Dr Vasiliki Iatridi

Within the ‘food addiction’ framework, overconsumption of sugars has been theorised to increase liking for sweetness perpetuating intake of sweet-tasting foods. Empirical evidence has primarily focused on the effect of repeated exposure to a single sweet-tasting product on subsequent liking and eating behaviour with mixed findings. Here, we tested whether exposure to a whole diet high in sugars influences overall sweet-liking and liking for and desire-to-eat palatable snacks; the role of distinct hedonic response patterns to sweetness (sweet-liking phenotypes) in the susceptibility to the effects of the high-sugar diet was also examined. Ninetythree young non-restraint eaters (31 sweet-likers, 31 moderate sweetlikers, 31 sweet-dislikers) rated sucrose solutions (overall sweet-liking) and snacks typical of a Westernised diet before and after an 8-day exposure to a diet providing at least 10% energy from sugars (exposure condition) or their usual diet (control group). Condition had a direct effect on overall sweet-liking: participants that received the high-sugar diet decreased their liking. For the palatable snacks, findings about liking were fully dependent on phenotype: sweet dislikers (SDs) in the exposure condition experienced a small rise in liking relative to a significant decline among SD controls. There was no significant change in desire-to-eat ratings
for the palatable snacks. Although sensory fatigue was evident for overall sweetness, a preliminary role of repeated exposure and overconsumption of sugars in directing food preferences toward palatable options was suggested; SDs were affected the most. Whether an exposure to diets exceeding sugars intake recommendations also alters voluntary intake of palatable foods warrants investigation.

Sugar intake is a key focus in government policies and dietary guidelines tackling the obesity epidemic. Despite the importance of taste hedonics on eating behaviour, informing food preference, selection and, consequently, nutritional intake and health, relatively few studies have explored the drivers of individual differences in liking sweet tastes, and those that have did not phenotype. Research strongly suggests three phenotypic responses to sweet taste (the sweet-liking phenotypes: extreme sweet-likers; moderate sweet-likers; and sweet dislikers), which have been confirmed with similar proportions across populations in the UK, USA, and Asia, suggesting a genetic basis. Here we explored for the first time the heritability of the sweet-liking phenotypes through twin modelling to see if the variation in sweet-liking is due to additive genetic (A), shared (C), or unshared environmental factors (E) in a genetically informative sample of monozygotic and dizygotic twins using two distinct populations from the UK (n = 468; 60% female, aged 21-24) and Finland (n = 967; 90% female, aged 18-81). Separate univariate models with age and sex as covariates were fit per cohort (UK/Finland) using Direct Symmetric Matrix Approach. Regardless of cohort or if sweet-liking was continuous or examined with phenotyping, an AE model was the best fit. Specifically, 32-38% of the variability in sweet taste liking in this population is due to variance in genetic factors (A), with the non-shared environment (E) being the larger driving force (52-68%). This study is the first to show a genetic component driving individual differences in the sweet-liking phenotypes and that unshared- environment modulates expression of liking.

In oncological outpatient settings, patients often require nutritional support after they have developed malnutrition. A delayed dietetic referral can lead to increased difficulties in providing therapies and surgery, and to poorer patient outcomes. The audit described in this article aimed to assess the frequency and completeness of patient record documentation of anthropometric measurements in a day treatment unit (DTU) in a single cancer centre in the UK. The underlying goal was to improve anthropometry monitoring procedures to ensure that documentation is sufficient to indicate weight loss and, hence, allow timely referrals for nutrition support. The results show that, for over 80% of patients, it was not possible to identify a weight trend between the latest two treatments received at the hospital. The audit findings highlight the need to improve malnutrition monitoring and to ensure patient records contain updated and accurate anthropometric measurements in order to facilitate medical staff to recognise early malnutrition risk and refer for appropriate nutritional support when needed.

Legislation aimed at reducing sugar intake assumes that sweetliking drives overconsumption. However, evidence that greater liking for sweet taste is associated with an unhealthier body size is mixed and
complicated by relatively small samples, an overreliance on body mass index (BMI) and a lack of classification using sweet-liking phenotypes. We aimed to address these issues by examining body size data in two larger samples with sweet-liking phenotyping (extreme sweet likers [ESL], moderate sweet likers [MSL] and sweet dislikers [SD]) to better answer the question: is sweet liking a key driver of obesity? Young adults (18-34 years old) in the UK attended a two-session lab-based experiment involving a 1.0M sucrose taste test and a body composition measurement using bioelectrical impedance (Study 1: N¼200 (68 men, 132 women): 71 ESL; 93 MSL; 36 SD; Study 2: N¼314 (125 men, 189 women): 96 ESL; 153 MSL; 65 SD). Most interestingly, a significant effect of phenotype on fat-free mass (FFM) was found in both studies, with ESL having significantly higher FFM than SD and in study 1, SD had a significantly higher body fat percentage than both ESL and MSL. This suggests that the higher BMI often seen in sweet-likers may be due to larger FFM, and considering the wellestablished positive association between FFM and energy requirements, these data support longstanding ideas that expression of sweet-liking may
reflect homoeostatic needs for energy and questions the simple model where sweet-liking alone is a risk factor for obesity.

There are well known phenotypic differences in sweet-liking across individuals, but it remains unknown whether these are related to broader underlying differences in interoceptive abilities (abilities to sense the internal state of the body). Here, healthy women (N = 64) classified as sweet likers (SLs) or sweet dislikers (SDs) completed a bimodal interoception protocol. A heartbeat tracking and a heartbeat discrimination task determined cardiac interoception; both were accompanied by confidence ratings. A water load task, where participants consumed water to satiation and then to maximum fullness was used to assess gastric interoceptive abilities. Motivational state, psychometric characteristics and eating behaviour were also assessed. SLs performed significantly better than SDs on both heartbeat tasks, independently of impulsivity, anxiety, depression, and alexithymia. No differences in metacognitive awareness and subjective interoceptive measures were found. With gastric interoception, SLs were more sensitive to stomach distention, and they ingested less water than SDs to reach satiety when accounting for stomach capacity. SLs also scored higher on mindful and intuitive eating scales and on emotional eating particularly in response to negative stimuli; emotional overeating was fully mediated via interoceptive performance. Overall, our data suggest the SL phenotype may reflect enhanced responsiveness to internal cues more broadly.

Building on a series of recent studies that challenge the universality of sweet liking, here we review the evidence for multiple sweet-liking phenotypes which strongly suggest, humans fall into three hedonic response patterns: extreme sweet likers (ESL), where liking increases with sweetness, moderate sweet likers (MSL), who like moderate but not intense sweetness, and sweet dislikers (SD), who show increasing aversion as sweetness increases. This review contrasts how these phenotypes differ in body size and composition, dietary intake and behavioural measures to test the widely held view that sweet liking may be a key driver of obesity. Apart from increased consumption of sugar-sweetened beverages in ESL, we found no clear evidence that sweet liking was associated with obesity and actually found some evidence that SD, rather than ESL, may have slightly higher body fat. We conclude that ESL may have heightened awareness of internal appetite cues that could protect against overconsumption and increased sensitivity to wider reward. We note many gaps in knowledge and the need for future studies to contrast these phenotypes in terms of genetics, neural processing of reward and broader measures of behaviour. There is also the need for more extensive longitudinal studies to determine the extent to which these phenotypes are modified by exposure to sweet stimuli in the context of the obesogenic environment.

Phenotypic differences in sweet-liking are well known, but how they relate to actual eating behaviour, and what causes these differences in liking, remains unclear. Here we first explored if sweet liking phenotypes (sweet likers, sweet dislikers, and moderate likers) differed in habitual intake of high fat sugar Western diets, with 244 healthy volunteers (18-34 yo). Sweet likers more frequently consumed items with high sugar content. However, phenotypes did not differ in use of sweet-fat or savoury-fat items, implying sweet dislikers tolerated sweetness when consumed with fat. Secondly, using a childhood eating questionnaire, we investigated whether phenotypic differences in sweet liking reflected differences in childhood food experience: no differences were found. Finally, we examined phenotypic differences in impulsivity (using Barratt Impulsiveness Scale - BIS) and reward sensitivity (using Arnett’s Inventory of Sensation Seeking - AISS). No differences were found on the BIS scores, but sweet likers scored higher on the intensity measure of the AISS. These data confirm that phenotypic differences in sweet liking do reflect habitual use of sugar-rich foods and drinks, suggesting a wider difference in reward sensitivity.

Taste hedonics drive food choices, and food choices affect weight maintenance. Despite this, the idea that hyper-palatability of sweet foods is linked to obesity development has been controversial for decades. Here, we investigate whether interpersonal differences in sweet-liking are related to body composition. Healthy adults aged 18–34 years from the UK (n = 148) and the US (n = 126) completed laboratory-based sensory tests (sucrose taste tests) and anthropometric measures (body mass index; BMI, body fat; fat-free mass; FFM, waist/hips circumferences). Habitual beverage intake and lifestyle and behavioural characteristics were also assessed. Using hierarchical cluster analysis, we classified participants into three phenotypes: sweet liker (SL), sweet disliker (SD), and inverted-U (liking for moderate sweetness). Being a SD was linked to higher body fat among those younger than 21 years old, while in the older group, SLs had the highest BMI and FFM; age groups reflected different levels of exposure to the obesogenic environment. FFM emerged as a better predictor of sweet-liking than BMI and body fat. In the older group, sweetened beverage intake partially explained the phenotype–anthropometry associations. Collectively, our findings implicate underlying energy needs as an explanation for the variation in sweet-liking; the moderating roles of age and obesogenic environment require additional consideration.

Taste hedonics is a well-documented driver of food consumption. The role of sweetness in directing ingestive behavior is largely rooted in biology. One can then intuit that individual differences in sweet-liking may constitute an indicator of variations in the susceptibility to diet-related health outcomes. Despite half a century of research on sweet-liking, the best method to identify the distinct responses to sweet taste is still debated. To help resolve this issue, liking and intensity ratings for eight sucrose solutions ranging from 0 to 1 M were collected from 148 young adults (29% men). Hierarchical cluster analysis (HCA) revealed three response patterns: a sweet-liker (SL) phenotype characterized by a rise in liking as concentration increased, an inverted U-shaped phenotype with maximum liking at 0.25 M, and a sweet-disliker (SD) phenotype characterized by a decline in liking as a function of concentration. Based on sensitivity and specificity analyses, present data suggest the clearest discrimination between phenotypes is seen with 1.0 M sucrose, where a liking rating between −15 and +15 on a −50/+50 scale reliably distinguished individuals with an inverted U-shaped response from the SLs and the SDs. If the efficacy of this approach is confirmed in other populations, the discrimination criteria identified here can serve as the basis for a standard method for classifying sweet taste liker phenotypes in adults. 

Human ingestive behavior depends on myriad factors, including both sensory and non-sensory determinants. Of the sensory determinants, sweet taste is a powerful stimulus and liking for sweetness is widely accepted as an innate human trait. However, the universality of sweet-liking has been challenged. Sub-groups exhibiting strong liking (sweet likers) or having aversive responses to sweet taste (sweet dislikers) have been described, but the methods defining these phenotypes are varied and inconsistent across studies. Here, we explore the strengths and weaknesses of different methodological approaches in identifying sweet taste liker phenotypes in a comprehensive review. Prior studies (N = 71) using aqueous sucrose solution-based taste tests and a definition of two or more distinct hedonic responses reported between 1970 and 2017 were summarized. Broadly speaking, four different phenotyping methods have been used: 1. Interpretation (visual or statistical) of the shape of hedonic response curves, 2. Highest preference using ratings, 3. Average liking above mid-point or Positive/Negative average liking method, and 4. Highest preference via paired comparisons. Key methodological weaknesses included the use of subjective or arbitrary criteria as well as adoption of protocols unsuitable for large-scale implementation. Overall, we did not identify a method distinctly superior to the others. Given the role of both hedonics and reward in food intake, a better understanding of individual variations in sweet taste perception could clarify how sweet-liking interplays with obesity or addictive behaviors such as alcohol misuse and abuse. The development of a universally used statistically robust and less time-consuming classification method is needed.

Objective. Excessive energy intake during evening hours is associated with several health problems. The aim of this study was to investigate for the first time the possible association of late-night overeating with breakfast habits and obesity in a large sample of Greek children ages 9 to 13 y.

Methods. In all, 2655 schoolchildren (9–13 y) participated in the Healthy Growth Study, a cross-sectional epidemiologic study conducted in 77 primary schools in four large regions in Greece. The present study presents results on 1912 children having full data regarding anthropometric, dietary, physical activity, and physical examination indices.

Results. High-energy intake at dinner and evening snack was associated with higher likelihood of skipping breakfast (odds ratio, 1.85; 95% confidence interval 1.42–2.39) and with lower caloric intake at breakfast (β = 0.14; P

Conclusions, Late-night overeating is associated with skipping and/or consuming a smaller breakfast. In children with low levels of physical activity, it is associated with increased body mass index. Future relevant studies are essential to further explore and confirm the findings of the present study.

Objectives. Excessive fat storage is accompanied by several comorbidities in children and early identification of elevated abdominal fat may be extremely valuable in early prevention of cardiometabolic risk. The aim of the present study was to establish cutoff points for waist circumference trunk and visceral fat, thus identifying increased likelihood of elevated inflammatory markers and adipokines in children.

Methods. A representative sample of schoolchildren (aged 9–13 y) participated in a cross-sectional epidemiologic study conducted in Greece. Anthropometric and physical examination data, biochemical indices, and socioeconomic information (collected from parents) were assessed for all children. Central adiposity markers (trunk and visceral fat) were collected with bioelectrical impedance analysis for 999 children.

Results. Specific cutoff values of abdominal adiposity indices indicating increased likelihood of elevated levels of C-reactive protein, interleukin-6, and leptin and decreased levels of adiponectin were calculated by sex. These cutoff values were; 67.5 cm for boys and 69.5 cm for girls for waist circumference, 17.75% for boys and 22.65% for girls for trunk fat mass percentage, and 3.95 for boys and 2.55 for girls for visceral fat rating.

Conclusions. To our knowledge, this is the first study to establish simple cutoff points for abdominal adiposity indices identifying children at high risk for elevated inflammatory markers and decreased adipokine levels. Future studies are essential to confirm these findings.

Background
The aim of the present study was to identify indicators of malnutrition, as obtained by anthropometric measurements, that might be potential predictors of transplant outcomes.

Methods
One hundred and three patients receiving a graft from a living or a deceased donor were included in this prospective study. Body mass index (BMI) based on pretransplant dry body weight, triceps skinfold, mid‐arm muscle circumference and corrected mid‐arm muscle area were measured. Post‐transplant data on delayed graft function (DGF) and glomerular filtration rate (GFR) at discharge were collected until patient discharge.

Results
Delayed graft function developed in 36.9% of the patients. BMI was the only anthropometric variable associated with a higher likelihood of DGF (odds ratio = 1.25, 95% confidence interval = 1.07–1.47) after adjusting for age, gender, donor group, donor age and years of dialysis before transplantation. Obesity was associated with a higher frequency of DGF (83.3% versus 31.1%, P = 0.001) compared to normal weight. GFR at discharge was negatively associated with BMI [β = −0.014 (0.005), P = 0.004], being overweight [β = −0.151 (0.041), P

Conclusions
The likelihood of DGF was higher among obese patients, whereas GFR at discharge was negatively associated with being overweight and obesity.

Objective. To identify among a wide range of perinatal indices, as well as certain family sociodemographic and parental characteristics, those independently associated with insulin resistance (IR) in late childhood.

Methods. A representative sample of 2195 Greek schoolchildren, aged 9–13 yr, was examined, and based on the biochemical indices collected IR was estimated using the homeostasis model assessment (HOMA‐IR

Results. The overall prevalence of IR was 28.4%, with a higher prevalence observed for girls compared with boys (p 30 000 €) as the only significant correlates of IR after also controlling for children's body mass index (BMI) and Tanner stage.

Conclusions. The current study highlighted small birth weight and female sex as the only perinatal factors independently associated with the occurrence of IR in late childhood, when examined at a multivariable level with a wide range of perinatal indices as well as certain family sociodemographic and parental characteristics.

Purpose.
To identify lifestyle patterns associated with blood lipid levels in children.

Methods.
A representative sample of 2,043 schoolchildren (9–13 years) participated in a cross-sectional epidemiologic study conducted in 77 primary schools in four large regions in Greece. Dietary intakes, breakfast patterns and eating frequency, physical activity levels, sleep duration, anthropometric and physical examination data, biochemical indices and socioeconomic information (collected from parents) were assessed in all children. Principal component analysis was used to identify the lifestyle patterns.

Results.
A lifestyle pattern of more screen time, shorter sleep duration and higher sugar-sweetened beverage consumption was inversely associated with HDL cholesterol (β = −0.077; P 44.8 min of MVPA per day and > 4.7 meals per day) were 29.7, 32.6 and 43.1 % less likely of having abnormal levels of total cholesterol, LDL and total/HDL cholesterol ratio, respectively, according to the National Cholesterol Education Program (NCEP) cutoff points.

Conclusions.
A lifestyle pattern of more than approximately 45 min of MVPA and 5 eating occasions per day was significantly associated with reduced likelihood of dyslipidemias in schoolchildren (9–13 years).

Objective
To examine the accuracy of maternal ability to classify their children's weight status correctly using a verbal and a visual classification instrument and to detect significant correlates of maternal misperceptions.

Design. Cross-sectional study.

Setting. Primary schools in four counties from north, west, central and south Greece.

Subjects. A representative sample of 1858 primary-school children aged 9–13 years was examined. Two different instruments to assess maternal perceptions of their children's weight status, i.e. a verbal and a visual one, were used.

Results. Verbal and visual maternal underestimation rates of children's weight status were 15·0 % and 41·3 %, respectively. The frequency of underestimation was much higher among overweight and obese children for both instruments. The highest underestimation rates of 87·9 % and 82·1 % in overweight and obese boys, respectively, were obtained with the visual instrument. Multiple logistic regression modelling revealed that the likelihood of both verbal and visual maternal underestimation of their children's weight status was significantly higher for overweight mothers and for those with a lower educational level. Furthermore, children's male gender and a nanny or someone other than the mother as the child's primary caregiver were found to increase the odds of visual and verbal maternal underestimation of children's weight status, respectively.

Conclusions. The present study showed that the verbal instrument used to assess maternal perceptions of their children's weight status was more accurate compared with the visual one. However, both instruments showed that a considerable number of overweight and obese boys had their weight status underestimated by their mothers. Educating mothers to classify their children's weight status correctly might be a key factor for the implementation of successful childhood obesity prevention initiatives.