Williams 2002

Methods	Study design: quasi‐experimental trial Intervention duration: 3 years Length of follow‐up from baseline: 6 months, 18 months Differences in baseline characteristics: not reported Unit of allocation: childcare service Unit of analysis: childcare service (child diet and weight status was assessed at the level of the individual)
Participants	Service type: Head Start Services ‐ preschools Region: Upstate New York, USA Demographic/socioeconomic characteristics: low‐income, predominantly minority preschool children Inclusion/exclusion criteria: not reported Number of services randomised: 9 (3 intervention: food service modification plus classroom education with nutrition modules, 3 intervention: food service modification plus classroom safety education, 3 control) Numbers by trial group: n (controls baseline) = 3 n (controls follow‐up) = 3 n (interventions: food service modification plus classroom education baseline) = 3 n (interventions: food service modification plus classroom education follow‐up) = 3 n (interventions: food service modification plus classroom safety education baseline) = 3 n (interventions: food service modification plus classroom safety education follow‐up) = 3 Recruitment: not reported Recruitment rate: not reported
Interventions	Number of experimental conditions: 3 (intervention: food service modification plus classroom education with nutrition modules, intervention: food service modification plus classroom safety education, control) Policies, practices or programmes targeted by the intervention: Food service modification: ‐ Achieving a 5 day a week meal/snack plan that provided no more than 30% energy from total fat and no more than 10% energy from saturated fat ‐ Increased offering of fruit, vegetables, breads and grains in meals, decreased total and saturated fat content of foods purchased for the service and decreased total and saturated fat due to alterations in food preparation techniques Implementation strategies: Intervention: food service modification plus classroom education with nutrition modules: ‐ Healthy Start Comprehensive Preschool Health Education Curriculum ‐ core curriculum plus nutrition‐related units ‐ 1‐day training programme for cooks, which covered the major food service intervention areas: menu planning, recipe development, food purchasing and food preparation ‐ A list of objectives was developed together with the cooks ‐ Ongoing support from registered dietitian ‐ Manual, newsletters and incentives Intervention: food service modification plus classroom safety education: ‐ Healthy Start Comprehensive Preschool Health Education Curriculum ‐ core curriculum plus safety‐related unit ‐ 1‐day training programme for cooks, which covered the major food service intervention areas: menu planning, recipe development, food purchasing and food preparation ‐ A list of objectives was developed together with the cooks ‐ Ongoing support from registered dietitian ‐ Manual, newsletters and incentives Who delivered the intervention: registered dietitians Theoretical underpinning: not reported Description of control: Healthy Start Comprehensive Preschool Health Education Curriculum ‐ core curriculum plus safety‐related units
Outcomes	Outcome relating to the implementation of childcare service policies, practices or programmes: Change in service menu: ‐ kcal ‐ Total fat ‐ Saturated fat ‐ % kcal from total fat ‐ % kcal from saturated fat Data collection method: service menus were analysed for nutrient content by obtaining menus, recipes and food labels for 5 days at each data collection time point Validity of measures used: unclear Outcome relating to staff knowledge, skills or attitudes: not applicable Outcome relating to cost: not applicable Outcome relating to adverse consequences: not applicable Outcome relating to child diet, physical activity or weight status: Change in child school meal dietary intake: ‐ Energy (kcal) ‐ Total fat ‐ Saturated fat ‐ % kcal from total fat ‐ % kcal from saturated fat Data collection method: direct observation of children during attendance at the service with plate waste measurement to determine amounts of foods and beverages consumed Validity of measures used: the complete dietary intake assessment protocol was adapted from existing protocols proven to be reliable and valid Child weight status: Data collection method: measurements of child weight (using digital scale) and height (using telescopic measuring rod) obtained by trained staff. Weight to height ratio calculated at baseline and at 6 months Validity of measures used: unclear – appears to be an objective measure
Notes	For the analysis, all services assigned to the food service intervention arm of the study were grouped together, as were the services assigned to the control condition
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	No random allocation to control and intervention conditions (random allocation to 1 of 2 intervention conditions).
Allocation concealment (selection bias)	Unclear risk	Unclear as to whether concealment of allocation occurred.
Blinding of participants and personnel (performance bias) All outcomes	High risk	We assumed that due to the nature of the intervention childcare service staff and study personnel delivering the intervention were not blind to the study allocation and therefore there is a potential high risk of performance bias.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information is provided on whether research personnel undertaking menu assessment and other data collection were blind to group allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Implementation data collected on all intervention (n = 6) and control services (n = 3) pre‐ and post‐intervention.
Selective reporting (reporting bias)	Low risk	Methodology paper also lists physiological measures ‐ these have been published elsewhere.
Potential confounding	Unclear risk	No information provided.
Other bias	Unclear risk	—

BMI: body mass index EPAO: Environment and Policy Assessment and Observation NAPSACC: Nutrition and Physical Activity Self‐Assessment for Child Care OSRAP: Observation System for Recording Activity in Preschools RCT: randomised controlled trial