Want another reason to control your weight? How about the fact that a healthy body weight helps prevent the development of certain cancers? Information from the World Cancer Research Fund (WCRF) indicates that cancers of the breast, bowel, kidney, pancreas, and esophagus have been linked to obesity. Professor Martin Wiseman, an adviser to the WCRF indicates that a “big dent” would be made in the incidence of cancers if everyone maintained a Body Mass Index (BMI) under 25. The classification for a healthy BMI is between 18.5 and 24.9. Values between 25 and 29.9 are classified as overweight, while a BMI greater than 30 is considered obese. Many are well aware of the limitations of using solely BMI to classify obesity due to the fact that very muscular individuals will have high BMIs although they may be considered very physically fit. However, just looking at BMI, there is very intriguing data. Scientists estimate that an individual at the top of the healthy range is 15% less likely to develop bowel cancer than someone at the bottom of the healthy range. They approximate that nearly 33% of the most common cancers could be prevented with regular physical activity and the maintenance of a healthy body weight. One obstacle still remains – education. A recent survey showed that nearly 40% were still unaware that excess body fat was associated with an increased risk of cancer development. As fitness professionals, it is important to educate clients about the risks of unhealthy lifestyle behaviors and the risks associated with unnecessary weight gain. (World Cancer Research Fund, 2009).