African American women and the obesity epidemic: a systematic review.

Author:Knox-Kazimierczuk, Francoise

The incidence of obesity in the U.S. has sparked a national conversation about how best to address this health crisis. In 2014, the National Institutes of Health (NIH) spent $857 million on obesity research (, accessed April 22, 2015). Despite investment in obesity research, rates remain high and among African Americans the prevalence of obesity is disproportionate (, accessed May 4, 2015). For African American women the obesity rate is staggering, and as such should be given substantial consideration. However, the research literature does not provide adequate attention to this issue with several literature reviews indicating a low number of studies conducted to examine African American women and obesity (Tussing-Humphreys, Fitzgibbon, Kong, & Odoms-Young, 2013). This study was undertaken to examine the current body of literature and to expand upon the knowledge through an interpretive framework situated in critical black feminism.

Obesity Prevalence. The prevalence of overweight and obesity among the U.S. population has increased dramatically since the 1970s. According to the Centers for Disease Control and Prevention (CDC), the rate of obesity among adults has doubled to 33.9% since 1980 to 2008 (Flegal et. al. 2010; Ogden, 2006). National Health and Nutrition Examination Survey (NHANES) data from 2009-2010 shows the obesity rate remains elevated with 36.0% of the population being obese (Fryar , Carroll, & Ogden, 2012). Data during this same time period shows similar obesity trends among racial/ethnic minorities. African American women during 2009-2010 showed a significant linear increase in obesity, with 58.5% of African American women being more likely to be obese than any other racial/ethnic group (Fryar et al., 2012).

Obesity Consequences. Obesity poses a number of significant problems, affecting the physical, mental, and financial health of the individual. Research indicates a correlation between weight, diabetes, and heart disease, with greater than 80% of overweight individuals suffering from type 2 diabetes (CDC, 2009). Overweight adults are at an increased risk for developing hypertension, type 2 diabetes, and orthopedic complications; and the incidence of hypertension in overweight adults is greater than the incidence in their non-overweight counterparts (Diaz, 2002). NHANES data shows a linear relationship between BMI and blood pressure with systolic blood pressure increasing 1 mmHg for every gain in BMI of 1.7kg/m2 and 1.25kg/m2 among men and women, respectively (Aneja, El-Atat, McFalane, & Sowers, 2004; Redon, 2001). Likewise, diabetes exhibits a linear relationship with obesity and has increased by 61% since 1990 (Mokdad, Ford, Bowman, Dietz, Vinicor, Bales, & Marks, 2003).

This trend of increased obesity, diabetes, and cardiovascular disease is nowhere more evident than in the African American community. National Health Interview Survey (NHIS) data indicates the majority of African Americans age 18 and over are overweight and/or obese, with African American women representing the most obese population in the U.S. today (CDC, 2009). African Americans are 2.5 times more likely to develop and die from complications of diabetes related to end stage renal disease (ESRD) than Caucasians (Karter et. al., 2002). Data has shown deterioration in health for African Americans in certain disease categories and a widening in standardized mortality rates (SMRs).

Obesity Etiology. The contributors to obesity are not entirely clear (Lahti-Koski, Pietinen, Heliovaara, & Vartiainen, 2002). Many of the factors that affect obesity are modifiable, including inactivity, dietary habits, the built environment, and socioeconomic status. Inactivity, dietary habits, and environmental conditions have received a great deal of attention in public health research, as these factors seem to be the most directly linked to obesity. Additionally, these three factors can be addressed at multiple levels through policy changes.

The activity level of an individual may play a large role in his/her predisposition to obesity. Westerterp (1999) reported a correlation between physical activity level (PAL) and body fatness, reporting a reduction in fat mass with increases in PAL for women and men. Work, school, and home life require limited energy expenditure, with most individuals sitting the vast majority of the day. Technological advances have mechanized much of the work force removing the physical labor that once dominated jobs. Additionally, schools have removed recess and physical education and home life is spent in front of a computer or television. Evidence supports the link between increased screen time and elevated BMI (Parsons, 2008). Investigators have hypothesized television viewing promotes an increased chance for obesity by one or more of three mechanisms: (1) displacement of physical activity, (2) increased calorie consumption while watching or caused by the effects of advertising, and (3) reduced resting metabolism (Robinson, 2001). Data from the 2000 Behavioral Risk Factor Surveillance Survey (BRFSS) found that 28.2% of Americans did not engage in regular physical activity and 27% did not participate in any leisure-time physical activities (Mokdad, Bowman, Ford, Vinicor, Marks, & Koplan, 2001). In 1999, the Surgeon General's report on Physical Activity and Health reported similar low rates of physical activity. Data from the National Health Interview Survey (NHIS) along with BRFSS showed approximately 22% of U.S. adults engaged in regular sustained activity, which is defined as rhythmic muscular movement for at least 30 minutes 5 days or more per week (Surgeon General, 1999).

There is a growing trend among Americans concerning their dietary habits. Despite the Surgeon General's endorsement for eating more fruits and vegetables, most Americans are consuming a record number of high fat, high sugar processed foods (Subar, 1992). Data suggest Americans are eating more high fat foods and less fruits, vegetables, and whole grains than recommended for good health. NHANES data from 1999-2002 found 62% and 75% of adults did not consume a whole fruit serving or fruit juice respectively. It is estimated that 29% of Americans consumed at least 2 servings of fruit per day meeting the United States Department of Agriculture (USDA) recommendations. NHANES and NHANES III data revealed a reduction in the consumption of vegetables between 1988-1994 and 1999-2002 (Casagrande, Wang, Anderson, & Gary, 2007). Approximately 27% U.S. adults met the recommendations of 3 vegetable servings per day, and only 11% of the population met the USDA guidelines for combined fruit and vegetable intake of 2 servings of fruit and 3 servings of vegetables per day (fried potatoes excluded) (Casagrande et. al., 2007).

More alarming than the inadequate intake of fruits and vegetables is the rise in fast food and sugary beverage consumption. Nutrient dense foods such as fruits, vegetables, and whole grains have been displaced in the American diet by high fat and/or refined carbohydrate nutrient depleted foods. French (2000) cited a 200% increase in the number of fast food sales from 1977 to 1995 along with a 150% increase in food consumption from other sources outside the home. On average, it is estimated that close to half of the American diet is from fast food outlets (Paeratakul, Ferdinand, Champagne, Ryan, & Bray, 2003). The Continuing Survey of Food Intakes by Individuals (CSFII) indicates fast food consumption is associated with higher intakes of fried potatoes, high sugar beverages, refined carbohydrates, high saturated fats, and trans-fat. The USDA's Economic Research Service (ERS) found a 39% increase in refined sugar consumption from 1950-2000. Sodas accounted for approximately 22% of the refined sugars in the American diet in 2000 (USDA, 2002). Additionally, greater energy availability by 15% in the U.S. food supply has been linked to increased caloric intake by Americans (Binkley, Eales, & Jekanowski, 2000). Positive energy balance related to overconsumption or decrease in activity level has been shown to lead to increases in weight (Binkley et. al., 2000).

Beginning in 1980, the Dietary Guidelines for Americans were issued to provide nutrition and physical activity recommendations to prevent chronic diseases. The guidelines were developed jointly by the Departments of Agriculture (USDA) and Health and Human Services (HHS) and are reissued every five years. Current recommendations focus on weight management, foods to reduce, foods to increase, and building healthy eating patterns. For the reduction and prevention of weight gain the USDA recommends overweight individuals reduce caloric intake and increase caloric output. Individuals with a BMI between 18.5-24.9 kg/m2 should aim for weight maintenance through balancing energy intake and output. Specific guidelines from HHS encourage at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic physical activity on at least 3 days during the week. Moderate to vigorous-intensity muscular strength exercises performed at least 2 days a week is also recommended for weight management (USDA, 2010).

Although the USDA and HHS have been providing recommendations for the last three decades, American dietary and physical activity habits have shown little improvement. Combined consumption of fruits and vegetables has remained at approximately 11%. American intake of dietary sodium, cholesterol, and fat all fail to meet USDA recommendations. On average, Americans consume 3400 mg of sodium, 350 mg of cholesterol, and 19% of saturated fat daily (USDA, 2010). Added sugars pose yet another threat to the health of Americans, contributing an estimated 16% of calories to the American diet. The primary source of added sugar in the diet is derived from sodas, energy drinks, sports drinks, and fruit juice; which collectively supplies...

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