Do non-nutritive sweeteners influence acute glucose homeostasis in humans? A systematic review

Impact of acute consumption of beverages containing plant-based or alternative sweetener blends on postprandial appetite, food intake, metabolism, and gastro-intestinal symptoms: Results of the SWEET beverages trial

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.

The Effect of Non-Nutritive Sweetened Beverages on Postprandial Glycemic and Endocrine Responses: A Systematic Review and Network Meta-Analysis

Background: There has been an emerging concern that non-nutritive sweeteners (NNS) can increase the risk of cardiometabolic disease. Much of the attention has focused on acute metabolic and endocrine responses to NNS. To examine whether these mechanisms are operational under real-world scenarios, we conducted a systematic review and network meta-analysis of acute trials comparing the effects of non-nutritive sweetened beverages (NNS beverages) with water and sugar-sweetened beverages (SSBs) in humans. Methods: MEDLINE, EMBASE, and The Cochrane Library were searched through to January 15, 2022. We included acute, single-exposure, randomized, and non-randomized, clinical trials in humans, regardless of health status. Three patterns of intake were examined: (1) uncoupling interventions, where NNS beverages were consumed alone without added energy or nutrients; (2) coupling interventions, where NNS beverages were consumed together with added energy and nutrients as carbohydrates; and (3) delayed coupling interventions, where NNS beverages were consumed as a preload prior to added energy and nutrients as carbohydrates. The primary outcome was a 2 h incremental area under the curve (iAUC) for blood glucose concentration. Secondary outcomes included 2 h iAUC for insulin, glucagon-like peptide 1 (GLP-1), gastric inhibitory polypeptide (GIP), peptide YY (PYY), ghrelin, leptin, and glucagon concentrations. Network meta-analysis and confidence in the network meta-analysis (CINeMA) were conducted in R-studio and CINeMA, respectively. Results: Thirty-six trials involving 472 predominantly healthy participants were included. Trials examined a variety of single NNS (acesulfame potassium, aspartame, cyclamate, saccharin, stevia, and sucralose) and NNS blends (acesulfame potassium + aspartame, acesulfame potassium + sucralose, acesulfame potassium + aspartame + cyclamate, and acesulfame potassium + aspartame + sucralose), along with matched water/unsweetened controls and SSBs sweetened with various caloric sugars (glucose, sucrose, and fructose). In uncoupling interventions, NNS beverages (single or blends) had no effect on postprandial glucose, insulin, GLP-1, GIP, PYY, ghrelin, and glucagon responses similar to water controls (generally, low to moderate confidence), whereas SSBs sweetened with caloric sugars (glucose and sucrose) increased postprandial glucose, insulin, GLP-1, and GIP responses with no differences in postprandial ghrelin and glucagon responses (generally, low to moderate confidence). In coupling and delayed coupling interventions, NNS beverages had no postprandial glucose and endocrine effects similar to controls (generally, low to moderate confidence). Conclusions: The available evidence suggests that NNS beverages sweetened with single or blends of NNS have no acute metabolic and endocrine effects, similar to water. These findings provide support for NNS beverages as an alternative replacement strategy for SSBs in the acute postprandial setting.

Oh So Sweet: A Comparative Investigation of Retail Market Composition of Sweetened and Flavoured Beverages in Singapore and Australia

The consumption of sugar and non-nutritive sweeteners has been associated with poor health outcomes. The aim of this paper was to provide a comparison of the range of sweetened or flavoured beverages between two high-income countries in the Asia-Pacific region: Australia and Singapore. Following the FoodTrackTM methodology, nutrition, labelling, and price data were collected from major Australian and Singaporean supermarket chains and convenience stores. The nutrient profiles of products were tested for differences using Kruskal−Wallis and Mann−Whitney U tests. The greatest number of products collected in Australia were from the ‘carbonated beverages’ category (n = 215, 40%), and in Singapore the greatest number of products were from the ‘tea and coffee ready-to-drink’ category (n = 182, 35%). There were more calorically sweetened beverages in Singapore compared with Australia (n = 462/517 vs. n = 374/531, p < 0.001). For calorically sweetened products, the median energy of Singaporean products was significantly higher than Australian products (134 kJ vs. 120 kJ per 100 mL, p = 0.009). In Australia, 52% of sweetened or flavoured beverages displayed a front-of-pack nutrient signposting logo, compared with 34% of sweetened or flavoured beverages in Singapore. These findings also indicate that the consumption of just one serving of calorically sweetened carbonated beverages or energy drinks would exceed the WHO maximum daily free sugar recommendations.

The Combined Effects of Aspartame and Acesulfame-K Blends on Appetite: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Aspartame (Asp) and acesulfame-K (Ace-K) are nonnutritive sweeteners (NNSs) commonly used in combination to replace added sugars in reduced- or low-calorie foods and beverages. Despite Asp/Ace-K blends having negligible calories, their effects on appetite have not been reviewed systematically. We therefore undertook a systematic review and meta-analysis of the metabolic effects of Asp/Ace-K blends on energy intake (EI), subjective appetite scores, blood glucose, and the incretin hormones glucose-dependent insulinotropic peptide and glucagon-like peptide. MEDLINE, Web of Science, and Cochrane CENTRAL databases (Embase, PubMed, and CINAHL) were searched (May 2021) for randomized controlled trials (RCTs). Human RCTs using Asp/Ace-K blends compared with sugar and water controls were included, whereas isolated cell and animal studies were excluded. An overall 4829 publications were identified and 8 studies, including 274 participants, were retrieved for review. The Asp/Ace-K group's EI was significantly reduced compared with sugar [mean difference (MD): -196.56 kcal/meal; 95% CI: -332.01, -61.11 kcal/meal; P = 0.004] and water (MD: -213.42 kcal/meal; 95% CI: -345.4, -81.44 kcal/meal; P = 0.002). Meta-analysis of subjective appetite scores and incretins could not be undertaken due to inconsistencies in data reporting and insufficient data, respectively, but of the 4 studies identified, no differences were observed between Asp/Ace-K blends and controls. The Asp/Ace-K group's blood glucose was nonsignificantly reduced compared with sugar (MD: -1.48 mmol/L; 95% CI: -3.26, 0.3 mmol/L; P = 0.1) and water (MD: -0.08 mmol/L; 95% CI: -0.62, 0.47 mmol/L; P = 0.78). Lower EI in participants who were predominantly healthy and assigned to Asp/Ace-K blends could not be reliably attributed to changes in subjective appetite scores. Blood glucose and incretins were also generally not affected by Asp/Ace-K blends when compared with controls. Additional short- and long-term RCTs using NNSs and sugars at dietarily relevant levels are needed. This trial was registered at the International Prospective Register of Systematic Reviews (PROSPERO: CRD42017061015).

Mapping the Homeostatic and Hedonic Brain Responses to Stevia Compared to Caloric Sweeteners and Water: A Double-Blind Randomised Controlled Crossover Trial in Healthy Adults

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.

Is There an Academic Bias against Low-Energy Sweeteners?

This perspective considers evidence of a common academic bias against low-energy sweeteners (LES). The core proposition is that this bias is manifested in research and reporting focused on generating and placing a negative spin on LESs, largely through selective citation, interpretation and reporting. The evidence centres on three inter-related points, which together may generate a misleading impression of the balance of evidence: (1) basic and mechanistic research on LES perpetuates “explanations” for unsubstantiated adverse effects of LES; (2) the literature on LES—particularly narrative reviews and commentaries—continually reprises hypotheses of adverse effects without acknowledging where these hypotheses have been rigorously tested and rejected; and (3) negative interpretations of the effects of LES largely rely upon selectively emphasising lower-quality research whilst ignoring or dismissing higher-quality evidence. The expert community should consider these issues in assuring scientific integrity and balance in the academic discourse on LES, and how this is translated into messages for public health and consumers.

The Effect of Artificial Sweeteners Use on Sweet Taste Perception and Weight Loss Efficacy: A Review

Excessive consumption of sugar-rich foods is currently one of the most important factors that has led to the development of the global pandemic of obesity. On the other hand, there is evidence that obesity contributes to reduced sensitivity to sweet taste and hormonal changes affecting appetite, leading to an increased craving for sweets. A high intake of sugars increases the caloric value of the diet and, consequently, leads to weight gain. Moreover, attention is drawn to the concept of the addictive properties of sugar and sugary foods. A potential method to reduce the energy value of diet while maintaining the sweet taste is using non-nutritive sweeteners (NNS). NNS are commonly used as table sugar substitutes. This wide group of chemical compounds features high sweetness almost without calories due to its high sweetening strength. NNS include aspartame, acesulfame-K, sucralose, saccharin, cyclamate, neohesperidin dihydrochalcone (neohesperidin DC), neotame, taumatin, and advantame. The available evidence suggests that replacing sugar with NNS may support weight control. However, the effect of NNS on the regulation of appetite and sweet taste perception is not clear. Therefore, the review aimed to summarize the current knowledge about the use of NNS as a potential strategy for weight loss and their impact on sweet taste perception. Most studies have demonstrated that consumption of NNS-sweetened foods does not increase sweetness preference orenergy intake. Nonetheless, further research is required to determine the long-term effects of NNS on weight management.

Sugar-Sweetened Beverages and Symptom Complaints among School-Aged Children: A National Longitudinal Study

The association between sugar-sweetened beverages (SSBs) and symptom complaints among school-aged children remains unclear. Children aged 6−17 years (n = 29,028) were recruited on the basis of a national school-based study. Data collection included two waves: the exposure was the amount and frequency of SSB consumption, collected in the 2013 autumn semester, and outcomes were defined as having clinical symptom complaints after two weeks of observation, collected in the 2014 spring semester. Symptom complaints were defined as fever, cough, headache, loose bowels, vomiting, sore throat, rash, conjunctival congestion, and stomachache. The associations between the amount/frequency of SSBs and symptoms complaints were explored by a general linear model, with adjustments made for socio-demographic and other lifestyle information. Among the 12,454 children (10.32 ± 3.15 years, 48.7% male) in the final analysis, the odds ratio for having symptom complaints (1.46, 95% CI: 1.10−1.95) among children whose SSB consumption was >75 mL/day was significantly higher than that among children who had no SSB consumption. Among children with a daily SSB intake of more than 75 mL, there was a higher risk for symptom complaints. We recommend more support for decreasing SSB consumption among children to minimize negative health outcomes.

Alterations in sweet taste function in adults with diabetes mellitus: a systematic review and potential implications

Diet therapy for diabetes involves controlling carbohydrate intake in order to manage blood glucose concentrations. Simple carbohydrates, like sucrose, quickly and potently raise blood glucose when ingested, and are typically perceived as sweet. Sweetness is innately pleasurable and contributes to the positive hedonic evaluation of foods and beverages. There is some evidence to suggest that individuals with diabetes mellitus may be less able to detect sweetness, which could result in increased intake and, thus, more difficulty managing blood glucose. A systematic review that included PubMed, PsycInfo, and Embase databases was conducted. Inclusion criteria included observational studies that investigated the sweet taste function of adults with and without diabetes mellitus (Prospero CRD42021225058). The quality of the final included studies was assessed using the Academy of Nutrition and Dietetics' Evidence Analysis Library Quality Criteria Checklist: Primary Research tool. Eighteen studies that compared sweet taste thresholds, intensity ratings, or hedonic responses in adults both with and without diabetes were included. Differences in sweet taste thresholds, both detection and recognition, indicated that individuals with diabetes were less sensitive than healthy controls. The same findings were observed for intensity ratings. Only two studies examined hedonic responses; results were inconclusive.

Effects of psychological, sensory, and metabolic energy prime manipulation on the acute endocrine stress response in fasted women

The stress response supports survival through energy mobilization. Paradoxically, a low blood glucose level dampens the endocrine stress response, and sugar consumption prior to stress restores it. Thus, energy availability may play a causal role in the endocrine stress response. Yet, it has never been tested whether sweet taste or expectations towards a drink content modulate the stress response. We investigated the potential role of sweetness, energy load and expectations towards energy load of a drink consumed prior to stress in restoring stress reactivity after fasting. N = 152 women (meanage=21.53, sdage=2.61) participated in the Trier Social Stress Test for groups in the morning after an overnight fast. Prior to stress induction, participants consumed a drink containing saccharose (sugar, n = 51), an equally sweet drink containing non-caloric sweetener (sweetener, n = 46), or water (n = 56). Additionally, participants in the sugar and sweetener group (n = 97) were informed whether or not their drink contained any calories (energy prime), which was deceptive in 50% of the cases. Eight salivary cortisol (-30, -20, -10, 0, +12, +25, +35, +45 min) and three blood glucose samples (-30, 0, +25 min) were assessed throughout the experiment. The effects of the experimental manipulations on cortisol trajectories were tested using multilevel mixed models. We found that compared with water, sugar and sweetener both significantly increased cortisol stress reactivity and with comparable intensity. However, our sensitivity analysis revealed a significant effect of sugar on cortisol trajectories compared to water and to sweetener. Drink-induced changes in blood glucose concentration were not associated with increases in cortisol. The energy prime did not affect the stress response. Overall, we could replicate the boosting effect of sugar consumption in a female sample after 8 h of fasting. The specific contribution of sweet taste and metabolic hormones to this boosting effect should be tested more rigorously in sex-balanced designs in the future.

Cephalic phase insulin release: A review of its mechanistic basis and variability in humans

Cephalic phase insulin release (CPIR) is a transient pulse of insulin that occurs within minutes of stimulation from foods or food-related stimuli. Despite decades of research on CPIR in humans, the body of literature surrounding this phenomenon is controversial due in part to contradictory findings . This has slowed progress towards understanding the sensory and neural basis of CPIR, as well as its overall relevance to health. This review examines up-to-date knowledge in CPIR research and identifies sources of CPIR variability in humans in an effort to guide future research. The review starts by defining CPIR and discussing its presumed functional roles in glucose homeostasis and feeding behavior. Next, the types of stimuli that have been reported to elicit CPIR, as well as the sensory and neural mechanisms underlying the response in rodents and humans are discussed, and areas where knowledge is limited are identified. Finally, factors that may contribute to the observed variability of CPIR in humans are examined, including experimental design, test procedure, and individual characteristics. Overall, oral stimulation appears to be important for eliciting CPIR, especially when combined with other sensory modalities (vision, olfaction, somatosensation). While differences in experimental design and testing procedure likely explain some of the observed inter- and intra-study variability, individual differences also appear to play an important role. Understanding sources of these individual differences in CPIR will be key for establishing its health relevance.

Low-calorie sweeteners and human health: a rapid review of systematic reviews

INTRODUCTION

Low-calorie sweeteners are increasingly prevalent in the food supply and their consumption has increased in recent decades. Although low-calorie sweeteners approved for use are considered safe from a toxicological perspective, their short- and long-term impacts on chronic disease risk remain uncertain. The aim of this review was to summarize the evidence from systematic reviews on low-calorie sweetener use and chronic conditions and risk factors in children and adults.

METHODS

MEDLINE and the Cochrane Database of Systematic Reviews were searched to identify systematic reviews of randomized and nonrandomized studies that considered low-calorie sweeteners in relation to type 2 diabetes, cardiovascular disease, cancer, anthropometric measures, hypertension, hyperglycemia, hyperlipidemia, insulin resistance, and dental caries. Data were extracted from 9 reviews deemed of moderate or high quality on the basis of AMSTAR-2.

RESULTS

Narrative synthesis suggested inconsistent evidence on low-calorie sweetener use in relation to chronic conditions and associated risk factors, with nonrandomized studies suggesting positive associations and randomized studies suggesting negative or no associations.

CONCLUSION

Continued research on the long-term health impacts of low-calorie sweeteners across all life stages is warranted.

Obesity and Sex-Related Associations With Differential Effects of Sucralose vs Sucrose on Appetite and Reward Processing: A Randomized Crossover Trial

IMPORTANCE

Nonnutritive sweeteners (NNSs) are used as an alternative to nutritive sweeteners to quench desire for sweets while reducing caloric intake. However, studies have shown mixed results concerning the effects of NNSs on appetite, and the associations between sex and obesity with reward and appetitive responses to NNS compared with nutritive sugar are unknown.

OBJECTIVE

To examine neural reactivity to different types of high-calorie food cues (ie, sweet and savory), metabolic responses, and eating behavior following consumption of sucralose (NNS) vs sucrose (nutritive sugar) among healthy young adults.

DESIGN, SETTING, AND PARTICIPANTS

In a randomized, within-participant, crossover trial including 3 separate visits, participants underwent a functional magnetic resonance imaging task measuring blood oxygen level-dependent signal in response to visual cues. For each study visit, participants arrived at the Dornsife Cognitive Neuroimaging Center of University of Southern California at approximately 8:00 am after a 12-hour overnight fast. Blood was sampled at baseline and 10, 35, and 120 minutes after participants received a drink containing sucrose, sucralose, or water to measure plasma glucose, insulin, glucagon-like peptide(7-36), acyl-ghrelin, total peptide YY, and leptin. Participants were then presented with an ad libitum meal. Participants were right-handed, nonsmokers, weight-stable for at least 3 months before the study visits, nondieters, not taking medication, and with no history of eating disorders, illicit drug use, or medical diagnoses. Data analysis was performed from March 2020 to March 2021.

INTERVENTIONS

Participants ingested 300-mL drinks containing either sucrose (75 g), sucralose (individually sweetness matched), or water (as a control).

MAIN OUTCOMES AND MEASURES

Primary outcomes of interest were the effects of body mass index (BMI) status and sex on blood oxygen level-dependent signal to high-calorie food cues, endocrine, and feeding responses following sucralose vs sucrose consumption. Secondary outcomes included neural, endocrine, and feeding responses following sucrose vs water and sucralose vs water (control) consumption, and cue-induced appetite ratings following sucralose vs sucrose (and vs water).

RESULTS

A total of 76 participants were randomized, but 2 dropped out, leaving 74 adults (43 women [58%]; mean [SD] age, 23.40 [3.96] years; BMI range, 19.18-40.27) who completed the study. In this crossover design, 73 participants each received water (drink 1) and sucrose (drink 2), and 72 participants received water (drink 1), sucrose (drink 2), and sucralose (drink 3). Sucrose vs sucralose was associated with greater production of circulating glucose, insulin, and glucagon-like peptide-1 and suppression of acyl-ghrelin, but no differences were found for peptide YY or leptin. BMI status by drink interactions were observed in the medial frontal cortex (MFC; P for interaction < .001) and orbitofrontal cortex (OFC; P for interaction = .002). Individuals with obesity (MFC, β, 0.60; 95% CI, 0.38 to 0.83; P < .001; OFC, β, 0.27; 95% CI, 0.11 to 0.43; P = .002), but not those with overweight (MFC, β, 0.02; 95% CI, -0.19 to 0.23; P = .87; OFC, β, -0.06; 95% CI, -0.21 to 0.09; P = .41) or healthy weight (MFC, β, -0.13; 95% CI, -0.34 to 0.07; P = .21; OFC, β, -0.08; 95% CI, -0.23 to 0.06; P = .16), exhibited greater responsivity in the MFC and OFC to savory food cues after sucralose vs sucrose. Sex by drink interactions were observed in the MFC (P for interaction = .03) and OFC (P for interaction = .03) after consumption of sucralose vs sucrose. Female participants had greater MFC and OFC responses to food cues (MFC high-calorie vs low-calorie cues, β, 0.21; 95% CI, 0.05 to 0.37; P = .01; MFC sweet vs nonfood cues, β, 0.22; 95% CI, 0.02 to 0.42; P = .03; OFC food vs nonfood cues, β, 0.12; 95% CI, 0.02 to 0.22; P = .03; and OFC sweet vs nonfood cues, β, 0.15; 95% CI, 0.03 to 0.27; P = .01), but male participants' responses did not differ (MFC high-calorie vs low-calorie cues, β, 0.01; 95% CI, -0.19 to 0.21; P = .90; MFC sweet vs nonfood cues, β, -0.04; 95% CI, -0.26 to 0.18; P = .69; OFC food vs nonfood cues, β, -0.08; 95% CI, -0.24 to 0.08; P = .32; OFC sweet vs nonfood cues, β, -0.11; 95% CI, -0.31 to 0.09; P = .31). A sex by drink interaction on total calories consumed during the buffet meal was observed (P for interaction = .03). Female participants consumed greater total calories (β, 1.73; 95% CI, 0.38 to 3.08; P = .01), whereas caloric intake did not differ in male participants (β, 0.68; 95% CI, -0.99 to 2.35; P = .42) after sucralose vs sucrose ingestion.

CONCLUSIONS AND RELEVANCE

These findings suggest that female individuals and those with obesity may be particularly sensitive to disparate neural responsivity elicited by sucralose compared with sucrose consumption.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02945475.

Sucralose and Cardiometabolic Health: Current Understanding from Receptors to Clinical Investigations

The excess consumption of added sugar is consistently found to be associated with weight gain, and a higher risk of type 2 diabetes mellitus, coronary heart disease, and stroke. In an effort to reduce the risk of cardiometabolic disease, sugar is frequently replaced by low- and null-calorie sweeteners (LCSs). Alarmingly, though, emerging evidence indicates that the consumption of LCSs is associated with an increase in cardiovascular mortality risk that is amplified in those who are overweight or obese. Sucralose, a null-caloric high-intensity sweetener, is the most commonly used LCS worldwide, which is regularly consumed by healthy individuals and patients with metabolic disease. To explore a potential causal role for sucralose in increased cardiovascular risk, this present review summarizes the preclinical and clinical data from current research detailing the effects of sucralose on systems controlling food intake, glucose homeostasis, and gut microbiota.

Low-calorie sweeteners in the human diet: scientific evidence, recommendations, challenges and future needs. A symposium report from the FENS 2019 conference

Overconsumption of free sugars, particularly from sugar-sweetened beverages (SSB), has potential negative health impacts. Implementation of a range of public health strategies is needed to reduce intakes of free sugars, including reducing portion sizes, promoting healthier dietary choices and reformulating foods and beverages. Although low-calorie sweeteners (LCS) are a useful tool for reducing energy intake and control glucose response when consuming sweet foods and drinks, several opinions persist about the adverse health effects of LCS, many of which are based on poor, little or no scientific evidence. This symposium report summarises key messages of the presentations and related discussions delivered at a scientific symposium at the 13th European Nutrition Conference (FENS 2019). These presentations considered the scientific evidence and current recommendations about the use and potential benefits of LCS for human health, with a particular focus on current evidence in relation to body weight and glycaemic control. Many of the studies to date on LCS have focused on low-calorie sweetened beverages (LCSB); however, the psychological and behavioural factors influencing consumer beliefs and consumption of LCSB need to be further explored. Current recommendations for LCS use are described, including the conclusions from a recent expert consensus report identifying the challenges that remain with LCS research. Finally, existing knowledge gaps and future actions are described, as well as two large ongoing research projects: SWITCH and SWEET.

Deletion of mu opioid receptors reduces palatable solution intake in a mouse model of binge eating

Binge eating in humans is driven by hedonic properties of food, suggesting that brain reward systems may contribute to this behaviour. We examined the role of mu opioid receptors (MOP) in binge eating by examining sweet solution intake in mice with genetic deletion of the MOP. Wildtype and MOP knockout mice had 4 hours access to food in the home cage combined with limited (4 hours) access to sucrose (17.1% w/v) or saccharin (0.09% w/v), or continuous (24 hours) access to sucrose. Only limited access groups exhibited binge intake, measured as increased solution consumption during the first hour. Knockout mice consumed less solution and food during the first hour as well as less food each day compared with wildtype mice. Limited access groups consumed more food and gained more weight than continuous access groups, and the effect was magnified in saccharin-consuming mice. Indeed, the increased food consumption in animals given limited access to saccharin was so excessive that caloric intake of this group was significantly higher than either of the sucrose groups (limited or continuous access). Within this group, females consumed more food per bodyweight than males, highlighting important sex differences in feeding behaviours under restricted access schedules.

Effects of the Daily Consumption of Stevia on Glucose Homeostasis, Body Weight, and Energy Intake: A Randomised Open-Label 12-Week Trial in Healthy Adults

Stevia is a non-nutritive sweetener, providing sweet taste with no calories. This randomised, controlled, open-label 2-parallel arm trial examined the effects of daily stevia consumption on glycaemia in healthy adults. Secondary endpoints included body weight (BW) and energy intake (EI). Healthy participants (n = 28; aged 25 ± 5y, body mass index 21.2 ± 1.7 kg/m²) were randomised into either the stevia group (n = 14)—required to consume a stevia extract daily—or to the control group (n = 14). At weeks 0 and 12, the glucose and insulin responses to an oral glucose tolerance test were measured; BW and EI were assessed at weeks 0, 6, and 12. There was no significant difference in the glucose or insulin responses. There was a significant main effect of group on BW change (F(1,26) = 5.56, p = 0.026), as the stevia group maintained their weight as opposed to the control group (mean weight change at week 12: −0.22 kg, 95%CI [−0.96, 0.51] stevia group, +0.89 kg, 95%CI [0.16, 1.63] control group). The energy intake was significantly decreased between week 0 and 12 in the stevia group (p = 0.003), however no change was found in the control group (p = 0.973). Although not placebo-controlled, these results suggest that daily stevia consumption does not affect glycaemia in healthy individuals, but could aid in weight maintenance and the moderation of EI.

Acute glycemic and insulinemic effects of low-energy sweeteners: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

It has been suggested that low-energy sweeteners (LES) may be associated with an increased risk of metabolic diseases, possibly due to stimulation of glucose-responsive mechanisms.

OBJECTIVE

We conducted a systematic review and meta-analysis of human intervention studies examining the acute effect of LES intake on postprandial glucose (PPG) and postprandial insulin (PPI) responses, in order to comprehensively and objectively quantify these relations.

METHODS

We systematically searched the Medline, OVID FSTA, and SCOPUS databases until January 2020. Randomized controlled trials comparing acute postprandial effects on PPG and/or PPI after exposure to LES, either alone, with a meal, or with other nutrient-containing preloads to the same intervention without LES were eligible for inclusion. PPG and PPI responses were calculated as mean incremental area under the curve divided by time. Meta-analyses were performed using random effects models with inverse variance weighing.

RESULTS

Twenty-six papers (34 PPG trials and 29 PPI trials) were included. There were no reports of statistically significant differences in the effects of LES on PPG and PPI responses compared with control interventions. Pooled effects of LES intake on the mean change difference in PPG and PPI were -0.02 mmol/L (95% CI: -0.09, 0.05) and -2.39 pmol/L (95% CI: -11.83, 7.05), respectively. The results did not appreciably differ by the type or dose of LES consumed, cointervention type, or fasting glucose and insulin levels. Among patients with type 2 diabetes, the mean change difference indicated a smaller PPG response after exposure to LES compared with the control (-0.3 mmol/L; 95% CI: -0.53, -0.07).

CONCLUSIONS

Ingestion of LES, administered alone or in combination with a nutrient-containing preload, has no acute effects on the mean change in postprandial glycemic or insulinemic responses compared with a control intervention. Apart from a small beneficial effect on PPG (-0.3 mmol/L) in studies enrolling patients with type 2 diabetes, the effects did not differ by type or dose of LES, or fasting glucose or insulin levels. This review and meta-analysis was registered at PROSPERO as CRD42018099608.

Expert consensus on low-calorie sweeteners: facts, research gaps and suggested actions

A consensus workshop on low-calorie sweeteners (LCS) was held in November 2018 where seventeen experts (the panel) discussed three themes identified as key to the science and policy of LCS: (1) weight management and glucose control; (2) consumption, safety and perception; (3) nutrition policy. The aims were to identify the reliable facts on LCS, suggest research gaps and propose future actions. The panel agreed that the safety of LCS is demonstrated by a substantial body of evidence reviewed by regulatory experts and current levels of consumption, even for high users, are within agreed safety margins. However, better risk communication is needed. More emphasis is required on the role of LCS in helping individuals reduce their sugar and energy intake, which is a public health priority. Based on reviews of clinical evidence to date, the panel concluded that LCS can be beneficial for weight management when they are used to replace sugar in products consumed in the diet (without energy substitution). The available evidence suggests no grounds for concerns about adverse effects of LCS on sweet preference, appetite or glucose control; indeed, LCS may improve diabetic control and dietary compliance. Regarding effects on the human gut microbiota, data are limited and do not provide adequate evidence that LCS affect gut health at doses relevant to human use. The panel identified research priorities, including collation of the totality of evidence on LCS and body weight control, monitoring and modelling of LCS intakes, impacts on sugar reduction and diet quality and developing effective communication strategies to foster informed choice. There is also a need to reconcile policy discrepancies between organisations and reduce regulatory hurdles that impede low-energy product development and reformulation.

Artificial sweeteners impair endothelial vascular reactivity: Preliminary results in rodents

BACKGROUND AND AIMS

Prospective epidemiological studies highlighted recently the link between artificial sweeteners (AS) consumption and the risk of developing cardiometabolic diseases. However, underlying mechanisms remain unknown. Thus, the aim of this preliminary study was to characterize, in a healthy rat population, the effect of chronic AS consumption on body composition and vascular function, an early marker for cardiovascular disease.

METHODS AND RESULTS

Healthy Wistar rats followed a 10-week standard diet including the consumption of water sweetened or not with a sucralose/acesulfame potassium solution at different concentrations: for moderate consumption at 1 and 2 mg.kg^-1.day^-1, respectively or high intake at 15 and 15 mg.kg^-1.day^-1 for both molecules (acceptable daily intake). Body fat composition has been evaluated and ex vivo aortic vasomotor function has been investigated with a pharmacological approach.

CONCLUSION

Both groups of AS-treated rats showed a significant increase in subcutaneous and perirenal adipose tissue mass storage, without changes in total body mass. However, rats that have consumed AS at Acceptable Daily Intake (ADI) concentration revealed a significant vascular endothelial dysfunction compared to other groups. These results are interesting because they will help to better explain the observed increase in cardiometabolic risk.

Stevia Beverage Consumption prior to Lunch Reduces Appetite and Total Energy Intake without Affecting Glycemia or Attentional Bias to Food Cues: A Double-Blind Randomized Controlled Trial in Healthy Adults

BACKGROUND

Stevia is a zero-calorie alternative to caloric sugars. Substituting caloric sweeteners with noncaloric sweeteners reduces available energy, but their effects on appetite, subsequent food intake, and neurocognitive responses are still unclear.

OBJECTIVE

The aim was to examine whether sweetness with or without calories influences food intake, appetite, blood glucose concentrations, and attentional bias (AB) to food cues.

METHODS

This was a randomized, controlled, double-blind crossover study. Healthy participants [n = 20; aged 27 ± 5 y,  55% female; BMI (kg/m2): 21.8 ± 1.5] completed 5 visits, consuming 5 study beverages: 330 mL water (control, no sweet taste, no calories) and either 330 mL water containing 40 g glucose or sucrose (sweet taste; calories, both 160 kcal), maltodextrin (no sweet taste; calories, 160 kcal), or 240 ppm stevia (sweet taste, no calories). Glucose and stevia beverages were matched for sweetness. Subjective appetite ratings and blood glucose were measured at baseline and at 15, 30, and 60 min postprandially. At 15 min participants performed a visual-dot probe task to assess AB to food cues; at 30 min, participants were offered an ad libitum lunch; food intake was measured.

RESULTS

Subjective appetite ratings showed that preload sweetness and calorie content both affected appetite. The total AUC for glycemia was significantly higher after the caloric beverages (mean ± SD: maltodextrin, 441 ± 57.6;  glucose, 462 ± 68.1;  sucrose, 425 ± 53.6 mmol × min × L-1 ) compared with both stevia (320 ± 34.2 mmol × min × L-1) and water (304 ± 32.0 mmol × min × L-1) (all P < 0.001). Total energy intake (beverage and meal) was significantly lower after the stevia beverage (727 ± 239 kcal) compared with water (832 ± 198 kcal,  P = 0.013), with no significant difference between the water and caloric beverages (P = 1.00 for water vs. maltodextrin, glucose, and sucrose). However, food-related AB did not differ across conditions (P = 0.140).

CONCLUSIONS

This study found a beneficial and specific effect of a stevia beverage consumed prior to a meal on appetite and energy intake in healthy adults. This trial is registered at clinicaltrials.gov as NCT03711084.

Perspective: Standards for Research and Reporting on Low-Energy ("Artificial") Sweeteners

Widely differing views exist among experts, policy makers, and the general public with regard to the potential risks and benefits of reduced- or low-energy sweeteners (LES) in the diet. These views are informed and influenced by different types of research in LES, with differing hypotheses, designs, interpretation, and communication. Given the high level of interest in LES, and the public health relevance of the research evidence base, it is important that all aspects of the research process are framed and reported in an appropriate and balanced manner. In this Perspective, we identify and give examples of a number of issues relating to research and reviews on LES, which may contribute toward apparent inconsistencies in the content and understanding of the totality of evidence. We conclude with a set of recommendations for authors, reviewers and journal editors, as general guidance to improve and better standardize the quality of LES research design, interpretation, and reporting. These focus on clarity of underlying hypotheses, characterization of exposures, and the placement and weighting of new research within the wider context of related prior work.

Sugar-sweetened beverages consumption are associated with behavioral problems among preschoolers: A population based cross-sectional study in China

BACKGROUND

Previous researches showed a positive association between sugar-sweetened beverages (SSB) and behavioral problems, but there is a little known in Chinese preschoolers.

METHODS

A population based survey was conducted in 109 kindergartens, in 11 cities across China. Children's SSB consumption was assessed by questionnaires completed by caregivers. The Strengths and Difficulties Questionnaire (SDQ) and the Clancy Autism Behavior Scale (CABS) were used to assessing the children's behavioral problems.

RESULT

The prevalence of SSB consumption ≥ 1 time/day was 24.9%. The adjusted odds ratios (95% confidence interval) of having elevated total difficulties by increasing levels of SSB consumption were 1.00, 1.13 (1.05, 1.22) and 1.24 (1.10, 1.41) (P for trend < 0.001), respectivly. Similar results were found in emotional symptoms, conduct problems, peer problems, and CABS. No significantly increased the risk of hyperactivity and prosocial were observed for higher SSB consumption. No gender differences were found in these associations.

LIMITATIONS

This is a cross-sectional survey and the causal relationship is unclear.

CONCLUSIONS

Higher SSB consumption is positively associated with behavioral problems among preschoolers in China.

Non-nutritive sweeteners are in concomitant with the formation of endogenous and exogenous advanced glycation end-products

This study investigated the role of non-nutritive sweeteners in the formation of advanced glycation end-products (AGEs) and their reactive intermediates using endogenous and exogenous models. In the endogenous model, xylitol and sorbitol formed similar levels of reactive intermediates compared to sucralose. Protein-bound fluorescent AGEs, N^ε-carboxymethyllysine (CML), and N^ε-carboxyethyllysine (CEL) levels in the xylitol and sorbitol treatment were significantly higher compared to the sucralose treatment. In the exogenous model, sucralose treatment showed significantly higher glyoxal and fructosamine levels compared to xylitol and sorbitol, respectively. However, protein-bound fluorescent AGEs, CML, and CEL were lower in the sucralose treatment compared to other sugar treatments. The data suggest that the structure of sugar alcohols which are similar to reducing sugars may contribute to the formation of AGEs and their reactive intermediates in the endogenous model. The long-term effects of non-nutritive sweeteners consumption on AGEs formation and health implications should be verified with population studies.

Low-calorie sweeteners cause only limited metabolic effects in mice

There are widespread concerns that low-calorie sweeteners (LCSs) cause metabolic derangement. These concerns stem in part from prior studies linking LCS consumption to impaired glucose tolerance in humans and rodents. Here, we examined this linkage in mice. In experiment 1, we provided mice with chow, water, and an LCS-sweetened solution (saccharin, sucralose, or acesulfame K) for 28 days and measured glucose tolerance and body weight across the exposure period. Exposure to the LCS solutions did not impair glucose tolerance or alter weight gain. In experiment 2, we provided mice with chow, water, and a solution containing saccharin, glucose, or a mixture of both for 28 days, and tested for metabolic changes. Exposure to the saccharin solution increased the insulinemic response of mice to the glucose challenge, and exposure to the saccharin + glucose solution increased the rate of glucose uptake during the glucose challenge. However, neither of these test solutions altered glucose tolerance, insulin sensitivity, plasma triglycerides, or percent body fat. In contrast, exposure to the glucose solution increased glucose tolerance, early insulin response, insulin sensitivity, and percent body fat. We conclude that whereas the LCS-containing solutions induced a few metabolic changes, they were modest compared with those induced by the glucose solution.

Non-nutritive sweeteners and type 2 diabetes: Should we ring the bell?

Non-nutritive sweeteners (NNS) were thought to be healthy sugar substitutes used instead of sugar for caloric and glycemic control but evidences blaming them for contributing to type 2 diabetes (T2D) are rising. We aim to investigate whether NNS consumption prevents or causes T2D. Articles of all designs conducted on humans were retrieved from three databases in addition to manually reviewed articles. The literature is highly heterogeneous, and conclusions vary with different studies' types and designs. While some studies highlighted the neutral effect of NNS on T2D or reported inconclusive evidences to make their conclusion, others either found NNS culprit for increasing the risk for T2D or reported their protective effect against it. Those results were changing after adjustment for confounders. Due to the inconsistency in the literature, well-designed studies that take into consideration all types of confounders are needed. RESEARCH IN CONTEXT: Evidence before this study: The epidemic of obesity is the result of many factors and causes several chronic diseases where its association with type 2 diabetes is well established. The first line of treatment for obesity is lifestyle changes including physical activity and dietary intervention where non-nutritive sweeteners have received a high attention; those were thought to be healthy sugar substitutes used instead of sugar for caloric and glycemic control but several evidences have blamed them for having a role in the development of type 2 diabetes. In our paper, we aim to investigate whether non-nutritive sweeteners consumption prevents or causes type 2 diabetes. To respond to this question, an extensive search of the literature was conducted between October and December 2018 using the key terms "non-nutritive sweeteners", "artificial sweeteners", "high-intensity sweeteners", "type 2 diabetes" and "prediabetes" on three databases including Pubmed, Science direct and Scopus. Additional search for relevant articles was carried out manually from the reference list of selected articles. Animal studies, studies involving sugar alcohols or those conducted on children, adolescents, pregnant women, or on participants with diabetes were excluded. Human studies conducted from January 2004 to October 2018 were included and divided into observational, interventional, and systematic review and meta-analysis for discussion and analysis Added value of this study: In the literature, the term high-intensity sweeteners has been used interchangeably with non-nutritive sweeteners, artificial sweeteners or low-calorie sweeteners but few articles, if any, clarified the difference between them. In our review, we gathered the different definitions and classifications and summarized them to help the reader understand the difference. Since artificial sweeteners are nowadays widely used and prescribed for caloric and glycemic control, and are unintentionally consumed because they enter in the manufacturing process of thousands of products and due to their potential side effects reported in several studies, we found it interesting to gather, summarize and discuss the available results assessing the role of non-nutritive sweeteners in the development of type 2 diabetes. Those results showed the heterogeneity of the literature and the difficulty in having a firm conclusion; this helps researchers to profit from our study and to conduct well-designed studies leading to firm conclusions and recommendations. Implications of all the available evidence: Despite the absence of strong conclusion that confirms the fact that non-nutritive sweeteners consumption increases the risk for diabetes, no firm conclusion rejects this statement. In result, the existing evidences in addition to our study should ring the bell for clinicians and practitioners who are prescribing those sugar-alternatives as "healthy substitute" to white sugar. Moreover, this encourages the manufacturers to search for a healthy natural alternative to artificial sweeteners to be used in the manufacturing process.

Sweet taste receptor agonists alter ovarian functions and ovarian cycles in aged mice

Saccharine sodium and rebaudioside A are low-calorie sweeteners, and the biologic effects of these sweeteners in rat ovaries are related to the activity of sweet taste receptors. Data on the impact and regulatory mechanisms underlying such sweeteners on the reproduction of aged animals are currently lacking. In the present study we assessed how the consumption of sweeteners affects the ovarian cycle, ovulation, biochemical indices, and other biologic functions. Thirty-six 1-year-old mice were randomly divided into 3 groups: a control (C) group receiving regular water, a saccharin sodium group receiving a 7.5 mM solution, and the rebaudioside A group receiving a 2.5 mM solution for 30 days. We observed no significant changes in body weights in any group. However, uterine weight in the rebaudioside A group significantly increased in diestrus, and we recorded a significant increase in the percentage of abnormal estrous cycles and the number of corpora lutea in the treatment groups. TUNEL staining and Immunoreactivity for the apoptosis-inducing factor (AIF) confirmed apoptosis in granulosa cells, oocyte, and corpus luteum. Serum glucose increased significantly in both treatment groups and there was a significant increase in cholesterol in the rebaudioside A group. Furthermore, the saccharin sodium-treated group exhibited elevated serum progesterone levels compared with the other groups. In conclusion, sweeteners manifested deleterious effects on reproductive indices in aged mice.

Energy Expenditure, Carbohydrate Oxidation and Appetitive Responses to Sucrose or Sucralose in Humans: A Pilot Study

Background: In light of obesity, replacing sugar with non-nutritive sweeteners is commonly used to reduce sugar content of food products. This study aimed to compare human energy expenditure (EE), carbohydrate oxidation and food intake after the ingestion of test foods sweetened with sucrose or a non-nutritive sweetener. Methods: This was an acute crossover feeding study that entailed consumption of three test foods: jelly sweetened with 50 g sucrose (SUCROSE), with 120 mg of sucralose only (NNS), or 120 mg sucralose but matched in carbohydrate with 50 g maltodextrin (MALT). On test days, participants arrived at the research facility after an overnight fast. Resting energy expenditure (indirect calorimeter) was measured for 30 min followed by jelly consumption. Participants’ EE and substrate oxidation were measured for 90 min subsequently. After EE assessment, participants completed a meal challenge before leaving the research facility, and recorded food intake for the remaining day. Subjective appetite ratings were assessed before and after test foods and meal challenge. Results: Eleven participants completed the study. EE was higher in SUCROSE and MALT than NNS, but not statistically significant. Carbohydrate oxidation was SUCROSE > MALT > NNS (p < 0.001). Earlier and bigger rise in carbohydrate oxidation was observed in SUCROSE than MALT, although both were carbohydrate-matched. NNS did not promote energy expenditure, carbohydrate oxidation or stimulate appetite. Conclusions: Foods sweetened with sucrose or non-nutritive sweeteners but matched in carbohydrate content have different effects on human EE and carbohydrate oxidation. Sucralose alone did not affect EE, but lower energy in the test food from sugar replacement was eventually fully compensated. Findings from this pilot study should be verified with bigger clinical studies in the future to establish clinical relevance.

A randomized controlled trial contrasting the effects of 4 low-calorie sweeteners and sucrose on body weight in adults with overweight or obesity

BACKGROUND

Low-calorie sweeteners (LCSs) provide sweetness with little or no energy. However, each LCS's unique chemical structure has potential to elicit different sensory, physiological, and behavioral responses that affect body weight.

OBJECTIVE

The purpose of this trial was to compare the effects of consumption of 4 LCSs and sucrose on body weight, ingestive behaviors, and glucose tolerance over a 12-wk intervention in adults (18-60 y old) with overweight or obesity (body mass index 25-40 kg/m2).

METHODS

In a parallel-arm design, 154 participants were randomly assigned to consume 1.25-1.75 L of beverage sweetened with sucrose (n = 39), aspartame (n = 30), saccharin (n = 29), sucralose (n = 28), or rebaudioside A (rebA) (n = 28) daily for 12 wk. The beverages contained 400-560 kcal/d (sucrose treatments) or <5 kcal/d (LCS treatments). Anthropometric indexes, energy intake, energy expenditure, appetite, and glucose tolerance were measured at baseline. Body weight was measured every 2 wk with energy intake, expenditure, and appetite assessed every 4 wk. Twenty-four-hour urine collections were completed every 4 wk to determine study compliance via para-aminobenzoic acid excretion.

RESULTS

Of the participants enrolled in the trial, 123 completed the 12-wk intervention. Sucrose and saccharin consumption led to increased body weight across the 12-wk intervention (Δweight = +1.85 ± 0.36 kg and +1.18 ± 0.36 kg, respectively; P ≤ 0.02) and did not differ from each other. There was no significant change in body weight with consumption of the other LCS treatments compared with baseline, but change in body weight for sucralose was negative and significantly lower compared with all other LCSs at week 12 (weight difference ≥ 1.37 ± 0.52 kg, P ≤ 0.008). Energy intake decreased with sucralose consumption (P = 0.02) and ingestive frequency was lower for sucralose than for saccharin (P = 0.045). Glucose tolerance was not significantly affected by any of the sweetener treatments.

CONCLUSIONS

Sucrose and saccharin consumption significantly increase body weight compared with aspartame, rebA, and sucralose, whereas weight change was directionally negative and lower for sucralose compared with saccharin, aspartame, and rebA consumption. LCSs should be categorized as distinct entities because of their differing effects on body weight. This trial was registered at clinicaltrials.gov as NCT02928653.

Consumption of low-calorie sweetened beverages and water is associated with lower intake of carbohydrates and sugars and not associated with glycemic response in U.S. non-diabetic adolescents: Results from the 2001-2014 National Health and Nutrition Examination Surveys

OBJECTIVES

Consumption of no- and low-calorie sweetened beverages (LCSBs) in the United States appears to be on the rise. To our knowledge, the relationships between LCSB consumption and dietary intake and metabolic outcomes in adolescents have not been thoroughly investigated. The aim of this study was to evaluate possible associations between LCSB and water consumption with nutrient intake and prediabetes criteria among adolescents who were free of diabetes.

METHODS

This cross-sectional study evaluated possible associations between LCSB consumption and water consumption using a 24-h diet recall from the National Health and Nutrition Examination Survey (NHANES) 2001-2014 in 8868 adolescents 12 to 18 y of age who were free of diabetes.

RESULTS

Compared with consuming <1 serving/d, consuming ≥1 serving/d of either LCSB or water was significantly associated with lower consumption of carbohydrates (LCSB: -22 g; water: -15 g), total sugars (LCSB: -29 g; water: -20 g), and added sugars (LCSB: -5.7 tsp eq; water: -6 tsp eq). Neither LCSB nor water intake were associated with any measures of glycemic response.

CONCLUSIONS

These findings suggest that consuming ≥1 serving/d of either LCSB or water is not associated with an increased risk for prediabetes. Confirmation of these findings with a larger sample within the context of a randomized clinical trial would further suggest that LCSBs may represent an additional beverage option other than water for adolescents to help moderate overall dietary sugar intake.

Effects of Sweeteners on the Gut Microbiota: A Review of Experimental Studies and Clinical Trials

The consumption of sugar-free foods is growing because of their low-calorie content and the health concerns about products with high sugar content. Sweeteners that are frequently several hundred thousand times sweeter than sucrose are being consumed as sugar substitutes. Although nonnutritive sweeteners (NNSs) are considered safe and well tolerated, their effects on glucose intolerance, the activation of sweet taste receptors, and alterations to the composition of the intestinal microbiota are controversial. This review critically discusses the evidence supporting the effects of NNSs, both synthetic sweeteners (acesulfame K, aspartame, cyclamate, saccharin, neotame, advantame, and sucralose) and natural sweeteners (NSs; thaumatin, steviol glucosides, monellin, neohesperidin dihydrochalcone, and glycyrrhizin) and nutritive sweeteners (polyols or sugar alcohols) on the composition of microbiota in the human gut. So far, only saccharin and sucralose (NNSs) and stevia (NS) change the composition of the gut microbiota. By definition, a prebiotic is a nondigestible food ingredient, but some polyols can be absorbed, at least partially, in the small intestine by passive diffusion: however, a number of them, such as isomaltose, maltitol, lactitol, and xylitol, can reach the large bowel and increase the numbers of bifidobacteria in humans. Further research on the effects of sweeteners on the composition of the human gut microbiome is necessary.

Metabolic Effects of Low-Calorie Sweeteners: A Brief Review

Low-calorie sweeteners (LCS) are found in a variety of foods and beverages, yet their role in diet, weight, and obesity-related chronic disease is controversial. This article summarizes proceedings from one of four presentations during a preconference session entitled "Low-Calorie Sweeteners and Weight Management," which took place at the 2017 Obesity Society Annual Meeting in Washington, District of Columbia. The objective of this brief review is to summarize findings of observational and interventional studies of LCS effects on weight and metabolic health and to provide potential explanations for their discrepant results. Key research priorities for advancing the understanding of the role of LCS in weight and chronic disease are also discussed. The existing literature suggests that LCS consumption is consistently associated with obesity, diabetes, and related cardiometabolic conditions in observational studies. Although several plausible mechanisms have been proposed to explain these associations and have received considerable support in cellular and rodent models, the relevance of these mechanisms to humans has yet to be confirmed. Meanwhile, randomized controlled trials demonstrate that NNS may benefit weight loss and weight maintenance. This is the case particularly when LCS are administered in the context of behavioral weight loss support and are consumed knowingly by habitual LCS consumers. Although these findings suggest that LCS may be useful for weight control among those cognitively engaged in weight loss and who are aware of their LCS consumption, LCS administration in these studies does not reflect typical consumption. Furthermore, few interventional studies have assessed the role of LCS on metabolic outcomes other than body weight. Additional factors must be considered before recommending LCS for weight management and chronic disease prevention and further study of LCS effects on a variety of cardiometabolic outcomes, including visceral adiposity and glucose homeostasis is warranted.

Ibero⁻American Consensus on Low- and No-Calorie Sweeteners: Safety, Nutritional Aspects and Benefits in Food and Beverages

International scientific experts in food, nutrition, dietetics, endocrinology, physical activity, paediatrics, nursing, toxicology and public health met in Lisbon on 2⁻4 July 2017 to develop a Consensus on the use of low- and no-calorie sweeteners (LNCS) as substitutes for sugars and other caloric sweeteners. LNCS are food additives that are broadly used as sugar substitutes to sweeten foods and beverages with the addition of fewer or no calories. They are also used in medicines, health-care products, such as toothpaste, and food supplements. The goal of this Consensus was to provide a useful, evidence-based, point of reference to assist in efforts to reduce free sugars consumption in line with current international public health recommendations. Participating experts in the Lisbon Consensus analysed and evaluated the evidence in relation to the role of LNCS in food safety, their regulation and the nutritional and dietary aspects of their use in foods and beverages. The conclusions of this Consensus were: (1) LNCS are some of the most extensively evaluated dietary constituents, and their safety has been reviewed and confirmed by regulatory bodies globally including the World Health Organisation, the US Food and Drug Administration and the European Food Safety Authority; (2) Consumer education, which is based on the most robust scientific evidence and regulatory processes, on the use of products containing LNCS should be strengthened in a comprehensive and objective way; (3) The use of LNCS in weight reduction programmes that involve replacing caloric sweeteners with LNCS in the context of structured diet plans may favour sustainable weight reduction. Furthermore, their use in diabetes management programmes may contribute to a better glycaemic control in patients, albeit with modest results. LNCS also provide dental health benefits when used in place of free sugars; (4) It is proposed that foods and beverages with LNCS could be included in dietary guidelines as alternative options to products sweetened with free sugars; (5) Continued education of health professionals is required, since they are a key source of information on issues related to food and health for both the general population and patients. With this in mind, the publication of position statements and consensus documents in the academic literature are extremely desirable.

Effects of Consuming Preloads with Different Energy Density and Taste Quality on Energy Intake and Postprandial Blood Glucose

Consumption of reduced energy dense foods and drink has the potential to reduce energy intake and postprandial blood glucose concentrations. In addition, the taste quality of a meal (e.g., sweet or savoury) may play a role in satiation and food intake. The objective of this randomised crossover study was to examine whether energy density and taste quality has an impact on energy intake and postprandial blood glucose response. Using a preload design, participants were asked to consume a sweet ("Cheng Teng") or a savoury (broth) preload soup in high energy density (HED; around 0.50 kcal/g; 250 kcal) or low energy density (LED; around 0.12 kcal/g; 50 kcal) in mid-morning and an ad libitum lunch was provided an hour after the preload. Participants recorded their food intake for the rest of the day after they left the study site. Energy compensation and postprandial blood glucose response were measured in 32 healthy lean males (mean age = 28.9 years, mean BMI = 22.1 kg/m²). There was a significant difference in ad libitum lunch intake between treatments (p = 0.012), with higher intake in sweet LED and savoury LED compared to sweet HED and savoury HED. Energy intake at subsequent meals and total daily energy intake did not differ between the four treatments (both p ≥ 0.214). Consumption of HED preloads resulted in a larger spike in postprandial blood glucose response compared with LED preloads, irrespective of taste quality (p < 0.001). Energy density rather than taste quality plays an important role in energy compensation and postprandial blood glucose response. This suggests that regular consumption of low energy-dense foods has the potential to reduce overall energy intake and to improve glycemic control.