Is BMI a relevant marker of fat mass in 4 year old children? Results from the MINISTOP trial. Issue 11 (November 2018)

• Record Type: Journal Article
• Authors: Delisle Nyström, Christine; Henriksson, Pontus; Ek, Anna; Henriksson, Hanna; Ortega, Francisco; Ruiz, Jonatan; Löf, Marie
• Is Part Of: European journal of clinical nutrition. Volume 72:Issue 11(2018)
• Page Start: 1561
• Page End: 1566
• Publication Date: 2018-11
• Subjects: Nutrition -- Periodicals; Nutrition disorders -- Periodicals; Nutritionally induced diseases -- Periodicals; 612.3
• DOI: 10.1038/s41430-018-0133-y
• Languages: English
• ISSNs: 0954-3007

Abstract

Abstract Background/objectives Due to the increase in childhood obesity, identifying children with excess body fat as early as possible is essential. Body mass index (BMI) is commonly used as a marker of body fat in children, adolescents, and adults, yet whether BMI is a valid marker of body fat in pre-school aged children remains to be confirmed. Therefore, we analyzed the associations of BMI with fat and fat-free mass in healthy 4-year-old Swedish children. Subjects/methods The study comprised of 303 children (135 girls) participating in the MINISTOP obesity prevention trial. Fat and fat-free mass were measured using air displacement plethysmography and we computed fat mass index (FMI) and fat free mass index (FFMI) as fat and fat free mass (kg)/height2 (m). Results BMI was positively yet weakly associated with percent fat mass (boys:r 2 = 0.120, P < 0.001 and girls:r 2 = 0.224, P < 0.001). There was a strong association between BMI and the FMI (boys:r 2 = 0.468, P < 0.001 and girlsr 2 = 0.598, P < 0.001) as well as between BMI and the FFMI (boys:r 2 = 0.621, P < 0.001 and girls:r 2 = 0.499, P < 0.001). Children classified as normal weight had a wide range of percent fat mass (12.3 to 35.3%) and FMI (1.75 to 5.78 kg/m2 ). Conclusions BMI was strongly associated to both FMI and FFMI. Therefore, caution is needed when interpreting body fat status based on BMI values in pre-school children.