Guidelines for Healthy Bodies
The National Institutes of Health have devised guidelines for four groups of adults, based on their body mass index (BMI). BMI is the ratio of weight (in kilograms) to height (in meters) squared, and it gives you a better measure of being overweight or obese than the number of pounds that register on your bathroom scale. Here are the guidelines for people who are 20 and over, based on BMI:
- Underweight: <18.5 BMI
- Healthy: 18.5 to 24.9 BMI
- Overweight: 25.0 to 29.9
- Obese: >30.0
If you are overweight or obese, your risk is higher than average for diabetes, high blood pressure, cardiovascular diseases, stroke, and some cancers, breast cancer included. In America, one-third of all adults and children are considered obese, and the problem is growing. Researchers have found that our love for high-fat, high-calorie foods and our avoidance of an active lifestyle are the main culprits.
Excess Weight Linked to Cancer Risk, Weight Loss Linked to Prevention
Research studies have shown that obesity increases your risk for these cancers:
- postmenopausal breast cancer
- colon cancer
- endometrial cancer
- kidney cancer
- esophageal cancer
- ovarian cancer
- gallbladder cancer
- pancreatic cancer
Relating Weight to Breast Cancer Risk and Menopausal Status
At some stages of life, a few extra pounds actually offer protection from breast cancer. A study published in February 2008 in Cancer Epidemiology Biomarkers & Prevention revealed that girls between the ages of 12 to 18 that were overweight had a lower than average risk of developing postmenopausal breast cancer during their lifetime. This protective effect was most noticeable for tumors that were estrogen-receptor positive and progesterone negative. The study took into consideration several risk factors, including family history of breast and ovarian cancer, hormone receptor status, and body weight at ages 12, 18, and their ages during the time of the study.
For women with no family history of breast cancer, extra weight before the years of menopause appears to reduce your risk of developing breast cancer. Once you enter menopause, shed those pounds to continue enjoying a lower risk. A study published in 2001 in Cancer Letters found that postmenopausal women who retained their extra weight had 1.5 times the risk of developing and dying from breast cancer, as compared to women of a healthy weight. Obese women have greater postmenopausal levels of estrogen than lean women. After menopause, your body is producing low levels of estrogen, and some of this hormone is produced in your fat (adipose) tissue. If you have excess body fat producing and releasing estrogen during and after menopause, you're exposed to higher levels of estrogen for a longer time. That increased exposure to estrogen increases your risk of breast cancer. In addition, being obese makes early detection more difficult. This makes it more common for fast-growing breast cancer being detected at a later stage. Losing weight during perimenopause and after reduces your lifetime exposure to estrogen and breast cancer.
