Sundfor 2018.

Study characteristics
Methods	Randomised clinical trial
Participants	112 participants based in Norway aged between 21 and 70 with a BMI of 30 to 45.0 kg/m2 Inclusion criteria: waist circumference ≥94/80 cm (men/women) and ≥1 additional metabolic syndrome component: circulating levels of TG ≥ 1.7 mmol/L, HDL cholesterol ≤1.0/1.3 (men/women), blood pressure ≥130/85 mmHg or use of antihypertensive drugs or fasting glucose ≥5.6 mmol/L, and weight stability within ±3 kg during the last three months. Exclusion criteria: diabetes if treated with insulin or incretin analogues, bariatric surgery, use of anti‐obesity drugs or other drugs affecting body weight, eating disorder, or psychiatric illness, or alcohol or drug abuse that could contribute to difficulties with study procedures.
Interventions	2‐arm trial Intervention (n = 54): twice‐weekly diet. Participants in the intermittent energy restriction group were advised to consume 400/600 (female/male) on each of two nonconsecutive days a week and to consume food as usual the remaining five days a week. Comparator (n = 58): continuous energy restriction
Outcomes	Body weight, BMI, Waist circumference, lipid profile, blood pressure, glucose, CRP
Notes	Funding: not stated Type of paper: full‐text publication
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "A statistician prepared a computer‐generated random number list"
Allocation concealment (selection bias)	Low risk	The project leader (TS) opened numbered and sealed envelopes consecutively with no exception.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Since this trial was a dietary intervention study, it was not feasible for participants or all study personnel to be blinded to the group assignment.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote:"Measurements were not blinded, but data entry was done by assistants who were blinded to study group."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low dropout rates in both groups and intention‐to‐treat analysis was performed; at 12 months, 4 out of 54 (7.4%) dropout rate in the IER group dropouts and 3 out of 58 (5.2%) dropout rate in the CER group.
Selective reporting (reporting bias)	Low risk	All pre‐specified outcomes (www.clinicaltrials.gov NCT02480504) were reported.
Other bias	Unclear risk	Study visits were not scheduled according to fasting days among participants in the intermittent energy restriction group, to limit lack of compliance, as participants were allowed to vary the day of the week on which they fasted.