According to the National Health and Nutrition Examination Survey from 2007-2008, 68% of adults in the U.S. are overweight or obese and 17% of children (2-19 years old) are obese. This has serious implications for long-term and chronic illnesses. For example, cancers of the esophagus, pancreas, colon, breast, endometrium, kidney, thyroid and gallbladder are all associated with obesity. It was estimated that about 4% of new cancer cases in men and 7% of new cancer cases in women were related to obesity.
This increased risk of has been attributed to a few possible mechanisms. Fat tissue produces higher amounts of estrogen, which can increase the risk of breast and endometrial cancer. The increased levels of insulin in the blood may promote the growth of tumors. Obese people often have chronic low-level inflammation, which has also been associated with increased cancer risk.
Studies by the NIH on weight loss and its impact on health found that losing weight reduces the risk of developing chronic diseases and cardiovascular disease. Patients who underwent bariatric surgery to lose weight have shown lower rates of obesity-related cancers than obese adults that did not undergo the surgery. 
Western diets that are high in fat or refined sugars have induced oxidative stress, or damage to tissues and cells, which can lead to cancer and other diseases. Diets that are high in whole grains, fruits and vegetables contain antioxidants and can reduce oxidative stress.
Studies on the food consumption habits of children and adolescents (ages 2-19) from 1997 found that 16% of children did not meet any of the food recommendations laid out by the USDA Food Pyramid. Only 36% of children met the daily vegetable requirements. Children in poverty and certain ethnic groups were less likely to meet the daily requirements than those children from other groups. To improve the health of children and reduce the possibility for future health issues (coronary heart disease, cancer, stroke, diabetes), it is necessary to encourage children to consume more fruit, vegetables and grains. 
The number of obese and overweight children has been increasing over the past 30 years and this trend is likely to continue. Obese children that do not decrease their body mass index (BMI) into adulthood are at an increased risk for certain health problems, including Type 2 diabetes, hypertension and cardiovascular disease.
Improving access to healthy foods and encouraging the consumption of fruits and vegetables is critical to dealing with this health epidemic. Environmental, behavioral and social factors all impact the prevalence of obesity.
As mentioned earlier, there is a strong correlation between poverty and poor nutrition. One potential solution for low-income areas that could be considered “food deserts” would be urban gardens. However, an issue with urban agriculture is the fact that urban soils may be contaminated. Bringing in clean soil from elsewhere can be costly and other methods of remediation may also be expensive or time consuming. It is still important to address these health issues and develop alternative remediation techniques.
While soil management research is extensive at the field level, less research has been conducted in emerging urban community gardens. Urban soils often have higher heavy metal concentrations due to contaminated industrial sites and vehicle exhaust . It is important that urban gardens can be established to provide fresh, healthy foods to combat food deserts and imbalanced diets, while also ensuring that crops are not grown in contaminated soils. Thus, more research into urban soil health is necessary.
Greenleaf Communities strives to create a healthy and sustainable world, with particular emphasis on improved human nutrition through sustainable agricultural practices. Greenleaf has experience with applied soil management research and partners with leading soil scientists. Additionally, Greenleaf partners with top health and nutrition experts to tackle environmental health problems.
 Munoz et al, 1997
 Turner, 2009
 Hughes et al, 2011
Hughes, M. F., Beck, B. D., Chen, Y., Lewis, A. S., & Thomas, D. J. (2011). Arsenic exposure and toxicology: a historical perspective. Toxicological Sciences, 123(2), 305-332.
Munoz, K. A., & Krebs-Smith, S. M. (1997). Food intakes of US children and adolescents compared with recommendations. Pediatrics, 100(3), 323.
National Institutes of Health, National Cancer Institute. (2012). Obesity and cancer risk. http://www.cancer.gov/cancertopics/factsheet/Risk/obesity
Turner, A. H. (2009). Urban agriculture and soil contamination: an introduction to urban gardening. Practice Guide, 25.