cancers. And, as waistlines increase, so do healthcare costs. Researchers estimate that if obesity trends continue, obesity-related medical costs could rise by $43 billion to $66 billion each year in the United States by 2030.³

While the link between obesity and disease is not new, the recent classification of obesity as a disease itself is still being debated. In June 2013, the American Medical Association (AMA) announced its controversial decision to classify obesity as a stand-alone disease requiring specific medical interventions to promote treatment and prevention. “Recognizing obesity as a disease will help change the way the medical community tackles this complex issue that affects approximately one in three Americans,” said AMA board member Patrice Harris, MD. “The AMA is committed to improving health outcomes and is working to reduce the incidence of cardiovascular disease and type 2 diabetes, which are often linked to obesity.”⁴

The new classification has far-reaching implications, influencing everything from provider reimbursement, public policy and patient stigma to the International Classification of Diseases coding.⁵ As healthcare providers are increasingly tasked with taking a broader view of obesity causes, interventions and treatment plans, it’s important to look at some of the common but erroneous beliefs about obesity, and separate fact from fiction.

Separating Myth from Fact

Myth: Slow and steady wins the weight-loss race: Gradual weight loss is better than rapid weight loss when it comes to long-range results.

Fact: According to recent studies, people who lose weight quickly are as likely to keep it off as those who slim down at a moderate pace. A meta-analysis of randomized, controlled trials that compared rapid weight loss (achieved with extremely low-energy diets) with slower weight loss (achieved with low-energy diets) showed that there was no significant difference between the two different diet plans and outcomes at the end of the long-term follow-up. In fact, within some weight-loss trials, more rapid and greater initial weight loss has been associated with lower body weight at the end of long-term follow-up.6 Researchers also noted that a recommendation to lose weight more slowly might cause participants to lose momentum and interfere with the ultimate success of weight-loss efforts.

Myth: Setting realistic goals for weight loss is important because otherwise patients will become frustrated and lose less weight.

Fact: Although from a behavioral standpoint this theory makes sense, studies show no consistent negative association between ambitious goals and program completion or weight loss. Some data point out that people achieve more by setting more challenging goals.⁷ Several studies have shown that more ambitious goals are sometimes associated with better weight-loss outcomes. Furthermore, two studies showed that interventions designed to improve weight-loss outcomes by altering unrealistic goals resulted in more realistic weight-loss expectations but did not improve outcomes.⁸

Myth: Breast-feeding helps prevent future obesity for the breast-fed baby.

Fact: Although breast-feeding has advantages for both mother and child, data does not confirm that it protects against obesity. This myth stems from a World Health Organization (WHO) report stating that individuals who were breast-fed as infants are less likely to be obese later in life. WHO later found clear evidence of publication bias in the published literature it synthesized,⁹ and follow-up studies with improved controls provided no compelling evidence that breast-feeding had any influence on obesity.¹⁰

Myth: Obesity is a result of poor education regarding proper diet and nutrition.

Fact: According to a physicians’ health study, 44 percent of male doctors in the U.S. are overweight.¹¹ Another study by the University of Maryland School of Nursing found that 55 percent of nurses surveyed were classified as overweight or obese.¹² These statistics suggest that if healthcare providers who have ample exposure to health and nutrition information struggle with obesity, clearly the problem is not rooted simply in a lack of information. On the other hand, race and socioeconomic status do play a role in obesity statistics. Among non-Hispanic black and Mexican-American men, those with higher incomes are more likely to battle obesity than those with low income, and overall, higher-income women are less likely to struggle with obesity than low-income women.¹³

Myth: Eating more fruits and vegetables encourages weight loss.

Fact: Fruits and vegetables are healthy food choices but may not encourage weight loss, according to a study in The New England Journal of Medicine.¹⁴ The common wisdom suggests that since fruits and vegetables contain fiber, they will keep you full longer and encourage you to eat less. But a report in the International Journal of Obesity noted that regularly consuming fruit, whether solid fruit or fruit juice, did not encourage people to eat less. The study concluded that the recommendation for increased consumption of fruits and vegetables may be well-founded but should not be based on a presumed beneficial effect on regulation of BMI.¹⁵

Myth: Obesity is genetically, not behaviorally, influenced.

Fact: A cohort study was used to investigate the extent to which people with a genetic susceptibility to obesity can change their weight with exercise. The research was based on previous genetic studies that had identified 12 possible positions on 11 genes where DNA sequencing differences could influence BMI. However, although the studies showed an association between variations in the genetic sequence and BMI, the variations seemed to have a very small effect on a person’s risk of obesity. Previous research suggested that lifestyle played a greater role in determining BMI, and the new study aimed to investigate this theory in more detail. Researchers found that although some genes increased the likelihood of having a higher BMI, an active lifestyle proved these “genetically predisposed” individuals were less likely to be overweight. Conversely, an inactive lifestyle increased the amount of weight the individuals were likely to gain.¹⁶

Myth: School-based physical education classes play an

important role in reducing or preventing childhood obesity.

Fact: Physical education, as typically provided in a school setting, has not been shown to reduce or prevent obesity. Findings in three studies that focused on expanded time in physical education indicated that even though there was an increase in the number of days children attended physical education classes, the effects on BMI were inconsistent across sexes and age groups. Two meta-analyses showed that even specialized school-based programs that promoted physical activity were ineffective in reducing BMI or the incidence or prevalence of obesity.¹⁷ Researchers did agree that certain levels of physical activity (a specific combination of frequency, intensity and duration) could potentially be effective in reducing or preventing obesity in children and adolescents, but whether that level is achievable in a traditional school has yet to be explored. Research also concluded that while weight-management programs in schools, daycare or other places away from the home are convenient, programs that involve a child’s parents and take place at home are likely to be more effective in the long run.

Myth: Obesity is a leading cause of breast cancer.

Fact: This statement is only partially true. Current evidence suggests that heavier body weight does not increase breast cancer risk before menopause and may even slightly lower risk. But, research by leading cancer organizations has concluded that there is convincing evidence that being obese or overweight may be linked to increased risk of breast cancer in post-menopausal women.¹⁸ The higher risk of breast cancer for women who gain weight is likely due to higher levels of estrogen, since fat tissue is the largest source of estrogen among women who are postmenopausal. Since being overweight increases a woman’s risk of post-menopausal breast cancer, cancer researchers are exploring whether weight loss can actually lower the risk.

Myth: Overweight children will outgrow their excess weight. It’s just “baby fat.”

Fact: Children and adolescents who are obese are likely to be obese as adults and are, therefore, more at risk for adult health problems such as heart disease, type 2 diabetes, stroke, several types of cancer and osteoarthritis. One study showed that children who became obese as early as age 2 were more likely to be obese as adults.¹⁹ In the United States alone, childhood obesity has more than doubled in children and quadrupled in adolescents over the past 30 years. The percentage of children aged 6 years to 11 years who were obese increased from 7 percent in 1980 to nearly 18 percent in 2012. Similarly, the percentage of adolescents aged 12 years to 19 years who were obese increased from 5 percent to nearly 21 percent over the same period. These statistics are worrisome; some have predicted that the current generation of youth could become the first to have a shorter life expectancy than their parents. In a study published in The New England Journal of Medicine, researchers stated: “If the prevalence of obesity continues to rise, especially at younger ages, the negative effect on health and longevity in the coming decades could be much worse. It is not possible to predict exactly when obesity among the young will have its largest negative effect on life expectancy. However, in the absence of successful interventions, it seems likely that it will be in the first half of this century, when at-risk populations reach the ages of greatest vulnerability.”20

Myth: Hypothyroidism is a primary cause of obesity.

Fact: Decreased thyroid function, or hypothyroidism, is commonly associated with weight gain. But contrary to popular belief, effective treatment to restore normal thyroid hormone levels is not associated with clinically significant weight loss in most people. Following an eight-year study, researchers from Boston University Medical Center noted that because obesity and hypothyroidism are very common, there are many patients who have both conditions. As a result, these patients (and sometimes their physicians) often assume the hypothyroidism is causing the obesity even though this may not be the case. The study showed that only about half of hypothyroid patients lose weight after successful treatment of their hypothyroidism.²¹

Treating Obesity: A Look Forward

It’s been nearly two years since the American Medical Association officially classified obesity as a disease, but healthcare providers remain divided in their opinions of the decision. Some argue that the problem of obesity in America has reached dire proportions: 78 million adults and 12 million children are obese — figures many regard as an epidemic. With that in mind, recognizing obesity as a disease may help change the way the medical community tackles this complex health issue. Proponents of the classification say recognizing obesity as a disease has the potential to spur new interventions and treatments for patients struggling with weight loss, and encourage improved dialogue between patients and their doctors about available behavioral, medicinal or surgical options. Still, opponents of the change say calling obesity a disease lessens personal responsibility and may provide less incentive to curb unhealthy eating habits or adopt healthier lifestyles. They worry the disease designation will create a victim mentality that will only lead to more overeating and weight gain.

New Guidelines and Treatment Recommendations

In November 2013, the American Heart Association, American College of Cardiology and the Obesity Society issued updated guidelines to more actively treat obese patients and encourage weight loss. The guidelines reflect the latest information that scientists have about weight-loss treatment plans, with a special emphasis on preventing heart disease and stroke, the nation’s No. 1 and No. 5 killers.²²

One of the biggest changes in the new guidelines is that the criteria have been expanded to include more categories of overweight and obese people. The current weight-loss guidelines recommend behavioral treatment for 140 million American adults — 65 percent of the population.23 Of these, 116 million would be candidates for adjunctive pharmacotherapy, and 32 million could be considered for bariatric surgery. “This huge number of Americans recommended for weight-loss therapy reinforces the need for broad, sweeping transformations in obesity management in the primary-care setting,” stated Dr. Donna Ryan, a coauthor of the guidelines and a spokesperson for the Obesity Society. “The good news is that there are evidence-based treatments readily available.”

The new guidelines recommend that all obese patients pursue weight-loss therapy. Overweight individuals need to have only one as opposed to two cardiovascular risk factors to qualify, with one of the key risk factors being excessive weight around the waist. The guidelines also include evidence-based recommendations for lifestyle management, including behavioral strategies, pharmacotherapy and metabolic (bariatric) surgery. The guidelines are expected to provide a tool to help physicians identify and treat patients who may not have achieved prior success with diet and exercise alone.

In January, the Endocrine Society issued a clinical-practice guideline for the pharmacological management of obesity, providing clinicians with yet another tool to help improve weight-loss treatment outcomes.²⁴ The guidelines state that medications approved for chronic weight management can be useful adjuncts to lifestyle change for patients who have been unsuccessful with diet and exercise alone. The authors also stress that providers should be mindful that medications prescribed for chronic diseases such as diabetes and depression can have effects on weight, noting that “knowledgeable prescribing of medications, choosing whenever possible those with favorable weight profiles, can aid in the prevention and management of obesity and thus improve health.”