Variations in the assessment of the fat content of the human body due to experimental technique in measuring body density.

The body fat content of 15 adults, 6 females and 9 males, was estimated from body density. The body density of each individual was measured by weighing under water after (i) maximal expiration, (ii) moderate expiration, (iii) minimal expiration, (iv) moderate inspiration, (v) light meal, (vi) heavy meal, (vii) carbonated drink. Variations in the levels of expiration and inspiration caused only about 1% difference in the estimated fat content of the body. Consumption of food before the experiment had a similar effect. Comparatively large volumes of gas in the alimentary tract (caused by a carbonated drink before the experiment) resulted in a difference of about 1.5% in the body fat content. These variations observed in the estimation of body fat by densitometry are well within the basic errors of the method.