Body Mass Index

Body Mass Index (BMI) is calculated by dividing your weight in kilograms by your height in meters squared.  Being overweight increases the chances of serious health risks like heart disease, diabetes, and high blood pressure. But Body Mass Index is not a foolproof measurement. Though muscle tissue weighs more than fat tissue, BMI calculation doesn't recognize the difference between muscle and fat; an aggravating footnote for people who spend a lot of time at the gym. For those who lead more sedentary lives however, BMI can be a useful first indicator of general fitness.

Waist to Hip Ratio

A Waist to Hip Ratio (WHR) of 0.7 for women and 0.9 for men have been shown to correlate strongly with general health and fertility. Women within the 0.7 range have optimal levels of estrogen and are less susceptible to major diseases such as diabetes, cardiovascular disorders and ovarian cancers. Men with WHRs around 0.9, similarly, have been shown to be more healthy and fertile with less prostate cancer and testicular cancer.

One of the benefits of waist-hip ratio calculation is that it takes into account the differences in body structure. Hence, it is possible for two women (or men) to have vastly different body mass indices but the same waist-hip ratio, or to have the same body mass index but vastly different waist-hip ratios.