The argument that obesity is correlated with poverty is one that is quite persistent in the popular literature and also the in the scientific research (e.g., Drewnowski, 2004; Pollan, 2006). To say that one thing is correlated with another should not be interpreted as meaning that one thing leads to another or that it causes another thing. Yet writers like Pollan do this very thing. The actual relationship of obesity to income level or poverty turns out to be a lot more complex than writers like Pollan take the time to consider. In fact, the relationship of obesity to poverty is in actuality almost nil. It is the writings of such individuals that skew the issues and simplify them that lead to such misinterpretations.
This is not to imply that obesity is not a serious issue. There has been a dramatic rise in obesity rates in the United States over the last decade. For instance, the Center for Disease Control (CDC) recently estimated that 65% of adults in the United States are either obese or overweight (CDC, 2004a). The terms obese or overweight are not judgment calls but have been defined by accepted medical standards using the measurement of Body Mass Index (BMI). The BMI is a ratio measurement using a person's weight in kilograms (kg) to the square of their height in kilograms (kg). Thus, a person with a BMI between 25 and 30 kg/m2 is overweight, whereas a person with a BMI greater than 30 kg/m2 is obese (National Institute of Health [NIH], 2004). Moreover, the World Health Organization (WHO) has divided obesity into different classes. Class I obesity is defined by a BMI of 30.0 -- 34.9; class II obesity defied by a BMI of 35.0 -- 39.9 and; class III obesity defined by a BMI of greater than or equal to 40.0 (NIH, 2004). It is important to understand that that even though BMI is strongly correlated with the ratio or amount of body fat a person has the BMI index is not a direct measure a person's body fat. For instance, certain people such as bodybuilders or other athletes could have a BMI index that would identify them as overweight or obese even though they have low ratios of excess body fat. Nonetheless the BMI index is the index most often used to determine rates of obesity and is utilized in nearly every study on obesity in the United States.
Several different agencies, including government sponsored agencies, have investigated the prevalence an incidence of obesity in the United States. The National Health and Nutrition Examination Survey (NHANES) is a program of studies put together by the CDC. These studies are designed to measure the health and the nutritional standing of adults and children in the United States. The surveys are unique in as they combine both interviews with people as well as physical examinations to derive their results. National data collected during the years 1999-2002 indicated that one adult in three had a BMI of 30 or higher. Comparing this figure to previous data collected in 1994 (23% of adults in 1994 with a BMI of greater than 30) the results indicate a trend of rising obesity (Flegal, Carroll, Ogden, & Curtin, 2010). One of the findings concerning this trend that is most disturbing is the rise of obesity in children and adolescents. The percentage of overweight children and adolescents between the ages of six and nineteen year of age has tripled since 1980 (CDC, 2004b). This consistent increase in obesity among young people is of special concern due to the consistent finding that overweight children and adolescents are much more likely to grow up to become overweight adults. The risk of contracting serious health problems is significantly higher in overweight children and adults (CDC, 2004a).
The causes of obesity have been investigated and include (NIH, 2004):
1. Genetic factors, the research indicates that obesity tends to run in families.
2. Environmental factors that include lifestyle as well as behaviors like eating patterns and the amount of physical activity a person engages in.
3. Psychological factors such as the tendency for some people to eat in response to their emotion states such as eating when bored, stressed, or feeling depressed.
4. Certain physical factors such as symptoms of medical conditions (e.g., hyperthyroidism) or the results of aging.
Notice that income level does not appear in the NIH conclusions. The effects of the rise in obesity in this country are just beginning to present themselves and they will continue to worsen. The cost of the effects of obesity in the United States is well over $100 billion (NIH, 2004). Dietary factors have been associated with at least four of the ten leading causes of death in the United States. In addition, people that are obese may experience significant emotional and psychological issues as well as suffering from discrimination and prejudice.
For practical purposes this paper will discussing the environmental factors such as SES, food access, and food choices that lead to obesity. If we consider the above causal factors we would have to conclude that environmental factors are the most important factors that contribute to the dramatic rise in the prevalence of obesity over the last decade. Specifically, increased food consumption or the consumption of the certain types of food over others are the two key factors that explain the rise in obesity (Block, Scribner, & DeSalvo, 2004; Bray, 2004).
There is research to indicate that a good number of health disparities in the United States can be linked to differences in socioeconomic status (SES). There have been a number of studies done in different industrialized countries that have found a relationship between household income and quality of diet (Drewnowski, 2004; Pollan, 2006). These studies suggest that obesity in America to a great extent is an economic or class issue. Most of these studies indicate that the highest rate of obesity in the United States occurs among communities with the least education and highest poverty rates. Even though the rates of obesity have been steadily rising among both genders, across all levels of income, and across ethnic group and age, the burden of the effects of obesity remains unequivocally the highest among those in the lowest-income brackets according to many (Drewnowski, 2004; Pollan, 2006). However, when comments like these are considered no one considers the exact nature of the relationship between income level and obesity.
Studies of this nature are correlational in type. The insinuation from these authors is that being in a lower income bracket is a cause of obesity and this type of inference needs to be questioned. Being poor makes you fat? Does that make conceptual sense at all? Moreover, correlational studies examine the relationships or associations between different variables and do not explain cause and effect relation (Nunnally & Bernstein, 1994). This is a common error that even sophisticated researchers make. Yet as mentioned above as there has been a great body of research conducted linking income levels with obesity in the United States and there have been some interesting proposals for explaining these links.
One recent popular theory to explain the relationship between income level and poverty is the notion of food insecurity. Food insecurity is relatively recent in the public health literature. The concept is related to yet distinct from mere hunger concerns. Food insecurity is defined as a limited access or an uncertain availability of certain nutritionally acceptable foods (Drewnowski, 2004). The theory goes on to state that people in lower income brackets have an inability or describe and incapacity to access healthy nutritional foods, particularly foods such as fresh fruit and vegetables. In addition, groups who suffer from are or prone to food insecurity are therefore more likely to be overweight or suffer from obesity. Of course the notion of food insecurity is a little vague, because there is no research that links income level to an actual lack of access to fruits and vegetables. However, there has been some research to indicate that certain lower SES groups are more likely to consume energy dense food that is composed of refined grains, white sugars, and high levels of fats as these foods are often seen as a bargain in price (e.g., see (Drewnowski, 2004. However, these studies also indicate that it is actually lest costly to buy fresh foods compared to fast food. Accessibility is an issue for many and there have been several studies indicating that low-income neighborhoods have as many as six more fast food restaurants than higher income families (e.g., see Block, Scribner, & DeSalvo, 2004). However, this does not implicate poverty as a potential cause for obesity, but instead indicates that personal choice in food consumption may be a significant contributing factor to obesity. Income level might be a mediating factor in which groups demonstrate higher levels of obesity,…