Determining Body Mass Index via dividing weight expressed in pounds (lbs) with height expressed in inches (in) squared then multiplying by 703 (a conversion factor). Therefore, formula for BMI: weight (lb) / [height (in)]2 x 703 (Frankenfield et al. 4).Weight = 134 lbs, Height = 5'4" (64").Calculation: [134 ÷ (64)2] x 703 = 23.0. This BMI is categorized as normal weight.
Underweight refers to a body mass index below 18.5 or anyone who is 15-20 percent below his/her normal weight for height and age is categorized as underweight (Benforado 9). A body mass index between 25 and 29.9 is overweight and a body mass index equal to or greater than 30 is obesity (Benforado 9).
Underweight may be caused by many factors ranging from psychological to physical. Stress can cause loss of appetite and weight. Moreover, underweight can be as a result of wasting diseases like cancer, HIV/AIDS, hyperthyroidism, tuberculosis, and diabetes (Flegal et al. 10). The primary cause of overweight and obesity is an imbalance of energy between calories taken and calories used (Flegal et al. 11). Besides, increased consumption of energy dense foods which are high in fat, as well as, increased physical inactivity resulting from increasingly sedentary lifestyles can cause overweight and obesity.
The risks associated with underweight are malnourishment, compromised immune function, digestive diseases, respiratory diseases, osteoporosis, and cancer. Overweight and obesity are associated with cardiovascular diseases, some cancers, musculoskeletal disorders, type 2 diabetes, high blood pressure, stroke, gallbladder and liver diseases, osteoarthritis, respiratory problems, sleep apnea, and gynecological problems (Flegal et al. 12).
Some of the benefits of weight maintenance and weight loss include adjusting energy balance, reduction in risk factors associated with overweight and obesity. In addition, weight loss enhances lipid profile for high risk patients. Weight loss due to sickness may cause malnourishment and other diseases; however, weight loss due to physical exercise has no adverse health effects.
Benforado, Joseph M. Overweight and Underweight. Madison, Wisconsin: University of Wisconsin, 2008. Print.
Flegal, Katherine M., Barry I. Graubard, David F. Williamson, and Mitchell H. Gail. "Excess Deaths Associated With Underweight, Overweight, and Obesity." 2.1 (2010): 10-12. Print.
Frankenfield, David C., William A. Rowe, Robert N. Cooney, J. S. Smith, and Dolores Becker. "Limits of body mass index to detect obesity and predict body composition." Nutrition 3.1 (2011): 4. Print.