Habitual high and low consumers of artificially-sweetened beverages: Effects of sweet taste and energy on short-term appetite

Effects on cardiometabolic risk factors after reduction of artificially sweetened beverage consumption in overweight subjects. A randomised controlled trial

BACKGROUND

The consumption of artificially sweetened beverages (ASBs) has been linked to metabolic alterations. The effect of reducing the regular consumption of these beverages on the metabolism is currently unknown.

OBJECTIVE

To evaluate the effect of reducing consumption of ASBs on the metabolism in overweight young adults.

DESIGN

A randomised, single-blind, controlled, 12-week, clinical trial was performed in overweight young adults who regularly consume ASBs. The 45 subjects who participated in the study were randomly divided into two groups: (1) control group (n=21) and (2) intervention group (no intake of ASBs, n=24). Body weight and composition, fasting plasma concentrations of glucose, triglycerides, insulin, cholesterol, low-density lipoproteins and high-density lipoproteins were measured at the beginning and end of the study. and the HOMA-IR was calculated.

RESULTS

At the end of 12 weeks, the intervention group showed a significant decrease (as opposed to an increase in the control group) in the percentage of change in body weight (-1.22% vs 1.31%, p<0.004), body fat (-6.28% vs 6.15%, p<0.001) and insulin resistance index (-12.06 vs 38.21%, p<0.00002), as well as in levels of glucose (-4.26% vs 0.51%, p<0.05), triglycerides (-14.74% vs 19.90%, p<0.006), insulin (-8.02% vs 39.23%, p<0.00005), cholesterol (-8.71% vs 0.77%, p<0.01) and LDL (-9.46% vs 9.92%, p<0.004).

CONCLUSION

A reduction in habitual consumption of ASBs in overweight young adults decreases biochemical measurements, body weight and composition, suggesting a participation in the metabolic processes.

Effects on cardiometabolic risk factors after reduction of artificially sweetened beverage consumption in overweight subjects. A randomised controlled trial

BACKGROUND

The consumption of artificially sweetened beverages (ASBs) has been linked to metabolic alterations. The effect of reducing the regular consumption of these beverages on the metabolism is currently unknown.

OBJECTIVE

To evaluate the effect of reducing consumption of ASBs on the metabolism in overweight young adults.

DESIGN

A randomised, single-blind, controlled, 12-week, clinical trial was performed in overweight young adults who regularly consume ASBs. The 45 subjects who participated in the study were randomly divided into two groups: (1) control group (n=21) and (2) intervention group (no intake of ASBs, n=24). Body weight and composition, fasting plasma concentrations of glucose, triglycerides, insulin, cholesterol, low-density lipoproteins and high-density lipoproteins were measured at the beginning and end of the study. and the HOMA-IR was calculated.

RESULTS

At the end of 12 weeks, the intervention group showed a significant decrease (as opposed to an increase in the control group) in the percentage of change in body weight (-1.22% vs 1.31%, p<0.004), body fat (-6.28% vs 6.15%, p<0.001) and insulin resistance index (-12.06 vs 38.21%, p<0.00002), as well as in levels of glucose (-4.26% vs 0.51%, p<0.05), triglycerides (-14.74% vs 19.90%, p<0.006), insulin (-8.02% vs 39.23%, p<0.00005), cholesterol (-8.71% vs 0.77%, p<0.01) and LDL (-9.46% vs 9.92%, p<0.004).

CONCLUSION

A reduction in habitual consumption of ASBs in overweight young adults decreases biochemical measurements, body weight and composition, suggesting a participation in the metabolic processes.

Offspring Birth Weight Is Associated with Specific Preconception Maternal Food Group Intake: Data from a Linked Population-Based Birth Cohort

The preconception period has been recognized as one of the earliest sensitive windows for human development. Maternal dietary intake during this period may influence the oocyte quality, as well as placenta and early embryonic development during the first trimester of pregnancy. Previous studies have found associations between macronutrient intake during preconception and pregnancy outcomes. However, as food products consist of multiple macro- and micronutrients, it is difficult to relate this to dietary intake behavior. Therefore, the aim of this study was to investigate the association between intake of specific food groups during the preconception period with birth weight, using data from the Perined-Lifelines linked birth cohort. The Perined-Lifelines birth cohort consists of women who delivered a live-born infant at term after being enrolled in a large population-based cohort study (The Lifelines Cohort). Information on birth outcome was obtained by linkage to the Dutch perinatal registry (Perined). In total, we included 1698 women with data available on birth weight of the offspring and reliable detailed information on dietary intake using a semi-quantitative food frequency questionnaire obtained before pregnancy. Based on the 2015 Dutch Dietary Guidelines and recent literature 22 food groups were formulated. Birth weight was converted into gestational age-adjusted z-scores. Multivariable linear regression was performed, adjusted for intake of other food groups and covariates (maternal BMI, maternal age, smoking, alcohol, education level, urbanization level, parity, sex of newborn, ethnicity). Linear regression analysis, adjusted for covariates and intake of energy (in kcal) (adjusted z score [95% CI], P) showed that intake of food groups "artificially sweetened products" and "vegetables" was associated with increased birth weight (resp. (β = 0.001 [95% CI 0.000 to 0.001, p = 0.002]), (β = 0.002 [95% CI 0.000 to 0.003, p = 0.03])). Intake of food group "eggs" was associated with decreased birth weight (β = -0.093 [95% CI -0.174 to -0.013, p = 0.02]). Intake in food groups was expressed in 10 g per 1000 kcal to be able to draw conclusions on clinical relevance given the bigger portion size of the food groups. In particular, preconception intake of "artificially sweetened products" was shown to be associated with increased birth weight. Artificial sweeteners were introduced into our diets with the intention to reduce caloric intake and normalize blood glucose levels, without compromising on the preference for sweet food products. Our findings highlight the need to better understand how artificial sweeteners may affect the metabolism of the mother and her offspring already from preconception onwards.

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 taste exposure and the subsequent acceptance and preference for sweet taste in the diet: systematic review of the published literature

Background

There are consistent, evidence-based global public health recommendations to reduce intakes of free sugars. However, the corresponding evidence for recommending reduced exposure to sweetness is less clear.

Objective

Our aim was to identify and review the published evidence investigating the impact of dietary exposure to sweet-tasting foods or beverages on the subsequent generalized acceptance, preference, or choice of sweet foods and beverages in the diet.

Design

Systematic searches were conducted to identify all studies testing relations of variation in exposure to sweetness through foods and beverages with subsequent variation in the generalized acceptance, preference, or choice of sweetened foods or beverages, in humans aged >6 mo.

Results

Twenty-one studies met our inclusion criteria, comprising 7 population cohort studies involving 2320 children and 14 controlled trials involving 1113 individuals. These studies were heterogeneous in study design, population, exposure, and outcomes measured, and few were explicitly designed to address our research question. The findings from these were inconsistent. We found equivocal evidence from population cohort studies. The evidence from controlled studies suggests that a higher sweet taste exposure tends to lead to reduced preferences for sweetness in the shorter term, but very limited effects were found in the longer term.

Conclusions

A small and heterogeneous body of research currently has considered the impact of varying exposure to sweet taste on subsequent generalized sweet taste preferences, and this evidence is equivocal regarding the presence and possible direction of a relation. Future work should focus on adequately powered studies with well-characterized exposures of sufficient duration. This review was registered with PROSPERO as CRD42016051840, 24 November 2016.

Alterations in behaviour, cerebral cortical morphology and cerebral oxidative stress markers following aspartame ingestion

OBJECTIVE

The study evaluated changes in open field behaviours, cerebral cortical histomorphology and biochemical markers of oxidative stress following repeated administration of aspartame in mice.

METHODOLOGY

Adult mice were assigned into five groups of twelve each. Vehicle (distilled water), or aspartame (20, 40, 80 and 160mg/kg body weight) were administered orally for 28days. Horizontal locomotion, rearing and grooming were assessed after the first and last dose of aspartame. Sections of the cerebral cortex were processed and stained for general histology, and also examined for neuritic plaques using the Bielschwosky's protocol. Glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE) immunoreactivity were assessed using appropriate antibodies. Aspartate and antioxidant levels were also assayed from cerebral cortex homogenates. Data obtained were analysed using descriptive and inferential statistics.

RESULTS

Body weight and food consumption decreased significantly with aspartame consumption. Locomotion, rearing and grooming increased significantly after first dose, and with repeated administration of aspartame. Histological changes consistent with neuronal damage were seen at 40, 80 and 160mg/kg. Neuritic plaque formation was not evident; while GFAP-reactive astrocytes and NSE-reactive neurons increased at 40 and 80mg/kg but decreased at 160mg/kg. Superoxide dismutase and nitric oxide increased with increasing doses of aspartame, while aspartate levels showed no significant difference.

CONCLUSION

The study showed morphological alterations consistent with neuronal injury and biochemical changes of oxidative stress. These data therefore supports the need for caution in the indiscriminate use of aspartame as a non-nutritive sweetener.

Low Calorie Sweetener (LCS) use and energy balance

For thirty years there has been a debate about whether low calorie sweeteners (LCS) provide a benefit for body weight management. Early studies showed that when consumed alone in a beverage appetite and food intake were increased. Some, observational longitudinal cohort studies reported an association between LCS usage and increasing BMI, suggesting that LCS may actually promote weight gain. In the ensuing decades numerous additional observational and experimental trials have been conducted with the experimental trials nearly uniformly showing a benefit for LCS, either in weight loss or weight gain prevention. The observational trials have been more inconsistent with two recent meta-analyses indicating either a small positive association between LCS usage and BMI (weighted group mean correlation, p=0.03) or an inverse association with body weight change (-1.35 kg, p=.004). Numerous potential mechanisms have been explored, mostly in animal models, in an attempt to explain this association but none have yet been proven in humans. It is also possible that the association between LCS and BMI increase in the observational studies may be due to reverse causality or residual confounding. Randomized controlled trials are consistent in showing a benefit of LCS which suggests that simple behavioral engagement by individuals attempting to control their weight is a sufficiently strong signal to overcome any potential mechanism that might act to promote energy intake and weight gain. Based on existing evidence, LCS can be a useful tool for people actively engaged in managing their body weight for weight loss and maintenance.

The effects of water and non-nutritive sweetened beverages on weight loss and weight maintenance: A randomized clinical trial

OBJECTIVE

To evaluate the effects of water versus beverages sweetened with non-nutritive sweeteners (NNS) on body weight in subjects enrolled in a year-long behavioral weight loss treatment program.

METHODS

The study used a randomized equivalence design with NNS or water beverages as the main factor in a trial among 303 weight-stable people with overweight and obesity. All participants participated in a weight loss program plus assignment to consume 24 ounces (710 ml) of water or NNS beverages daily for 1 year.

RESULTS

NNS and water treatments were non-equivalent, with NNS treatment showing greater weight loss at the end of 1 year. At 1 year subjects receiving water had maintained a 2.45 ± 5.59 kg weight loss while those receiving NNS beverages maintained a loss of 6.21 ± 7.65 kg (P < 0.001 for difference).

CONCLUSIONS

Water and NNS beverages were not equivalent for weight loss and maintenance during a 1-year behavioral treatment program. NNS beverages were superior for weight loss and weight maintenance in a population consisting of regular users of NNS beverages who either maintained or discontinued consumption of these beverages and consumed water during a structured weight loss program. These results suggest that NNS beverages can be an effective tool for weight loss and maintenance within the context of a weight management program.

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.

Energy-dense snacks can have the same expected satiation as sugar-containing beverages

Sugar-sweetened beverages (SSBs) are thought to be problematic for weight management because energy delivered in liquid form may be less effective at suppressing appetite than solid foods. However, little is known about the relative 'expected satiation' (anticipated fullness) of SSBs and solid foods. This is relevant because expected satiation is an important determinant of portion selection and energy intake. Here, we used a method of constant stimuli to assess the expected satiation of test meals that were presented in combination with different caloric and non-caloric beverages (500 ml) (Experiment 1 and 2), as well as with high-energy solid snack foods (Experiment 2). All energy-containing beverages and snack foods were presented in 210 kcal portions. Both experiments found that expected satiation was greater for meals containing caloric versus non-caloric beverages (201.3 ± 17.3 vs. 185.4 ± 14.1 kcal in Experiment 2; p < 0.05). Further, Experiment 2 showed that this difference was greater in participants who were familiar with our test beverages, indicating a role for learning. Notably, we failed to observe a significant difference in expected satiation between any of the caloric beverages and snack foods in Experiment 2 (range: 192.5-205.2 kcal; p = 0.87). This finding suggests that it may be more appropriate to consider beverages and solid foods on the same continuum, recognizing that the expected satiation of some solid foods is as weak as some beverages.

Non-caloric artificial sweeteners and the microbiome: findings and challenges

Non-caloric artificial sweeteners (NAS) are common food supplements consumed by millions worldwide as means of combating weight gain and diabetes, by retaining sweet taste without increasing caloric intake. While they are considered safe, there is increasing controversy regarding their potential ability to promote metabolic derangements in some humans. We recently demonstrated that NAS consumption could induce glucose intolerance in mice and distinct human subsets, by functionally altering the gut microbiome. In this commentary, we discuss these findings in the context of previous and recent works demonstrating the effects of NAS on host health and the microbiome, and the challenges and open questions that need to be addressed in understanding the effects of NAS consumption on human health.

Energy compensation in the real world: good compensation for small portions of chocolate and biscuits over short time periods in complicit consumers using commercially available foods

While investigations using covert food manipulations tend to suggest that individuals are poor at adjusting for previous energy intake, in the real world adults rarely consume foods of which they are ill-informed. This study investigated the impact in fully complicit consumers of consuming commercially available dark chocolate, milk chocolate, sweet biscuits and fruit bars on subsequent appetite. Using a repeated measures design, participants received four small portions (4 × 10-11 g) of either dark chocolate, milk chocolate, sweet biscuits, fruit bars or no food throughout five separate study days (counterbalanced in order), and test meal intake, hunger, liking and acceptability were measured. Participants consumed significantly less at lunch following dark chocolate, milk chocolate and sweet biscuits compared to no food (smallest t(19) = 2.47, p = 0.02), demonstrating very good energy compensation (269-334%). No effects were found for fruit bars (t(19) = 1.76, p = 0.09), in evening meal intakes (F(4,72) = 0.62, p = 0.65) or in total intake (lunch + evening meal + food portions) (F(4,72) = 0.40, p = 0.69). No differences between conditions were found in measures of hunger (largest F(4,76) = 1.26, p = 0.29), but fruit bars were significantly less familiar than all other foods (smallest t(19) = 3.14, p = 0.01). These findings demonstrate good compensation over the short term for small portions of familiar foods in complicit consumers. Findings are most plausibly explained as a result of participant awareness and cognitions, although the nature of these cognitions cannot be discerned from this study. These findings however, also suggest that covert manipulations may have limited transfer to real world scenarios.

β-Glucan and dark chocolate: a randomized crossover study on short-term satiety and energy intake

Aim: The aims of this study were to adapt a traditional recipe into a healthier form by adding 3 g of oat β-glucan, substituting milk chocolate to dark chocolate with 70% cocoa, and to examine the effect of these alterations on short-term satiety and energy intake. Materials and Methods: Study subjects (n = 25) were tested in a randomized, crossover design with four products closely matched for energy content. Four different versions of a traditional recipe including milk chocolate-control (CON), oat β-glucan (B-GLU), dark chocolate (DARK) or oat β-glucan and dark chocolate (B-GLU + DARK) were given to subjects on different test days. After subjects were asked to report visual analog scale (VAS) scores on sensory outcomes and related satiety for four hours ad libitum, lunch was served and energy intake of individuals was measured. Results: VAS scores indicated that none of the test foods exerted an improved effect on satiety feelings. However, energy intake of individuals during ad libitum lunch was significantly lower in dark chocolate groups (CON: 849.46 ± 47.45 kcal versus DARK: 677.69 ± 48.45 kcal and B-GLU + DARK: 691.08 ± 47.45 kcal, p = 0.014). Conclusion: The study demonstrated that substituting dark chocolate for milk chocolate is more effective in inducing satiety during subsequent food intake in healthy subjects.

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.

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.

Recommendations for healthier hydration: addressing the public health issues of obesity and type 2 diabetes

Given the rapid increase in the prevalence of overweight, obesity, type 2 diabetes and other obesity-related conditions across the world, despite a plethora of evidence-based guidance for clinicians, innovative campaigns aimed at the general public and widespread government public health initiatives, it is clear that a novel approach is required. The importance of fluid intake has been overlooked in campaigns and guidelines and also in the clinical setting, where the question 'what do you drink?' is often omitted. It is a significant oversight that food pyramids and healthy-eating plates across the world omit fluids from their graphics and advice. While guidelines include recommendations on changes in physical activity and diet, often little or no advice is offered on the importance of healthier hydration practices, neglecting to highlight the contribution of beverages high in sugar, alcohol or additives. An interdisciplinary group of experts in medicine, nutrition, physiology and public health discussed issues surrounding healthy-hydration practices in March 2010 in Paris to create a consensus statement on hydration and gain of body weight and provide recommendations.

Reviewing studies with diverse designs: the development and evaluation of a new tool

RATIONALE, AIMS & OBJECTIVE: Tools for the assessment of the quality of research studies tend to be specific to a particular research design (e.g. randomized controlled trials, or qualitative interviews). This makes it difficult to assess the quality of a body of research that addresses the same or a similar research question but using different approaches. The aim of this paper is to describe the development and preliminary evaluation of a quality assessment tool that can be applied to a methodologically diverse set of research articles.

METHODS

The 16-item quality assessment tool (QATSDD) was assessed to determine its reliability and validity when used by health services researchers in the disciplines of psychology, sociology and nursing. Qualitative feedback was also gathered from mixed-methods health researchers regarding the comprehension, content, perceived value and usability of the tool.

RESULTS

Reference to existing widely used quality assessment tools and experts in systematic review confirmed that the components of the tool represented the construct of 'good research technique' being assessed. Face validity was subsequently established through feedback from a sample of nine health researchers. Inter-rater reliability was established through substantial agreement between three reviewers when applying the tool to a set of three research papers (κ = 71.5%), and good to substantial agreement between their scores at time 1 and after a 6-week interval at time 2 confirmed test-retest reliability.

CONCLUSIONS

The QATSDD shows good reliability and validity for use in the quality assessment of a diversity of studies, and may be an extremely useful tool for reviewers to standardize and increase the rigour of their assessments in reviews of the published papers which include qualitative and quantitative work.

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.

Beverage consumption and adult weight management: A review

Total energy consumption among United States adults has increased in recent decades, and energy-containing beverages are a significant contributor to this increase. Because beverages are less satiating than solid foods, consumption of energy-containing beverages may increase energy intake and lead to weight gain; trends in food and beverage consumption coinciding with increases in overweight and obesity support this possibility. The purpose of this review is to present what is known about the effect of beverage consumption on short-term (i.e., meal) energy intake, as well as longer-term effects on body weight. Specific beverages addressed include water, other energy-free beverages (diet soft drinks, coffee and tea), and energy-containing beverages (soft drinks, juices and juice drinks, milk and soy beverages, alcohol). Existing evidence, albeit limited, suggests that encouraging water consumption, and substituting water and other energy-free beverages (diet soft drinks, coffee and tea) for energy-containing beverages may facilitate weight management. Energy-containing beverages acutely increase energy intake, however long-term effects on body weight are uncertain. While there may be health benefits for some beverage categories, additional energy provided by beverages should be compensated for by reduced consumption of other foods in the diet.

General and persistent effects of high-intensity sweeteners on body weight gain and caloric compensation in rats

In an earlier work (S. E. Swithers & T. L. Davidson, 2008), rats provided with a fixed amount of a yogurt diet mixed with saccharin gained more weight and showed impaired caloric compensation relative to rats given the same amount of yogurt mixed with glucose. The present 4 experiments examined the generality of these findings and demonstrated that increased body weight gain was also demonstrated when animals consumed a yogurt diet sweetened with an alternative high-intensity sweetener (acesulfame potassium; AceK) as well as in animals given a saccharin-sweetened base diet (refried beans) that was calorically similar but nutritionally distinct from low-fat yogurt. These studies also extended earlier findings by showing that body weight differences persist after saccharin-sweetened diets are discontinued and following a shift to a diet sweetened with glucose. In addition, rats first exposed to a diet sweetened with glucose still gain additional weight when subsequently exposed to a saccharin-sweetened diet. The results of these experiments add support to the hypothesis that exposure to weak or nonpredictive relationships between sweet tastes and caloric consequences may lead to positive energy balance.

Satiation due to equally palatable sweet and savory meals does not differ in normal weight young adults

Sensory properties are greatly involved in the process of satiation. Regarding the nature of sensory signals, an important distinction can be made between sweet and savory taste. It is unclear, however, whether sweet and savory differ in their influence on satiation. Our objective was to investigate the difference between a sweet and savory taste on satiation, independent of palatability, texture, energy density, and macronutrient composition. A crossover design was used, consisting of 3 test conditions in which 2 tastes (sweet and savory) were compared. Sixty-four healthy, nonsmoking, unrestrained participants (18 males and 46 females), with a mean age of 22.3 +/- 2.4 y and a mean BMI of 21.6 +/- 1.7 kg/m(2), enrolled. Rice was used as a test meal served in either a sweet or savory version. The meals were similar in palatability, texture, energy density, and macronutrient composition. Ad libitum intake, eating rate, and changes in pleasantness and appetite during the meals were measured. Ad libitum intake did not differ between the 2 meals; participants ate a mean of 314 +/- 144 g of the sweet meal and 333 +/- 159 g of the savory meal. Eating rate (sweet, 38 +/- 14 g/min; savory, 37 +/- 14 g/min) and changes in pleasantness and appetite during the meals were similar. Homogeneous meals with a sweet or savory taste, similar in palatability, texture, energy density, and macronutrient composition, do not differ in their influence on satiation in normal weight young adults.

Sip size of orangeade: effects on intake and sensory-specific satiation

Sensory-specific satiation (SSS) drives food selection and contributes to meal termination. We hypothesised that smaller sips would increase SSS due to increased oro-sensory exposure, irrespective of energy content. The objective was to determine the effects of sip size and energy content on ad libitum intake of orangeade and subjective SSS for orangeade. Orangeade intake and ratings of wanting and liking were measured before and after ad libitum orangeade consumption in a 2 × 2 cross-over design (n 53). Conditions differed in energy content (no-energy v. regular-energy orangeade) and in sip size (large, 20 g/sip v. small, 5 g/sip). The mean intake of both orangeades was lower when consumed with small sips than when consumed with large sips (regular-energy, 352 v. 493 g; no-energy, 338 v. 405 g; both P < 0·001). When consumed with large sips, the mean intake of no-energy orangeade was lower than that of regular-energy orangeade (P = 0·02). When consumed with small sips, subjective SSS (based on the desire to drink) was higher for no-energy orangeade than for regular-energy orangeade (P = 0·01), while mean intake was comparable. We concluded that smaller sip size, i.e. increased oro-sensory exposure per unit of consumption, can lower intake of sweet drinks. Only with low oro-sensory exposure (large sip size) was intake higher for an energy-containing sweet drink than for a no-energy sweet drink. This suggests that intake of sweet drinks is stimulated by (metabolic) reward value and inhibited by sensory satiation. This underpins the importance of SSS for meal termination.

Nonnutritive sweetener consumption in humans: effects on appetite and food intake and their putative mechanisms

Nonnutritive sweeteners (NNS) are ecologically novel chemosensory signaling compounds that influence ingestive processes and behavior. Only about 15% of the US population aged >2 y ingest NNS, but the incidence is increasing. These sweeteners have the potential to moderate sugar and energy intakes while maintaining diet palatability, but their use has increased in concert with BMI in the population. This association may be coincidental or causal, and either mode of directionality is plausible. A critical review of the literature suggests that the addition of NNS to non-energy-yielding products may heighten appetite, but this is not observed under the more common condition in which NNS is ingested in conjunction with other energy sources. Substitution of NNS for a nutritive sweetener generally elicits incomplete energy compensation, but evidence of long-term efficacy for weight management is not available. The addition of NNS to diets poses no benefit for weight loss or reduced weight gain without energy restriction. There are long-standing and recent concerns that inclusion of NNS in the diet promotes energy intake and contributes to obesity. Most of the purported mechanisms by which this occurs are not supported by the available evidence, although some warrant further consideration. Resolution of this important issue will require long-term randomized controlled trials.

Modified sham feeding of sweet solutions in women with and without bulimia nervosa

Although it is possible that binge eating in humans is due to increased responsiveness of orosensory excitatory controls of eating, there is no direct evidence for this because food ingested during a test meal stimulates both orosensory excitatory and postingestive inhibitory controls. To overcome this problem, we adapted the modified sham feeding technique (MSF) to measure the orosensory excitatory control of intake of a series of sweetened solutions. Previously published data showed the feasibility of a "sip-and-spit" procedure in nine healthy control women using solutions flavored with cherry Kool Aid and sweetened with sucrose (0-20%). The current study extended this technique to measure the intake of artificially sweetened solutions in women with bulimia nervosa (BN) and in women with no history of eating disorders. Ten healthy women and 11 women with BN were randomly presented with cherry Kool Aid solutions sweetened with five concentrations of aspartame (0, 0.01, 0.03, 0.08 and 0.28%) in a closed opaque container fitted with a straw. They were instructed to sip as much as they wanted of the solution during 1-minute trials and to spit the fluid out into another opaque container. Across all subjects, presence of sweetener increased intake (p<0.001). Women with BN sipped 40.5-53.1% more of all solutions than controls (p=0.03 for total intake across all solutions). Self-report ratings of liking, wanting and sweetness of solutions did not differ between groups. These results support the feasibility of a MSF procedure using artificially sweetened solutions, and the hypothesis that the orosensory stimulation of MSF provokes larger intake in women with BN than controls.