Overweight people are at a higher risk of developing cancer, evidence has shown. However, this risk can be reduced naturally by reducing body fat, through changing eating habits and increasing physical activity.
Being overweight or obese is generally caused when the intake of food energy exceeds the amount of energy being burned. Experts have concluded that the chief causes of obesity are a sedentary lifestyle and over consumption of high-calorie food . The intake of refined carbohydrates is a factor in the obesity epidemic.
It has been found that obesity and physical inactivity causes about 25-30 percent of several of the major cancers in the U.S, including colon, breast, endometrial, kidney, and esophageal cancers. Studies have also reported links between obesity and cancers of the gallbladder, ovaries, and pancreas . In a recent report, the relationship between body fat and 19 different cancers was highlighted by a panel of experts. Of the 19 cancers evaluated, 8 were linked to body fatness . Obesity is estimated to cause 14 percent of cancer deaths in men and 20 percent of cancer deaths in women.
Some possible reasons why excess body fat can cause problems are that it increases the amount of estrogen in the blood, exposing the female reproductive system to higher risk of cancer. It can also increase the risk of acid reflux that can cause esophagus cancer; and raise insulin levels, causing the body to create a hormone that causes cells to multiply.
Preventing weight gain can reduce the risk of contracted these cancers. Experts recommend that people establish habits of healthy eating and physical activity early in life to prevent overweight and obesity. Those who are already overweight or obese are advised to avoid additional weight gain, and to lose weight through a low-calorie diet and exercise. These studies show that even a weight loss of only 5 to 10 percent of total weight can provide health benefits. Some of the recommendations given are:
- Avoid sugary drinks.
- Limit or stop intake of processed fast foods.
- Limit or stop intake of refined carbohydrates
- Avoid intake of MSG (monosodium glutamate) in your diet (flavoring in many processed foods)
- Limit consumption of red meat and eat very little, if any processed meat.
- Strive to have a Body Mass Index (BMI) in the range of 21-23.
-  Vainio H, Bianchini F. IARC handbooks of cancer prevention. Volume 6: weight control and physical activity. Lyon, France: IARC Press, 2002.
-  Cancer Trends Progress Report - 2007 Update, National cancer Institute, NIH, DHHS, Bethesda, MD, December 2007.