Relevance of body mass index and bioelectrical impedance analysis vs. deuterium dilution technique to assess excess of fat among young adults

ABSTRACT

Our study aimed to assess the nutritional status by using body composition among young Tunisian adults through three measurement methods: body mass index (BMI), bioelectrical impedance analysis (BIA) and deuterium oxide dilution technique (²H₂O) and to determine the accuracy of BMI and BIA in order to evaluate the overweight and obesity among young adults in Tunisia. Our study involved 144 young adults. Anthropometric parameters were measured. The fat mass percentage (%FM) was determined by ²H₂O and BIA techniques. The analysis of deuterium enrichment was performed using a Fourier transform infrared spectrophotometer (FTIR). According to BMI, 26.4% of subjects were overweight and 5.5% were obese. The mean of %FM estimated by BIA was significantly higher than that determined by ²H₂O (29.7 ± 7.7 vs. 26.3 ± 10.6, p < .0001). Consequently, the prevalence of overweight and obesity assessed by BIA was significantly higher than by ²H₂O (51.4% vs. 34%, p < .0001). Using BMI, the prevalence of overweight and obesity was similar to that estimated by ²H₂O (31.9% vs. 34%, p = 0.544). Compared to ²H₂O, BIA overestimates the prevalence of overweight and obesity in young adults. On the other hand, the BMI showed an interesting correlation with the %FM determined by ²H₂O.

KEYWORDS:

• Bioelectrical impedance analysis
• body mass index
• deuterium dilution technique
• fat mass
• heavy water
• hydrogen-2
• obesity
• Tunisia
• young people

Acknowledgments

The authors acknowledge the volunteers who participated in the present study and are grateful to the support of Dr Christian Carpéné (Institut des maladies métaboliques et cardiovasculaires, I2MC – UMR1048, INSERM UPS Toulouse) in proofreading this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the International Atomic Energy Agency (IAEA) which provided the equipment and materials (Project RAF6/0/42).