Bergqvist 2005.

Study characteristics
Methods	Prospective, randomised, single‐centre study comparing Fast KD and Grad KD over a 3‐month period. Baseline data of seizure activity was collected 28 days prior to diet initiation.
Participants	48 children, 24 in each of the 2 arms, aged 1‐14 years (mean 5.3, SD 2.7 years), having ≥ 1 seizures per 28 days, tried at least 3 AEDs and a discontinuation of steroidal medication 3 months previous. Study undertaken in Philadelphia, USA. All generalised and focal seizures included; Exclusion criteria: children with metabolic disorders, genetic disorders and known or suspected neurodegenerative disorders. 42% of children included in the study had cerebral palsy.
Interventions	Speed of introduction of KD: Fast KD (< 48 hour fast, followed by 4:1 KD with increase in portion size over 6 days) or Grad KD (gradual increase in KD ratio from 1:1 to 4:1 over 6 days)
Outcomes	Proportion of participants with > 50% seizure reduction in target seizure type; Level of ketosis; Adverse effects.
Notes	In the first 6 days of the KD trial, 2 participants dropped out, 1 with pancreatitis (Fast KD) and 1 due to viral gastrointestinal illness (Grad KD). 3 further drop outs occurred in the Fast KD prior to 3 months' follow‐up, 1 due to respiratory distress and 2 due to lack of efficacy. In the Grad KD group, 1 participant withdrew due to lack of efficacy; This study was supported in part by RRK‐23 16074 and General Clinical Research Center (MO1RR00240), the Nutrition Center of the Children's Hospital of Philadelphia, P30 HD26979, and the Catharine Brown Foundation.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants stratified by age (1 to 2 years and 2 to 14 years); randomisation in permuted blocks of random size (2 to 4).
Allocation concealment (selection bias)	Low risk	Randomisation through permuted blocks of random size of groups of 2 or 4 participants in order to prevent any ability to guess the next assignment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding was not discussed in this paper, but considering the design of the study, blinding of participants and study personnel does not seem possible.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Blinding was not discussed in this paper, but considering the design of the study, blinding of outcome assessors does not seem possible.
Incomplete outcome data (attrition bias)	Unclear risk	Similar attrition rate in both groups, numbers too small for statistical analysis. No ITT analysis completed.
Selective reporting (reporting bias)	Unclear risk	Protocol unavailable.
Other bias	Low risk	All participants admitted received same care; no other bias identified.