BMI is defined as an individual’s weight in kilograms divided by the square of his or her height in meters (kg/m 2 ). BMI can be used to estimate a healthy body weight based on someone’s height. On average, underweight individuals have a BMI below 18.5; normal-weight people have a BMI between 18.5 and 24.9; overweight persons have a BMI between 25 and 29.9, and obese persons have a BMI equal to or greater than 30
If you are obese, the higher your BMI the greater your risk for developing conditions like “heart disease, osteoarthritis, cancer (in postmenopausal women), gallstones, high blood pressure, sleep apnea, and respiratory problems” to name a few. According to these NIH sites linked above: “An increased waist circumference also increases heart disease risk in people with BMIs in the ‘healthy’ range.” This tells me this is an important point when talking about BMI numbers in any age group. I’ll get back to that below . . .
The range of BMI for a Woman
The healthy BMI range for women is typically different from the ranges for men. The healthy weight range reflects how much you should weigh in order to live a full, active and happy life. Also, it is important that women understand that when we talk about BMI levels, we are talking about weights that will allow them to maintain their health throughout their entire life uninterrupted by illness and disease.
Please note: Although the exact numbers may vary depending on which online resource you reference, this article lists female “healthy” average weight values at 22% over bodyweight according to age groupings. Please keep in mind the following information is given as a general guideline only and may vary somewhat from resource to resource. In addition, because Body Mass Index (BMI) is not a factor in things like lean muscle vs. fat ratio, it should only be used as a rough reference point.
Average healthy BMI for a woman by age
AGE Average Healthy Weight Women 18-24 130 lbs 25-34 145 lbs 35-44 155 lbs 45+ 160 lbs
These healthy weight ranges for women are usually given in terms of Body Mass Index (BMI), a measurement that uses a mathematical formula that takes both a person’s height and weight into consideration.
The benefits of normal BMI for a woman
Normal BMI can reduce the incidence of cancer, heart disease, and strokes. This is because obesity raises insulin levels which in turn may increase estrogen levels. High estrogen levels are linked to cancers such as breast cancer, ovarian cancer, and endometrial cancer.
Normal weight may also reduce PMS and other menstrual irregularities, as well as headaches, sleep apnea, and asthma. Obesity can affect fertility by changing hormone levels, causing anovulation (not allowing the ovary to release an egg every month) or irregular periods. It also increases the risk of miscarriage and birth defects. The fetus is at higher risk for many problems when the mother is obese during pregnancy including stillbirths, premature births, low birth weight infants, and birth defects such as neural tube defects (spina bifida). Overweight mothers are more likely to need a cesarean section or instrumental vaginal delivery than normal-weight women.