The sharply increasing occurrence of obesity has attracted the attention of the World Health Organization, which has issued a statement concerning this matter. Obesity is associated with various disease states such as hypertension, hypercholesterolemia, and diabetes. Body fat is also connected with higher mortality rate. Weight loss decreases cardiovascular disease risk and makes insulin sensitivity better. Weight loss practices and techniques with an emphasis on fat loss have become very common, and the necessity of precise measurements for the evaluation of body composition is essential. There are several methods to evaluate body composition. Whereas some of them are more precise than others, the cost of more accurate methods is not always reasonable. Hence, it is relevant to evaluate the validity of cheaper techniques. There is few studies comparing body composition methods over a period of weight loss. The crucial aim of this research was to evaluate body composition by three different methods, DXA, bioelectrical impedance analysis (BIA), and ADP, before and after a six-month weight loss program. The scientists used both conventional bioelectrical impedance machines and the Tanita body fat analyzer.
Fifty-six healthy but overweight participants, thirty four women and twenty two men (age, 52 [+ or -] 8.6 years; weight, 92.2 [+ or -] 11.6 kg; body mass inside (BMI), 33.3 [+ or -] 2.9 kg/[m.sup.2]) were examined in an outpatient setting before and after six months of weight loss (weight loss, 5.6 [+ or -] 5.5 kg). Subjects were expelled if they had initiated a new medication therapy within thirty days of randomization, participated in a weight loss program, or took a weight loss medication within ninety days of randomization. Subjects were randomly chosen either to a self-help program, consisting of two 20-minute sessions with a nutritionist and provision of printed materials and other self-help aids, or to participation in meetings of a commercial program (Weight Watchers). Body composition was scrutinized by each of the methods before and after weight loss.
BIA (42.4 [+ or -] 5.8%) underestimated percentage fat, while the BodPod overestimated percentage fat in comparison with DXA (46.1 [+ or -] 7.9%) before weight loss. Tanita and tetrapolar BIA overestimated FFM before weight loss, while BodPod underestimated FFM. BIA as well as ADP are precise in comparison with DXA when evaluating body composition. However, these findings, together with previous research comprising athletes and leaner individuals, suggest that these methods can be less trustworthy with increasing body fat, which may have to do with hydration status. Generally, the correlation coefficients between each of the methods for body composition in comparison with DXA were very high. Additionally, every methods was sensitive enough to detect alterations with weight loss. Brozek was a bit more precise in anticipating changes with weight loss in comparison with Siri. BIA using the hand/foot method was also more precise than the Tanita scale method. Nevertheless, it would not be advantageous to use these methods interchangeably to identify body compositional changes over weight loss.
