Low calorie sweeteners: Science and controversy: Conference proceedings

Just noticeable difference in sweetness perception of cola: Small changes in sugar are noticeable

Sugar-sweetened beverage consumption contributes to obesity and related diseases. Fortunately, beverages with reduced sweetness are a growing category in the beverage industry. These lower sweetness products could be useful for reducing the total dietary intake of sugar, but publicly available data are sparse on how much sweetness can be reduced without the change becoming noticeable to consumers. We investigated the just noticeable difference (JND) in sweetness of a cola-flavored carbonated beverage. Two sensory tests were conducted to detect the JND from 12.00% w/w sucrose. In each test, we used cola-flavored seltzer water with five decreasing sucrose concentrations (test 1:8.02-12.00% w/w; test 2:10.21-12.00% w/w). In both tests, samples were paired with the 12.00% reference, and participants were instructed to identify the sweeter sample. Participants correctly identified the reference sample at 10.21% in test one (p = .0039) and at 10.89% (p = .014) in test two. The data indicate that in a cola beverage, sucrose can be reduced by ~9.25% of the original concentration (12.00-10.89% w/w) before the sweetness becomes apparent to consumers. However, further work should consider whether sugar reductions greater than 9.25% would be acceptable, even if the difference in sweetness is apparent.

Practical Applications

These data could help researchers and industry product developers know how much sugar can be reduced from a cola-flavored beverage before the change is apparent to consumers.

The effects of low-calorie sweeteners on energy intake and body weight: a systematic review and meta-analyses of sustained intervention studies

Previous meta-analyses of intervention studies have come to different conclusions about effects of consumption of low-calorie sweeteners (LCS) on body weight. The present review included 60 articles reporting 88 parallel-groups and cross-over studies ≥1 week in duration that reported either body weight (BW), BMI and/or energy intake (EI) outcomes. Studies were analysed according to whether they compared (1) LCS with sugar, (2) LCS with water or nothing, or (3) LCS capsules with placebo capsules. Results showed an effect in favour of LCS vs sugar for BW (29 parallel-groups studies, 2267 participants: BW change, -1.06 kg, 95% CI -1.50 to -0.62, I2 = 51%), BMI and EI. Effect on BW change increased with 'dose' of sugar replaced by LCS, whereas there were no differences in study outcome as a function of duration of the intervention or participant blinding. Overall, results showed no difference in effects of LCS vs water/nothing for BW (11 parallel-groups studies, 1068 participants: BW change, 0.10 kg, 95% CI -0.87 to 1.07, I2 = 82%), BMI and EI; and inconsistent effects for LCS consumed in capsules (BW change: -0.28 kg, 95% CI -0.80 to 0.25, I2 = 0%; BMI change: 0.20 kg/m2, 95% CI 0.04 to 0.36, I2 = 0%). Occurrence of adverse events was not affected by the consumption of LCS. The studies available did not permit robust analysis of effects by LCS type. In summary, outcomes were not clearly affected when the treatments differed in sweetness, nor when LCS were consumed in capsules without tasting; however, when treatments differed in energy value (LCS vs sugar), there were consistent effects in favour of LCS. The evidence from human intervention studies supports the use of LCS in weight management, constrained primarily by the amount of added sugar that LCS can displace in the diet.

Effects of nonnutritive sweeteners on body weight and BMI in diverse clinical contexts: Systematic review and meta-analysis

There is an ongoing debate about the possible influences of nonnutritive sweeteners (NNS) on body weight. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) with NNS to assess their impact on body weight. We systematically searched for RCTs at least 4 weeks in duration, evaluating the effect of NNS on body weight, both in subjects with healthy weight and in subjects with overweight/obesity at any age, and compared the effects of NNS vs caloric and noncaloric comparators. The primary outcome was the difference in body weight between NNS and comparators. Twenty studies were eligible (n = 2914). Participants consuming NNS showed significant weight/BMI differences favouring NNS compared with nonusers. Grouping by nature of comparator revealed that NNS vs placebo/no intervention and NNS vs water produced no effect. When comparing NNS vs sucrose, significant weight/BMI differences appeared favouring NNS. Consumption of NNS led to significantly negative weight/BMI differences in unrestricted energy diets, but not in weight-reduction diets. Participants with overweight/obesity and adults showed significant favourable weight/BMI differences with NNS. Data suggest that replacing sugar with NNS leads to weight reduction, particularly in participants with overweight/obesity under an unrestricted diet, information that could be utilized for evidence-based public policy decisions.

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.

SWEET MAPS: A Conceptualization of Low-Calorie Sweetener Consumption Among Young Adults

BACKGROUND

The extent to which low-calorie sweeteners (LCSs) are helpful or harmful for weight management and metabolic health is unclear, because LCS effects may depend on the context in which they are consumed.

OBJECTIVE

To develop a conceptual framework for LCS consumption.

METHODS

Young adults ages 18-35 y, who reported LCS consumption, were recruited from a private, urban, university in the mid-Atlantic United States. Concept mapping, a mixed-method approach was used to identify, organize, and quantify determinants of LCS consumption. First, participants (n = 68) identified reasons for their LCS consumption through brainstorming; content analysis of those reasons identified 37 specific determinants of LCS consumption. Second, participants (n = 93) sorted all 37 determinants conceptually. Third, participants (n = 97) rated the extent to which each of the 37 determinants was reflective of their own consumption. Similarity matrices, multidimensional scaling, and hierarchical cluster analysis produced a series of 2-dimensional concept maps (SWEET MAPS).

RESULTS

The SWEET MAPS identified 37 determinants, organized within 8 factors reflective of 3 overarching motives: perceived health benefits, palatability, and accessibility of LCSs. At the determinant level, the most highly rated determinants that exceeded the boundary (rating >3.0) were: "I want something that tastes sweet," "I am trying to maintain/control my weight," "They contain fewer calories," "They are available," and "I want to save calories because I am eating a high-calorie meal."

CONCLUSIONS

LCS consumption is a function of many inter-related determinants spanning biological, psychological, and social domains. The SWEET MAPS are an important and novel use of concept mapping methods that can be used to inform the design and interpretation of future studies evaluating LCS effects.

Prevalence of low-calorie sweetener intake in South Asian adults

BACKGROUND

Consumption of low-calorie sweeteners (LCS) has increased in the US and is associated with cardiometabolic risk. No data exist on LCS consumption in South Asians.

AIM

The aim of this study was to assess the prevalence of LCS use across socio-demographic characteristics, chronic disease status, and cardiometabolic risk factors.

METHODS

Cross-sectional analyses were conducted using data from the Mediators of Atherosclerosis in South Asians Living in America study (N = 892; 47% women; mean age = 55 (standard deviation = 9.4) y). Chi-squared and ANOVA tests were used to compare LCS consumption across socio-demographic characteristics and cardiometabolic risk factors.

RESULTS

Twenty-two percent of participants reported LCS use, with higher consumption among men and those with longer residency in the US. LCS use was associated with adiposity and higher odds of hypertension, high cholesterol, and diabetes.

CONCLUSIONS

LCS use is prevalent among South Asians, emphasizing the need for long-term, prospective studies to investigate its role in incident cardiometabolic risk in an already metabolically vulnerable population.

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.

Nonnutritive Sweeteners in Weight Management and Chronic Disease: A Review

OBJECTIVE

The objective of this review was to critically review findings from recent studies evaluating the effects of nonnutritive sweeteners (NNSs) on metabolism, weight, and obesity-related chronic diseases. Biologic mechanisms that may explain NNS effects will also be addressed.

METHODS

A comprehensive review of the relevant scientific literature was conducted.

RESULTS

Most cross-sectional and prospective cohort studies report positive associations between NNS consumption, body weight, and health conditions, including type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease. Although findings in cellular and rodent models suggest that NNSs have harmful effects on metabolic health, most randomized controlled trials in humans demonstrate marginal benefits of NNS use on body weight, with little data available on other metabolic outcomes.

CONCLUSIONS

NNS consumption is associated with higher body weight and metabolic disease in observational studies. In contrast, randomized controlled trials demonstrate that NNSs may support weight loss, particularly when used alongside behavioral weight loss support. Additional long-term, well-controlled intervention studies in humans are needed to determine the effects of NNSs on weight, adiposity, and chronic disease under free-living conditions.

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.

Low-Calorie Sweeteners: Disturbing the Energy Balance Equation in Adolescents?

OBJECTIVE

The aim of this study was to investigate the relationship between low-calorie sweeteners (LCSs), energy intake, and weight in US youth.

METHODS

Data were collected from individuals aged 2 to 19 years who participated in the National Health and Nutrition Examination Survey (NHANES) 2009-2010 (n  =  3,296), 2011-2012 (n  =  3,139), and 2013-2014 (n  =  3,034). Logistic regression, unadjusted and adjusted for age, sex, race/ethnicity, income, energy intake, and physical activity, was used to estimate the odds of obesity in LCS consumers versus nonconsumers, both overall and across product categories (foods vs. beverages) and sociodemographic subgroups.

RESULTS

Among adolescents, the odds of obesity were 55% and 70% higher in LCS beverage consumers than in nonconsumers in unadjusted and adjusted models, respectively. Energy intakes did not differ based on LCS consumption. In contrast, associations between LCS consumption and obesity risk were not statistically significant among children (2-11 y old), except in boys and those who self-identified as Hispanic.

CONCLUSIONS

LCS consumption is associated with increased odds of obesity among adolescents. This relationship is strikingly independent of total energy intake. Although findings should be interpreted cautiously because of the limitations of self-reported dietary intake and the cross-sectional nature of this analysis, the observational analysis in this study supports the need to investigate the mechanisms by which LCS may influence body weight, independently of changes in energy intake.

Personal Variation in Preference for Sweetness: Effects of Age and Obesity

BACKGROUND

Use of nonnutritive sweeteners (NNSs), which provide sweet taste with few to no calories, has increased, but data on whether children's hedonic responses to NNSs differ from nutritive sugars or from adults' hedonic responses are limited.

METHODS

Most preferred levels of sucrose and the NNS sucralose were determined via a forced-choice tracking procedure in 48 children, 7-14 years (mean = 10 years), and 34 adults. Each participant also rated the liking of these taste stimuli, as well as varying concentrations of aspartame on 3- and 5-point facial hedonic scales. Anthropometric measures were obtained, and motives for palatable food intake were assessed with the Palatable Eating Motives Scale (PEMS, adults) and Kids PEMS.

RESULTS

While use of the 3-point scale showed no age-related differences in liking of sweeteners, the 5-point scale showed that more children than adults liked higher concentrations of sucrose, sucralose, and aspartame, and the tracking procedure showed that children most preferred higher concentrations of sucrose and sucralose than adults. Regardless of age, sweet preference did not differ between obese and nonobese participants and showed no association with motives for eating palatable foods. Children's body mass index z-scores were positively associated with social and conformity motive scores for eating palatable foods.

CONCLUSION

Research should move beyond measures of variation in sweet taste hedonics to include identifying motives, and the physiological and psychological consequences of eating sweets, to shed light on what children are more vulnerable to develop unfavorable eating habits, increasing risk for obesity, and other diseases.

Hormonal responses to non-nutritive sweeteners in water and diet soda

Background

Non-nutritive sweeteners (NNS), especially in form of diet soda, have been linked to metabolic derangements (e.g. obesity and diabetes) in epidemiologic studies. We aimed to test acute metabolic effects of NNS in isolation (water or seltzer) and in diet sodas.

Methods

We conducted a four-period, cross-over study at the National Institutes of Health Clinical Center (Bethesda, Maryland). Thirty healthy adults consumed 355 mL water with 0 mg, 68 mg, 170 mg, and 250 mg sucralose, and 31 individuals consumed 355 mL caffeine-free Diet Rite Cola™, Diet Mountain Dew™ (18 mg sucralose, 18 mg acesulfame-potassium, 57 mg aspartame), and seltzer water with NNS (68 mg sucralose and 41 mg acesulfame-potassium, equivalent to Diet Rite Cola™) in randomized order, prior to oral glucose tolerance tests. Blood samples were collected serially for 130 min. Measures included GLP-1, GIP, glucose, insulin, C-peptide, glucose absorption, gastric emptying, and subjective hunger and satiety ratings.

Results

Diet sodas augmented active GLP-1 (Diet Rite Cola™ vs. seltzer water, AUC, p = 0.039; Diet Mountain Dew™ vs. seltzer water, AUC, p = 0.07), but gastric emptying and satiety were unaffected. Insulin concentrations were nominally higher following all NNS conditions without altering glycemia. Sucralose alone (at any concentration) did not affect metabolic outcomes.

Conclusions

Diet sodas but not NNS in water augmented GLP-1 responses to oral glucose. Whether the trends toward higher insulin concentrations after NNS are of clinical importance remains to be determined. Our findings emphasize the need to test metabolic effects of NNS after chronic consumption.

Trial registration

The data for this manuscript were gathered from clinical trial #NCT01200940.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-016-0129-3) contains supplementary material, which is available to authorized users.