Can Body Mass Index Effectively Determine Need For Weight Loss?
Posted Aug 24 2008 9:46pm
As we know, excess body fat is a risk factor for many health issues such as heart disease, hypertension, diabetes, etc. Body Mass Index ( BMI ) has been used to determine whether one is overweight or obese. However, health experts have raised concerns that BMI may not be accurate enough to identify such health risks.
A recent study, conducted by researchers from the University of Pavia in Italy, has reported in the Nutrition Journal that measuring body fat instead of BMI appears to be more accurately identify people who need lifestyle interventions to lose weight.
Why is this so? According to the researchers, the use of BMI alone could not differentiate between fat mass and fat-free mass, nor reflect the fat mass distribution.
In the study, 23 men and 40 women, aged 20 to 65, were recruited to undergo body composition analysis in the Human Nutrition and Eating Disorders Research Centre at the University. These volunteers were healthy but had sedentary lifestyle and were not following a low-calorie diet.
The BMI as well as body-fat measurements including waist circumference and total percent body fat were obtained for each person. In fact, a measurement similar to BMI , known as Body Fat Mass Index ( BFMI ), was calculated by the researchers to identify fat mass.
Based on BMI calculations, there were 11 percent of the group needed strong recommendations and 41 percent needed basic recommendations to lose weight. The calculations of waist measurements indicated that about 25 percent would require strong recommendations to cut down the weight whereas 36 percent would require basic weight loss recommendations.
On the other hand, figures from total percent body fat measurements showed that there were 29 percent and 48 percent would require strong and basic recommendations to lose weight, while figures from BFMI showed that 21 percent and 54 percent would receive the similar recommendations.
The results clearly showed that a greater percentage of the study population would receive recommendations for weight loss using criteria based on fatness rather than body weight. The researchers felt that studies that focus on changes in body fat among larger groups of people recommended for lifestyle change might better identify which body fat index is most clinically relevant.