Sweeteners and sweetness enhancers (S&SE) are used to replace energy yielding sugars and maintain sweet taste in a wide range of products, but controversy exists about their effects on appetite and endocrine responses in reduced or no added sugar solid foods. The aim of the current study was to evaluate the acute (1 day) and repeated (two-week daily) ingestive effects of 2 S&SE vs. sucrose formulations of biscuit with fruit filling on appetite and endocrine responses in adults with overweight and obesity. In a randomised crossover trial, 53 healthy adults (33 female, 20 male) with overweight/obesity in England and France consumed biscuits with fruit filling containing 1) sucrose, or reformulated with either 2) Stevia Rebaudioside M (StRebM) or 3) Neotame daily during three, two-week intervention periods with a two-week washout. The primary outcome was composite appetite score defined as [desire to eat + hunger + (100 - fullness) + prospective consumption]/4. Each formulation elicited a similar reduction in appetite sensations (3-h postprandial net iAUC). Postprandial insulin (2-h iAUC) was lower after Neotame (95% CI (0.093, 0.166); p < 0.001; d = -0.71) and StRebM (95% CI (0.133, 0.205); p < 0.001; d = -1.01) compared to sucrose, and glucose was lower after StRebM (95% CI (0.023, 0.171); p < 0.05; d = -0.39) but not after Neotame (95% CI (-0.007, 0.145); p = 0.074; d = -0.25) compared to sucrose. There were no differences between S&SE or sucrose formulations on ghrelin, glucagon-like peptide 1 or pancreatic polypeptide iAUCs. No clinically meaningful differences between acute vs. two-weeks of daily consumption were found. In conclusion, biscuits reformulated to replace sugar using StRebM or Neotame showed no differences in appetite or endocrine responses, acutely or after a two-week exposure, but can reduce postprandial insulin and glucose response in adults with overweight or obesity. The present study was funded by the Horizon 2020 program: Sweeteners and sweetness enhancers: Impact on health, obesity, safety and sustainability (acronym: SWEET, grant no: 774293).

Recent studies suggest that some non-nutritive sweeteners (NNS) have deleterious effects on the human gut microbiome (HGM). The effect of steviol glycosides on the HGM has not been well studied. We aimed to evaluate the effects of stevia- versus sucrose-sweetened beverages on the HGM and fecal short-chain-fatty-acid (SCFA) profiles. Using a randomized, double blinded, parallel design study, n=59 healthy adults (female/male n=36/23, aged 31±9 years, BMI: 22.6±1.7 kg/m2) consumed 16oz of a beverage containing either 25% of the Acceptable-Daily-Intake (ADI) of stevia or 30g sucrose daily for 4 weeks followed by a 4-week washout. At weeks 0 (baseline), 4 and 8 the HGM was characterized via shotgun sequencing, fecal SCFA concentrations were measured using ultra-high performance liquid chromatography-tandem mass spectrometry and anthropometric measurements, fasting serum glucose, insulin and lipids, blood pressure, pulse and 3-day diet records were obtained. There were no significant differences in the HGM or fecal SCFA between the stevia and sucrose groups at baseline (P > 0.05). At week 4 (post-intervention) there were no significant differences in the HGM at the phylum, family, genus or species level between the stevia and sucrose groups and no significant differences in fecal SCFA. At week 4, BMI had increased by 0.3 kg/m² (P = 0.013) in sucrose versus stevia but all other anthropometric and cardiometabolic measures and food intake did not differ significantly (P > 0.05). At week 8 (post-washout) there were no significant differences in the HGM, fecal SFCA, or any anthropometric or cardiometabolic measure between the stevia and sucrose groups (P > 0.05). Daily consumption of a beverage sweetened with 25% of the ADI of stevia for 4 weeks had no significant effects on the HGM, fecal SCFA or fasting cardiometabolic measures, compared to daily consumption of a beverage sweetened with 30g sucrose. Clinicaltrials.gov as NCT05264636.

Project SWEET examined the barriers and facilitators to the use of non-nutritive sweeteners and sweetness enhancers (hereafter "S&SE") alongside potential risks/benefits for health and sustainability. The Beverages trial was a double-blind multi-centre, randomised crossover trial within SWEET evaluating the acute impact of three S&SE blends (plant-based and alternatives) vs. a sucrose control on glycaemic response, food intake, appetite sensations and safety after a carbohydrate-rich breakfast meal. The blends were: mogroside V and stevia RebM; stevia RebA and thaumatin; and sucralose and acesulfame-potassium (ace-K). At each 4 h visit, 60 healthy volunteers (53% male; all with overweight/obesity) consumed a 330 mL beverage with either an S&SE blend (0 kJ) or 8% sucrose (26 g, 442 kJ), shortly followed by a standardised breakfast (∼2600 or 1800 kJ with 77 or 51 g carbohydrates, depending on sex). All blends reduced the 2-h incremental area-under-the-curve (iAUC) for blood insulin (p < 0.001 in mixed-effects models), while the stevia RebA and sucralose blends reduced the glucose iAUC (p < 0.05) compared with sucrose. Post-prandial levels of triglycerides plus hepatic transaminases did not differ across conditions (p > 0.05 for all). Compared with sucrose, there was a 3% increase in LDL-cholesterol after stevia RebA-thaumatin (p < 0.001 in adjusted models); and a 2% decrease in HDL-cholesterol after sucralose-ace-K (p < 0.01). There was an impact of blend on fullness and desire to eat ratings (both p < 0.05) and sucralose-acesulfame K induced higher prospective intake vs sucrose (p < 0.001 in adjusted models), but changes were of a small magnitude and did not translate into energy intake differences over the next 24 h. Gastro-intestinal symptoms for all beverages were mostly mild. In general, responses to a carbohydrate-rich meal following consumption of S&SE blends with stevia or sucralose were similar to sucrose.

Sweeteners are used in the food industry to provide sweetness similar to sugar and to decrease the caloric intake and risks associated with obesity. However, some sweeteners are characterized by bitter, metallic and other off-tastes. Sensory and cellular studies have demonstrated synergies between sweetener blends, which are responsible for enhancing sweetness. This study aimed to identify new sweetener blends that are able to enhance sweetness intensity without causing bitter off-taste using in vitro functional expression of taste receptors. The dose–response of the sweet taste receptor (TAS1R2/TAS1R3) was determined for sucrose and 9 sweeteners and was consistent with their sweetness potency. Stimulation of TAS1R2/TAS1R3 by 6 binary sweetener blends confirmed 3 known synergies determined by sensory analysis, including sucralose/acesulfame-K, rebaudioside A/erythritol and rebaudioside A/thaumatin, and revealed 2 new synergies, known as, neotame/D-allulose and mogroside V/thaumatin. No synergy was observed for the rebaudioside M/mogroside V blend, probably due to their common binding sites on the sweet taste receptor. The ability of the 9 selected sweeteners to activate the 25 human bitter taste receptors (TAS2Rs) was tested. The cellular-based assay demonstrated that sucralose, acesulfame-K, rebaudioside A, mogroside V and D-allulose activated at least 2 TAS2Rs. Sucralose, acesulfame-K and rebaudioside A exhibited lower EC50 values for TAS1R2/TAS1R3 than for TAS2Rs, which may explain their absence of bitter off-taste at low concentrations, unlike mogroside V and D-allulose. Our data provide a receptor-based understanding of the complex synergies among sweetener blends and an effective approach for testing new sweeteners while avoiding the activation of TAS2Rs.

Non-nutritive sweeteners have potential effects on brain function. We investigated neural correlates of responses to beverages differing in sweetness and calories. Healthy participants completed 4 randomised sessions: water vs. water with stevia, glucose, or maltodextrin. Blood-oxygenation level-dependent (BOLD) contrast was monitored for 30 min post-ingestion by functional Magnetic Resonance Imaging. A food visual probe task at baseline was repeated at 30 min. A significant interaction of taste-by-calories-by-time was demonstrated mainly in motor, frontal, and insula cortices. Consumption of the stevia-sweetened beverage resulted in greater BOLD decrease, especially in the 20–30 min period, compared to other beverages. There was a significant interaction of taste-by-time in BOLD response in gustatory and reward areas; sweet beverages induced greater reduction in BOLD compared to non-sweet. The interaction calories-by-time showed significantly greater incremental area under the curve in thalamic, visual, frontal, and parietal areas for glucose and maltodextrin 10–20 min post-consumption only, compared to water. In the visual cue task, the water demonstrated an increased response in the visual cortex to food images post-consumption; however, no difference was observed for the three sweet/caloric beverages. In conclusion, both sweet taste and calories exert modulatory effects, but stevia showed a more robust and prolonged effect.

Sweeteners and sweetness enhancers (S&SEs) are ingredients used in foods and beverages to reduce sugar while providing the sweetness of sugar with little to no calories. Although S&SEs have global regulatory approval and acceptance, questions remain regarding their overall safety and efficacy. Information on the effects of S&SEs in regard to health and efficacy can be found in randomised controlled trials (RCTs) that exist in peer‐reviewed literature. With the large number of RCT publications on various S&SEs, a need exists to organise and collect each of the published studies in a useful database. Currently, a database containing human clinical information on S&SEs does not exist and so The SWEET project has created a publicly available and comprehensive Health Impact Database that includes available human clinical information on sweeteners. This paper describes the process and development of a database that collects comprehensive information on published human clinical studies evaluating S&SEs between the years January 2000 and September 2024. Ovid Medline was used to search for RCT publications from the year 2000 to 2024. The search produced 1538 publications, of which 257 complied with the predetermined eligibility criteria. There was a large variability in the number of studies that fit the inclusion criteria. For example, some S&SEs had numerous studies (i.e., sucralose, n = 63 eligible publications) and some S&SEs had no publications that fit the criteria (aspartame‐acesulfame K salt and neohesperidine DC). The Health Impact Database is located at https://sweetproject.eu/HIdatabase and is contained in Microsoft Excel spreadsheets which are organised by health impact criteria. This database will be a useful tool for researchers as it provides comprehensive information on human clinical studies on S&SEs that can be leveraged as a general resource and for systematic reviews and meta‐analyses.