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

Resource Signaling via Blood Glucose in Embodied Decision Making

Food, money, and time are exchangeable resources essential for survival and reproduction. Individuals live within finite budgets of these resources and make tradeoffs between money and time when making intertemporal choices between an immediate smaller reward and a delayed lager reward. In this paper, I examine signaling functions of blood glucose in regulating behaviors related to resource regulations beyond caloric metabolisms. These behavioral regulations include choices between energy expenditure and energy conservation, monetary intertemporal choices, and self-control in overcoming temptations. I begin by comparing potential embodied signals for resource forecasting and proactive decision making in terms of their pros and cons as a signal for regulating both metabolism and behavioral decision making and self-control. Based on this analysis, circulating glucose emerges as not only the designated fuel for brain metabolism but also a privileged resource forecasting signal for regulating immediate, short-term, and long-term behavioral adaptations to the resource budget of the decision maker. In the context of an on-going debate between the limited resource model and the motivation accounts of behavioral effects of blood glucose, I propose a dual functions (caloric provision and resource forecasting) and dual signaling (glucose taste and ingestion) hypothesis of circulating glucose in resource management, and provide behavioral and neurophysiological evidence of the separate effects of glucose taste to motivate effort for resource acquisition and glucose ingestion to promote resource conservation and future orientation. Accumulating evidence indicates that the body is able to detect fake signals of non-caloric sweeteners and react to such “caloric crisis” with an enhanced preference for immediate rewards over future rewards, revealing the wisdom of the body

No effects of ingesting or rinsing sucrose on depleted self-control performance

Self-control tasks appear to deplete a limited resource resulting in reduced subsequent self-control performance; a state of ego depletion. Evidence of reduced peripheral glucose by exertion of self-control, and attenuation of ego depletion by carbohydrate metabolism underpins the proposition that this macronutrient provides the energetic source of self-control. However, the demonstration of positive, non-metabolic effects on ego depletion when merely sensing carbohydrates orally contradicts this hypothesis. Recent studies have also failed to support both metabolic and non-metabolic accounts. The effects of ingesting or rinsing a carbohydrate (sucrose) and an artificially sweetened (sucralose) solution on capillary blood and interstitial glucose, and depleted self-control performance were examined in older adults. Forty, healthy, adults (50-65. years) ingested and rinsed sucrose and sucralose solutions in a 2 (method). × 2 (source), fully counterbalanced, repeated measures, crossover design. Capillary blood and interstitial glucose responses were assayed. Depleted self-control performance (induced by the Bakan visual processing task) on an attention switch task was assessed under each study condition. Ego depletion had no consistent effects on peripheral glucose levels and no significant effects of ingesting or rinsing sucrose on self-control were observed. The act of rinsing the solutions, independent of energetic content, resulted in a small, non-significant enhancement of performance on the attention switch task relative to ingesting the same solutions (RT: p= 05; accuracy: p= 09). In conclusion, a metabolic account of self-control was not supported. Whilst a positive effect of rinsing on depleted self-control performance was demonstrated, this was independent of energetic content. Findings suggest glucose is an unlikely physiological analogue for self-control resources

THE IMPACT OF CALORIC AND NON-CALORIC SWEETENER CONSUMPTION ON THE BEHAVIORAL, HORMONAL AND BRAIN RESPONSESTO FOOD

Sight is a primary channel conveying information about food, in turn influencing appetite control via homeostatic, hedonic and cognitive factors. Brain responses to visual food cues have been increasingly studied in the past decades. However, the influence of specific dietary factors such as caloric (sugar) and non-caloric sweetener (NNS) consumption on subsequent visual responses to food remains poorly understood. Yet, both sweeteners have been associated to long-term weight gain. The thesis at hand aims at a more integrative view to understand the impact of sugar and NNS consumption on visual food perception and intake behavior, by combining measures of behavioral, physiological and brain responses towards food. The first exploratory project (study A) investigated changes in behavioral and brain responses to food viewing via a 3-month replacement of sugar-sweetened beverages with NNS-sweetened beverages. We showed intervention-induced modulations in neural activity in response to high-fat, sweet food viewing that were mostly apparent in dorsal prefrontal and precentral cortices, i.e. brain areas associated with inhibitory control and attention. The decrease in activity within the dorsal prefrontal cortex was inversely correlated with changes in body weight, i.e. participants who failed to lose weight also showed decreased activity to palatable food cues in brain areas that have been related to food intake control. The second project (study B) investigated the acute effects of sucrose- and NNS-beverage consumption, as compared to water, on the subsequent brain responses to food viewing and later spontaneous food intake at an ad libitum buffet. Sucrose consumption elicited a differential pattern of neural activity to food viewing as compared to water, and a subsequent decrease in spontaneous food intake. NNS consumption, on the other hand, did not affect food intake, but modified post-prandial brain responses to food viewing, most pronounced in prefrontal areas and the insula, i.e. brain regions that have been associated with food intake control and nutrient-flavor conditioning. Altogether, the thesis at hand provides insights on the impact of caloric and non-caloric sweetener consumption on the visual perception of tempting food cues. This is of great relevance in our modern environment where visual cues are ubiquitous and guide consumption behavior in daily life. Detailed mechanisms as to how NNS might impact behavior when repeatedly consumed yet need to be investigated in more detail in the future, in particular to disentangle effects driven by NNS-containing foods and beverages as such, as opposed to individuals’ expectations related to the consumption of such non-caloric products. La vision est utilisée comme principal vecteur d’informations lorsqu’un individu est confronté à la nourriture, influençant de ce fait le contrôle de l’appétit par des facteurs homéostatiques, hédoniques et cognitifs. Les réponses cérébrales lors de la perception visuelle de nourriture ont été fortement étudiées dans les dernières décennies. Cependant, l’influence de facteurs alimentaires spécifiques tels que la consommation d’agents sucrants caloriques (les sucres) et non-caloriques (les édulcorants) sur les réponses visuelles ultérieures reste encore peu claire. Les sucres et édulcorants ont pourtant été associés à une prise de poids corporel sur le long terme. Cette thèse a pour but de mieux comprendre l’impact de la consommation de sucres et d’édulcorants sur la perception visuelle de nourriture et sur le comportement alimentaire, en combinant des mesures comportementales, physiologiques et cérébrales. Le premier projet (étude A) a exploré les changements dans les réponses cérébrales et comportementales à la vision de nourriture induits par un remplacement de la consommation de boissons sucrées par leurs équivalents édulcorés. A la suite de trois mois d’intervention, nous avons mis en évidence des modulations de l’activité neuronale lors de la vision d’aliments sucrés et riches en gras dans des aires cérébrales préfrontales dorsales et précentrales, associées au contrôle inhibiteur et à l’attention. Une diminution d’activité dans l’aire préfrontale dorsale était inversement corrélée au changement de poids corporel, c’est-à-dire que les participants qui n’ont pas perdu de poids ont aussi montré les plus grandes baisses d’activités dans cette aire cérébrale liée au contrôle inhibiteur de la prise alimentaire. Le deuxième projet (étude B) a étudié les effets aigus d’une consommation de boissons sucrées ou édulcorées, en comparaison à l’eau, sur les réponses cérébrales subséquentes à la vision de nourriture, ainsi que sur le comportement alimentaire lors d’un buffet ad libitum. La consommation de sucre, en comparaison à l’eau, a modifié l’activité cérébrale à la vue de nourriture. Ceci était associé à une moindre prise alimentaire lors du buffet. En revanche, la consommation d’édulcorants n’a pas affecté le comportement alimentaire, mais a modifié les réponses cérébrales postprandiales en particulier dans les aires préfrontales ainsi que dans l’insula, des régions associées aux habilités de contrôle de la prise alimentaire et au conditionnement goût-nutriment. Ensemble, les études réalisées dans le cadre de cette thèse ont fourni des indications sur l’impact d’une consommation de sucres et d’édulcorants sur la perception visuelle de nourriture appétissante. Ceci est particulièrement important dans notre environnement alimentaire moderne, dans lequel les stimuli visuels de nourriture sont omniprésents et guident notre comportement alimentaire quotidien. Les mécanismes d’action des édulcorants sur notre comportement lorsqu’ils sont consommés de manière répétée restent cependant à étudier de manière plus détaillée, en particulier dans le but de distinguer les effets des édulcorants eux-mêmes des attentes individuelles liées à la consommation de ces produits

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\u27s 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 determinants of food choice

Health nudge interventions to steer people into healthier lifestyles are increasingly applied by governments worldwide, and it is natural to look to such approaches to improve health by altering what people choose to eat. However, to produce policy recommendations that are likely to be effective, we need to be able to make valid predictions about the consequences of proposed interventions, and for this, we need a better understanding of the determinants of food choice. These determinants include dietary components (e.g. highly palatable foods and alcohol), but also diverse cultural and social pressures, cognitive-affective factors (perceived stress, health attitude, anxiety and depression), and familial, genetic and epigenetic influences on personality characteristics. In addition, our choices are influenced by an array of physiological mechanisms, including signals to the brain from the gastrointestinal tract and adipose tissue, which affect not only our hunger and satiety but also our motivation to eat particular nutrients, and the reward we experience from eating. Thus, to develop the evidence base necessary for effective policies, we need to build bridges across different levels of knowledge and understanding. This requires experimental models that can fill in the gaps in our understanding that are needed to inform policy, translational models that connect mechanistic understanding from laboratory studies to the real life human condition, and formal models that encapsulate scientific knowledge from diverse disciplines, and which embed understanding in a way that enables policy-relevant predictions to be made. Here we review recent developments in these areas.</p

Soft drinks and sweeteners intake: Possible contribution to the development of metabolic syndrome and cardiovascular diseases. Beneficial or detrimental action of alternative sweeteners?

Abstract The rapid increase in obesity, metabolic syndrome, and cardiovascular diseases (CVDs) has been related to the rise in sugar-added foods and sweetened beverages consumption. An interesting approach has been to replace sugar with alternative sweeteners (AS), due to their impact on public health. Preclinical and clinical studies, which analyze the safety of AS intake, are still limited. Major pathogenic mechanisms of these substances include ROS and AGEs formation. Indeed, endothelial dysfunction involving in the pathogenesis of micro- and macro-vascular diseases is mitochondrial dysfunction dependent. Hyperglycemia and endoplasmic reticulum stress together produce ROS, contributing to the development and progression of cardiovascular complications during type 2 diabetes (T2D), thus causing oxidative changes and direct damage of lipids, proteins, and DNA. Epidemiological studies in healthy subjects have suggested that the consumption of artificial AS can promote CV complications, such as glucose intolerance and predisposition to the onset of T2D, whereas natural AS could reduce hyperglycemia, improve lipid metabolism and have antioxidant effects. Long-term prospective clinical randomized studies are needed to evaluate precisely whether exposure to alternative sugars can have clinical implications on natural history and clinical outcomes, especially in children or during the gestational period through breast milk

Psychophysical evaluation of sweetness functions across multiple sweeteners

Sweetness is one of the 5 prototypical tastes and is activated by sugars and non-nutritive sweeteners (NNS). The aim of this study was to investigate measures of sweet taste function [detection threshold (DT), recognition threshold (RT), and suprathreshold intensity ratings] across multiple sweeteners. Sixty participants, 18-52 years of age (mean age in years = 26, SD = &plusmn;7.8), were recruited to participate in the study. DT and RT were collected for caloric sweeteners (glucose, fructose, sucrose, erythritol) and NNS (sucralose, rebaudioside A). Sweetness intensity for all sweeteners was measured using a general Labeled Magnitude Scale. There were strong correlations between DT and RT of all 4 caloric sweeteners across people (r = 0.62-0.90, P &lt; 0.001), and moderate correlations between DT and RT for both of the NNS (r = 0.39-0.48, P &lt; 0.05); however, weaker correlations were observed between the DT or RT of the caloric sweeteners and NNS (r = 0.26-0.48, P &lt; 0.05). The DT and RT of glucose and fructose were not correlated with DT or RT of sucralose (P &gt; 0.05). In contrast, there were strong correlations between the sweetness intensity ratings of all sweeteners (r = 0.70-0.96, P &lt; 0.001). This suggests those caloric sweeteners and NNS access at least partially independent mechanisms with respect to DT and RT measures. At suprathreshold level, however, the strong correlation between caloric sweeteners and NNS through weak, moderate, and strong intensity indicates a commonality in sweet taste mechanism for the perceived intensity range