Fat-free mass hydration in newborns : assessment and implications for body composition studies

• Equipment (Pea Pod) for assessing infant body density accurately and conveniently has recently become available. This density can be converted to body composition using the “Fomon” or the “Butte” model. These models differ regarding the water content in fat-free mass (hydration factor, HF). We assessed HF and its biological variability in newborns and compared results calculated using the two models at one and 12 weeks. Body volume and body weight were measured in 12 infants less than 10 days old using Pea Pod. Their total body water was assessed using isotope dilution. Their HF was found to be 80.9% with low biological variability (0.81% of average HF). Further, Pea Pod was used to assess body density of 108 infants at one and 12 weeks of age. Values for body fat (%) calculated using the “Butte” model were significantly lower than when using the “Fomon” model at one week (p<0.05) and 12 weeks (p<0.01). The difference between the two models was particularly large at one week, probably due to their different HF-values. Our HF-value is in agreement with that in the “Fomon” model and our results support the conclusion that this model is preferable when calculating body composition in infants.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Näringslära (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Nutrition and Dietetics (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Pediatrik (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Pediatrics (hsv//eng)

Keyword

MEDICINE

MEDICIN

Publication and Content Type

ref (subject category)

art (subject category)