Infant feeding practices and body mass index up to 7.5 years in the French nationwide ELFE study.

BACKGROUND/OBJECTIVES: The infant diet represents one of the main modifiable determinants of early growth. This study aimed to investigate the associations of infant feeding practices with body mass index (BMI) until 7.5 years. SUBJECTS/METHODS: Analyses were based on data from the French nationwide ELFE birth cohort. Data on breastfeeding (BF) and complementary feeding (CF) were collected monthly from 2 to 10 months. Infant feeding practices were characterized using principal component analyses (PCA) and hierarchical ascendant classification. BMI z-score was computed at 1, 2, 3, 5 and 7.5 years, from data collected in the child's health booklet; 7.5-year overweight was defined according to IOTF references. Associations between infant feeding practices and BMI were investigated by linear regression models adjusted for main confounders. RESULTS: Ever breastfeeding was not associated with BMI up to 7.5 years. Compared to intermediate breastfeeding duration (1 to <3 months), longer breastfeeding duration (≥6 months) was related to lower 1-year BMI, but not at older ages. Compared to the recommended age at CF introduction (4-6 months), early CF (<4 months) was related to higher BMI up to 5 years with a similar trend at 7.5 years, but not to the risk of overweight. The PCA patterns characterized by early baby cereal introduction and late food pieces introduction or by frequent intake of main food groups were related to a lower BMI up to 7.5 years. CONCLUSION: Breastfeeding was related with a lower BMI in infancy but not thereafter, whereas an early CF initiation (<4 months) was associated with a higher BMI in childhood.

The sweet tooth of infancy: Is sweetness exposure related to sweetness liking in infants up to 12 months of age?

Infants become increasingly exposed to sweet-tasting foods in their first year of life. However, it is still unclear whether repeated exposure to sweet taste is linked to infants' sweetness liking during this period. Making use of data from the OPALINE cohort, this study aimed to examine the link between sweetness exposure and sweetness liking during two important periods in early infant feeding: at the start of complementary feeding (3-6 months) and the transition to the family table (10-12 months). Infants' sweetness exposure was assessed using 7-d food records which were completed by mothers every month (n 312), reporting daily consumption rates of formula/breast milk or complementary food and the type of formula milk and/or complementary foods for each feeding occasion. Infants' sweetness liking was studied in the laboratory at 3, 6 and 12 months of age by assessing their response to a lactose-water solution and the amount drunk of this solution compared with plain water. Linear regressions and structural equation model assessed associations between exposure to and liking for sweetness at 6 and 12 months. Neither at 6 (n 182) nor at 12 months (n 197) was sweetness exposure associated with sweetness liking. While sweetness liking at 3 months was unrelated to liking at 6 months, the latter predicted sweetness liking at 12 months. These findings demonstrate no association between sweetness exposure at 3 to 12 months and liking at 6 and 12 months despite a sharp increase in sweetness exposure in that period. However, sweetness liking at 6 and 12 months was positively associated.

Increasing Parental Knowledge About Child Feeding: Evaluation of the Effect of Public Health Policy Communication Media in France.

Background: Unhealthy eating behaviors are risk factors for non-communicable diseases. Parents largely influence the development of eating behaviors during childhood through their feeding practices. Parental feeding practices in line with recommendations are more likely to turn into healthier outcomes in children. From a public health perspective, it should be first ascertained whether providing parents with recommendations about child feeding is a useful approach for increase parental knowledge. Recently, the French health authorities developed a brochure covering updated child feeding recommendations. The present study aims to evaluate the short-term effects of reading this brochure on parental knowledge about child feeding, distinguishing knowledge accuracy and certainty. Methods: A brochure containing updated child feeding recommendations for 0-3 years old was developed by the French public health agency. A representative sample of French parents (n = 400) was targeted to complete an online questionnaire (T0) comprising 30 statements regarding child feeding. For each statement, parents indicated whether it was true/false and how certain they were of their answer (4-point scale). After receiving and reading the brochure, the same parents completed the same questionnaire 3 weeks later (T1). Accuracy (number of correct answers) and certainty (number of mastered answers: correct answers given with the maximal degree of certainty) were compared at T1 vs. T0 using paired t-tests. Knowledge evolution based on parental age, parity and education level was tested with linear models. Results: A total of 452 parents responded at T0 and T1 and were considered for analysis. Between T0 and T1, the number of correct answers [median 22-25, t(451) = 17.2, p ≤ 0.001] and mastered answers [median 11-17, t(451) = 18.8, p ≤ 0.001] significantly increased. The median of the difference between T1 and T0 was larger for mastered than for correct answers. The observed evolution in knowledge was independent of parental age, parity or education level. Conclusions: A brochure containing child feeding recommendations has the potential to increase the accuracy and, to an even greater degree, the certainty of parental knowledge. This increase was observed even for younger or less educated parents.

Inhibition and shifting across the weight status spectrum.

Executive functioning (EF) is of major interest in the study of cognitive factors involved in obesity. Among EF, shifting is related to behavioral flexibility, and inhibition to the ability to refrain from impulsive behavior. A deficit in those two EF could predict individual difficulties to maintain a healthy lifestyle. Weak evidence of deficits in shifting and inhibition in individuals of higher Body Mass Index (BMI) have been observed. The objective was to clarify the relationship between inhibition and shifting regarding weight status group differences in healthy adults. Two neuropsychological tests from the Test of Attentional Performance (TAP) battery were used to measure EF performance of three groups of men and women: normal-weight (NW, n = 38), overweight (OW, n = 40) and obesity (OB, n = 37). The results show that individuals with higher BMI have lower inhibition capacities and that classically used weight status categories might not capture cognitive variability. No differences in shifting were observed concerning weight status nor BMI. This paper provides new insights on cognitive factors in obesity by presenting data from healthy individuals with overweight and obesity. The results support that assessing inhibition capacities might be of interest in a clinical setting for patients with difficulties to lose weight.

Parental feeding practices and parental involvement in child feeding in Denmark: Gender differences and predictors.

Studies about fathers and feeding are scarce and little is known about predictors of parental involvement in child feeding and of paternal feeding practices. Therefore, this study aimed to examine possible differences between Danish mothers and fathers with regard to their feeding practices and involvement in feeding related tasks, and to assess possible parent-related predictors of parental practices and involvement. A total of 261 mothers and 321 fathers of pre-schoolers completed an online survey with items from validated questionnaires. Gender differences were observed; fathers reported using higher levels of coercive control practices, while mothers reported using higher levels of structure practices and autonomy support practices. Both mothers and fathers reported to be highly involved in feeding their child. Regressions showed that a higher concern for child weight and a higher motivation for child preference when buying food were linked to a higher use of coercive control practices while a higher motivation for health control when buying food, cooking confidence, feeding/general self-efficacy and perceived responsibility for feeding were linked to a higher use of structure and autonomy support practices. The results of this study provide valuable insight into maternal and paternal practices in Denmark and their determinants.

Young Children's Eating in the Absence of Hunger: Links With Child Inhibitory Control, Child BMI, and Maternal Controlling Feeding Practices.

This study aimed to gain a better understanding of the associations between young children's eating in the absence of hunger (EAH), inhibitory control, body mass index (BMI) and several maternal controlling feeding practices (food as reward, restriction for health, restriction for weight control). In addition, to more properly assess the relationship between children's and maternal variables, the link between EAH and restriction was explored separately in two directionalities: "child to parent" or "parent to child." To do this, mothers of 621 children aged 2.00-6.97years (51% boys, M=4.11years, SD=1.34) filled in a questionnaire with items from validated questionnaires. Structural equation modeling (SEM) was used to analyze the data. The results showed, whatever the directionality considered, a positive association between children's eating in the absence of hunger and their BMI z-scores. Restriction for health and restriction for weight control were differently linked to EAH and to children's BMI z-scores. Namely, low child inhibitory control, food as reward and restriction for health were identified as risk factors for EAH. Restriction for weight control was not linked to EAH, but was predicted by child BMI z-scores. Interventions aiming to improve children's abilities to self-regulate food intake could consider training children's general self-regulation, their self-regulation of intake, and/or promoting adaptive parental feeding practices.

Associations between Infant Dietary Intakes and Liking for Sweetness and Fattiness Sensations in 8-to-12-Year-Old Children.

An exposure to sweetened and fatty foods early in life may be involved in high liking later in life. The objective is to investigate the association between dietary exposure to carbohydrate, sugars and fat in infancy, with liking for sweetness, fattiness and fattiness-and-sweetness sensations at 8-to-12-year-old. Analyses were conducted on 759 French children from the EDEN mother-child cohort. Carbohydrate, sugar or fat intake, being a consumer of added sugars or added fats were assessed at 8 and 12 months using 3-day food records. The liking score (0-10) for the different sensations was assessed through an online child-completed questionnaire. Associations were tested by linear regressions adjusted for main confounders and the interaction with sex was tested. None of the early dietary exposure variables was related to fattiness liking. Carbohydrate intake at 8 months was positively but weakly associated with liking for sweetness-and-fattiness. In girls only, carbohydrate intake at 12 months was positively associated with liking for sweetness. Globally, no marked associations were observed between infant dietary exposure to sweet and fat and liking for sweetness and fattiness in young children. The positive link in girls between early carbohydrate exposure and later liking for sweetness needs to be confirmed in further studies.

Are food parenting practices gendered? Impact of mothers' and fathers' practices on their child's eating behaviors.

Past research has mainly focused on the links between child eating behaviors and maternal food practices. The impact of fathers and of concordant/discordant food parenting practices within families has received much less attention. To fill this gap, both parents of 105 French children aged 2.01-6.51 years (54 boys, Mage = 3.88 years, SD = 1.40) filled in a survey with items from validated questionnaires. Results showed that fathers and mothers perceived their child's eating behaviors in similar ways (Pearson correlations between 0.34 and 0.78; M = 0.60), despite mothers taking significantly more meals with their child than fathers. Fathers reported using significantly more pressure to eat and food as reward, but reported lower levels of "family meal setting" than mothers. Moderate to high correlations were observed between mothers' and fathers' feeding practices and styles. Regression analyses showed that both maternal and paternal practices and styles were predictors for child eating behaviors. One interaction effect was observed: in households where both parents used higher levels of pressure to eat, the child showed a significantly lower food enjoyment than expected if the effects were additive. Our findings underline the importance of studying the individual role of each parent in child feeding research and that both parents within families should avoid using coercive practices. This could finally stimulate new interventions and recommendations addressed to both parents.

11 and 15-month-old infants do not compensate immediately for energy variation, and no further adjustment occurs 12 or 24 hours later.

Previously, we demonstrated that, in the short term, infants undercompensated for the energy from a preload given 25 min before an ad libitum meal. However, although not consistent, there is evidence in young children that caloric adjustment may occur over longer periods. We investigated the extent to which further energy adjustment occurs up to 24 h after a single meal preceded by preloads of varying energy density (ED) in infants that are 11 and 15 months old. Short-term caloric adjustment was measured in 11- and 15-month-old infants through a preload paradigm meal in the laboratory. To assess their caloric adjustment over longer periods (12 and 24 h), we used 24 h dietary records to evaluate the energy intake (EI) after each visit to the laboratory. Three COMPX scores were calculated according to three different time periods after preload consumption (0 h [i.e., short-term], 12 h or 24 h). Our main result was that, on average, regardless of the time period considered, the infants undercompensated their EI after preload consumption: at 11 and 15 months, caloric adjustment was partial and similar overtime. Considering that a slight repeated imbalance of the energy balance may promote rapid weight gain over the first months, this study calls for further research focusing on facilitators and barriers of efficient appetite control abilities in infancy.

Child eating behaviors, parental feeding practices and food shopping motivations during the COVID-19 lockdown in France: (How) did they change?

The COVID-19 pandemic caused France to impose a strict lockdown, affecting families' habits in many domains. This study evaluated possible changes in child eating behaviors, parental feeding practices, and parental motivations when buying food during the lockdown, compared to the period before the lockdown. Parents of 498 children aged 3-12 years (238 boys; M = 7.32; SD = 2.27) completed an online survey with items from validated questionnaires (e.g., CEDQ, CEBQ, HomeSTEAD). They reported on their (child's) current situation during the lockdown, and retrospectively on the period before the lockdown. Many parents reported changes in child eating behaviors, feeding practices, and food shopping motivations. When changes occurred, child appetite, food enjoyment, food responsiveness and emotional overeating significantly increased during the lockdown. Increased child boredom significantly predicted increased food responsiveness, emotional overeating and snack frequency in between meals. When parents changed their practices, they generally became more permissive: less rules, more soothing with food, more child autonomy. They bought pleasurable and sustainable foods more frequently, prepared more home-cooked meals and cooked more with the child. Level of education and increased stress level predicted changes in parental practices and motivations. This study provides insights in factors that can induce positive and negative changes in families' eating, feeding and cooking behaviors. This can stimulate future studies and interventions.

Characterization of Infant Feeding Practices and Related-Family Characteristics in the French Nationwide ELFE Birth Cohort.

Family characteristics such as education level or income are related to infant feeding practices. This study aimed to characterize infant feeding practices and investigate their associations with family characteristics. Analyses were performed with data from a French nationwide cohort, Etude Longitudinale Française depuis l'Enfance (ELFE). Feeding practices were characterized by two methods, a principal component analysis and a hierarchical ascendant classification (n = 8922). This characterization was conducted in three steps: considering firstly only introduction of main food groups, then also food pieces and finally adding the type of complementary food. The associations between family characteristics and the infant feeding patterns or clusters were tested by linear or multinomial regressions (n = 7556). Besides breastfeeding duration and age of first introduction of complementary foods, it appeared also important to consider specific food groups such as sweetened beverages and cow's milk, and the introduction of food pieces, to describe feeding practices. Recommended feeding practices (longer breastfeeding, complementary food in the right period) were related to higher maternal age and education level, so was migration status, the presence of older children, low income or the mothers' attendance to pre-birth preparation classes. The interrelations between feeding practices and family characteristics must be considered when examining the influence of feeding practices on child's health.

Implicit food odour priming effects on reactivity and inhibitory control towards foods.

The food environment can interact with cognitive processing and influence eating behaviour. Our objective was to characterize the impact of implicit olfactory priming on inhibitory control towards food, in groups with different weight status. Ninety-one adults completed a modified Affective Shifting Task: they had to detect target stimuli and ignore distractor stimuli while being primed with non-attentively perceived odours. We measured reactivity and inhibitory control towards food pictures. Priming effects were observed on reactivity: participants with overweight and obesity were slower when primed with pear and pound cake odour respectively. Common inhibitory control patterns toward foods were observed between groups. We suggest that non-attentively perceived food cues influence bottom-up processing by activating distinguished mental representations according to weight status. Also, our data show that cognitive load influences inhibitory control toward foods. Those results contribute to understanding how the environment can influence eating behaviour in individuals with obesity.

Impact of a front-of-pack nutritional traffic-light label on the nutritional quality and the hedonic value of mid-afternoon snacks chosen by mother-child dyads.

The aim of this study was to assess the impact of a nutritional traffic-light label, the Nutri-Score, on snack choices in mother-child dyads and to assess a potential hedonic cost associated with a change in favour of healthier choices. French mothers and children (n = 95; children's age: 7-11 years) who participated were asked to choose, for themselves and for the other dyad member, a snack composed of one beverage and two food items selected among several products with different nutritional quality. In the first step, the products were presented without any information. In the second step, the products were labelled with the Nutri-Score. Mothers and children were asked to rate their liking for all proposed products before being informed of their nutritional quality. The nutritional quality, the hedonic score, and the estimated budget of the selected snacks were compared before and after labelling. As hypothesized, the Nutri-Score label led to a significant increase in the nutritional quality of the chosen snacks. The budget for the chosen snacks was unchanged or decreased after the nutritional labelling was applied. Children and mothers had significantly lower liking for the snacks after nutritional labelling than before nutritional labelling, suggesting a hedonic cost associated with a change in favour of healthier snack choices. This raises the question of the sustainability of the behavioural change induced by the Nutri-Score label.

Weight Status and Attentional Biases Toward Foods: Impact of Implicit Olfactory Priming.

Objective: Numerous studies highlight the involvement of cognitive factors in the development and maintenance of obesity. We aimed to measure attentional biases (AB) toward foods (i.e., the individual tendency to automatically orient one's attention toward food stimuli) in normal-weight (NW) individuals and those with overweight (OW) and obesity (OB). We evaluated whether implicit or explicit exposure to olfactory food cues could modify AB. Methods: Eighty-five participants with different weight statuses took part in this experiment. We measured AB toward food pictures with an adapted visual probe task and the variations in AB, while participants were primed with olfactory food cues (within-subject design: no odor/low-energy dense food odor/high-energy dense food odor). Odors were non-attentively perceived during session 1 (implicit condition) and attentively perceived during session 2 (explicit condition). Results: Our results highlighted AB toward food pictures, especially when foods were energy dense, regardless of weight status (p < 0.001). The olfactory priming effect was only significant in the implicit condition. Participants with obesity had a stronger AB toward foods when they were primed with a non-attentively perceived high-energy dense food odor than with a non-attentively perceived low-energy dense food odor (p = 0.02). The trend was reversed for normal-weight participants, while no significant effect was found for participants with overweight. Conclusion: Our results support the hypothesis that an obesity-specific cognitive vulnerability may influence the processing of food-related stimuli and only while food cues are non-attentively perceived. Future research should seek to understand the mechanisms of this phenomenon.

Caloric compensation ability around the age of 1 year: Interplay with the caregiver-infant mealtime interaction and infant appetitive traits.

Previously, we demonstrated that infants' caloric compensation ability decreases between 11 and 15 months old. Here, we explored whether the inter-individual variation in infants' caloric compensation ability is associated with caregiver-infant interaction during laboratory test meals or with infant appetitive traits. To describe caregiver-infant interaction, we recorded feeding in laboratory ad libitum meals when the infants were 11 and 15 months old by using a connected weighing scale. We extracted the weight of each offered spoonful and the time interval between two spoonfuls. The caloric compensation score (COMPX) was assessed during the same meals. At 11 and 15 months old, the caregiver rated their infant's appetitive traits by completing the CEBQ-T. Student's t tests were applied to test the relationships between the variables describing the caregiver-infant interaction and the COMPX score. The relationships between the COMPX score or its change and the infants' appetitive traits were assessed with Kendall correlations. Regarding appetitive traits, the more the caloric compensation ability decreased between 11 and 15 months old, the more the infants were perceived as food responsive between these ages (τ = -0.36, p = 0.01, n = 28). At 11 months old, when the time interval between two spoonfuls was positively associated with the previous spoonful weight (i.e., a longer time interval after a larger spoonful weight), the infants exhibited a better caloric compensation ability (t = -2.1, p = 0.04, n = 38). Moreover, this study provides new evidence regarding the importance of a responsive feeding style by suggesting that adapting the feeding pace to the spoonful weight could be a favourable practice associated with better caloric compensation ability by the end of the first year. TRIAL REGISTRATION: This trial was registered at clinicals.gov as NCT03409042 (https://clinicaltrials.gov/ct2/show/NCT03409042).

Caloric compensation in infants: developmental changes around the age of 1 year and associations with anthropometric measurements up to 2 years.

BACKGROUND: Previous results based on dietary recall suggest that the ability to adjust eaten quantities to food energy density (ED) may deteriorate around the age of 1 y. However, this hypothesis has not been investigated experimentally. OBJECTIVES: The first aim of the study was to describe changes in the short-term caloric compensation ability of infants around the age of 1 y. We expected a decrease in this ability with age. The second aim was to identify individual factors [e.g., breastfeeding duration, body mass index (BMI) z-score, and change in BMI z-score] related to interindividual variations in caloric compensation ability. METHODS: We adapted the preload paradigm to calculate a COMPX score. The measure was performed in the laboratory at 11 and 15 mo. The parent offered a food preload that was either low or high in ED (LED = 33 kcal/100 g or HED = 97.9 kcal/100 g, respectively), followed by an ad libitum meal after 25 min. The infants were measured and weighed. Information about the infants' milk-feeding history was collected. RESULTS: We obtained COMPX scores at 11 and 15 mo for 31 infants (12 females). As hypothesized, the caloric compensation ability significantly decreased with age (COMPX11 = 52% ± 133%; COMPX15 = -14% ± 151%; P = 0.03). The more the COMPX score decreased, the more the BMI z-score between 11 and 15 mo increased (P = 0.03) and the higher the BMI z-score was at 2 y (P = 0.03). No associations were found between COMPX scores and breastfeeding duration (all P > 0.60). CONCLUSIONS: Caloric compensation ability decreases between 11 and 15 mo. This decrease is associated with a larger increase in weight status from 11 to 15 mo and a higher weight status at 2 y. This study calls for further research to better understand the early determinants of caloric compensation ability. This trial was registered at www.clinicaltrials.gov as NCT03409042 (https://clinicaltrials.gov/ct2/show/NCT03409042).

Development of a new questionnaire to assess the links between children's self-regulation of eating and related parental feeding practices.

Young children have an innate ability to self-regulate food intake, driven primarily by hunger and satiety cues, but this ability tends to decrease during early childhood. The study aimed to first examine the development and initial validation of a self-report questionnaire suitable for French samples that assess two dimensions of children's self-regulation of eating (eating in the absence of hunger, poor eating compensation abilities) and potential related parental feeding practices. The second aim was to assess the links between children's self-regulation of eating and parental feeding practices as well as the links between children's self-regulation and children's body mass index. An initial 28-item questionnaire was developed. It included items related to the child's eating in the absence of hunger and eating compensation, which were selected mainly from interviews conducted with 45 mothers, and items related to parental feeding practices selected from existing tools. This questionnaire was then completed by 793 parents. A 21-item questionnaire was validated using a confirmatory factor analysis that showed satisfying fit indices. The structural equation modeling indicated that the use of food as reward was positively associated with eating in the absence of hunger, whereas parental awareness of children's cues was negatively associated with both children's eating in the absence of hunger and poor eating compensation ability. Interestingly, positive associations between eating in the absence of hunger and child's BMI, and between poor eating compensation ability and child's BMI were reported. The current study offered an initial validation of a new questionnaire that combines parental feeding practices and constructs involved in children's self-regulation of eating. Further studies are needed to disentangle these links and their directionality as well as the associations with children's body mass index.

Weanling Infants Prefer the Odors of Green Vegetables, Cheese, and Fish When Their Mothers Consumed These Foods During Pregnancy and/or Lactation.

Infants' olfactory experience begins before birth and extends after birth through milk and complementary foods. Until now, studies on the effects of chemosensory experience in utero and/or through human milk focused on experimentally controlled exposure to only 1 target food bearing a specific odor quality and administered in sizeable amounts. This study aimed to assess whether early olfactory experience effect was measurable in "everyday conditions" of maternal food intake during pregnancy and lactation, and of infant intake at weaning, leading to expose the infant to corresponding odors as fetus, neonate, and infant up to 8 and 12 months of age. Infants' early food exposures were assessed by asking mothers to fill out diaries about their food consumption during pregnancy and breastfeeding, and about their infant's consumption during complementary feeding. To test odor liking, odorants representing a priori pleasant and unpleasant food odors, as well as odorless stimuli, were presented. The infant's exploratory behavior toward odorized bottles and nonodorized control bottles was measured in terms of mouthing duration, which is thought to reflect attraction and/or appetence. At age 8 months only, positive correlations were found between liking of some unpleasant odors and early exposure to these odors through mother's diet. No correlations were found between infants' liking of the pleasant odors and early exposures to the foods bearing these odors. This study highlights that early exposure to unpleasant food odors may increase subsequent liking (or reduce subsequent dislike) of these food odors at least until the age of 8 months.

Infant Acceptance of Primary Tastes and Fat Emulsion: Developmental Changes and Links with Maternal and Infant Characteristics.

Previous studies on taste acceptance have been conducted taste-by-taste and with a cross-sectional design. The aim of this study was to longitudinally evaluate the acceptance of sweet, salty, bitter, sour and umami solutions, and a fat emulsion comparatively in a birth cohort from 3 to 20 months old. The acceptance of each taste relative to water was defined using proportional variables that are based on ingestion (IR) or liking evaluated by the experimenter (LR). These data were analyzed with mixed models that accounted for age and subject effects (minimum 152 observations/age/taste; maximum 216). For saltiness, acceptance increased sharply between 3 and 12 months old. The trajectories of acceptance were parallel for sweetness, sourness, and the umami tastes between 3 and 20 months old, with sweetness being preferred. Between 12 and 20 months old, the acceptance of all tastes, except bitterness, decreased, and at 20 months old, only sweetness was not rejected. The acceptance of bitterness remained stable. For the fat emulsion, acceptance evolved from indifference to rejection. The acceptance of saltiness and umami tastes were lower in girls than boys at 20 months old. The acceptance of the fat emulsion was higher in infants who were born heavier and taller. At 20 months old, the fat emulsion acceptance was higher in infants who were born from mothers with a higher prepregnancy body mass index. Finally, the taste differential reactivity (the standard deviation of the IRs) significantly increased from 3 to 20 months old.

The basal free fatty acid concentration in human saliva is related to salivary lipolytic activity.

Fat perception during eating is a complex sensation that involves various sensory modalities, such as texture, aroma and taste. Taste is supported by the discovery of fatty acid receptors in the tongue papillae. Dietary fat is mainly composed of esterified fatty acids, whereas only free fatty acids can bind to taste receptors. Some authors have mentioned the necessity and efficiency of salivary lipolytic activity to hydrolyse the esterified fatty acids present in foods and enable fat perception. Our hypothesis is that salivary lipolytic activity is also involved in regulating the basal level of salivary fatty acids in humans. To test this hypothesis, total fatty acid (TFA) and free fatty acid (FFA) concentrations and selected salivary characteristics (such as lipolytic activity) were analysed in the resting saliva of 54 subjects. The results show differences in the TFA and FFA profiles, with TFA and FFA concentrations of 8.99 and 3.56 µg/mL of saliva, respectively. Interestingly, lipolytic activity had a significant positive correlation with FFA concentration (0.51, p < 0.01). This result highlights a possible physiological role of salivary lipolytic activity in the regulation of the basal FFA concentration. This regulation could be involved in fat taste sensitivity.