Trends in body fatness from 2001 to 2016: objective measures from the Tromsø Study

The increase in body fat, including the harmful visceral fat, underpins the need for public health interventions to halt the observed increased prevalence of obesity and obesity-related diseases.

Background: Obesity is reaching pandemic proportions and most adults in Norway now have body mass index in the overweight or obesity range (BMI ≥ 25 kg/m2). Common measures of obesity do not assess body composition and their accuracy is often questioned. This study examined trends in objectively measured body fatness from 2001 to 2016 in a general Norwegian adult population.

Methods: Repeated measures of total body fat and visceral fat were obtained from dual-energy x-ray absorptiometry (DXA) from women and men aged 40-88 years participating in one or more of the three latest surveys of the population-based Tromsø Study: Tromsø5 in 2001 (n=1662), Tromsø6 in 2007-2008 (n=901), and Tromsø7 in 2015-2016 (n=3670). Trends in total body fat and visceral fat were analyzed by generalized estimation equation models in subgroups of sex and age.

Results: Both total fat mass and visceral fat mass increased between 2001 and 2016. The most pronounced increase was observed between 2007 and 2016. Particularly in women, the changes differed by age and was strongest in the youngest age-group (40-49 years).

Conclusions: Body fatness have increased during the past decades. The observed trends using DXA is coherent with numerous studies using anthropometric measures. Of particular concern for future public health is that we found the largest increase in body fatness in the youngest age-group and during the last time period in this Norwegian adult population.