Products sweetened with non-nutritive sweeteners (NNS) are widely available. Many
people with type 1 or type 2 diabetes use NNS as a replacement for nutritive sweeteners
to control their carbohydrate and energy intake. Health outcomes associated with NNS
use in diabetes are unknown.To assess the effects of non-nutritive sweeteners in people
with diabetes mellitus.We searched the Cochrane Central Register of Controlled Trials
(CENTRAL), MEDLINE Ovid, Scopus, the WHO ICTRP, and ClinicalTrials.gov. The date of
the last search of all databases (except for Scopus) was May 2019. We last searched
Scopus in January 2019. We did not apply any language restrictions.We included randomised
controlled trials (RCTs) with a duration of four weeks or more comparing any type
of NNS with usual diet, no intervention, placebo, water, a different NNS, or a nutritive
sweetener in individuals with type 1 or type 2 diabetes. Trials with concomitant behaviour-changing
interventions, such as diet, exercise, or both, were eligible for inclusion, given
that the concomitant interventions were the same in the intervention and comparator
groups.Two review authors independently screened abstracts, full texts, and records
retrieved from trials registries, assessed the certainty of the evidence, and extracted
data. We used a random-effects model to perform meta-analysis, and calculated effect
estimates as risk ratios (RRs) for dichotomous outcomes and mean differences (MDs)
for continuous outcomes, using 95% confidence intervals (CIs). We assessed risk of
bias using the Cochrane 'Risk of bias' tool and the certainty of evidence using the
GRADE approach.We included nine RCTs that randomised a total of 979 people with type
1 or type 2 diabetes. The intervention duration ranged from 4 to 10 months. We judged
none of these trials as at low risk of bias for all 'Risk of bias' domains; most of
the included trials did not report the method of randomisation. Three trials compared
the effects of a dietary supplement containing NNS with sugar: glycosylated haemoglobin
A1c (HbA1c) was 0.4% higher in the NNS group (95% CI -0.5 to 1.2; P = 0.44; 3 trials;
72 participants; very low-certainty evidence). The MD in weight change was -0.1 kg
(95% CI -2.7 to 2.6; P = 0.96; 3 trials; 72 participants; very low-certainty evidence).
None of the trials with sugar as comparator reported on adverse events. Five trials
compared NNS with placebo. The MD for HbA1c was 0%, 95% CI -0.1 to 0.1; P = 0.99;
4 trials; 360 participants; very low-certainty evidence. The 95% prediction interval
ranged between -0.3% and 0.3%. The comparison of NNS versus placebo showed a MD in
body weight of -0.2 kg, 95% CI -1 to 0.6; P = 0.64; 2 trials; 184 participants; very
low-certainty evidence. Three trials reported the numbers of participants experiencing
at least one non-serious adverse event: 36/113 participants (31.9%) in the NNS group
versus 42/118 participants (35.6%) in the placebo group (RR 0.78, 95% CI 0.39 to 1.56;
P = 0.48; 3 trials; 231 participants; very low-certainty evidence). One trial compared
NNS with a nutritive low-calorie sweetener (tagatose). HbA1c was 0.3% higher in the
NNS group (95% CI 0.1 to 0.4; P = 0.01; 1 trial; 354 participants; very low-certainty
evidence). This trial did not report body weight data and adverse events. The included
trials did not report data on health-related quality of life, diabetes complications,
all-cause mortality, or socioeconomic effects.There is inconclusive evidence of very
low certainty regarding the effects of NNS consumption compared with either sugar,
placebo, or nutritive low-calorie sweetener consumption on clinically relevant benefit
or harm for HbA1c, body weight, and adverse events in people with type 1 or type 2
diabetes. Data on health-related quality of life, diabetes complications, all-cause
mortality, and socioeconomic effects are lacking.