Intense sweeteners, energy intake and the control of body weight

Sensory influences on food intake control: moving beyond palatability

The sensory experience of eating is an important determinant of food intake control, often attributed to the positive hedonic response associated with certain sensory cues. However, palatability is just one aspect of the sensory experience. Sensory cues based on a food's sight, smell, taste and texture are operational before, during and after an eating event. The focus of this review is to look beyond palatability and highlight recent advances in our understanding of how certain sensory characteristics can be used to promote better energy intake control. We consider the role of visual and odour cues in identifying food in the near environment, guiding food choice and memory for eating, and highlight the ways in which tastes and textures influence meal size and the development of satiety after consumption. Considering sensory characteristics as a functional feature of the foods and beverages we consume provides the opportunity for research to identify how sensory enhancements might be combined with energy reduction in otherwise palatable foods to optimize short-term energy intake regulation in the current food environment. Moving forward, the challenge for sensory nutritional science will be to assess the longer-term impact of these principles on weight management.

Effects on weight loss in adults of replacing diet beverages with water during a hypoenergetic diet: a randomized, 24-wk clinical trial

BACKGROUND

Obese people believe that drinking diet beverages (DBs) may be a simple strategy to achieve weight loss. However, nutritionists advise drinking water when attempting to lose weight. It is unclear how important drinking water instead of DBs is during a weight-loss program.

OBJECTIVE

In this study, we compared the effect on weight loss of either replacing DBs with water or continuing to consume DBs in adults during a 24-wk weight-loss program.

DESIGN

Overweight and obese women [n = 89; body mass index (BMI; in kg/m(2)): 27-40; age: 18-50 y] who usually consumed DBs in their diet were asked to either substitute water for DBs (water group) or continue drinking DBs 5 times/wk after their lunch for 24 wk (DB group) while on a weight-loss program.

RESULTS

Sixty-two participants (71%) completed the trial (32 in the DB group, 30 in the water group). Baseline variables were not statistically significantly different between groups. A statistically significant reduction in anthropometric measurements and statistically significant improvements in cardiometabolic risk characteristics were observed over 24 wk in both groups. Compared with the DB group, the water group had a greater decrease in weight (mean ± SD: water: -8.8 ± 1.9 kg; DBs: -7.6 ± 2.1 kg; P = 0.015, time × group), fasting insulin (mean ± SD: water: -2.84 ± 0.77 mU/L; DBs: -1.78 ± 1.25 mU/L, P < 0.001), homeostasis model assessment of insulin resistance (mean ± SD: water: -0.097 ± 0.049; DBs: -0.057 ± 0.042, P < 0.001), and 2-h postprandial glucose (mean ± SD: water: -1.02 ± 0.25 mmol/L; DBs: -0.72 ± 0.27 mmol/L; P < 0.001) over the 24 wk. However, there was no significant time × group interaction for waist circumference, fasting plasma glucose, and lipid profiles within both groups over 24 wk.

CONCLUSIONS

Replacement of DBs with water after the main meal may lead to greater weight reduction during a weight-loss program. It may also offer clinical benefits to improve insulin resistance. This trial was registered at www.irct.ir/ as IRCT201402177754N5.

Sweet taste of saccharin induces weight gain without increasing caloric intake, not related to insulin-resistance in Wistar rats

In a previous study, we showed that saccharin can induce weight gain when compared with sucrose in Wistar rats despite similar total caloric intake. We now question whether it could be due to the sweet taste of saccharin per se. We also aimed to address if this weight gain is associated with insulin-resistance and to increases in gut peptides such as leptin and PYY in the fasting state. In a 14 week experiment, 16 male Wistar rats received either saccharin-sweetened yogurt or non-sweetened yogurt daily in addition to chow and water ad lib. We measured daily food intake and weight gain weekly. At the end of the experiment, we evaluated fasting leptin, glucose, insulin, PYY and determined insulin resistance through HOMA-IR. Cumulative weight gain and food intake were evaluated through linear mixed models. Results showed that saccharin induced greater weight gain when compared with non-sweetened control (p = 0.027) despite a similar total caloric intake. There were no differences in HOMA-IR, fasting leptin or PYY levels between groups. We conclude that saccharin sweet taste can induce mild weight gain in Wistar rats without increasing total caloric intake. This weight gain was not related with insulin-resistance nor changes in fasting leptin or PYY in Wistar rats.

Diet, growth, and obesity development throughout childhood in the Avon Longitudinal Study of Parents and Children

Publications from the Avon Longitudinal Study of Parents and Children covering diet, growth, and obesity development during childhood are reviewed. Diet was assessed by food frequency questionnaires and food records. Growth data were collected by routine measurements, and in standardized clinics, body fatness was assessed by bioelectrical impedance and DXA (dual-energy X-ray absorptiometry) scans. Diets changed dramatically during the preschool period with an increase in the intake of free (added) sugars (12.3% rising to 16.4% of energy) that remained similar until adolescence. This was due to increased intake of energy-dense, nutrient-poor foods. Two periods of rapid growth were identified; infancy and mid-childhood (ages 7-11 y) and both were associated with obesity development. Diets with high energy density were associated with increasing fat mass from mid-childhood until adolescence. Genetic and dietary factors showed independent associations with increasing adiposity. At all ages studied, there were dietary inequalities related to maternal educational attainment that may influence inequalities found in obesity development. The Avon Longitudinal Study of Parents and Children has provided valuable insights into how disparities in diet and growth may affect the development of ill health in adulthood.

Does low-energy sweetener consumption affect energy intake and body weight? A systematic review, including meta-analyses, of the evidence from human and animal studies

By reducing energy density, low-energy sweeteners (LES) might be expected to reduce energy intake (EI) and body weight (BW). To assess the totality of the evidence testing the null hypothesis that LES exposure (versus sugars or unsweetened alternatives) has no effect on EI or BW, we conducted a systematic review of relevant studies in animals and humans consuming LES with ad libitum access to food energy. In 62 of 90 animal studies exposure to LES did not affect or decreased BW. Of 28 reporting increased BW, 19 compared LES with glucose exposure using a specific ‘learning' paradigm. Twelve prospective cohort studies in humans reported inconsistent associations between LES use and body mass index (−0.002 kg m⁻² per year, 95% confidence interval (CI) −0.009 to 0.005). Meta-analysis of short-term randomized controlled trials (129 comparisons) showed reduced total EI for LES versus sugar-sweetened food or beverage consumption before an ad libitum meal (−94 kcal, 95% CI −122 to −66), with no difference versus water (−2 kcal, 95% CI −30 to 26). This was consistent with EI results from sustained intervention randomized controlled trials (10 comparisons). Meta-analysis of sustained intervention randomized controlled trials (4 weeks to 40 months) showed that consumption of LES versus sugar led to relatively reduced BW (nine comparisons; −1.35 kg, 95% CI –2.28 to −0.42), and a similar relative reduction in BW versus water (three comparisons; −1.24 kg, 95% CI –2.22 to −0.26). Most animal studies did not mimic LES consumption by humans, and reverse causation may influence the results of prospective cohort studies. The preponderance of evidence from all human randomized controlled trials indicates that LES do not increase EI or BW, whether compared with caloric or non-caloric (for example, water) control conditions. Overall, the balance of evidence indicates that use of LES in place of sugar, in children and adults, leads to reduced EI and BW, and possibly also when compared with water.

Chlorogenic acid/chromium supplement rescues diet-induced insulin resistance and obesity in mice

Abdominal obesity is a major risk factor for insulin resistance, type 2 diabetes and cardiovascular diseases. Dietary fat induces insulin resistance in humans and rodents. The current study investigates whether a Chlorogenic acid/Chromium III supplement rescues obesity and insulin resistance caused by high-fat feeding of male C57BL/6 J mice for 7 weeks. Administering an oral daily dose of this supplement in the last 3 weeks of feeding reversed diet-induced body weight gain and insulin resistance, assessed by hyperglycemia, glucose intolerance and insulin intolerance. Indirect calorimetry analysis revealed that this effect is mediated at least partly, by increasing energy expenditure and spontaneous locomoter activity. These findings underscore the important role that chlorogenic acid and chromium play in maintaining glucose metabolism and insulin response in mice fed a high-fat diet.

The basolateral nucleus of the amygdala mediates caloric sugar preference over a non-caloric sweetener in mice

Neurobiological and genetic mechanisms underlying increased intake of and preference for nutritive sugars over non-nutritive sweeteners are not fully understood. We examined the roles of subnuclei of the amygdala in the shift in preference for a nutritive sugar. Food-deprived mice alternately received caloric sucrose (1.0 M) on odd-numbered training days and a non-caloric artificial sweetener (2.5 mM saccharin) on even-numbered training days. During training, mice with sham lesions of the basolateral (BLA) or central (CeA) nucleus of the amygdala increased their intake of 1.0 M sucrose, but not saccharin. Trained mice with sham lesions showed a significant shift in preference toward less concentrated sucrose (0.075 M) over the saccharin in a two-bottle choice test, although the mice showed an equivalent preference for these sweeteners before training. No increased intake of or preference for sucrose before and after the alternating training was observed in non-food-deprived mice. Excitotoxic lesions centered in the BLA impaired the increase in 1.0M sucrose intake and shift in preference toward 0.075 M sucrose over saccharin. Microlesions with iontophoretic excitotoxin injections into the CeA did not block the training-dependent changes. These results suggest that food-deprived animals selectively shift their preference for a caloric sugar over a non-caloric sweetener through the alternate consumption of caloric and non-caloric sweet substances. The present data also suggest that the BLA, but not CeA, plays a role in the selective shift in sweetener preference.

Dietitian perceptions of low-calorie sweeteners

BACKGROUND

Lowering energy (calorie) intake is essential in managing a healthy weight. One method of doing this is substituting sugar with low/no-calorie sweeteners. The safety of sweeteners has been debated, but little is known about how they are perceived by professionals responsible for weight management advice. We sought to explore dietitian perceptions of sweeteners and to identify the practical advice they provide about them.

METHODS

We collected data in France, Germany, Hungary, Portugal and the United Kingdom. We used face-to-face interviews and a novel online tool designed to engage people with online content in a way that approximates everyday processes of making sense of information.

RESULTS

We identified four approaches to sweeteners that dietitians took: (1) sweeteners should not be used, (2) they should be limited and used primarily as a transitional product, (3) sweetener use was decided by the client and (4) sweeteners should be recommended or at least allowed. Where dietitians are reticent to recommend sweeteners this is because they feel it is important for consumers to reduce their attachment to sweet tastes and of evidence linking the consumption of sweeteners to increased appetite. There is also uncertainty about the possible negative health effects of sweeteners.

CONCLUSIONS

Dietitians' perceptions about sweeteners are uncertain, ambivalent and divergent, sometimes explicitly being linked to fears about adverse health effects. Clear and authoritative guidance is required on scientific evidence around sweeteners as well as the ways in which they can be used in dietetic practice.

Consumption of low-calorie sweeteners among U.S. adults is associated with higher Healthy Eating Index (HEI 2005) scores and more physical activity

The possibility that low-calorie sweeteners (LCS) promote lower quality diets and, therefore, weight gain has been noted as a cause for concern. Data from a representative sample of 22,231 adults were obtained from five cycles of the National Health and Nutrition Examination Survey (1999–2008 NHANES). A single 24-hour recall was used to identify consumers of LCS beverages, foods and tabletop sweeteners. Diet quality was assessed using the Healthy Eating Index 2005 (HEI 2005) and its multiple subscores. Health behaviors of interest were physical activity, smoking and alcohol use. LCS consumers had higher HEI 2005 scores than did non-consumers, largely explained by better SoFAAS subscores (solid fats, added sugar and alcohol). LCS consumers had better HEI subscores for vegetables, whole grains and low-fat dairy, but worse subscores for saturated fat and sodium compared to non-consumers. Similar trends were observed for LCS beverages, tabletop LCS and LCS foods. Consumers of LCS were less likely to smoke and were more likely to engage in recreational physical activity. LCS use was associated with higher HEI 2005 scores, lower consumption of empty calories, less smoking and more physical activity.

Impact of energy density on liking for sweet beverages and caloric-adjustment conditioning in children

BACKGROUND

The contribution of sweet beverages to weight gain in children is controversial; the impact of these beverages on caloric adjustment needs clarification.

OBJECTIVE

We studied the influence of energy-density (ED) conditioning on the liking for sweet beverages and caloric adjustment after their consumption in children.

DESIGN

We used a within-subject design. Forty-four 8-11-y-old children were exposed to the following 2 distinctly flavored, sweetened beverages: a high-energy (HE) version (150 kcal) and a no-energy (NE) version (0 kcal). During a 4-wk initial conditioning period, children were exposed either 2 or 7 times to each beverage. After a 3-wk stability period (without exposure), children were exposed 3 times to both beverages with a reversed association between the ED and flavor (4-wk reversed-conditioning period). Flavor liking and food intake during meals after the consumption of each beverage were assessed before and after each period.

RESULTS

After the initial conditioning, the liking for both beverages increased (P < 0.001). After the stability period, the liking for the HE flavor was higher than for the NE flavor (P = 0.024). After the reversed conditioning, the liking for the flavor initially paired with the HE beverage tended to remain higher than for the NE flavor (P = 0.089). Initially, energy intakes during the meal did not differ after the consumption of NE or HE beverages. After the initial conditioning and up until the end of the reversed conditioning, energy intakes were lower after the HE beverage than after the NE beverage regardless of the beverage flavor (eg, after reversal; caloric compensation score: 29%). The number of exposures did not influence liking or energy intake.

CONCLUSION

After the association between a flavor and ED and reversal of this association, liking may be first guided by ED and then the flavor firstly associated with ED, whereas the partial caloric compensation may consistently be guided by ED. This trial was registered at clinicaltrials.gov as NCT02070185.

The role of sweet taste in satiation and satiety

Increased energy consumption, especially increased consumption of sweet energy-dense food, is thought to be one of the main contributors to the escalating rates in overweight individuals and obesity globally. The individual’s ability to detect or sense sweetness in the oral cavity is thought to be one of many factors influencing food acceptance, and therefore, taste may play an essential role in modulating food acceptance and/or energy intake. Emerging evidence now suggests that the sweet taste signaling mechanisms identified in the oral cavity also operate in the gastrointestinal system and may influence the development of satiety. Understanding the individual differences in detecting sweetness in both the oral and gastrointestinal system towards both caloric sugar and high intensity sweetener and the functional role of the sweet taste system may be important in understanding the reasons for excess energy intake. This review will summarize evidence of possible associations between the sweet taste mechanisms within the oral cavity, gastrointestinal tract and the brain systems towards both caloric sugar and high intensity sweetener and sweet taste function, which may influence satiation, satiety and, perhaps, predisposition to being overweight and obesity.

Low-calorie sweeteners and body weight and composition: a meta-analysis of randomized controlled trials and prospective cohort studies

BACKGROUND

Replacement of caloric sweeteners with lower- or no-calorie alternatives may facilitate weight loss or weight maintenance by helping to reduce energy intake; however, past research examining low-calorie sweeteners (LCSs) and body weight has produced mixed results.

OBJECTIVE

The objective was to systematically review and quantitatively evaluate randomized controlled trials (RCTs) and prospective cohort studies, separately, that examined the relation between LCSs and body weight and composition.

DESIGN

A systematic literature search identified 15 RCTs and 9 prospective cohort studies that examined LCSs from foods or beverages or LCSs consumed as tabletop sweeteners. Meta-analyses generated weighted mean differences in body weight and composition values between the LCS and control groups among RCTs and weighted mean correlations for LCS intake and these parameters among prospective cohort studies.

RESULTS

In RCTs, LCSs modestly but significantly reduced all outcomes examined, including body weight (-0.80 kg; 95% CI: -1.17, -0.43), body mass index [BMI (in kg/m²): -0.24; 95% CI: -0.41, -0.07], fat mass (-1.10 kg; 95% CI: -1.77, -0.44), and waist circumference (-0.83 cm; 95% CI: -1.29, -0.37). Among prospective cohort studies, LCS intake was not associated with body weight or fat mass, but was significantly associated with slightly higher BMI (0.03; 95% CI: 0.01, 0.06).

CONCLUSIONS

The current meta-analysis provides a rigorous evaluation of the scientific evidence on LCSs and body weight and composition. Findings from observational studies showed no association between LCS intake and body weight or fat mass and a small positive association with BMI; however, data from RCTs, which provide the highest quality of evidence for examining the potentially causal effects of LCS intake, indicate that substituting LCS options for their regular-calorie versions results in a modest weight loss and may be a useful dietary tool to improve compliance with weight loss or weight maintenance plans.

The effect of non-caloric sweeteners on cognition, choice, and post-consumption satisfaction

Consumers often turn to non-caloric sweeteners (NCS) as a means of promoting a healthy body weight. However, several studies have now linked their long-term use to increased weight gain, raising the question of whether these products produce unintended psychological, physiological, or behavioral changes that have implications for weight management goals. In the following, we present the results of three experiments bearing on this issue, testing whether NCS-consumption influences how individuals think about and respond to food. Participants in each of our three experiments were randomly assigned to consume a sugar-sweetened beverage, an unsweetened beverage, or a beverage sweetened with NCS. We then measured their cognition (Experiment 1), product choice (Experiment 2), and subjective responses to a sugar-sweetened food (Experiment 3). Results revealed that consuming NCS-sweetened beverages influences psychological processes in ways that - over time - may increase calorie intake.

The effects of water and non-nutritive sweetened beverages on weight loss during a 12-week weight loss treatment program

OBJECTIVE

To compare the efficacy of non-nutritive sweetened beverages (NNS) or water for weight loss during a 12-week behavioral weight loss treatment program.

METHODS

An equivalence trial design with water or NNS beverages as the main factor in a prospective randomized trial among 303 men and women was employed. All participants participated in a behavioral weight loss treatment program. The results of the weight loss phase (12 weeks) of an ongoing trial (1 year) that is also evaluating the effects of these two treatments on weight loss maintenance were reported.

RESULTS

The two treatments were not equivalent with the NNS beverage treatment group losing significantly more weight compared to the water group (5.95 kg versus 4.09 kg; P < 0.0001) after 12 weeks. Participants in the NNS beverage group reported significantly greater reductions in subjective feelings of hunger than those in the water group during 12 weeks.

CONCLUSION

These results show that water is not superior to NNS beverages for weight loss during a comprehensive behavioral weight loss program.

Non-nutritive sweeteners: no class effect on the glycaemic or appetite responses to ingested glucose

There is considerable interest in whether non-nutritive sweeteners are sensed in the gastrointestinal tract to modulate appetitive or absorptive responses to ingested carbohydrate. We determined the effect of a panel of non-nutritive sweeteners, aspartame, saccharin and acesulfame-K, delivered in doses that would be consumed in normal usage. Each was given in combination with glucose, assessing their effect on glycemic responses and appetite in ten healthy human subjects. There was no additional effect of aspartame or saccharin on the blood glucose response to oral glucose at any time point, although acesulfame-K exerted a small effect. However, none had an effect on perceptions of hunger or fullness. We conclude that there is no consistent evidence that non-nutrient sweeteners, when acutely consumed with glucose in dietetically relevant doses, have a class effect in modulating blood glucose in healthy human subjects. However, acesulfame-K may require further exploration.

Diet-beverage consumption and caloric intake among US adults, overall and by body weight

OBJECTIVES

We examined national patterns in adult diet-beverage consumption and caloric intake by body-weight status.

METHODS

We analyzed 24-hour dietary recall with National Health and Nutrition Examination Survey 1999-2010 data (adults aged ≥ 20 years; n = 23 965).

RESULTS

Overall, 11% of healthy-weight, 19% of overweight, and 22% of obese adults drink diet beverages. Total caloric intake was higher among adults consuming sugar-sweetened beverages (SSBs) compared with diet beverages (2351 kcal/day vs 2203 kcal/day; P = .005). However, the difference was only significant for healthy-weight adults (2302 kcal/day vs 2095 kcal/day; P < .001). Among overweight and obese adults, calories from solid-food consumption were higher among adults consuming diet beverages compared with SSBs (overweight: 1965 kcal/day vs 1874 kcal/day; P = .03; obese: 2058 kcal/day vs 1897 kcal/day; P < .001). The net increase in daily solid-food consumption associated with diet-beverage consumption was 88 kilocalories for overweight and 194 kilocalories for obese adults.

CONCLUSIONS

Overweight and obese adults drink more diet beverages than healthy-weight adults and consume significantly more solid-food calories and a comparable total calories than overweight and obese adults who drink SSBs. Heavier US adults who drink diet beverages will need to reduce solid-food calorie consumption to lose weight.

Effect of replacing sugar with non-caloric sweeteners in beverages on the reward value after repeated exposure

BACKGROUND

The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance.

OBJECTIVE

To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink (soft drink) versus nutrient-rich drink (yoghurt drink) on reward value after repeated exposure.

DESIGN

We used a randomized crossover design whereby forty subjects (15 men, 25 women) with a mean ± SD age of 21 ± 2 y and BMI of 21.5 ± 1.7 kg/m(2) consumed a fixed portion of a non-caloric sweetened (NS) and sugar sweetened (SS) versions of either a soft drink or a yoghurt drink (counterbalanced) for breakfast which were distinguishable by means of colored labels. Each version of a drink was offered 10 times in semi-random order. Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting, liking, and expected satiety. In a subgroup (n=18) fMRI was performed to assess brain reward responses to the drinks.

RESULTS

Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly. Overall, subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks. In addition, they expected the yoghurt drinks to be more satiating, they reduced hunger more, and delayed the first eating episode more. Conditioning did not influence these effects.

CONCLUSION

Our study showed that repeated consumption of a non-caloric sweetened beverage, instead of a sugar sweetened version, appears not to result in changes in the reward value. It cannot be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period, during lifetime, affected the reward value of the drinks.

Children's understandings and motivations surrounding novelty sweets: a qualitative study

BACKGROUND

Novelty sweets resemble or can be used as toys, are brightly coloured, with striking imagery, and sold at pocket money prices. They encourage regular consumption as packaging can be resealed, leading to prolonged exposure of these high-sugar and low pH products to the oral tissues, risk factors for dental caries and erosion, respectively.

AIM

To determine how children conceptualise novelty sweets and their motivations for buying and consuming them.

DESIGN

Focus groups conducted using a brief schedule of open-ended questions, supported by novelty sweets used as prompts in the latter stages. Participants were school children (aged 9-10) from purposively selected state primary schools in Cardiff, UK.

RESULTS

Key findings related to the routine nature of sweet eating; familiarity with and availability of novelty sweets; parental awareness and control; lack of awareness of health consequences; and the overall appeal of novelty sweets.

CONCLUSIONS

Parents reported vagueness regarding consumption habits and permissiveness about any limits they set may have diluted the concept of treats. Flexible permissiveness to sweet buying applied to sweets of all kinds. Parents' reported lack of familiarity with novelty sweets combined with their low cost, easy availability, high sugar content, and acidity give cause for concern.

The Role of Low-calorie Sweeteners in Diabetes

As the incidence and prevalence of type 2 diabetes continue to rise, the identification of components that contribute to or are associated with this disease has become a priority. One of the main factors that has been linked to type 2 diabetes is excessive weight gain, and reduction in weight has been recommended for both diabetes prevention and management. Low-calorie sweeteners (LCS) provide an alternative to added sugars and may facilitate weight loss or maintenance by limiting caloric intake. Considerable attention has been given to the role of LCS and their relationship to type 2 diabetes. Research suggests that LCS can serve an important role in diabetes prevention and management. Substituting sugars with LCS provides patients with type 2 diabetes considerable flexibility in their health goals and personal dietary preferences.

Assessment of Korean consumer exposure to sodium saccharin, aspartame and stevioside

The dietary intakes of sodium saccharin, aspartame and stevioside were estimated on the basis of food consumption data of the Korean consumer and the concentration of sweeteners in processed foods. Results were compared with the acceptable daily intake (ADI) of sweeteners. Among the 28 food categories for which the application of sodium saccharin, aspartame and stevioside is permitted in Korea, they were detected in 5, 12 and 13 categories, respectively. The estimated daily intake (EDI) of sodium saccharin and aspartame were high in infants and children, whereas the EDI of stevioside was high in adolescents and adults. The most highly consumed sweetener was aspartame, and the highest EDI/ADI ratio was found for sodium saccharin. The main food categories contributing to sweetener consumption were beverages, including alcoholic beverages. For most Korean consumers, the EDIs were no greater than 20% of their corresponding ADI; however, the EDI of sodium saccharin for conservative consumers aged 1-2 years reached 60% of their ADI.

Assessment of exposure of Korean consumers to acesulfame K and sucralose using a stepwise approach

Using a stepwise assessment of the exposure of Korean consumers to acesulfame K and sucralose, theoretical maximum daily intakes of the sweeteners were calculated using the Budget screening method, which resulted in values greater than the acceptable daily intakes (ADIs). Accordingly, the daily intakes of the sweeteners based on food consumption data and concentrations determined by instrumental analysis of 605 food samples were estimated for the more refined approach. The estimated daily intakes (EDIs) of all ordinary consumers were lower than the ADI, which was considered safe. However, for infants and 95th percentile high-level consumers (especially those who choose sucralose-containing foods), the EDIs of sucralose were very close to and higher than the ADI. Therefore, the sucralose concentration in sweetened beverages should be reduced; this would benefit the health of both high-level consumers and infants.

Adverse effects of high-intensity sweeteners on energy intake and weight control in male and obesity-prone female rats

The use of high-intensity sweeteners has been proposed as a method to combat increasing rates of overweight and obesity in the human population. However, previous work with male rats suggests that consumption of such sweeteners might contribute to, rather than ameliorate, weight gain. The goals of the present experiments were to assess whether intake of high-intensity sweeteners is associated with increased food intake and body weight gain in female rats; to evaluate whether this effect depends on composition of the maintenance diet (i.e., standard chow compared with diets high in energy, fat, and sugar [HE diets]); and to determine whether the phenotype of the rats with regard to propensity to gain weight on HE diets affects the consequences of consuming high-intensity sweeteners. The data demonstrated that female rats fed a low-fat, standard laboratory chow diet did not gain extra weight when fed yogurt dietary supplements sweetened with saccharin compared with those fed glucose-sweetened dietary supplements. However, female rats maintained on a "Westernized" diet high in fat and sugar (HE diet) showed significant increases in energy intake, weight gain, and adiposity when given saccharin-sweetened compared with glucose-sweetened yogurt supplements. These differences were most pronounced in female rats known to be prone to obesity prior to the introduction of the yogurt diets. Both selectively bred Crl:OP[CD] rats and outbred Sprague-Dawley rats fed an HE diet showing high levels of weight gain (diet-induced obese [DIO] rats) had increased weight gain in response to consuming saccharin-sweetened compared with glucose-sweetened supplements. However, in male rats fed an HE diet, saccharin-sweetened supplements produced extra weight gain regardless of obesity phenotype. These results suggest that the most negative consequences of consuming high-intensity sweeteners may occur in those most likely to use them for weight control, females consuming a "Westernized" diet and already prone to excess weight gain.

Beverages and body weight: challenges in the evidence-based review process of the Carbohydrate Subcommittee from the 2010 Dietary Guidelines Advisory Committee

Concern about the role of beverages, especially those containing sugar, in the obesity epidemic continues to escalate. Bans on sugar-sweetened beverages and chocolate milk have expanded from the school cafeteria to the ballpark and convenience store. This review describes the experience of the 2010 Dietary Guidelines Advisory Committee (DGAC) in conducting an evidence-based review of dietary exposure and health outcomes. The following four topics relevant to fluids and body weight were reviewed: added sugar, noncaloric sweeteners, food form and body weight, and macronutrients and satiety. There were limited and conflicting data on how liquids and solids affect energy intake and body weight. Fluid intake is typically not tracked in prospective, cohort longitudinal studies; thus, data are not available on fluid intake and health status from studies using the strongest epidemiologic designs. Despite public perception that beverages are linked to increased body weight compared with whole foods, evidence-based reviews of this topic do not support that liquid calories are processed differently in the body. The practical recommendation to replace caloric beverages with water as an aid to control weight is based on calorie reduction, rather than a link between added-sugar intake and obesity.

Influence of ovarian and non-ovarian estrogens on weight gain in response to disruption of sweet taste--calorie relations in female rats

Regulation of energy balance in female rats is known to differ along a number of dimensions compared to male rats. Previous work from our lab has demonstrated that in female rats fed dietary supplements containing high-intensity sweeteners that may disrupt a predictive relation between sweet tastes and calories, excess weight gain is demonstrated only when females are also fed a diet high in fat and sugar, and is evidenced primarily in animals already prone to gain excess weight. In contrast, male rats show excess weight gain when fed saccharin-sweetened yogurt supplements when fed both standard chow diets and diets high in fat and sugar, and regardless of their proneness to excess weight gain. The goal of the present experiments was to determine whether ovarian, or other sources of estrogens, contributes to the resistance to excess weight gain in female rats fed standard chow diets along with dietary supplements sweetened with yogurt. Results of the first experiment indicated that when the ovaries were removed surgically in adult female rats, patterns of weight gain were similar in animals fed saccharin-sweetened compared to glucose-sweetened yogurt supplements. In the second experiment, when the ovaries were surgically removed in adult female rats, and local production of estrogens was suppressed with the aromatase inhibitor anastrozole, females fed the saccharin-sweetened yogurt consumed more energy and gained more weight than females fed the glucose-sweetened yogurt. However, when the ovaries were surgically removed prior to the onset of puberty (at 24-25 days of age), females given saccharin-sweetened yogurt along with vehicle gained excess weight. In contrast, weight gain was similar in those given saccharin-sweetened and glucose-sweetened yogurt along with anastrozole. The results suggest that behavioral differences between males and females in response to disruption of sweet→calorie relations may result from differences in patterns of local estrogen production. These differences may be established developmentally during the pubertal period in females.

Contribution of foods consumed away from home to energy intake in Brazilian urban areas: the 2008-9 Nationwide Dietary Survey

The objectives of the present study were to estimate the dietary contribution of away-from-home food consumption, to describe the contribution of away-from-home foods to energy intake, and to investigate the association between eating away from home and total energy intake in Brazilian urban areas. In the first Brazilian Nationwide Dietary Survey, conducted in 2008-9, food records were collected from 25 753 individuals aged 10 years or older, living in urban areas of Brazil. Foods were grouped into thirty-three food groups, and the mean energy intake provided by away-from-home food consumption was estimated. Linear regression models were used to evaluate the association between away-from-home food consumption and total energy intake. All analyses considered the sample design effect. Of the total population, 43 % consumed at least one food item away from home. The mean energy intake from foods consumed away from home was 1408 kJ (337 kcal), averaging 18 % of total energy intake. Eating away from home was associated with increased total energy intake, except for men in the highest income level. The highest percentage of away-from-home energy sources was for food with a high content of energy, such as alcoholic beverages (59 %), baked and deep-fried snacks (54 %), pizza (42 %), soft drinks (40 %), sandwiches (40 %), and sweets and desserts (30 %). The consumption of foods away from home was related to a greater energy intake. The characterisation of away-from-home food habits is necessary in order to properly design strategies to promote healthy food consumption in the away-from-home environment.

Sweetness, satiation, and satiety

Satiation and satiety are central concepts in the understanding of appetite control and both have to do with the inhibition of eating. Satiation occurs during an eating episode and brings it to an end. Satiety starts after the end of eating and prevents further eating before the return of hunger. Enhancing satiation and satiety derived from foodstuffs was perceived as a means to facilitate weight control. Many studies have examined the various sensory, cognitive, postingestive, and postabsorptive factors that can potentially contribute to the inhibition of eating. In such studies, careful attention to study design is crucial for correct interpretation of the results. Although sweetness is a potent sensory stimulus of intake, sweet-tasting products produce satiation and satiety as a result of their volume as well as their nutrient and energy content. The particular case of energy intake from fluids has generated much research and it is still debated whether energy from fluids is as satiating as energy ingested from solid foods. This review discusses the satiating power of foods and drinks containing nutritive and nonnutritive sweeteners. The brain mechanisms of food reward (in terms of "liking" and "wanting") are also addressed. Finally, we highlight the importance of reward homeostasis, which can help prevent eating in the absence of hunger, for the control of intake.

The use of low-calorie sweeteners by children: implications for weight management

The rise in pediatric obesity since the 1970s has been well established in the United States and is becoming a major concern worldwide. As a potential means to help slow the obesity epidemic, low-calorie sweeteners (LCS) have gained attention as dietary tools to assist in adherence to weight loss plans or prevention of excess weight gain. Observational studies tend to show positive correlations between LCS consumption and weight gain in children and adolescents. Although the data are intriguing, these epidemiologic studies do not establish that LCS cause weight gain, because there are likely many lifestyle and genetic differences between children and families who choose to consume LCS and those who do not. Short-term randomized controlled trials have shown LCS use to be BMI neutral or to have modest weight-reducing effects in overweight and obese adolescents. The long-term effects of LCS in children and adolescents are unknown. Some compelling research is currently underway and may provide needed insight into the potential role of LCS in weight management. The paucity of data regarding the effects of LCS use in children and adolescents creates challenges in decision-making for health care providers and parents.

Sweetness and food preference

Human desire for sweet taste spans all ages, races, and cultures. Throughout evolution, sweetness has had a role in human nutrition, helping to orient feeding behavior toward foods providing both energy and essential nutrients. Infants and young children in particular base many of their food choices on familiarity and sweet taste. The low cost and ready availability of energy-containing sweeteners in the food supply has led to concerns that the rising consumption of added sugars is the driving force behind the obesity epidemic. Low-calorie sweeteners are one option for maintaining sweet taste while reducing the energy content of children's diets. However, their use has led to further concerns that dissociating sweetness from energy may disrupt the balance between taste response, appetite, and consumption patterns, especially during development. Further studies, preferably based on longitudinal cohorts, are needed to clarify the developmental trajectory of taste responses to low-calorie sweeteners and their potential impact on the diet quality of children and youth.

The use of low-calorie sweeteners by adults: impact on weight management

The application of low-calorie sweeteners (LCS) in foods and beverages has increased over the past 35 y. At the same time, many characteristics of the American diet have changed, including variations in fat and carbohydrate content and composition, increased nutrient additions, and new dietary patterns due to changing lifestyles and attitudes toward food and the changing cost of food. During this same time period, the prevalence of overweight and obesity has increased from ~30 to 70% of adults in the United States. Clearly, these trends lead to a variety of hypotheses and efforts to explain the role of LCS in this association. The aim of this review is to gain clarity on the role of LCS in weight management and their impact on diet quality. In addition, because the majority of studies aimed at identifying associations between LCS and these outcomes are based on observational data, the pitfalls in designing and evaluating data from observational studies are also discussed. We conclude that there is no evidence that LCS can be claimed to be a cause of higher body weights in adults. Similarly, evidence supporting a role for LCS in weight management is lacking. Due to the confounders in most observational studies, randomized controlled trials are needed to advance understanding.

Sweet taste receptor signaling in beta cells mediates fructose-induced potentiation of glucose-stimulated insulin secretion

Postprandial insulin release is regulated by glucose, but other circulating nutrients may target beta cells and potentiate glucose-stimulated insulin secretion via distinct signaling pathways. We demonstrate that fructose activates sweet taste receptors (TRs) on beta cells and synergizes with glucose to amplify insulin release in human and mouse islets. Genetic ablation of the sweet TR protein T1R2 obliterates fructose-induced insulin release and its potentiating effects on glucose-stimulated insulin secretion in vitro and in vivo. TR signaling in beta cells is triggered, at least in part, in parallel with the glucose metabolic pathway and leads to increases in intracellular calcium that are dependent on the activation of phospholipase C (PLC) and transient receptor potential cation channel, subfamily M, member 5 (TRPM5). Our results unveil a pathway for the regulation of insulin release by postprandial nutrients that involves beta cell sweet TR signaling.

Sucrose-predictive cues evoke greater phasic dopamine release than saccharin-predictive cues

Cues that have been paired with food evoke dopamine in nucleus accumbens (NAc) and drive approach behavior. This cue-evoked dopamine signaling could contribute to overconsumption of food. One manner in which individuals try to restrict caloric intake is through the consumption of foods containing artificial (non-nutritive) sweeteners. We were interested in whether cues paired with a non-nutritive sweetener (saccharin) would evoke similar dopamine release as cues paired with a nutritive sweetener (sucrose). We trained food-restricted rats to associate distinct cues with sucrose or saccharin pellets. In the first group of rats, training sessions with each pellet took place on different days, maximizing the opportunity for rats to detect nutritional differences. After training, voltammetry recordings in NAc core revealed that sucrose cues evoked greater phasic dopamine release than saccharin cues. In a second group of rats, on each training day, sucrose and saccharin pellets were presented in pseudorandom order within the same session, to mask nutritional differences. In this condition, the difference in dopamine between sucrose and saccharin cues was attenuated, but not abolished. These results suggest that sucrose-paired cues will more powerfully motivate behavior than saccharin-paired cues. The differing responses to each cue seem to be driven by overall preference with both the nutritional value that the pellets predict as well as other factors, such as taste, contributing.

Amygdala response to sucrose consumption is inversely related to artificial sweetener use

Controversy exists over whether exposure to artificial sweeteners degrades the predictive relationship between sweet taste and its post-ingestive consequences. Here we tested whether brain response to caloric sucrose is influenced by individual differences in self-reported artificial sweetener use. Twenty-six subjects participated in fMRI scanning while consuming sucrose solutions. A negative correlation between artificial sweetener use and amygdala response to sucrose ingestion was observed. This finding supports the hypothesis that artificial sweetener use may be associated with brain changes that could influence eating behavior.

The role of added sugars in pediatric obesity

This article provides an overview for pediatricians and other health care providers of the role of added sugars (caloric sweeteners) in the diets of US children and the recent evidence linking added sugar consumption to increased obesity and other chronic disease risk in children. The hypothesized biologic mechanisms for these associations are summarized, and evidence-based strategies are provided that may help children and their families to reduce their sugar consumption. Primary health care providers play an important role in assessing the added sugar intake of their patients and in providing nutrition and behavior change counselling to high-risk children and their families.

A systematic review on the effect of sweeteners on glycemic response and clinically relevant outcomes

BACKGROUND

The major metabolic complications of obesity and type 2 diabetes may be prevented and managed with dietary modification. The use of sweeteners that provide little or no calories may help to achieve this objective.

METHODS

We did a systematic review and network meta-analysis of the comparative effectiveness of sweetener additives using Bayesian techniques. MEDLINE, EMBASE, CENTRAL and CAB Global were searched to January 2011. Randomized trials comparing sweeteners in obese, diabetic, and healthy populations were selected. Outcomes of interest included weight change, energy intake, lipids, glycated hemoglobin, markers of insulin resistance and glycemic response. Evidence-based items potentially indicating risk of bias were assessed.

RESULTS

Of 3,666 citations, we identified 53 eligible randomized controlled trials with 1,126 participants. In diabetic participants, fructose reduced 2-hour blood glucose concentrations by 4.81 mmol/L (95% CI 3.29, 6.34) compared to glucose. Two-hour blood glucose concentration data comparing hypocaloric sweeteners to sucrose or high fructose corn syrup were inconclusive. Based on two ≤10-week trials, we found that non-caloric sweeteners reduced energy intake compared to the sucrose groups by approximately 250-500 kcal/day (95% CI 153, 806). One trial found that participants in the non-caloric sweetener group had a decrease in body mass index compared to an increase in body mass index in the sucrose group (-0.40 vs 0.50 kg/m2, and -1.00 vs 1.60 kg/m2, respectively). No randomized controlled trials showed that high fructose corn syrup or fructose increased levels of cholesterol relative to other sweeteners.

CONCLUSIONS

Considering the public health importance of obesity and its consequences; the clearly relevant role of diet in the pathogenesis and maintenance of obesity; and the billions of dollars spent on non-caloric sweeteners, little high-quality clinical research has been done. Studies are needed to determine the role of hypocaloric sweeteners in a wider population health strategy to prevent, reduce and manage obesity and its consequences.

Leptin regulates the reward value of nutrient

We developed an assay for quantifying the reward value of nutrient and used it to analyze the effects of metabolic state and leptin. In this assay, mice chose between two sippers, one of which dispensed water and was coupled to optogenetic activation of dopaminergic (DA) neurons and the other of which dispensed natural or artificial sweeteners. This assay measured the reward value of sweeteners relative to lick-induced optogenetic activation of DA neurons. Mice preferred optogenetic stimulation of DA neurons to sucralose, but not to sucrose. However, the mice preferred sucralose plus optogenetic stimulation versus sucrose. We found that food restriction increased the value of sucrose relative to sucralose plus optogenetic stimulation, and that leptin decreased it. Our data suggest that leptin suppresses the ability of sucrose to drive taste-independent DA neuronal activation and provide new insights into the mechanism of leptin's effects on food intake.

Sugar substitutes: Health controversy over perceived benefits

Sugar is an inseparable part of the food we consume. But too much sugar is not ideal for our teeth and waistline. There have been some controversial suggestions that excessive sugar may play an important role in certain degenerative diseases. So artificial sweeteners or artificially sweetened products continue to attract consumers. A sugar substitute (artificial sweetener) is a food additive that duplicates the effect of sugar in taste, but usually has less food energy. Besides its benefits, animal studies have convincingly proven that artificial sweeteners cause weight gain, brain tumors, bladder cancer and many other health hazards. Some kind of health related side effects including carcinogenicity are also noted in humans. A large number of studies have been carried out on these substances with conclusions ranging from "safe under all conditions" to "unsafe at any dose". Scientists are divided in their views on the issue of artificial sweetener safety. In scientific as well as in lay publications, supporting studies are often widely referenced while the opposing results are de-emphasized or dismissed. So this review aims to explore the health controversy over perceived benefits of sugar substitutes.

Taste-nutrient relationships in commonly consumed foods

Taste is expected to represent a food's nutrient content. The objective was to investigate whether taste acts as nutrient-sensor, within the context of the current diet, which is high in processed foods. Intensities of the five basic tastes of fifty commonly consumed foods were rated by nineteen subjects (aged 21·0 (SD 1·7) years, BMI 21·5 (SD 2·0) kg/m(2)). Linear regression was used to test associations between taste and nutrient contents. Food groups based on taste were identified using cluster analysis; nutrient content was compared between food groups, using ANOVA. Sweetness was associated with mono- and disaccharides (R(2) 0·45, P < 0·01). Saltiness and savouriness were correlated, with r 0·92 (P < 0·01) and both were associated with Na (both: R(2) 0·33, P < 0·01) and protein (R(2) 0·27, P < 0·01 and R(2) 0·33, P < 0·01, respectively). Cluster analysis indicated four food groups: neutral, salty and savoury, sweet-sour and sweet foods. Mono- and disaccharide content was highest in sweet foods (P < 0·01). In salty and savoury foods, protein content (P = 0·01 with sweet-sour foods, not significant with neutral or sweet foods) and Na content (P < 0·05) were the highest. Associations were more pronounced in raw and moderately processed foods, than in highly processed foods. The findings suggest that sweetness, saltiness and savouriness signal nutrient content, particularly for simple sugars, protein and Na. In highly processed foods, however, the ability to sense nutrient content based on taste seems limited.

Fat substitutes promote weight gain in rats consuming high-fat diets

The use of food products designed to mimic the sensory properties of sweet and fat while providing fewer calories has been promoted as a method for reducing food intake and body weight. However, such products may interfere with a learned relationship between the sensory properties of food and the caloric consequences of consuming those foods. In the present experiment, we examined whether use of the fat substitute, olestra, affect energy balance by comparing the effects of consuming high-fat, high-calorie potato chips to the effects of consuming potato chips that sometimes signaled high calories (using high-fat potato chips) and that sometimes signaled lower calories (using nonfat potato chips manufactured with the fat substitute olestra). Food intake, body weight gain and adiposity were greater for rats that consumed both the high-calorie chips and the low-calorie chips with olestra compared to rats that consumed consuming only the high-calorie chips, but only if animals were also consuming a chow diet that was high in fat and calories. However, rats previously exposed to both the high- and low-calorie chips exhibited increased body weight gain, food intake and adiposity when they were subsequently provided with a high fat, high calorie chow diet suggesting that experience with the chips containing olestra affected the ability to predict high calories based on the sensory properties of fat. These results extend the generality of previous findings that interfering with a predictive relationship between sensory properties of foods and calories may contribute to dysregulation of energy balance, overweight and obesity.

Application of the BRAFO tiered approach for benefit-risk assessment to case studies on dietary interventions

The respective examples, described in this paper, illustrate how the BRAFO-tiered approach, on benefit-risk assessment, can be tested on a wide range of case studies. Various results were provided, ranging from a quick stop as the result of non-genuine benefit-risk questions to continuation through the tiers into deterministic/probabilistic calculations. The paper illustrates the assessment of benefits and risks associated with dietary interventions. The BRAFO tiered approach is tested with five case studies. In each instance, the benefit-risk approach is tested on the basis of existing evaluations for the individual effects done by others; no new risk or benefit evaluations were made. The following case studies were thoroughly analysed: an example of food fortification, folic acid fortification of flour, macronutrient replacement/food substitution; the isocaloric replacement of saturated fatty acids with carbohydrates; the replacement of saturated fatty acids with monounsaturated fatty acids; the replacement of sugar-sweetened beverages containing mono- and disaccharides with low calorie sweeteners and an example of addition of specific ingredients to food: chlorination of drinking water.