Stern 1976.

Study characteristics
Methods	Study design: parallel randomised controlled trial
Participants	Inclusion criteria: adults with type 2 diabetes aged 21 to 70 years diabetes managed by diet or oral hypoglycaemic agents, or both not receiving insulin individuals with tests (complete blood count, pregnancy test, partial thromboplastin time, BUN, creatinine, bilirubin, plasma phenylalanine, plasma tyrosine) within normal limits Exclusion criteria: — Diagnostic criteria: — Setting: outpatients Age group: adults Sex: females and males Country where trial was performed: USA
Interventions	Intervention(s): aspartame 1.8 g daily, in the form of 2 capsules 3 times daily added to the usual diet Comparator(s): matched placebo Duration of intervention: 13 weeks Duration of follow‐up: 13 weeks Run‐in period: 1 week Number of study centres: 2
Outcomes	Reported outcomes in full text of publication: body weight (unit unclear), adverse events, lipid profile (total‐C, TG), glucose levels (fasting)
Identification	Trial identifier: — Trial terminated early: no
Publication details	Language of publication: English Funding: non‐commercial funding: grant‐in‐aid from G.D. Searle & Co. (for presentation of study results at a scientific meeting) Publication status: peer‐reviewed journal and full article
Stated aim for study	Quote from publication: "The present study was designed to determine whether non‐insulin‐dependent diabetic subjects could consume 1.8 g aspartame daily for 90 days (a) without signs or symptoms of intolerance occurring, (b) without fasting plasma phenylalanine levels exceeding 4 mg/100 ml, and/or (c) without deterioration in diabetic control"
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote from publication: "randomly assigned volunteers" Comment: no information on sequence generation
Allocation concealment (selection bias)	Unclear risk	Quote from publication: "randomly assigned volunteers" Comment: no information on allocation concealment
Blinding of participants and personnel (performance bias) adverse events	Low risk	Quote from publication: "The study design was double blind with the subjects randomly assigned to receive aspartame or matching placebo capsules." Comment: it is stated that placebos were similar; self‐reported outcome measure
Blinding of participants and personnel (performance bias) body weight	Low risk	Quote from publication: "The study design was double blind with the subjects randomly assigned to receive aspartame or matching placebo capsules." Comment: it is stated that placebos were similar; investigator‐assessed outcome measure
Blinding of participants and personnel (performance bias) glucose levels	Low risk	Quote from publication: "The study design was double blind with the subjects randomly assigned to receive aspartame or matching placebo capsules." Comment: it is stated that placebos were similar; fasting glucose levels; investigator‐assessed outcome measure
Blinding of participants and personnel (performance bias) lipid profile	Low risk	Quote from publication: "The study design was double blind with the subjects randomly assigned to receive aspartame or matching placebo capsules." Comment: it is stated that placebos were similar; investigator‐assessed outcome measure
Blinding of outcome assessment (detection bias) adverse events	Low risk	Comment: outcome assessors (i.e. participants) were blinded; self‐reported outcome
Blinding of outcome assessment (detection bias) body weight	Unclear risk	Comment: not reported; investigator‐assessed outcome
Blinding of outcome assessment (detection bias) glucose levels	Low risk	Comment: this outcome is unlikely to have been influenced by lack of blinding; investigator‐assessed
Blinding of outcome assessment (detection bias) lipid profile	Low risk	Comment: this outcome is unlikely to have been influenced by lack of blinding; investigator‐assessed
Incomplete outcome data (attrition bias) adverse events	Unclear risk	Quote from publication: "Sixty‐nine subjects completed the study." "Six other participants were lost to follow‐up or were discontinued for medical reasons not related to the study" Comment: dropout rate: 8%; reasons for attrition and whether they were balanced across groups was not described
Incomplete outcome data (attrition bias) body weight	Unclear risk	Quote from publication: "Sixty‐nine subjects completed the study." "Six other participants were lost to follow‐up or were discontinued for medical reasons not related to the study" Comment: dropout rate: 8%; reasons for attrition and whether they were balanced across groups was not described; unit for body weight is missing, therefore results are incomplete
Incomplete outcome data (attrition bias) glucose levels	High risk	Comment: glucose levels were measured in both centres, but data are reported for only 1 study centre; missing data: 62.3%
Incomplete outcome data (attrition bias) lipid profile	Unclear risk	Quote from publication: "Sixty‐nine subjects completed the study." "Six other participants were lost to follow‐up or were discontinued for medical reasons not related to the study" Comment: dropout rate: 8%; reasons for attrition and whether they were balanced across groups was not described
Selective reporting (reporting bias)	Unclear risk	Comment: data for body weight were reported incompletely (without unit), data for glucose levels were reported only for 1 of the 2 study centres
Other bias	Unclear risk	Comment: funding of the study is unclear

—: denotes not reported

BMI: body mass index; BP: blood pressure; BUN: blood urea nitrogen; HbA1c: glycosylated haemoglobin A1c; HDL: high‐density lipoprotein; HOMA: homeostatic model assessment; IA: investigator‐assessed; JECFA: Joint FAO/WHO Expert Committee on Food Additives; LDL: low‐density lipoprotein; ORBIT: Outcome Reporting Bias In Trials; SR: self‐reported; total‐C: total cholesterol; TG: triglycerides; WHO: World Health Organization.