The influence of sleep on human taste function and perception: A systematic review.

Sleep problems are associated with increased risk of obesity. Multiple mechanisms have been identified to support this relationship, including changes in sensory processing and food choice. Taste researchers have recently begun to explore whether changes in taste occur as a result of short-term or long-term sleep habits. A systematic review was conducted to investigate these relationships. A total of 13 studies were included in the review. Heterogeneity in both the sleep and taste measurements used was noted, and most studies failed to assess sour, bitter and umami tastes. Still, the available evidence suggests that sweet taste hedonic perception appears to be undesirably influenced by short sleep when viewed through the lens of health. That is, preferred sweetness concentration increases as sleep duration decreases. Habitual sleep and interventions curtailing sleep had minimal associations or effects on sweet taste sensitivity. Salt taste sensitivity and hedonic responses appear to be relatively unaffected by insufficient sleep, but more work is needed. Solid evidence on other taste qualities is not available at the present time.

Alterations in sweet taste function in adults with diabetes mellitus: a systematic review and potential implications.

Diet therapy for diabetes involves controlling carbohydrate intake in order to manage blood glucose concentrations. Simple carbohydrates, like sucrose, quickly and potently raise blood glucose when ingested, and are typically perceived as sweet. Sweetness is innately pleasurable and contributes to the positive hedonic evaluation of foods and beverages. There is some evidence to suggest that individuals with diabetes mellitus may be less able to detect sweetness, which could result in increased intake and, thus, more difficulty managing blood glucose. A systematic review that included PubMed, PsycInfo, and Embase databases was conducted. Inclusion criteria included observational studies that investigated the sweet taste function of adults with and without diabetes mellitus (Prospero CRD42021225058). The quality of the final included studies was assessed using the Academy of Nutrition and Dietetics' Evidence Analysis Library Quality Criteria Checklist: Primary Research tool. Eighteen studies that compared sweet taste thresholds, intensity ratings, or hedonic responses in adults both with and without diabetes were included. Differences in sweet taste thresholds, both detection and recognition, indicated that individuals with diabetes were less sensitive than healthy controls. The same findings were observed for intensity ratings. Only two studies examined hedonic responses; results were inconclusive.

SLeep Education for Everyone Program (SLEEP) Results in Sustained Improvements in Sleep Outcomes at Six Months.

OBJECTIVE: Community-delivered sleep education interventions have been demonstrated to be effective in improving sleep outcomes, but whether these benefits persist once the program ends is not well characterized. This study sought to determine whether the previously reported positive effects attributed to the SLeep Education for Elders Program (SLEEP) were maintained six months after program completion. METHOD: Nineteen participants were surveyed three times: at baseline, program completion (six weeks), and the six-month post-program timepoint. Sleep outcomes for quality, duration, insomnia symptoms, sleep hygiene behaviors, and excessive daytime sleepiness were assessed using validated surveys, including the Pittsburgh Sleep Quality Index (from which duration was also extracted), the Insomnia Severity Index, the Sleep Hygiene Index, and the Epworth Sleepiness Scale. RESULTS: Longitudinal models adjusted for baseline sleep problems revealed the benefits achieved immediately after the program were retained at six months for sleep quality (estimate: -2.0 (95%CI: -2.7, -1.3)), sleep duration (estimate: 0.9 (95%CI: 0.6, 1.2)), insomnia symptoms (estimate: -3.5 95%CI: (-4.6, -2.3)), and sleep hygiene behaviors (estimate: -2.6 (-4.3, -0.9)). CONCLUSIONS: These results suggest that a community-delivered sleep education intervention can produce sustained benefits for participants and should be considered as a tool to address uncomplicated sleep issues.

Use of Ripple Effects Mapping to assess student-perceived benefits of undergraduate research and learning objective attainment with Irish nutrition students.

Ripple Effects Mapping (REM) is a qualitative data analysis approach that combines mind mapping with inductive analysis to condense data obtained from group interviews. One benefit of REM is the ability to identify unintended outcomes, or "ripples," of the intervention of interest. Ripples are visually represented by a mind map created during the REM session. Mind maps connect related concepts, typically with the main concept in the center of the map and supporting ideas radiating from a central node. This project applied REM to undergraduate course evaluation. The purpose of this study was threefold: to use REM to identify undergraduate student-perceived benefits of research projects, to assess whether REM could be used to confirm achievement of course learning objectives, and to compare the themes identified from the mind mapping component of REM to those identified by inductive analysis. Mind maps were generated with Xmind (Xmind Ltd., Hong Kong) during online sessions by two groups of students, those who completed a "mandatory" research project (n = 11) and those who chose to participate in an additional "optional" research project (n = 9). There was considerable overlap in identified themes between mind mapping and inductive analysis, with skills, relationships, career direction, and unexpected benefits identified by both techniques. Mind mapping identified several additional themes. Findings from both approaches were compared to course learning objectives, and both confirmed that all objectives were met. In situations where time is a limiting factor, mind mapping could be superior to the complete REM approach for course learning objective assessments.NEW & NOTEWORTHY This study used Ripple Effects Mapping (REM) to identify undergraduate student-perceived benefits of research projects, to assess whether REM could confirm achievement of course learning objectives for a research project-based course, and to compare themes identified from the mind mapping component of REM to those identified by inductive analysis. Mind mapping confirmed achievement of course objectives and may be a better choice compared to inductive reasoning when time is limited.

The complicated impact of media use before bed on sleep: Results from a combination of objective EEG sleep measurement and media diaries.

Media use has been linked to sleep disturbance, but the results are inconsistent. This study explores moderating conditions. A media diary study with 58 free-living adults measured the time spent with media before bed, the location of use, and multitasking. Electroencephalography (EEG) captured bedtime, total sleep time, and the percent of time spent in deep (Stage N3), and rapid eye movement (REM) sleep. Media use in the hour before sleep onset was associated with an earlier bedtime. If the before bed use did not involve multitasking and was conducted in bed, that use was also associated with more total sleep time. Media use duration was positively associated with (later) bedtime and negatively associated with total sleep time. Sleep quality, operationalised as the percent of total sleep time spent in N3 and REM sleep, was unaffected by media use before bed. Bedtime media use might not be as detrimental for sleep as some previous research has shown. Important contextual variables moderate the relationship, such as location, multitasking, and session length.

The impact of COVID-19 on student learning during the transition from remote to in-person learning: using mind mapping to identify and address faculty concerns.

The COVID-19 pandemic led to the suspension of in-person learning at many higher education institutions (HEIs) in March 2020. In response, HEIs transitioned most courses to online formats immediately and continued this mode of instruction through the 2020-2021 academic year. In fall 2021, numerous HEIs resumed in-person courses and some hybrid courses, and faculty began noting academic-related behavior deficiencies not previously observed in students. Focus groups of teaching faculty (n = 8) from one university department were conducted to gather information on changes in student academic-related behaviors attributed to the disruption of teaching and learning due to COVID-19 and to compare observed deficiencies with the university's undergraduate learning goals. Mind mapping software was utilized to capture themes and subthemes. Identified themes were related to problem-solving skills, grades, time management, attendance, and interpersonal communication, both in terms of student-to-student and student-to-faculty communication. For these identified areas, outcomes during the return to in-person learning were mostly undesirable. Based on these identified issues, suggested modifications that HEIs could use to modify course content and delivery to offset skill gaps and improve interpersonal communication were identified. Furthermore, observations may indicate that fully remote learning inhibited student learning and skill development during the 2020-2021 academic year. Future work should examine the effectiveness of the proposed modifications on student success.NEW & NOTEWORTHY This article contains information gathered from mind map-driven faculty focus group observations of student academic-related deficiencies resulting from transitioning from remote to in-person learning and how said deficiencies compare to university undergraduate learning goals.

Characterization of the Relationships Between Sleep Duration, Quality, Architecture, and Chemosensory Function in Nonobese Females.

Little is known about the relationship between sleep and chemosensation. The purpose of this study was to characterize the relationship between chemosensory function and sleep duration, quality, and architecture. A total of 56 nonobese (body mass index <30 kg/m2) female participants who denied having diagnosed sleep disorders completed testing. Sleep was measured for two nights using a single-channel (A1-A2) electroencephalogram (Zmachine). Sweet taste threshold and preference as well as olfactory threshold, recognition ability, and pleasantness ratings were evaluated. Sweet taste preference was correlated with total sleep time (TST) (P = 0.0074) as well as with the sum of rapid eye movement (REM) and stage N3/slow wave sleep (SWS) duration (P = 0.0008). Participants who slept more than the average TST or more than the average REM + SWS time preferred lower concentrations of sweetness (P = 0.041 and 0.049, respectively), than those whose sleep times fell below the means. Multiple linear regression revealed that REM and SWS predicted ~18% of the variance of sweet taste preference. These findings suggest that scientific and consumer studies related to sweet preference might benefit from screening participants for short sleep duration prior to testing.

Sweet liker status in children and adults: Consequences for beverage intake in adults.

Different patterns of sweet liking exist. For some, liking increases as concentration increases up to a point at which it typically plateaus. These individuals are referred to as sweet likers. How sweet likers' beverage intake, especially sugar sweetened beverage intake, differs from sweet dislikers' beverage intake is not well characterized. A total of 953 visitors (650 adults; 62.0% women; 303 children; 58.7% girls) to the Denver Museum of Nature & Science rated the taste intensity and liking of 5 sucrose solutions that spanned concentrations typically encountered in sugar-sweetened beverages (0.0-13.7% w/v) using visual analog scales. Beverage intake by adults was quantified using the validated BEVQ-15 questionnaire. Among adults, hierarchical cluster analysis identified three clusters of liking patterns (likers, dislikers, and neutrals). Among children, two clusters of liking patterns were identified (likers and dislikers). For both adults and children, BMI, percent body fat, age, and sex did not differ between clusters. Concentration by cluster interaction effects were observed for both adults and children. Adult sweet likers consumed more energy from all beverages, more sweetened juice and tea, and less water than those in other clusters. Sweet liker status may be a useful predictor of increased energy intake from beverages, but prospective trials are necessary to confirm this utility.

Taste Responses to Linoleic Acid: A Crowdsourced Population Study.

Dietary fats serve multiple essential roles in human health but may also contribute to acute and chronic health complications. Thus, understanding mechanisms that influence fat ingestion are critical. All sensory systems may contribute relevant cues to fat detection, with the most recent evidence supporting a role for the sense of taste. Taste detection thresholds for fat vary markedly between individuals and responses are not normally distributed. Genetics may contribute to these observations. Using crowdsourced data obtained from families visiting the Denver Museum of Nature & Science, our objective was to estimate the heritability of fat taste (oleogustus). A pedigree analysis was conducted with 106 families (643 individuals) who rated the fat taste intensity of graded concentrations of linoleic acid (LA) embedded in taste strips. The findings estimate that 19% (P = 0.043) of the variability of taste response to LA relative to baseline is heritable at the highest concentration tested.

No Difference in Perceived Intensity of Linoleic Acid in the Oral Cavity between Obese and Nonobese Individuals.

Findings from studies examining interactions between fat taste and dietary fat intake or body weight are mixed. A convenience sample of 735 visitors to the Denver Museum of Nature & Science ≥8 years old rated the taste intensity of edible taste strips impregnated with varying concentrations (%v/v) of linoleic acid (LA) (blank = 0.0, low = 0.06, medium = 0.15, high = 0.38). Percent body fat (BF%) was measured using bioelectrical impedance. Fat taste intensity was rated as significantly different across all concentrations (P < 0.001) except between the blank and low concentrations (P = 0.1). Ratings increased monotonically across concentrations. Children (<18 years; N = 180) rated all concentrations as more intense than adults (P < 0.001 for all). Women and girls rated the highest concentration as more intense than men and boys (P < 0.02 for all). BF% was not correlated with fat taste intensity ratings. Self-reported dietary intake indicated that obese individuals' intensity ratings for medium and high concentrations of LA were inversely related to recent mono- and poly-unsaturated fat exposure (r = -0.19 to -0.27; P < 0.03 for all). No such associations were observed in the nonobese group. Findings suggest that factors other than simple adiposity status influence fat taste intensity ratings, and that participants in fat taste studies should receive standardized meals prior to testing.

Associations between BMI and fat taste sensitivity in humans.

The objective of this study was to examine the reliability of associations between fat taste, hunger, dietary fat intake, and body mass index (BMI). Detection thresholds for oleic acid (OA) were obtained during each of 7 consecutive visits using a modified staircase procedure. Participants were 48 (N = 17 male; N = 31 female) healthy adults (mean age: 28.5 ± 10.4 years) with BMI's ranging from 18.9 to 47.2 (≥ 25 kg · m(-2), N = 24). OA detection thresholds and self-reported hunger (100-mm visual analog scale) were assessed at each visit. BMI and dietary fat intake (Block Rapid Fat Screener) were determined at baseline. There was a significant decrease of threshold concentration over repeated trials among lean and overweight (BMI between 25.0 and 29.9 kg · m(-2)) participants but not in the obese. Combining the lean and overweight and contrasting their responses to the obese revealed the lean plus overweight group to be significantly more sensitive at visits 6 and 7. No change of threshold sensitivity or correlation with fat intake was observed in the obese participants unlike findings in the lean and lean plus overweight participants. Correlations between saturated fat intake and threshold sensitivity were positive (greater intake associated with higher thresholds) at baseline for the group, with additional correlations observed among the lean plus overweight but not in the obese, leaving open questions about the nutritional significance of the association. No significant associations were observed between sensitivity to OA and hunger. Repeated testing is required to assess associations between fat taste and other outcome variables.

Influences of repeated testing on nonesterified fatty acid taste.

Findings that support the ability of humans to taste nonesterified fatty acids have been qualified by claims of substantial individual variability in sensitivity. We tested whether the number of testing visits impacted detection thresholds. Additionally, we explored the possibility that methodological differences in reported studies contributed to the high level of variance. Participants were randomized to either the modified staircase or ascending 3-alternative forced-choice methods, completed 10 test visits, and then switched to the alternate method. Repeated testing lowered the threshold concentration, and regardless of starting method, threshold concentrations were significantly lower with the second method. The staircase method generated data with less variation. The ascending method appears to be able to distinguish hypo and hypersensitive individuals as the variance at each visit increased over time, suggesting that the top performers continued to improve while the hyposensitive subjects maintained their low level of performance. The best individual threshold performance (lowest stimulus concentration) at each visit was obtained with the ascending method for 7 out of the first 10 visits (P = 0.117) and 17 out of the 20 visits (P = 0.001). Despite potential advantages of the ascending method in terms of sensitivity separation, there was no difference between the median of the first 10 visits, second 10 visits, and overall median obtained by the 2 testing methods. The most appropriate detection threshold testing method will depend on the goals of the researcher.

How Are You Sleeping? Why Nutrition Professionals Should Ask Their Patients About Sleep Habits.

Current literature has identified relationships among sleep, nutrition, and diet-related chronic diseases; however, knowledge about how sleep influences diet-related diseases is lacking in dietetics practice. This narrative review briefly explains sleep physiology and outlines the relationships between sleep duration and quality and common nutrition-related diseases, including obesity, diabetes, cardiovascular disease, obstructive sleep apnea, and cancer. Additionally, the review discusses how sleep influences wound healing and pregnancy outcomes and why hospitalized patients are likely to experience sleep problems. Plausible mechanisms explaining the relationships between sleep and disease are presented. Finally, commonly used sleep assessment tools and interventions are reviewed. Given the importance of sleep to health, dietitians should not only be aware of the role sleep plays in disease development and prevention but also assess sleep when feasible and refer patients and clients who are at high risk for sleep problems to a sleep clinic or community program that can address sleep issues.Teaching points:Sleep duration and quality influence risk and outcomes of common nutrition-related diseases.Sleep health evaluation is a missing piece in dietetic practice.There are easy-to-use, validated tools that dietitians can use to screen for sleep problems in order to refer patients and clients to sleep experts.

Equivalent Improvements in Sleep Duration and Sleep Quality Regardless of Program Delivery Modality: The SLeep Education for Everyone Program (SLEEP).

Sleep issues are pervasive, and treatment can be difficult to access, if available at all. The purpose of this study was to test whether the delivery modality (online vs. in person) of the SLeep Education for Everyone Program (SLEEP) influenced programmatic outcomes. A total of 60 participants completed the study, 28 in the online group and 32 in the in-person group. Across all participants, SLEEP improved sleep duration, sleep quality, and sleep hygiene behaviors (p < 0.001 for all). When comparing delivery modality, sleep duration and quality improved similarly between groups; however, sleep hygiene behaviors improved more in the in-person group (p = 0.033). Sleep hygiene scores did not correlate with sleep duration or quality after the program. Based on these findings, SLEEP appears to be equally effective in improving sleep duration and quality when delivered online or in person. These findings suggest that SLEEP can be delivered based on the organization's and participant's resources, needs, and preferred style of interaction.

The Effects of Acute Sleep Curtailment on Salt Taste Measures and Relationships with Energy-Corrected Sodium Intake: A Randomized Cross-Over Trial with Methodology Validation.

(1) Background: Sleep may be a factor that influences the taste-dietary intake relationship. The effect of sleep on salt taste measures has not been adequately studied, and no standardized methodology has been developed for measuring salt taste preference. (2) Methods: A sweet taste forced-choice paired-comparison test was adapted and validated to determine salt taste preference. In a randomized cross-over trial, participants slept a curtailed night (33% reduction in sleep duration) and a habitual night, confirmed by a single-channel electroencephalograph. Salt taste tests were conducted the day after each sleep condition using five aqueous NaCl solutions. One 24-h dietary recall was obtained after each taste test. (3) Results: The adapted forced-choice paired-comparison tracking test reliably determined salt taste preference. No changes in salt taste function (intensity slopes: p = 0.844) or hedonic measures (liking slopes: p = 0.074; preferred NaCl concentrations: p = 0.092) were observed after the curtailed sleep condition compared to habitual sleep. However, sleep curtailment disrupted the association between liking slope and energy-corrected Na intake (p < 0.001). (4) Conclusions: The present study serves as the first step toward more standardized taste assessments to facilitate comparison between studies and suggests accounting for sleep when exploring taste-diet relationships.

Health behavior changes associated with weight gain among first-year international students studying at an American university.

Objectives: To characterize the health behaviors and outcomes of first-year international students (FYIS) studying in the U.S. Participants and methods: Three different cohorts of FYIS from a large midwestern university in the U.S. completed three laboratory visits between August and March. The study began in 2017 and ended in March 2020. Anthropometrics, acculturative stress, eating behaviors, sleep, physical activity, and eating habits were assessed. Results: Fifty-four students completed the study. Females had a significant increase in percent body fat (p = .036) and a decrease in sleep quality (p = .006) at the final visit vs. baseline, and uncontrolled (p = .006) and emotional (p < .001) eating behaviors were higher. FYIS who gained more than the median 1.2 kg over the study period experienced higher acculturative stress (p = .004) and a decline in sleep quality (p = .003). Conclusion: Reducing acculturative stress and improving sleep quality should be explored as interventions to protect against undesirable changes in adiposity among FYIS.

Emotional Eating among Ghanaian University Students: Associations with Physical and Mental Health Measures.

Eating behaviors are a set of cognitive processes that influence dietary decision making and, thus, overall health. Some of the most studied eating behaviors are those characterized by the Three Factor Eating Questionnaire-18 (TFEQ). The TFEQ examines three eating behaviors: emotional eating (EE), uncontrolled eating (UE), and restrained eating (RE). While frequently used, there is little information characterizing these eating behaviors in the Ghanaian population. This cross-sectional study describes EE, UE, and RE behaviors in a university student population (n = 129) in Ghana. Of the three behaviors, EE was the only one associated with any of the health outcomes in this study: BMI for males (r = 0.388, p = 0.002) and anxiety (r = 0.471, p < 0.001, higher score is less desirable), and sleep quality (r = 0.464, p < 0.001, higher score is less desirable) for females. Overweight and obese females reported significantly higher EE scores compared to healthy weight females (35.7 ± 23.7 vs. 11.9 ± 15.6, p = 0.002). No such observation was observed among overweight and obese males (p > 0.05). EE, UE, and RE scores did not differ between males and females. While this study provides important information about the eating behaviors of Ghanaian university students and allows for comparison to students from other cultures, future work must develop culturally relevant tools for the Ghanaian population.

Comparing mental health and well-being of US undergraduate and graduate students during the early stages of the COVID-19 pandemic.

Objective: This study explored how COVID-related mental health and well-being varied between undergraduate and graduate students. Relationships with physical health behaviors were also examined. Participants: Undergraduate (n = 897) and graduate (n = 314) students were recruited from three US universities between mid-April and late-May 2020. Methods: Participants in this cross-sectional survey self-reported perceived stress, financial stress, resilience, repetitive negative thinking, mood, anxiety, diet, sleep, and physical activity using validated instruments. Results: Undergraduate students reported more perceived stress, more repetitive negative thinking, less positive mood, and less support from professors than graduate students. Perceived stress, repetitive negative thinking, negative mood, and anxiety increased among all students (p < .05 for all). Correlations between mental health outcomes and physical health behaviors were weak to moderate (r = .08 to .49). Conclusions: College students, particularly undergraduates, perceived negative mental health impacts during COVID. Creative approaches for meeting student needs are necessary.

Snacking behavior differs between evening and morning chronotype individuals but no differences are observed in overall energy intake, diet quality, or food cravings.

There is a growing body of literature that links chronotype to certain undesirable eating behaviors. However, the relationship between chronotype and dietary intake is poorly characterized among adults in the United States (U.S.). This cross-sectional study examined the associations among chronotype, snacking habits, dietary intake and quality, and food cravings. One-hundred adults living in the U.S. completed the study. Based on the Horne-Östberg Morningness-Eveningness Questionnaire score, an individual was categorized as having either a morning (M)-type, intermediate (I)-type, or evening (E)-type chronotype. Snack intake was assessed using a previously published specialized food frequency questionnaire. Sugar-sweetened beverage (SSB) intake was assessed using the updated version of the Beverage Intake Questionnaire-15. Alcohol misuse was measured using the Alcohol Use Disorders Identification Test-Consumption. Diet quality was obtained using the Diet History Questionnaire III. The validated General Food Cravings Questionnaire-Trait measured participants' food cravings. E-type individuals reported consuming snacks more often over the course of a week than M-types (p = .002) but not I-types. In terms of timing of snacking, E-type individuals consumed more snacks after dinner than M-types (p < .001). E-type individuals consumed more energy-dense snacks (p = .005), especially candies (p = .005), than M-types. However, there were no significant differences in healthy snack frequency, diet quality, energy and macronutrient intake, SSB consumption, alcohol misuse, or food cravings among chronotypes (p > .05, for all). In conclusion, E-type individuals consumed snacks more frequently and later than M-types; however, chronotype was not associated with an individual's energy intake, diet quality, and food cravings, which suggests that chronotype is negligibly associated with weight gain-related behaviors in this population.

Relationships between Dairy and Calcium Intake and Mental Health Measures of Higher Education Students in the United States: Outcomes from Moderation Analyses.

BACKGROUND: The prevalence of mental health concerns among university students in the United States (U.S.) continues to increase, while current treatments, including medication and counseling, present shortcomings. Higher dairy and calcium intakes are associated with protective effects on mental health; however, previous studies have focused on investigating singular relationships between dairy and calcium intakes and mental health measures. A more complex exploration of these relationships is warranted to better examine whether increasing dairy and calcium intakes could serve as an intervention to improve mental health. The present study sought to further characterize the relationships between dairy and calcium intake, perceived stress, and a variety of mental health measures using linear regression and moderation analyses. METHODS: The present cross-sectional study involved students studying at three large U.S. universities, and data collection occurred from April to May 2020 when students were learning remotely due to the COVID-19 pandemic. An online survey comprising validated tools was distributed among students to assess dairy and calcium intake, perceived stress, anxiety, negative and positive moods, rumination, and resilience, sleep quality and duration, dietary risk, and physical activity. RESULTS: A total of 1233 students completed the study. Higher dairy and calcium intake was coincident with lower perceived stress and higher positive mood scores, while higher calcium intake was also coincident with lower anxiety, rumination, and higher resilience scores. Additionally, as calcium intake increased, the relationship between perceived stress and anxiety and the relationship between perceived stress and negative mood weakened. Dairy intake did not have this effect. CONCLUSIONS: Based on the results, and considering that calcium is a shortfall nutrient, universities should consider initiating programs and public health campaigns to promote dairy and calcium intake among this population.