Unfortunately, there can be a large variance in body composition results depending on the testing method used. There are certain procedures that are referenced as gold standard (most accurate tests possible under reasonable conditions), consisting of skinfold assessments, DEXA scans, and hydrostatic weighing. However, a popular method that is not acknowledged as gold standard is bioelectrical impedance, used frequently in bodyweight scales and InBody scans. Therefore, if you are interested in analysing and tracking your body composition, we would encourage you to use gold standard methods.
When testing your body composition, it is important to keep certain variables consistent to avoid skewing your results. Most importantly is being in a fasted state as water and food bulk can be misinterpreted as lean tissue. In addition, avoid having your body composition tested after training and use the same piece of equipment or tester (in the case of skinfolds).
Also, keep in mind that an estimated body fat percentage value will differ depending on the testing method used, for example DEXA vs Skinfolds. This is because DEXA scans measure visceral and subcutaneous fat mass, whereas skinfolds only measure subcutaneous fat. Therefore, DEXA values are likely to be higher than skinfolds. However, remember it’s not the body fat % that necessarily matters (because this really is just an estimate…) but rather how your total body composition is changing over time in terms of fat vs lean mass tissue.
Skinfold assessments in particular are a method we like to use because they are replicable and accurate (if conducted by the same tester), cost effective, time efficient, and not as influenced by external variables (food and water intake, time of day).
The benefit of skinfold measurements is that they produce a skinfold thickness across 6-9 different sites. These readings can then be compared to previous results for weeks, months and years to come! E.g. if your bodyweight has increased, yet total skinfold thickness has stayed the same or decreased, it can be safely assumed that your lean body mass has increased!