Demographic information included age and sex. Anthropometric data were collected at study enrolment and at follow-up about 8 months later. Participants were asked to remove shoes, socks and outdoor clothes for weighing. Weight was measured to the nearest tenth of a kilogram with the TANITA scale (TBF-300 MA, Sindlfingen, Germany). Height was measured to the nearest centimetre using the Leicester Height Measure (Marsden Group, UK). BMI was calculated from weight and height (kg/m2), and classified according to World Health Organization cut-off points (underweight/normal weight < 25.0 kg/m2, overweight ≥25.0 to <30.0 kg/m2, obese ≥30 kg/m2) [17 (link)]. Participants could opt to receive a printout of their anthropometric results, and all chose to do so.
A saliva sample for DNA extraction was collected after enrolment by asking the participant to place some sugar on their tongue to stimulate saliva flow and then spit into a plastic tube to generate 1.5-2 ml of saliva. Saliva samples were coded with a unique identifier number immediately after collection so that they were anonymous but could be linked to the anthropometric data. DNA was isolated from saliva and analysed at The Institute of Metabolic Science, Cambridge, UK, as previously published [2 (link)].
A saliva sample for DNA extraction was collected after enrolment by asking the participant to place some sugar on their tongue to stimulate saliva flow and then spit into a plastic tube to generate 1.5-2 ml of saliva. Saliva samples were coded with a unique identifier number immediately after collection so that they were anonymous but could be linked to the anthropometric data. DNA was isolated from saliva and analysed at The Institute of Metabolic Science, Cambridge, UK, as previously published [2 (link)].
