Effect of Physical Exercise on Taste Perceptions: A Systematic Review

Abstract

The effect of physical exercise on nutrition has gained substantial interest in the last decade. Meaningful results have been produced concerning the effect of physical exercise on different appetite hormones and food choice/preference. While it is well known that taste and nutrition are related, the relation between taste and physical activity has not yet been fully explored. This systematic review aims to provide a detailed view of the literature on physical exercise and its effect on taste perceptions. Five tastes were included in this review: sweet, salty, bitter, sour, and umami. Sweet taste intensity, sensitivity, and preference were increased by acute physical exercise, but sweet preference was reduced by chronic physical activity. Perceived intensity and sensitivity decreased overall for salty taste, but an increased preference was noted during/following exercise. Sour taste intensity ratings were decreased following exercise and preference was enhanced. Umami taste intensity and sensitivity increased following exercise and preference was decreased. No significant results were obtained for bitter taste. While evidence regarding the effect of exercise on taste has arisen from this review, the pre-testing nutrition, testing conditions, type of test, and exercise modality must be standardized in order to produce meaningful and reproducible results in the future.

1. Introduction

Food consumption, appetite, and desire to eat are intrinsically connected and primarily depend on energy homeostasis and the hedonic aspect of food; these factors drive food consumption through both hormonal and reward pathways [1]. Ultra-processed foods have the characteristics of being palatable and rich in sugar, fat, and salt [2]. A study published by Hall and colleagues showed that, when presented with an ad libitum ultra-processed food buffet, participants tended to eat approximately 500 kcal/day more than those exposed to a low-processed food buffet [3]. Food palatability correlates with higher energy intake and has been heavily linked with obesity. In addition, a preference for fat is associated with a higher likelihood of developing obesity within the overall adult population, while a preference for fat and salt combined is positively associated with the risk of developing obesity within the adult male population [4]. Food consumption related to palatability has a perception-based anchorage in which taste plays a role; thus, reduced taste perceptions may also promote energy intake [5]. A study conducted by Jayasinghe et al. found that the frequency of daily sweet food intake had a negative correlation with sweet taste intensity perception, meaning that the intake increased as the perceived intensity decreased [6]. The same principle applies for energy intake and absolute carbohydrate intake in relation to sweet taste intensity [6].

It is well established that obesity fosters many comorbidities, such as metabolic syndrome [7] and diabetes mellitus [8]. Fortunately, physical activity has been negatively correlated with the appearance of these conditions by actively promoting a negative energy balance and thus helps with bodyweight control [9]. Physical activity has also been shown to reduce hunger feelings, prospective food consumption, and plasma acetylated ghrelin levels, which directly dictate the quantity of food consumed onwards [10]. To date, many studies evaluating the effect of weight loss on taste perceptions have focused on physical activity paired with behavioral changes and nutritional interventions. For example, Umabiki and Sauer found a positive association between bodyweight loss and sweet and sour taste perceptions, but the independent role of exercise in these changes has not yet been reported [11,12]. Although it has been determined that physical activity has an impact on appetite and food consumption, a growing body of research has studied the link(s) between physical activity and taste. A study published in 2019 unveiled many protective effects and treatment effects of physical activity on basic senses, including taste [13]. In fact, this study suggested that high physical activity levels are positively associated with higher taste sensitivity in older populations [13]. A better understanding of the impact of physical activity on taste perceptions will provide important evidence regarding the multifactorial effect of physical activity on overall energy metabolism, sensory perceptions, and nutrition.

This systematic review aims to highlight the state of the literature on the impact of physical activity and its structured form, i.e., exercise, regarding taste perceptions among humans. With the development of new technology with great potential regarding taste evaluation, the establishment of a meaningful relation between physical exercise and taste could create a new avenue for preventing and treating energy imbalances. 2. Materials and Methods

This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines [14].

Studies were selected if they included (1) protocols based on humans, children, or adults; (2) results that measured the effect of physical activity on gustation/taste perceptions; (3) study designs such as observational studies, experimental studies, and experimental mixed-model studies. Studies were not selected if they included (1) only food preference as a measurement for taste, given that food preference is too broad of a concept, or (2) solely languages other than French or English. Moreover, all of the studies had to be fully completed and published; abstract-only, presentation-only, and unpublished studies were excluded. Taste intensity is defined by the authors as the literal intensity of a tastant. It is a by-product of anchored sensory perceptions by which the one perceiving becomes aware, through his gustative organs, of the the tastant and its strength. It is usually correlated with the concentration of a substance and is often measured with scales rating the strength/power of the tastant within the drink. Taste intensity can also be related to the primary characteristic of a certain food/solution, such as the sweetness, saltiness, bitterness, etc. Taste sensitivity was defined as the absolute concentration threshold necessary for detection of the tastant in a certain food/solution. Taste sensitivity can also relate to one’s ability to discern a tastant when compared with a non-tasting solution, a solution containing another tastant, or a solution with a different concentration of the same tastant. Taste preference is strongly associated with the hedonic aspect of a single food/solution and was assessed by the authors using various parameters such as pleasantness, tastiness, overall liking, ideal concentration, and palatability. This factor is a subjective aspect that is highly situational and time-dependent. 2.1. Literature Search In this work, 6 databases were searched: PubMed (1946–present), Embase (1974–present), Cab Abstracts (1973–present), PsycNET, CINAHL Plus with Full Text (1937–present), and Web of Science (1945–present). The last search was conducted on February 4, 2020. The following keywords were used for physical activity: “aerobic training” OR exercise* OR “physical activity” OR “physical training” OR “resistance training” OR sport* OR “strength training” OR “weight training” OR weightlifting OR “weight lifting”. For gustation, the following keywords were used: bitter OR bitterness OR flavor OR flavour OR gustation OR gustatory OR saltiness OR salty OR savory OR savoriness OR savoury OR savouriness OR sour OR sourness OR sweet OR sweetness OR taste OR umami. 2.2. Study Selection

The initial study selection was performed via title and abstract screening by two authors (A.-C.G., R.d.F.G.). Duplicates were removed. To be included in the final cut, studies had to implement some type of physical activity and taste perception test. A final selection was made by the reviewers (A.-C.G., R.d.F.G.) using full texts. Studies were selected in accordance with the eligibility and exclusion criteria. Any disagreements between authors were resolved internally by consensus. The number of articles included and excluded at each stage of selection are shown in the flow chart below (Figure 1. Systematic review flowchart).

2.3. Data Gathering and Analyses

The full texts of the articles that remained were carefully read and analyzed by A.-C.G. in order to extract the appropriate data from each text. K.N. independently verified and validated the extraction. In the case of discrepancy, a consensus was reached through discussion. The data, including detailed descriptions of each selected study, are summarized in Table 1, with the protocols given in Table 2.

2.4. Risk of Bias and Quality Assessment

The quality of the primary diagnostic accuracy of each article included in this study was assessed using the QUADAS-2 tool for assessing the risk of bias [15]. This tool consists of four key domains covering (1) patient selection, (2) index tests, (3) reference standards, and 4) flow of patients through the study and timing of the index test(s) and reference standard (“flow and timing”) [15]. Each domain was assessed in terms of the risk of bias, and the first three domains were also assessed in terms of concerns regarding applicability. The risk of bias was assessed by one reviewer (R.d.F.G.), and, in cases of uncertainty, a consensus was reached through discussion with two authors (A.-C.G. and M.-E.M.).

Abbreviations: MSG = Monosodium glutamate; TFEQ = Three-Factor Eating Questionnaire; POMS = Profile of Mood States; MHR = Maximum heart rate; HR = Heart rate; BP = Blood pressure; rpm = Revolution per minute; VO₂max = Maximal oxygen uptake; MICT = Moderate-intensity continuous training; HIIT = High-intensity interval training; FFQ = Food frequency questionnaire.

Abbreviations: BMI = Body mass index; rpm = Revolution per minute; MSG = Monosodium glutamate; PA = Physical activity; TFEQ = Three-Factor Eating Questionnaire; POMS = Profile of Mood States MHR = Maximum heart rate; HR = Heart rate; VO₂max = Maximal oxygen uptake; MICT = Moderate-intensity continuous training; HIIT = High-intensity interval training; STST = Salt Taste Sensitivity Threshold; RPE = Rate of perceived exertion.

3. Results 3.1. Study Selection

From the 5699 titles screened, 88 were approved based on their title, 49 were assessed using the full text, and 18 were analyzed and included in this systematic review. From the 18 studies, 17 had an experimental design, including non-defined [18], nonrandomized control trials [16,17,19,20,21,22,23,24,26,27,28,30,32,33], and randomized control trials [25,31]. One case control study [29] was also included. The number of participants ranged from 12 to 900, with a total of n = 1608 individuals. All articles included the effect of exercise on gustative perceptions and/or hedonic responses to different tastes: sweet, salty, bitter, umami, and/or sour. Intervention outcomes included different effects on taste intensity, taste preference, taste sensibility/detection threshold, or other hedonic responses.

3.2. Study and Intervention Characteristics

The studies originated from Canada [33], China [29], Ireland [32], Israel [21,22], Japan [18,19,23,26,28], the Netherlands [25], New Zealand [30], Norway [31], the United States of America [16,17,24,27], and the United Kingdom [20]. Most of the studies were conducted on healthy normal-weight males and females, but some studies included participants who were obese [31], clinically ill [29], or athletic [16,24,26,27].

Exercise intervention ranged from one session to a 12-week exercise program. Most of the exercise interventions were treadmill or ergometer sessions based on the maximal oxygen uptake [19,20,23,31,33] and/or calculated/predicted maximal heart rate [19,23,24,25,30]. Other interventions included organized sports [21,22], circuit stations [21,27], a half marathon [26], hiking [28], or questionnaires on physical activity levels [16,17,29,32]. In most cases, the subjects were trained in a controlled environment [18,19,20,23,24,25,27,30,31,33]; however, some participants trained outdoors [21,22,26,28] and/or were assessed on self-claimed activity specifications [16,17,29,32].

3.3. Taste Protocols and Tests

Most of the protocols used solutions with a predetermined quantity of ingredients, with salty [17,19,21,22,24,27,29,30,32,33], sweet [16,18,19,20,21,22,23,24,25,26,27,28,30,31,32,33], and bitter [18,19,27,32] as the most common tastes evaluated. Three studies used food with varying concentrations of salt, sugar, and/or fat for the taste evaluation [17,21,22], and one study used the Leeds Food Preference Questionnaire paired with images of food with varying energetic content and taste characteristics for taste evaluation [31].

In addition, 100- to 200-mm visual analog line/point scales were used for taste evaluation in nine [16,20,22,24,25,27,28,30,33] of the 18 studies, measuring variables such as intensity, overall liking, sweetness, saltiness, bitterness, tartness, sensory ratings, pleasantness, fattiness, and preference, among others. Hedonic scales ranging from 4 to 9 points were used in six studies [17,19,23,24,27,28], and one study used the Leeds Food Preference Questionnaire [31] for the taste evaluation test. Other tests included a time intensity scale test [18], a triangle taste test or absolute taste threshold test [19,26], a general labeled magnitude scale and a general degree of liking scale, which are both validated scales [32], and the salt taste sensitivity threshold (STST) test [29]. Only one study did not include any form of written/subjective taste evaluation with a scale or questionnaire [21].

3.4. Effectiveness of Intervention and Outcomes

Of the 18 studies considered in this systematic review, three offered no significant results regarding the impact of physical exercise on gustative/taste perceptions [25,28,33]. Perceived pleasantness, preferences, hedonic ratings, overall liking, liking of flavor of sweetness, sourness, bitterness, umami, or saltiness, which all relate to the hedonic aspect of the gustative response, were all significantly affected in 12 studies; a decreasing effect in four studies [16,30,31,32] and an increasing effect in eight studies [17,19,20,21,22,23,27,30] were found. Physical exercise increased taste intensity in five studies [16,24,27,30,32] and decreased taste intensity in two studies [18,30]. Taste sensitivity was increased in two studies [26,32] and decreased in one study [29].

While all five tastes were evaluated at least once in the 18 selected articles, saltiness and sweetness were the most commonly used tastes and produced the majority of significant results in terms of taste intensity, sensitivity, and preference [16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33]. Although some assessed the impact of physical exercise on savoriness/umami [19,32] and bitterness [18,19,27,32], tartness/sourness was the third most common taste evaluated with physical exercise in terms of perceived intensity, sensitivity, or preference [18,19,24,27,32].

3.5. Risk of Bias Assessment

The overall risk of bias was unclear or nonexistent. The risk of bias for all 18 studies is summarized in Table 3. Four studies were rated as having an unclear potential risk of bias for patient selection, while three studies were rated as having an unclear potential risk of bias for time and flowing. Regarding applicability concerns, which represent one of the methodological quality indicators (e.g., studies lacking information on inclusion criteria or randomization, allocation and outcome assessment concealment, and inadequate missing data handling), only five studies were rated as having an unclear potential risk of bias. For most studies, there was adequate information to make judgements about the methodological quality and risk of bias. Studies were not excluded due to these unclear risks of bias.

4. Discussion 4.1. Overall Results and Takeaways

The aim of this review was to determine whether physical activity (chronic) and exercise (acute) have a direct impact on taste perception. Following a systematic process, 18 studies were included. Of the 18 studies included in this systematic review, three did not supply significant results [25,28,33]. Taste intensity, preference, and sensitivity were all affected by exercise. Four studies showed decreasing trends towards the overall liking and preference of certain tastes [16,30,31,32], while eight studies showed augmentation trends following exercise [17,19,20,21,22,23,27,30]. Similar results were obtained for studies conducted on taste intensity and sensitivity: seven studies reported significant increases for both parameters and showed that physical activity increases taste intensity [16,24,27,30,32] and/or taste sensitivity [26,32] following an exercise session/program, with three studies showing significant decreases [18,29,30]. Table 4 offers a brief summary of these results in order to facilitate overall implications of physical exercise, in its acute and chronic forms, on taste perceptions.

4.2. Sweet

The effect of physical exercise on sweet taste received the most attention by far, with 16 out of the 18 articles including some sort of sweet taste evaluation [16,18,19,20,21,22,23,24,25,26,27,28,30,31,32,33].

Data analysis indicates that physical exercise increases sweet taste intensity. Based on before- and after-intervention results, the intervention groups showed significant differences for taste intensity ratings compared with the control groups. In general, such differences were also observed when comparing people who are physically active on a daily basis to those who are not [16,30,32]. A time effect was also observed. More specifically, sweet taste intensity is greater during exercise when compared with the before and after conditions, and sweetness ratings for a given stimulus increase in relation to the exercise duration [30]. Sweetness taste sensitivity was higher following a half marathon, with the absolute taste detection threshold of sucrose decreasing from 11.9 ± 1.0 mM (p = 0.14) to 7.7 ± 0.8 mM (p < 0.001) [26]. This sensitivity increase is attributed to a reduced absolute detection of sucrose following the exercise session [26]. While preference was the most commonly studied parameter, the results are contradictory. Although it seems clear that the preference for sweet solution increases both during and following (acute) exercise [19,20,23,24], one study presented different trends. When exercising and given a drink with a low concentration of carbohydrates, participants had a decreased preference for the drink compared with the control group [32]. Physical activity (chronic) seems to present different results. In fact, only one study presented meaningful results regarding a decrease in sweet preference; in this study, weekly physical activity levels were measured [16]. The group that was considered active reported a decrease in high sugary/fatty food preferences compared with the non- or less-active groups. It appears that physical exercise yields an immediate taste preference and acceptance of sugary foods following its completion, while diminishing this taste preference in everyday settings. Energy balance and overall glycogen depletion may influence sweet taste preference, sensitivity, and intensity following exercise, considering the effects of these factors on food choices and overall nutrition [34,35]. Knowing that chronic exercise is associated with weight reduction, and that weight loss yields positive results regarding sweet taste sensitivity, these factors may play a non-negligible role regarding taste preference [9,12]. The differences observed between exercise and physical activity regarding sweet taste preference may lie in these fundamentally different metabolic states, one being acute and one being chronic.

4.3. Salty

In this systematic review, 10 of the 18 selected studies included a testing of salty taste regarding intensity, sensitivity, or preference [17,19,21,22,24,27,29,30,32,33].

Overall, saltiness intensity ratings were lower during exercise compared with the before-exercise condition [30]. Saltiness intensity also seems to depend on the exercise duration, as the ratings for saltiness intensity decrease with exercise duration [30]. Significant results concerning salty taste sensitivity were present in only one study. Salty taste threshold sensitivity and physical activity levels showed a light correlation, trending towards an augmented salty taste sensitivity threshold [29]. The authors hypothesized that this effect comes from the sweat loss associated with physical activity [29]. As observed previously for the sweet taste, taste preference is one of the most studied variables when analyzing the effect of exercise on gustative perceptions. One key difference for salty taste compared with sweet taste is the all-round increase in preference. In fact, this increase is present during and following one exercise session [21,22,27], as well as when comparing people with different weekly physical activity levels; participants who were more active had a higher preference and overall acceptability of salty taste compared with less-active or non-active groups [17]. It is known that sweat loss affects overall sodium quantity within the exercising system [36]. This fluctuation has immediate and secondary effects on sodium preference and consumption following exercise and is well documented with rats [37] and within the human literature [21,22,27].

4.4. Bitter/Sour/Umami

Studies that evaluated sourness, umami, and/or bitterness were less common. Five such studies have been included in this systematic review, all of which produced significant results [18,19,24,27,32].

Overall, taste intensity for sourness decreased following the exercise condition when compared with sedentary or pre-exercise conditions [18,27]. Perceived taste intensity for umami was evaluated in only one study, and the results showed that the intensities of a high and low concentration of the umami tastant were perceived as higher in the exercising group compared with the control or non-exercising group [32]. Taste intensity results for bitterness were not significant in any study in this systematic review. For taste sensitivity in general, people who exercised were significantly better at identifying the umami taste compared with the control group; however, this result was reported in only one study [32]. Similarly, taste sensitivity results for bitterness and sourness were not significant in any study in this systematic review. A comparison of pre- and post-exercise conditions showed that physical exercise increases the preference for sourness [19,27]; this increase is also related to exercise status and/or sodium level [27]. Overall preference ratings for umami, at both low and high concentrations, were significantly lower for the exercise condition compared with control or non-active conditions [32]. Taste preference results for bitterness were not significant in any study in this systematic review. More studies on umami, sourness, and particularly bitterness are needed in order to draw stronger hypotheses regarding why certain phenomena are observed.

4.5. How Can We Measure Taste with a Novel Scope and How Can We Produce More Meaningful Results?

Over the last few decades, many discrepancies have been observed regarding energy intake and expenditure within the population [38]. Knowing that appetite and hunger are both responsible for eating behaviors, the accessibility of food and the reward-driven system associated with its consumption have created an obesogenic environment that promotes overconsumption and alters satiety signals [39]. Physical activity has been frequently linked to nutrition, highlighting its impact on appetite control, food choices, and intake [40,41]. The physiological basis of these changes has been explored and partly explained by the effect of physical activity on numerous appetite-regulating hormones, such as peptide YY-36, ghrelin, and glucagon-like peptide-1 [42]. It is currently known that people who are physically active tend to have lower cortical representation/activity within the food reward-related brain when shown images of high-caloric-density food compared with non-exercising participants [43]. Knowing that taste perceptions also regulate food preference and overall consumption, this systematic review aimed to clarify the state of the literature regarding the effect of exercise/physical activity on taste perceptions [6,44].

Food consumption and preference are highly regulated by palatability and macronutrient content; however, the chemosensory aspect of food also plays a significant role in its intake [45]. As taste exposure seems to be highly correlated with satiation, an increase in intensity and sensitivity to taste could lead to quicker meal termination, possibly regulating the quantity of food consumed onwards [46]. Although this could be observed regarding sweet and umami taste, salty taste would not be affected by this phenomenon; salty taste sensitivity and intensity are lowered with chronic and acute exercise, as seen in Table 4. As discussed in this review, exercise seems to have a chemosensory impact on overall taste perceptions. By exercising frequently, people could more quickly attain taste satiation, potentially lowering the consumption of highly tasty and energetic food and lowering the overall food quantity. The impact of physical activity in this matter could potentiate energy restriction by its effect on taste perceptions. Changes in taste perceptions and preferences, especially for the sweet taste, may lead to a weaker desire to consume foods that are hyperpalatable and rich in sugar. Currently, it has been documented that highly palatable foods tend to increase energy consumption [47]. A sharp decrease in the consumption of highly palatable foods, which are usually energetically dense, could decrease overall energy intake.

In the future, the usage of different tools for taste evaluation and detection remains a key aspect to consider in order to strengthen, improve, and expand our comprehension and testing abilities regarding this subject. As discussed previously in this review, most articles have studied the effect of physical activity on different taste sensory perceptions, but none have evaluated its impact with unique and novel equipment, such as the gustometer. Changes that could potentially occur without the participant’s full awareness could deeply change taste perception and detection. With this vision, the usage of an objective tool for assessment, as a new testing variable, in addition to questionnaires, scales, etc., issued by the participants could broaden our understanding and testing ability of the role of physical activity on gustative perceptions. In recent years, the use of a gustometer, such as the GU002 from Burghart Messtechnik, paired with an electroencephalogram has enriched our ability to test and assess gustative perceptions and thus refine our approach and understanding of this matter [48,49].

4.6. Strengths and Limitations

Most studies in this systematic review were published before the 2010s, with six published before the 2000s. Although this may seem like a methodological problem, the protocols and taste interventions were unexpectedly similar. Similarities were observed among most studies, such as the use of varying concentrations for the tastant of choice and, within the intervention details, the exercise selection and the type of taste test description. Nearly all studies in this systematic review, in which exercise was included as the intervention, used aerobic exercise as their preferred exercise method, with an intensity based on VO₂max or a calculated/predicted maximal heart rate value [19,20,23,24,25,30,31,33]. Different scales were used to assess each parameter, but visual analog scales were the most common [16,20,22,24,25,27,28,30,32,33]. Considering that visual analog scales are considered by some as the gold standard for clinical experiments, offering more precise subjective results, their usage is usually associated with evidence of the effect of treatment [50,51]. The main discrepancies observed within this systematic review lie in the time of day for testing (in the morning, at noon, or in the evening) and the great variance between the pre-testing conditions and nutrition. Taste perceptions constantly change throughout the day, and the nutrition prior to testing may impact test results, as participants would have had different levels of hunger, appetite, and substrate utilization [52]. While most studies included in this systematic review had a normal-weight/healthy population [17,18,19,20,21,22,23,25,26,28,30,32,33], some had athletes [16,24,27], obese subjects [31], or partly clinically ill patients [29] as their testing subjects. Overall taste measures are known to be altered with weight gain and are usually negatively associated with higher BMI/adiposity [53,54]. Considering that these changes are crucial in understanding the role of adiposity/BMI in overall taste perceptions, future reviews that include a greater quantity of articles with BMI/adiposity as a central parameter should include detailed analyses regarding this matter.

5. Conclusions To summarize, exercise and physical activity both exert significant effects on taste intensity, preference, and sensitivity, with the results and effects varying according to different modalities and the taste evaluated. Concerns regarding loss of smell and taste have emerged within the medical community. Thus, studies evaluating whether physical exercise can be a useful tool to enhance taste and smell could be critical for our understanding of this matter.

Figure 1. Systematic review flowchart.

Author, year	Risk of Bias				Applicability Concerns
	Patient Selection	Index Test	Reference Standard	Flow and Timing	Patient Selection	Index Test	Reference Standard
Chrystal et al., 1995 [16]	(+)	(+)	(+)	(?)	(?)	(+)	(+)
Kanarek et al., 1995 [17]	(?)	(+)	(+)	(+)	(+)	(+)	(+)
Nakagawa et al., 1996 [18]	(+)	(+)	(+)	(?)	(+)	(+)	(+)
Horio and Kawamura, 1998 [19]	(?)	(+)	(+)	(+)	(+)	(+)	(+)
King et al., 1999 [20]	(+)	(+)	(+)	(+)	(+)	(+)	(+)
Leshem et al., 1999 [21]	(+)	(+)	(+)	(+)	(+)	(+)	(+)
Wald and Leshem, 2003 [22]	(+)	(+)	(+)	(+)	(+)	(+)	(+)
Horio, 2004 [23]	(?)	(+)	(+)	(+)	(?)	(+)	(+)
Passe et al., 2004 [24]	(?)	(+)	(+)	(?)	(+)	(+)	(+)
Havermans et al., 2009 [25]	(+)	(+)	(+)	(+)	(+)	(+)	(+)
Narukawa et al., 2009 [26]	(+)	(+)	(+)	(+)	(?)	(+)	(+)
Passe et al., 2009 [27]	(+)	(+)	(+)	(+)	(+)	(+)	(+)
Narukawa et al., 2010 [28]	(+)	(+)	(+)	(+)	(?)	(+)	(+)
Wen and Song, 2010 [29]	(+)	(+)	(+)	(+)	(?)	(+)	(+)
Ali et al., 2011 [30]	(+)	(+)	(+)	(+)	(+)	(+)	(+)
Martins et al., 2017 [31]	(+)	(+)	(+)	(+)	(+)	(+)	(+)
Feeney et al., 2019 [32]	(+)	(+)	(+)	(+)	(+)	(+)	(+)
Josaphat et al., 2020 [33]	(+)	(+)	(+)	(+)	(+)	(+)	(+)

(+)—Low Risk; (-)—High Risk; (?)—Unclear Risk.

		Perceptions
		Intensity	Sensitivity	Preference
Taste	Sweet	↑ (17, 18, 29)	↑ (25)	↑ (19, 20, 23, 24) ↓ (17, 29)
	Salty	↓ (28)	↓ (33)	↑ (18, 21, 22, 26)
	Sour	↓ (16, 26)	-	↑ (19, 26)
	Bitter	-	-	-
	Umami	↑ (29)	↑ (29)	↓ (29)

↓ = Decreasing results; ↑ = increasing results.

Author Contributions

Conceptualization, A.-C.G. and M.-E.M.; Methodology, A.-C.G. and R.d.F.G.; Software, A.-C.G.; Validation, A.-C.G., R.d.F.G. and M.-E.M.; Formal Analysis, A.-C.G. and K.N.; Investigation, A.-C.G.; Resources, M.-E.M.; Data Curation, A.-C.G. and R.d.F.G.; Writing-Original Draft Preparation, A.-C.G.; Writing-Review and Editing, A.-C.G., R.d.F.G., K.N., and M.-E.M.; Visualization, M.-E.M.; Supervision, M.-E.M.; Project Administration, MEM; V.D. is responsible for the funding with M.-E.M. All authors have read and agreed to the published version of the manuscript.

Funding

A.-C.G. was funded by a Canadian Institutes of Health Research grant with V.D. and M.-E.M. as co-principal investigators (#421027). M.-E.M. holds a Canada Research Chair-Tier 2 on Physical activity and juvenile obesity.

Conflicts of Interest

The authors declare no conflict of interest.

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