There were, however, no corresponding between-group differences in body composition outcomes at 12 months.
The primary outcome is between-group differences in body mass index (BMI, kg/m) after 2 years.
As such, both baseline and follow-up measures of aerobic fitness and PAEE were expressed relative to fat-free mass (FFM; kJ kg−1 FFM min−1) to adjust for between-individual differences in body size [ 17, 18].Free-living total body movement was assessed with an MTI Actigraph (formerly known as the CSA activity monitor) model WAM7164 (Manufacturing Technology, Fort Walton Beach, FL, USA).
One other study has found no association of between-study differences in body weight according to socio-economic factors [ 3], but several studies have found differences in reporting of anthropometry according to sex, age, education or ethnicity [ 1, 16, 48, 49].
Details of this analysis are included in Additional File 4. We tested for associations between differences in clade size, body size and substitution rates, using linear regressions forced through the origin [ 47, 67].
In our second analysis we found a significant relationship between migration strategy and body condition (LRT: χ = 13.47, p = 0.001) in addition to the between-year difference in body condition (LRT: χ = 18.29, p < 0.001).
The significantly lower diet quality that we found during the year of higher population density, together with the concurrent between-year difference in body condition and recruitment previously reported [ 33], provides evidence for a resource-limitation control of the performance of our study population.
For example, on average across chemicals, the dose in milligrams per day eliciting the same effect differs between species due to differences in body size.
This may reflect the variation observed between ethnic populations and/or differences in body mass index.
Baek et al. showed no significant differences in body size between the two sides in patients with facial asymmetry [8].
