Assessment of dietary intake
FOOD ALLERGIES
We conducted a longitudinal assessment of dietary and Na intake in a randomly selected subset of 100 participants of the CHAP trial, including forty-seven participants in the control arm and fifty-three in the intervention arm (Fig. 
CONSORT flowchart: screening, randomisation and follow-upDietary intake was assessed using 24-h dietary recalls administered at participants households by three local, licensed nutritionists. Dietary recalls were collected using the multiple-pass approachIn conjunction with every 24-h recall questionnaire, field workers administered a supplementary questionnaire that collected information on food allergies, whether or not food consumption during the recall period was representative of usual intake, and any illness during the recall period that could have affected the habitual dietary intake. Dietary 24-h recall questionnaires were collected using paper forms, given the large variety in types of meals and ingredients consumed.Furthermore, Na intake was assessed using one 24-h urine sample from each participant at baseline, and at 6-months and 12-months post-randomisation. Na content in urine was chosen over dietary questionnaires to prevent under-reporting and other challenges on quantifying the salt in each recipe, added when cooked or processed foodBody weight was measured in kilograms at baseline and 12 months post-randomisation using the SECA 220089 scale (SECA GMBH & Co) with a precision of ± 100 g, along with standing height and sitting height. At each time point, each measurement was taken 3 times and averaged to obtain a final value. Body weight scales were calibrated weekly. We used height and weight to calculate the BMI in kg/mAt baseline, field workers also administered a questionnaire to collect demographic information including age, education level, main occupation, monthly income and asset ownership. Wealth quintiles were calculated from these variables, as an indicator of socioeconomic status, based on previous national surveys as previously describedSurveys were conducted on tablets using the Research Electronic Data Capture (REDCap) software (Vanderbilt University Medical Centre).