Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health. A crude population measure of obesity is the body mass index (BMI). A person with a BMI of 30 or more is generally considered obese. A person with a BMI equal to or more than 25 is considered overweight.
The World Health Organization (WHO) defines "Overweight" as a BMI equal to or more than 25, and "Obesity" as a BMI equal to or more than 30. These cut-off points provide a benchmark for individual assessment, but there is evidence that risk of chronic disease in populations increases progressively from a BMI of 21.
Overweight and obesity are major risk factors for a number of chronic diseases, including diabetes, cardiovascular diseases and cancer. Obesity and overweight were considered a problem only in high income countries earlier, but they are now dramatically on the rise in low- and middle-income countries, particularly in urban settings. The risk of health problems starts when the person is very slightly overweight, and that the likelihood of problems increases as he becomes more and more overweight. Many of these conditions cause long-term suffering for individuals and families. In addition, the costs for the health care system can be extremely high.
In the western world, non-communicable diseases constitute the largest burden on public health costs, and diet is one of the factors in their development. Specifically, overweight and obesity and the associated poor health prognoses are the major public health concerns of the moment. However, the underlying causes including the role of certain foods in the diet and other lifestyle factors are still subject to considerable debate.Overview of the lecture
The seminar mainly focused on the issues like impact of the global epidemic of obesity, specific outcomes of obesity, target of actions to be taken to prevent obesity, decision frameworks to be considered and finally important conclusions and implications of the topic.
The shifting distribution of BMI of five population groups of men and women aged 20-59 years derived from 52 surveys in 32 countries as shown in the report of WHO consultation in 1997 shows that when a graph is plotted against BMI and probability density, there is an increase in the BMI with increase in the probability density,
The global prevalence of obesity in adult females in different parts of the world shows that, some parts of North America, some population areas in Eastern Mediterranean and South east Asia and Pacific regions has high intensity of obese people than the other populations of the world. Surprisingly developing countries also had their share in obese population. On one side the male population of North America has the highest prevalence of obesity.
The data on the prevalence of overweight in girls prior to 1990 has a very less distribution around the world except for few parts of North America but, there is a drastic change in the situation between 2000- 2006. Many parts of the North America and few parts of Europe and Australia has high percentages of overweight girls between 25%- > 30%. Asia has 10%-19.9% of overweight girls which is comparatively lower than the other regions of the world. The incidence of overweight in boys prior to 1990 was just 10%-14.9% these results are almost same as that of girls, surprisingly by 2000-2006 the distribution of boys with overweight around the world as shown in North America with >30% of overweight, Australia takes the second place with 25-29.9% and the Russian federation has 10-14.9% boys overweight.
As obesity is the main cause of many diseases in many countries like Cardiovascular diseases, Diabetes, cancers and so on. Diabetes is one of the wide spread non-communicable disease which is increasing with the prevalence of obesity in all the continents of the world especially above mentioned. Astonishingly developing countries are also under this roof where, India tops the list with highest number of diabetic people, followed by china, USA, Indonesia, Japan, Pakistan, Russia, brazil, Italy, Bangladesh. The number of people with diabetes in India until 2000 was 31.7 millions but this number is going to increase by 79.4 millions by the year 2030.
As per the survey of the National Center for Health Statistics 2007, which suggests that since 1960's average weights of men and women have increased by approximately 11kg and the average height has increased by 2.5 cm this portrays the present situation of increased obesity in the western world. The projected increase in adult obesity, if the current trend continues with BMI > 30 in men and women after 20 years of age will lead to a increased progression in the number of obese people irrespective of the economic status of the countries.
The weight related outcomes are related to average population, where BMI will increase leading to prevalence of obesity in adults and children which will guide to increased body fatness and other obesity related risk factors and finally diseases prevails in these population groups with decrease in child growth trajectories.
With special reference to targets for action, people with same behaviors but from different environment. The present targets of action are how do we enable people to respond differently to the present situation of increasing prevalence of obesity, how can we improve the environment to curb excess weight gain or enable weight loss and how has the environment changed the population to attain the present situation. All these should be targeted to reduce the risk prevalence at least to save the future generations.
In the causal model of societal processes which influences the population prevalence of obesity in various levels, At population level obesity is the prevailing factor, at the individual level energy expenditure and food intake with nutrient density influence the individual, at work/ school/ home level the activities, type of work and place of work/school and food activity are influencing factors with respect to the community the transport systems, health care, infrastructure and sanitation has their own mark in the causal model, at national level transport, urbanization, health, social security, cultural factors, food and nutrition and finally the education on the food are the relative factors for obesity occurrence, finally at the international level globalization of the markets, development and advertising are the influencing factors in this context. All the factors mentioned above either directly or indirectly has a relation at each level and also within.
The main consideration for obesity control is maintaining a balance between energy intake and energy expenditure, people should be educated to maintain their food intake in this context. Individual traits should also be encouraged to consume healthy diets that hinder the obesity prevalence. There are many factors at the individual level, family level, community level and at the macro level which influences people to take energy rich foods. These factors have a broad context like age, genetic factors, feeding practices knowledge on food intake, advertising and other broader context problems. The policies developed operate only at the outer two levels as in macro level and community level, these policies are not much effective on the inner rings which are considered to be the main culprits.
The target group of people should be educated on the ill effects of obesity and the future selective groups should be made aware of the facts. The risk factors where the population is under concern is with respect to the co existence with under nutrition where stunted obesity and gestational imprinting of chronic diseases may be a consequence.
The special target groups like the high and middle income groups, pregnant women and postpartum women are to be educated prior, as maternal health is very important consideration. The interventions planned should be mainly focused on the individual eating behaviors, there should be much more research to be done in this field to come up with new interventions to educate the population. The expanded knowledge domains may be extended to cultural and psychosocial processes, historical and social contexts, physical and economic environments and finally to the biology- behavior interactions. There is no evidence to what extent these interventions reach effectively to the individual and this is the biggest puzzle.
Literature reviewFacts of obesity
"Globally, there are more than 1 billion overweight adults, at least 300 million of them obese. Obesity and overweight pose a major risk for chronic diseases, including type 2 diabetes, cardiovascular disease, hypertension and stroke, and certain forms of cancer. The key causes are increased consumption of energy-dense foods high in saturated fats and sugars, and reduced physical activity."The report of American heart association
On the basis of 2003-06 data from NHANES (NCHS), the prevalence of overweight and obesity in children 2-5 years of age, based on BMI-for-age at or above the 85th percentile of the 2000 CDC growth charts, was 25.4 percent for non-Hispanic white boys and 20.9 percent for non-Hispanic white girls; for non-Hispanic black boys it was 23.2 percent and for non-Hispanic black girls it was 26.4 percent.
In children 6-11 years of age, the prevalence was 31.7 percent for non-Hispanic white boys and 31.5 percent for non-Hispanic white girls; for non-Hispanic black boys it was 33.8 percent and for non-Hispanic black girls it was 40.1 percent.
In children 12-19 years of age, the prevalence was 34.5 percent for non-Hispanic white boys and 31.7 percent for non-Hispanic white girls; for non-Hispanic black boys it was 32.1 percent for non-Hispanic black girls it was 44.5 percent.Speech given by Prof. Shiriki Kumanyika, Ph.D., R.D., M.P.H.,
"Almost all of our current eating or activity patterns are those that promote weight gain using the least possible amount of energy or maximizing quantity rather than quality in terms of food," said Shiriki Kumanyika, Ph.D., R.D., M.P.H., chair of the working group that wrote the statement. "People haven't just made the decision to eat more and move less; the social structure has played into people's tendencies to go for convenience foods and labor-saving devices."Critical assessment
Obesity has reached epidemic proportions globally, with more than 1 billion adults overweight at least 300 million of them clinically obese and is a major contributor to the global burden of chronic disease and disability. Often coexisting in developing countries with under-nutrition, there is a shift towards over-consumption and sedentary lifestyles which occurred globally as other countries become increasingly westernized. obesity is a complex condition, with serious social and psychological dimensions, affecting virtually all ages and socioeconomic groups. Increased consumption of more energy-dense, nutrient poor foods with high levels of sugar and saturated fats, combined with reduced physical activity, have led to increase in obesity rates. Obesity epidemic is not restricted to industrialized societies; this increase is often faster in developing countries than in the developed world.
Advancements in nutrition, hygiene, and the control of infectious disease are being replaced in developing countries by new health threats such as obesity, cardiovascular disease, and diabetes. The health consequences range from increased risk of premature death, to serious chronic conditions that reduce the overall quality of life. Of especial concern is the increasing incidence of child obesity.
The rise in overweight and obesity can be attributed to an imbalance between calories consumed and calories expended or a shift away from healthful food and lifestyle choices. These have resulted from gradual changes in a complex set of social and environmental factors. Individuals have become less active in all areas of their lives. Work and free time have become much more sedentary. Food habits such as diet composition, increased eating away from the home, and larger portion sizes have also changed. There has also been a societal shift in the way communities are designed and built. Often, there is a lack of resources or foresight to design urban and suburban environments that encourage active lifestyles, such as sidewalks and walking paths. Areas that require more study are the impact of genetics and psychological factors on the development of obesity and overweight.
A comprehensive, population-based strategy is needed to reduce the alarming prevalence of obesity in the population in developed and developing countries, an approach that would complement individually-oriented strategies, including clinic-based prevention and treatment programs. A broad range of policy and environmental strategies (at the local, state and federal levels) can help people adopt healthy behaviors, such as being physically active and eating right.
"Almost all of our current eating or activity patterns are those that promote weight gain using the least possible amount of energy or maximizing quantity rather than quality in terms of food," said Shiriki Kumanyika, Ph.D., R.D., M.P.H., People haven't just made the decision to eat more and move less; the social structure has played into people's tendencies to go for convenience foods and labor-saving devices.
Preventing weight gain should be easier, socially acceptable and more rewarding for the average person, noting that passive, whole-population approaches through environmental and policy changes could increase opportunities for healthful eating and physical activity without requiring deliberate action by individuals, and can also help address inequalities. Its not talking about creating a dieting society, but looking at choices people make in day-to-day living that affect their ability to manage their weight and then trying to change the environment to facilitate healthier choices.
Modifying the environment to affect people's choices includes assessing the following areas to identify targets for change:
- Locations of fast-food restaurants
- Restaurant portion sizes
- Availability of high-fat, low-fiber foods and sweetened drinks
- Community design and infrastructure, which involves assessing land use mix and "walkability" of neighborhoods, including Adequate sidewalks and areas for physical activity
- Accessibility of jobs, schools, and recreation by walking or cycling
- Availability of public transportation.
Changes in these areas can eventually become 'normal' and displace the current 'normal' ways of doing things, Right now people should have to be pretty single-minded to make some of these choices, such as walking or riding a bike instead of driving. We advocate changes that will move the social norm to where physical activity is the custom. About 67 million American adults are obese, and an additional 75 million are overweight, according to the 2001-04 U.S. National Health and Nutrition Examination Survey (NHANES). About 4.2 million children 6-11 years old and 5.7 million adolescents (age 12-19) are also overweight.
A recent sign that recent public health efforts in raising awareness of childhood obesity are working. Regardless, childhood obesity must remain on the population health agenda for years to come. We need much more than a plateau. We need a reversal.
On the other side along with obesity the resulting problems like Diabetes Mellitus are increasing its prevalence in developed and developing countries where in India, there are as many as eighty percent of all diabetics from the entire world population concentrated there which makes India the diabetic capital of the world. The statistics show that the disease is not the one that affects only the rich population or a rich country, though it is most likely to affect those with a sedentary lifestyle and who consume diets that are mainly unhealthy.
Diabetes has emerged as a major healthcare problem in India. According to Diabetes Atlas published by the International Diabetes Federation (IDF), there were an estimated 40 million persons with diabetes in India in 2007 and this number is predicted to rise to almost 80 million people by 2025. The countries with the largest number of diabetic people will be India, China and USA by 2030. It is estimated that every fifth person with diabetes will be an Indian. Due to these sheer numbers, the economic burden due to diabetes in India is amongst the highest in the world. The real burden of the disease is however due to its associated complications which lead to increased morbidity and mortality. WHO estimates that mortality from diabetes, heart disease and stroke costs about $210 billion in India in the year 2005. Much of the heart disease and stroke in these estimates was linked to diabetes. WHO estimates that diabetes, heart disease and stroke together will cost about $ 333.6 billion over the next 10 years in India alone.
Rapid urbanization and industrialization have produced advancement on the social and economic front in developing countries such as India which have resulted in dramatic lifestyle changes leading to lifestyle related diseases. The transition from a traditional to modern lifestyle, consumption of diets rich in fat and calories combined with a high level of mental stress has compounded the problem further. There are several studies from various parts of India which reveal a rising trend in the prevalence of type II diabetes in the urban areas. A National Urban Survey in 2000 observed that the prevalence of diabetes in urban India in adults was 12.1 per cent per cent. Recent data has illustrated the impact of socio-economic transition occurring in rural India. The transition has occurred in the last 15 years and the prevalence has risen from 2.4 per cent to 6.4 per cent.
The Risk Factors for Diabetes in Indians Are:
- Family HistoryThe prevalence of diabetes increases with a family history of diabetes. The risk of a child developing diabetes with a parental history increases above 50 per cent. A high incidence of diabetes is seen among the first degree relatives. Indians have a high genetic risk for diabetes as observed in Asian Indians who have migrated to other countries. They have been found to have a higher rate of diabetes as compared to the local population .
- Central ObesityThe association of obesity with Type II Diabetes is well known. Even with an acceptable body weight range, weight gain could increase the risk of diabetes . An excess of body fat specially concentrated within the abdomen has an increased risk of diabetes. The cut-off limit for waist circumference for Indians have been recommended to be 90 cm for males and 80 cm for females. Abdominal obesity is defined by waist circumference above these limits.
- Physical Inactivity and Sedentary LivingThere is enough evidence to demonstrate that physical inactivity as a independent factor for the development of type II diabetes. The availability of motorized transport and a shift in occupations combined with the plethora of television programmes has reduced the physical activity in all groups of populations.
These three above mentioned factors are immediate causes of Diabetes Mellitis, these factors are also seen in the causal model of obesity. Accepting the fact that diabetes is related to obesity and overweight.
In India, the lack of proper healthcare infrastructure, rampant ignorance and absence of clear cut guidelines mean that approach to the management of diabetes is ad hoc. The lack of awareness among patients and General Practitioners (GPs) is a key factor in the poor care. There are practically no nurse educators or diabetic counselors, no podiatrists (foot experts) and very few dieticians to paln specific diets for such population groups, surprisingly most of the General Practitioners are not aware of the factors which cause diabetes, which means that the treating doctor has no support and has to take the entire burden of caring for these patients. The patients inability/unwillingness to pay for this additional support also hinders the treatment.reatment of obesity
The general goals for weight loss and weight management are the following:
- Reduce body weight;
- Maintain a lower body weight over the long term; and,
- Prevent further weight gain as a minimum goal.
Weight loss should be achieved at a safe and healthful rate of 1-2 pounds per week based on a reduction of 500 to 1,000 calories per day. Six months is a reasonable time period to achieve a 10 percent reduction in body weight. Effective weight management requires multiple techniques and strategies including diet, physical activity, behavior therapy, pharmacotherapy, and weight loss surgery.
Guidelines to selecting the appropriate treatments can be based on the degree of obesity as measured by BMI and the presence of comorbidities. Successful interventions for weight loss and maintenance may combine a low-calorie diet, increased physical activity, and behavior therapy. The addition of weight loss drugs may be useful in people who are not successful in losing the recommended one pound per week after six months. For people with clinically severe obesity (BMI >35 with comorbid conditions or a BMI >40) in whom other methods of treatment have failed, weight loss surgery, is an option.
Weight loss surgery involves restricting the size of the stomach or bypassing a portion of the intestines which cause weight loss by limiting the amount of food a person can consume in one meal and decreasing the proportion of nutrients absorbed from a meal, respectively. A substantial number of complications are associated with the procedure, although most of these are sometimes fatal to the health of the individual, instead consuming balanced nutritious food combined with sufficient physical activity will be a much better option.
On the other side at a broader context the implementation of these recommendations requires sustained political commitment and the collaboration of many stakeholders, public and private. Governments, international partners, civil society and nongovernmental organizations and the private sector have vital roles to play in shaping healthy environments and making healthier diet options affordable and easily accessible. This is especially important for the most vulnerable in society - the poor and children - who have limited choices about the food they eat and the environments in which they live.
Initiatives by the food industry to reduce the fat, sugar and salt content of processed foods and portion sizes, to increase introduction of innovative, healthy, and nutritious choices, and to review current marketing practices could accelerate health gains worldwide.Conclusion
'Overweight and obesity, as well as their related chronic diseases, are largely preventable.'
The good news is that overweight and obesity are largely preventable. The key to success is to achieve an energy balance between calories consumed on one hand, and calories used on the other hand.
To reach this goal, people can limit energy intake from total fats and shift fat consumption away from saturated fats to unsaturated fats; increase consumption of fruit and vegetables, as well as legumes, whole grains and nuts; and limit their intake of sugars. And to increase calories used, people can boost their levels of physical activity - to at least 30 minutes of regular, moderate-intensity activity on most days.
Effective weight management for individuals and groups at risk of developing obesity involves a range of long-term strategies. These include prevention, weight maintenance, management of co-morbidities and weight loss. They should be part of an integrated, multi-sectoral, population-based approach, which includes environmental support for healthy diets and regular physical activity.
Key elements include:
- Creating supportive population-based environments through public policies that promote the availability and accessibility of a variety of low-fat, high-fibre foods, and that provide opportunities for physical activity.
- Promoting healthy behaviors to encourage, motivate and enable individuals to lose weight by:
- eating more fruit and vegetables, as well as nuts and whole grains;
- engaging in daily moderate physical activity for at least 30 minutes;
- cutting the amount of fatty, sugary foods in the diet;
- moving from saturated animal-based fats to unsaturated vegetable-oil based fats.
- Mounting a clinical response to the existing burden of obesity and associated conditions through clinical programmes and staff training to ensure effective support for those affected to lose weight or avoid further weight gain.
The burden of weight increase can be achieved by improving the scientific basis of weight management from a public health perspective which can be a very effective weight management strategy. It focuses on the wider social, cultural and economic determinants of diet and lifestyle and the implications for public health, concurrently identifying gaps in scientific knowledge, across different demographic groups.
A significant added value to the obesity field by providing a sound scientific basis for harmonizing monitoring the treatment along with this raise awareness on the need for multi-sectoral collaboration, trained personnel are always important for any field to achieve maximum success rates, thus trained professionals in weight management treatments will be much useful to the general public.
- Power point presentation of Shiriki Kumanyika, Ph.D., R.D., M.P.H., at the Wageningen nutrition science forum 2009