Levy 2012.

Study characteristics
Methods	Study name: Nutrition on the go Study design: 2‐stage cluster‐RCT Intervention period: 6 months Follow‐up period (post‐intervention): nil Differences in baseline characteristics: reported Reliable outcomes: reported Protection against contamination: NR Unit of allocation: school Unit of analysis: individual accounting for cluster
Participants	N (control baseline) = 510 N (control follow‐up) = 499 N (intervention baseline) = 510 N (intervention follow‐up) = 498 Setting (and number by study group): 60 public elementary schools (30 in each group) Recruitment: 60 schools were selected at random, of a total of 2969 public schools in the State of Mexico that receive school breakfasts Geographic region: 125 municipalities of the State of Mexico Percentage of eligible population enrolled: NR Mean age: intervention: 78.6% = 10; control: 75.3% = 10 Sex: intervention: 51.6% female; control: 49.7% female
Interventions	To evaluate the effectiveness of a diet and PA strategy among school‐aged children in the State of Mexico–known as 'Nutrition on the go' to maintain BMI, as a basis for establishing public health policy The strategy mentions 4 components as listed below. However, does not give details about how components 1‐3 are carried out. This paper appears to concentrate on component 4, 'Healthy break', further details of which are provided. “The strategy “Nutrition on the Go” consisted of 4 components: a gradual decrease of the energy content of school breakfasts by reducing the fat content in milk, not increasing carbohydrates, decreasing the sugar content of the cereals provided and including fruit. the gradual regulation of food offered within the school, through the technical council of the State of Mexico. gradual adherence to the PA programme, according to the requirements of the Ministry of Public Education implementation of an educational campaign, called 'Healthy break' for healthy eating and PA. The objectives of this programme are to promote consuming 1 fruit and 1 vegetable, drinking pure water and performing PA (organised games and callisthenics) during break.” The components of the intervention are described as follows: (labelled here a to j as described in the paper). "(a) Nutrition and PA workshops. These were divided into 6 sessions which included participatory recreational activities for children to gain knowledge and skills to properly select healthy foods and promoting PA. (b) Puppet Theatre, based on the theory of peer learning. The 5th grade students participating in the study presented a puppet show to students from 1st to third grades after they studied the script and rehearsed for the performance. (c) Two day workshop in each school for elementary school teachers. “The workshops sought to convey to teachers the importance of healthy eating and PA through dynamic and playful activities to promote participation. (d) A session was held for store personnel to convey information about healthy eating, make suggestions about types of food to sell in schools and recommend the daily sale of vegetables, fruit and pure water. The importance of the responsibility of the cooperative (the food store inside the school) for preserving the health of the school community was addressed. (e) School PA systems were used to promote consumption of water. Water bottles were delivered to children and teachers to encourage consumption. (f) Physical activation. Organized activities involving motion were conducted twice per week. Activities per‐ formed each day before the start of classes included warm‐ups, activation and relaxation. Recommendations to support physical activation were provided through the school guide and a CD with music for established activities. Weekly activation sessions gradually increased from 2 to 5 days. (g) Broadcasting of audio spots on the schools’ PA systems. Spots were broadcast 3 times per week during the break. The central messages were aimed at promoting the consumption of fruits, vegetables and pure water during break and to promote PA in children, with an average length of 1 min and 15 seconds per spot. (h) Organized games during break (once per week). Active and safe participation of teachers and children was promoted during break (i) Placement of banners at the entrance of the school. In order to highlight the campaign in the school community, a banner was hung that read, “This school pro‐ motes healthy breaks. (j) Calendars with healthy recipes for school lunches were provided to parents. Diet and PA combination intervention vs control"
Outcomes	Outcome measures Primary outcome: % overweight, % obese, BMI Secondary outcomes: dietary intake, PA, knowledge, self‐efficacy Process evaluation: NR
Implementation‐related factors	Theoretical basis: NR Resources for intervention implementation: reported Who delivered the intervention: NR PROGRESS categories assessed at baseline: gender, SES PROGRESS categories analysed at outcome: gender, SES Outcomes relating to harms/unintended effects: NR Intervention included strategies to address diversity or disadvantage: NR; intervention targeted children receiving school breakfasts Economic evaluation: NR
Notes	Funding: "this study was supported by: state system for the comprehensive development of the family, State of Mexico (DIFEM) Materials were validated including a pilot study and an efficacy study prior to this RCT. Subjects were beneficiaries of a school breakfast program in both federal and state educational systems with morning and evening shifts.”
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly assigned schools then randomly selected participants within the schools, no further details
Allocation concealment (selection bias)	Unclear risk	Randomly assigned schools then randomly selected participants within the schools, no further details
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Quote: "A blind cluster‐randomized field trial was conducted with fifth grade school children. No indication who was blind"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Loss to follow‐up was 3.2% and was evenly distributed by treatment group
Selective reporting (reporting bias)	Unclear risk	Protocol mentioned, but we were unable to find it
Other bias	Low risk
Other bias‐ timing of recruitment of clusters	Low risk	Figure 1 indicates that recruitment happened prior to randomisation