New data from the Centers for Disease Control and Prevention showed that 16 states now have obesity rates of 35% or higher. This is an increase of four states, Delaware, Iowa, Ohio and Texas, in just one year. Obesity prevalence maps Adult obesity prevalence by state and territory using self-reported information from the Behavioural Risk Factor Surveillance System. Try PMC Labs and let us know what you think.
Despite growing recognition of the problem, the obesity epidemic continues in the U.S. The latest estimates are that approximately 34 percent of adults and 15-20 percent of children and adolescents in the U.S. Obesity affects all segments of the U.S. Obesity increases the risk of many chronic diseases in children and adults.
The obesity epidemic emerged gradually over time, apparently from a small and consistent degree of positive energy balance. Major public health efforts are underway to tackle obesity, but there is as yet no clear evidence of success. Because of the complexity of obesity, it is likely to be one of the most difficult public health problems our society has ever faced. The obesity epidemic in the US In recent years, obesity rates have not increased significantly in some US subpopulations, but it is too early to know whether this means that the epidemic has reached peak levels in these populations, 1, 2 There is clear evidence that obesity rates are increasing in much of the rest of the world, 3, 4 A great deal of research is now directed towards better understanding and treatment of obesity, and substantial public health efforts are directed towards reducing obesity rates.
To date, however, there is little evidence of success in reversing the epidemic in the US. BMI categories and disease risk* relative to normal weight and waist circumference. Obesity prevalence rates increased over time in all ethnic and gender groups. Obesity rates are the same at all income levels.
Obesity rates are the same at all levels of education. Prevalence of obesity by race and gender The finding that minorities and people with low incomes are disproportionately affected by obesity is not surprising. The cheapest foods are those containing high levels of fat and sugar, 11 so the way to get the most calories for the least money is to eat a diet high in fat and sugar. This illustrates the interplay of biology and economics in supporting the obesity epidemic.
Foods for which we have a strong biological preference (i.e. people who have more economic resources combat these circumstances more easily and are consequently more physically active and less obese than those with fewer resources. Obesity rates in children and adolescents have continued to increase over the last 3 decades. Among children and adolescents, Mexican-American males and African-American females are more likely to have a higher BMI Obesity negatively affects most body systems.
It is linked to the most prevalent and costly medical problems seen in our country, such as type 2 diabetes, hypertension, coronary artery disease, many forms of cancer and cognitive dysfunction. BMI, abdominal fat distribution and weight gain are important risk factors for the development of type 2 diabetes. It is estimated that 90 e individuals with type 2 diabetes are obese, 15 It is further estimated that 30 e US adults have pre-diabetes, 16 Visceral obesity is associated with elevated triglycerides, low HDL cholesterol and an increase in small, dense LDL particles, 17 Obese individuals, particularly those with abdominal fat distribution, are at increased risk for CAD. The American Heart Association added obesity to its list of major risk factors for CAD in 1998,18 Obese men and women are also at high risk for sleep apnoea, in which partial or complete obstruction of the upper airway during sleep results in episodes of apnoea or hypopnoea.
Interrupted nocturnal sleep and repeated episodes of hypoxaemia lead to daytime sleepiness, morning headache and systemic hypertension, and may eventually lead to pulmonary hypertension and right heart failure. Data on the relationship between obesity and cognitive dysfunction are conflicting. Numerous studies have shown an association between obesity and cognitive dysfunction, including poorer executive function19-21 and memory deficits, 22 Although obesity is related to many diseases that are associated with cognitive dysfunction, some imaging studies have shown lower global brain volume23 and grey24, 25 and white26 matter in obese individuals compared to those of normal weight without weight-related comorbidities. Lower brain volumes have also been found in obese individuals with mild cognitive impairment and Alzheimer's disease.
27 One study found that obesity in middle age may be associated with the development of dementia later in life, but may be protective in older adults, 28 Another study found that overweight and obesity are protective against cognitive decline associated with mild cognitive impairment, Alzheimer's disease and vascular dementia, 29 A meta-analysis30 of prospective studies looking at BMI in midlife and dementia showed that underweight, overweight and obesity were all associated with the development of dementia later in life. A systematic review of population-based longitudinal studies concluded that higher BMI is probably a risk factor for developing dementia, 31 Obesity is associated with a spectrum of liver disease known as non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH). Manifestations of this disorder include hepatomegaly, abnormal liver function tests and abnormal liver histology, including macrovesicular steatosis, steatohepatitis, fibrosis and cirrhosis, 32, 33 Overweight and obesity are associated with an increased risk of endometrial, oesophageal, renal cell, pancreatic, ovarian, breast, colorectal, thyroid and gallbladder cancers. They are also associated with leukaemia, multiple myeloma, non-Hodgkin's lymphoma and malignant melanoma, 34, 35 As the number of obese children and adolescents increases, they begin to develop risk factors for chronic diseases that often appear much later in life, such as dyslipidaemia, hypertension and hyperinsulinaemia, 36 For example, an increasing number of obese children and adolescents are being diagnosed with type 2 diabetes,37 a disease that was virtually non-existent in this population a few generations ago.
Similarly, there is evidence that obesity in children and adolescents facilitates the progression of cardiovascular disease, 36, 38 To understand how the obesity epidemic arose, we will briefly examine how body weight is regulated. The key to understanding body weight regulation is to understand energy balance. The body's state of energy balance is determined by the amount of energy ingested in food relative to the amount of energy expended in metabolism and physical activity, 39, 40 To maintain a stable body weight, energy intake must, over time, exactly equal energy expenditure. A negative energy balance (where energy expenditure exceeds energy intake) results in weight loss, whereas a positive energy balance (where energy intake exceeds energy expenditure) results in weight gain.
The body appears to have some ability to actively regulate or adjust the energy balance, as altering one component of the energy balance can affect other components. For example, chronic changes in the amount of food consumed lead to changes in metabolism that serve to oppose a change in body weight, 41 Similarly, chronic changes in physical activity can affect food intake, 42, 43 However, these compensatory physiological changes are not sufficient to completely prevent changes in body weight in the face of a strong and persistent positive or negative energy balance, 42, 43 Our physiological system appears to protect more against body weight loss than against body weight gain. This makes sense in the sense that, for most of human history, starvation was a much more serious problem than obesity, 44 Each component of energy balance can be influenced by genetic, epigenetic and environmental factors. We know, for example, that genes can affect each of the components of energy balance45 and can explain some of the differences between individuals in body weight and body composition.
Although we can conclude that our genes are permissive to weight gain, the gradual weight gain in the population does not appear to be primarily due to genetic factors. The extent to which the body's physiological regulatory mechanisms serve to maintain a healthy weight depends on the environment. In an environment where high levels of physical activity are necessary to secure food and shelter and for transport, and where food is inconsistently available, the body's physiological regulatory mechanisms appear to work best and serve to help facilitate sufficient food intake to prevent loss of body mass. However, as the environment has gradually changed to one where high levels of physical activity are not required in daily life and where food is plentiful, cheap and served in large portions, physiological regulation of body weight appears to be insufficient to oppose positive energy balance, weight gain and obesity.
In these situations, becoming obese is an adaptation to environmental conditions and seems to represent a new "settling point". Obesity researchers increasingly recognise the importance of the physical and social environment in facilitating weight gain and obesity. Our current food environment is one in which food is cheap, plentiful and served in very large portions, 40 Similarly, we have created a physical activity environment with an infrequent need for significant energy expenditure for food, shelter and transport, 40 These environmental influences make it easier for us to overeat and under-exercise. The body's physiological system for adjusting energy balance is not strong enough in most people to completely oppose the positive energy balance that results.
Our environment arose as an unintended consequence of our social progress. In fact, it is likely that our environment has been shaped in large part by our biological preferences for energy-dense foods and lack of biological preference for physical activity. The environment we have created is one to which our ancestors aspired, and includes a constant supply of good-tasting, cheap and available food, and the possibility of not having to work hard to secure food, shelter and transport. The realisation that the environment is facilitating obesity has increased interest in modifying the environment to help tackle the obesity epidemic.
Although research in this area has only just begun, it represents an interesting new approach to obesity. Firstly, environmental modification alone is unlikely to solve the problem of obesity. The problem is that many of the factors that have contributed to obesity are things that enrich our lives in other ways. For example, we have instant access to information around the world through televisions, computers and personal digital assistants.
The fact that these tools contribute to reduced physical activity, and therefore encourage weight gain, is something that has only recently been discovered. Similarly, the increase in families where both parents work has increased and contributed to the rise of "fast food restaurants", as few people have the time or energy after work to prepare home-cooked meals. New York City forced restaurants to put calorie counts on menus to help them control their intake. However, one study found no change in the number of calories purchased at fast-food restaurants before and after labelling menus, 47 It is unlikely that we can "turn back the clock by giving these things up".
It is more likely that we will learn to modify the environment to support and maintain specific behavioural changes in the population to help people maintain a healthy weight. Both environment and behaviour need to be taken into account when assessing energy balance. The situation is different in today's environment, which requires very little physical activity. Technology has made it possible to be productive while being largely sedentary.
Under these conditions, weight gain can only be avoided by a conscious effort to eat less or to engage in physical activity without the need to do so. The minority of Americans who maintain a healthy weight are probably exercising cognitive control of eating and physical activity patterns to eat less than they otherwise would and to be physically active without needing to do so. In today's environment, maintaining a healthy body weight cannot be left to physiological processes, but requires cognitive effort. This does not mean that we should not look for ways to modify the environment to make it easier for people to avoid overeating and sedentary lifestyles.
It does mean that we should focus not exclusively on changing individual behaviour or changing the environment, but on the combination. We must change the environment to facilitate and sustain the behavioural changes needed to avoid obesity. There is a debate in the public health community whether to focus on changing the diet and the food environment or the physical activity and the physical activity environment. From an energy balance perspective, it does not make sense to focus on only one side of the equation.
While it is necessary to modify the factors that promote overeating, it may be impossible to control body weight by diet alone in a highly sedentary population. In fact, most of the Most of the US population may be so physically inactive that it is virtually impossible for them to eat little enough over the long term to match their low energy expenditure. The more we understand about the aetiology of obesity, the more complex it appears. For example, we have learned that the maternal environment can have lasting consequences for the regulation of body weight and the development of chronic disease in offspring, 49 Understanding and addressing obesity requires an understanding and appreciation of our biology, our behaviour, our environment and our culture.
Our scientific community is making great efforts to focus on each of these areas, but little effort to integrate them. Focusing on just one of these major areas is likely to be incomplete. We need to understand the biology of obesity, but only rarely is obesity the result of a biological "defect". Similarly, we need to better understand how to change behaviour, but to do so we need to assess our biology and the environment in which we live.
Figuring out how to change the environment so that obesity changes will also require an appreciation of biology and behaviour. Finally, obesity is also about how we have constructed our society, our collective worldview and the material basis of this worldview. We need to better understand the complex economic factors that underpin our current diet and physical activity patterns, and we need to think about how these might be changed to support a healthier lifestyle, 12, 50, 51 We need to begin to examine ways in which we can replace the aspects of society that support obesity with those that support healthier lifestyles. We need to begin to build a vision of what our society would look like if it supported healthy body weight maintenance and supported acceptable obesity prevalence rates.
What strategies could we use to reverse the obesity epidemic? Figure 8, adopted from the work of Dr. If we do nothing, population weight will continue to increase until everyone who is not genetically protected is overweight or obese. How could we reduce obesity prevalence rates to acceptable levels over time? Strategies to reverse the obesity epidemic. Adapted from Rossner, 1992, full citation needed here.
One possibility is to reduce the weight of many of those who are already overweight or obese. The problem is that our ability to produce and maintain substantial weight loss is not good, 52-54 Most people who lose large amounts of weight regain this weight completely within a few years, 52-54 Rarely does anyone permanently move from the obese to the healthy weight category. A meta-analysis showed that obese people were 3.2 below their initial weight at 5 years, reflecting 23 per cent maintenance of their initial weight loss, 55 Another study of NHANES data concluded that only 17 per cent of overweight or obese adults maintained a weight loss of at least 10 or 1 year, 56 Health professionals now recommend that weight loss goals of 5-10 the initial weight can be achieved and maintained in many people, 57 The conclusion is that we do not currently have a good ability to produce and maintain significant weight loss in large numbers of overweight and obese individuals. While we will undoubtedly improve our obesity treatment strategies over time, we cannot currently rely on this treatment to reverse the obesity epidemic.
Using a strategy to stop excessive weight gain, the prevalence of obesity would decline with each successive generation. Although it may take decades to reverse the obesity epidemic using this strategy, the positive view is that we may be able to produce and maintain the behavioural changes that would be necessary to stop excess weight gain. This can be done through a combination of focusing on specific behaviour change and modifying the environment in a way that supports and maintains the desired behaviour changes. Addressing obesity requires an understanding of energy balance.
From an energy balance point of view, it should be easier to prevent obesity than to reverse it. Furthermore, from an energy balance point of view, it may not be possible to solve the problem by focusing on diet alone. Currently, the energy needs of much of the population may be below the level of energy intake that can be reasonably maintained over time. Many initiatives are underway to review the way we build our communities, the ways in which we produce and market our food, and the ways in which we inadvertently promote sedentary behaviour.
Efforts are underway to prevent obesity in schools, workplaces and communities. It is probably too early to evaluate these efforts, but to date there have been no large-scale successes in preventing obesity. There are reasons to be optimistic about the fight against obesity. We have successfully addressed many previous public health threats.
In the 1950s it was probably inconceivable that major public health initiatives could have such a dramatic effect on reducing smoking prevalence in the United States. However, this serious problem was addressed through a combination of strategies including public health, economics, political advocacy, behavioural change and environmental change. Similarly, Americans have been persuaded to wear seat belts and recycle, addressing two other public health challenges, 65 But there are also reasons to be pessimistic. Certainly, we can learn from our previous efforts at social change, but we must realise that our challenge with obesity may be greater.
In the other examples cited above, we had clear goals in mind. Our goals were to stop smoking, increase seat belt use and increase recycling. The difficulty of achieving these goals should not be minimised, but they were clear and simple goals. In the case of obesity, there is no clear agreement on targets.
Moreover, experts do not agree on what strategies should be widely implemented to achieve the behavioural changes in the population needed to reverse the high prevalence rates of obesity. We need a successful model to help us understand what to do to tackle obesity. A good example is the recent HEALTHY study, 66 This comprehensive intervention was implemented in several schools and aimed to reduce obesity by focusing on behaviour and environment. This intervention applied most of the strategies that we believe are effective in schools.
Although the programme resulted in a reduction in obesity, this reduction was no greater than that observed in control schools that did not receive the intervention. This does not mean that we should not intervene in schools, but that concerted efforts across all behavioural domains may be necessary to reduce obesity. However, while we need successful models, there is a great urgency to respond to the obesity epidemic. A great example is the effort to achieve menu labelling in restaurants.
This is rapidly moving towards a national policy. While evaluation of this strategy is still ongoing, it is unclear what impact it will have on obesity rates. We should encourage efforts like this, but we need to evaluate them rigorously. Once we get serious about tackling obesity, it is likely to take decades to reverse obesity rates to the levels of 30 years ago.
In the meantime, the prevalence of overweight and obesity remains high and is likely to continue to rise. National Center for Biotechnology Information, U, S. National Library of Medicine 8600 Rockville Pike, Bethesda MD, 20894 USA. The adult obesity rate exceeds 40%; the highest ever recorded.
COVID-19 related food insecurity puts more Americans at risk for obesity or worsening obesity. Demographic trends and people's living conditions have a major impact on their ability to maintain a healthy weight. Policy solutions include increasing access to nutrition support programmes and creating more opportunities for people to be physically active. Childhood obesity rates are also on the rise, with the latest data showing that 19.3 per cent of US youth aged 2-19 are at a healthy weight.
Young people aged 2-19 are obese. In the mid-1970s, 5.5 per cent of young people were obese. Being overweight or obese in youth increases the risk of obesity and the associated health risks in adulthood. In addition, children show an earlier onset of what was previously considered an adult disease, such as hypertension and high cholesterol.
In general, the data show that the more a person earns, the less likely they are to become obese. People with less education are also more likely to be obese. Rural communities have higher rates of obesity and severe obesity than suburban and metropolitan areas. Socio-economic factors, such as poverty and discrimination, have contributed to increased rates of obesity among certain racial and ethnic populations.
Black adults have the highest level of adult obesity nationally at 49.6%; this rate is largely due to an adult obesity rate among black women of 56.9%. Latino adults have an obesity rate of 44.8%. White adults have an obesity rate of 42.2%. Asian adults have an obesity rate of 17.4%.
The State of Obesity Report series has been funded by the Robert Wood Johnson Foundation. The views expressed in this report do not necessarily reflect the views of the Foundation. Subscribe to the Wellness and Prevention Digest Stay connected with the latest news and events in public health and TFAH. Rates of US adults with obesity have continued to rise over the past decade, according to researchers at the Centers for Disease Control and Prevention (CDC).
Obesity has serious health consequences, including increased risk of type 2 diabetes, high blood pressure, stroke and many types of cancer. In addition, a 12-week small change telephone intervention was evaluated in sedentary obese veterans. Obesity increased during the coronavirus pandemic, as stressed Americans lost their jobs, changed their eating habits, reduced their physical activity and had higher rates of food insecurity, said Nadine Gracia, CEO of the Trust for America's Health. The finding that minorities and low-income people are disproportionately affected by obesity is not surprising.
The adult obesity rate stands at 42.4%, the first time the national rate has surpassed the 40% mark, and further evidence of the nation's obesity crisis.
