Cow's milk-based infant formula supplements in breastfed infants and primary prevention of cow's milk allergy: A commentary of the Committee on Nutrition of the French Society of Pediatrics.

The role of nutritional interventions for the primary prevention of cow's milk allergy (CMA) remains debated as well as the role of early introduction of allergenic foods, which is largely encouraged from the beginning of complementary feeding. Considering the introduction of cow's milk protein (CMP), current recommendations suggest avoidance of any cow's milk formula (CMF) supplements in breastfed infants in the maternity ward. By contrast, based on poor evidence, some authors support systematic supplements of CMP in breastfed children at risk of allergy from the first week of life. The Committee on Nutrition of the French Society of Pediatrics considers that such a proposal requires more clinical studies and mainly randomized and placebo-controlled clinical trials before becoming a recommendation.

Undernutrition is still highly frequent in hospitalized children with cystic fibrosis.

The aim of our study was to assess the nutritional status of hospitalized children with cystic fibrosis. We extracted data from the ePINUT surveys. Undernutrition was defined as a body mass index (BMI) of <18.5 according to the International Obesity Task Force cut-off, and the nutritional status goal was defined as a BMI z-score ≥0 SD for children older than 2 years and a weight-for-height z-score ≥0 SD for those younger than 2 years. Undernutrition frequency in the 114 patients with cystic fibrosis was 46% and was higher than in children with other chronic diseases (n = 5863; 30.5%; p = 0.001); 81% of children were below the nutritional status goal. Undernutrition frequency in cystic fibrosis is higher than in other chronic diseases.

3-Month Post-Operative Increase in FGF21 is Predictive of One-Year Weight Loss After Bariatric Surgery.

PURPOSE: The association between bariatric surgery outcome and blood levels of fibroblast growth factor 21 (FGF21) remains controversial. Many patients displayed stable or decreased FGF21 one year after bariatric surgery. Nevertheless, there is often an early increase FGF21 concentration in the post-surgery period. The aim of this study was to investigate the relationship between 3-month FGF21 response and percentage total weight loss at one year after bariatric surgery. MATERIALS AND METHODS: In this prospective monocentric study, a total of 144 patients with obesity grade 2-3 were included; 61% of them underwent a sleeve gastrectomy and 39% a Roux-en-Y gastric bypass. Data analysis was carried out to determine the relation between 3-month plasma FGF21 response and weight loss one year after bariatric surgery. Multiple adjustments were done including degree of weight loss after 3 months. RESULTS: FGF21 significantly increased between baseline and Month 3 (n = 144, p < 10-3), then decreased between Month 3 and Month 6 (n = 142, p = 0.047) and was not different from baseline at Month 12 (n = 142, p = 0.86). The 3-month-FGF21 response adjusted to body weight loss was not different between types of bariatric surgery. The 3-month-FGF21 response was associated to body weight loss at Month 6 (r = -0.19, p = 0.02) and Month 12 (r = -0.34, p < 10-4). After multiple regression analysis, only Month 12 body weight loss remained associated to 3-month FGF21 response (r = -0.3, p = 0.02). CONCLUSION: This study showed that the magnitude of changes in FGF21 at 3 months after bariatric surgery emerged as an independent predictor of one-year body weight loss irrespective of the type of surgery.

Concentration of Polycyclic Aromatic Hydrocarbons (PAHs) in Human Serum and Adipose Tissues and Stimulatory Effect of Naphthalene in Adipogenesis in 3T3-L1 Cells.

Polycyclic aromatic hydrocarbons (PAHs) are one of the most prevalent classes of environmental pollutants. Some evidence shows that PAHs could be involved in human obesity. However, little is known about the distribution patterns of PAHs in human adipose tissue (AT) and the role of PAHs on adipogenesis/lipogenesis. The aims of this pilot study were to determine concentrations of 16 PAHs defined as high-priority pollutants in the plasma and adipose tissue of French and Polish bariatric patients, as well as their correlation with body mass index (BMI), plasma and AT adipokines expression levels. We finally investigated the role of naphthalene on cell proliferation, viability, and differentiation in 3T3-L1 preadipocytes. The concentration of most PAHs was similar in the three types of AT and it was significantly higher in AT as compared to plasma, suggesting bioaccumulation. Polish patients had higher PAH levels in AT than French ones. Only the concentration of naphthalene in AT was positively correlated with the BMI and serum or adipose chemerin, adiponectin and resistin expression, in French but not in Polish patients, who had significantly higher BMIs. Moreover, naphthalene exposure increased the cell proliferation of 3T3-L1 preadipocytes and lipogenesis, and increased the expression of genes involved in adipogenesis after cell differentiation. Taken together, PAHs and more particularly naphthalene could be an obesogenic molecule and increase the risk of obesity.

Nutri-Score: Its Benefits and Limitations in Children's Feeding.

Reducing the burden of noncommunicable diseases (NCDs) is one of the top priorities of public health policies worldwide. One of the recognized means of achieving this objective is to improve the diet quality. The Nutri-Score (N-S) is a [five-color-A, B, C, D, E letters] front-of-pack labeling logo intended to help consumers quickly identify the healthier prepackaged foods within a food category. Available studies have shown that the N-S is an efficient tool to achieve this aim in terms of consumers' awareness, perception, understanding, and purchasing and that its use may help to reduce the prevalence of NCDs. The N-S is currently implemented on a voluntary basis in 7 European countries and a discussion is underway within the European Commission to achieve a harmonized mandatory label. However, no study on the putative impact of the N-S on children's dietary patterns and health is available. The N-S is not applicable to infants' and young children's formulas and to specific baby foods, the compositions of which are already laid down in European Union regulations. The N-S does not replace age-appropriate dietary guidelines. As children consume an increasing number of adult type and processed foods, the relevance of the N-S for children should be evaluated considering the children's high specific requirements, especially in younger children. This is especially necessary for fitting fat and iron requirements, whereas protein-rich foods should be better framed. Moreover, efforts should be made to inform on how to use the N-S and in education on healthy diets.

Impact of the HAS 2019 French guidelines on the frequency of hospital undernutrition in children.

In 2019, the French National Authority for Health (Haute Autorité de Santé, HAS) published guidelines on the diagnosis of undernutrition. The present article focuses on the impact of switching from the 2012 guidelines of the Nutrition Committee of the French Paediatric Society (CNSFP) to the HAS guidelines on the frequency of hospital undernutrition in children. We selected for the period 2010-2019 from the ePINUT database: (1) all children aged more than 2 years with (2) clinically confirmed nutritional status in (3) French sites. The frequency of undernutrition was 15.4% vs. 28.8% using the CNSFP and HAS criteria, respectively (p < 0.01; n = 6304). When compared to non-malnourished children regardless of the criteria used, malnourished children: (1) stayed longer in hospital (CNSFP: 9.0 ±â€¯11.8 vs. 6.5 ±â€¯8.7 days, p < 0.01; HAS: 7.8 ±â€¯10.1 vs. 6.4 ±â€¯8.4 days, p < 0.01), (2) gained more weight during hospitalization (% of weight at admission) (CNSFP: +1.4 ±â€¯4.1 vs. -0.3 ±â€¯3.5%, p < 0.01; HAS: +2.3 ±â€¯4.7 vs. -0.1 ±â€¯3.4%, p < 0.01), and (3) received nutritional support more frequently during hospitalization (CNSFP: 20% vs. 5%, p < 0.01; HAS: 13% vs. 4%, p < 0.01). Switching to the HAS guidelines resulted in an almost twofold higher frequency of undernutrition in hospitalized children. Initiation of nutritional care remained low considering the nutritional status. The present study warrants interventional studies to determine which children may benefit more from nutritional therapy to improve their outcome.

N-3 Fatty Acid Supplementation Impacts Protein Metabolism Faster Than it Lowers Proinflammatory Cytokines in Advanced Breast Cancer Patients: Natural 15N/14N Variations during a Clinical Trial.

While clinical evidence remains limited, an extensive amount of research suggests a beneficial role of n-3 polyunsaturated fatty acid supplementation in cancer treatment. One potential benefit is an improvement of protein homeostasis, but how protein metabolism depends on proinflammatory cytokines in this context remains unclear. Here, using the natural abundance of the stable isotopes of nitrogen as a marker of changes in protein metabolism during a randomized, double-blind, controlled clinical trial, we show that protein homeostasis is affected way faster than proinflammatory cytokines in metastatic breast cancer patients supplemented with n-3 polyunsaturated fatty acids. We provide some evidence that this response is unrelated to major changes in whole-body substrate oxidation. In addition, we demonstrate that more fatty acids were impacted by metabolic regulations than by differences in their intake levels during the supplementation. This study documents that the percentage of patients that complied with the supplementation decreased with time, making compliance assessment crucial for the kinetic analysis of the metabolic and inflammatory responses. Our results highlight the time-dependent nature of metabolic and inflammatory changes during long-chain n-3 fatty acid supplementation.

Do Emotion Dysregulation, Alexithymia and Personality Dimensions Explain the Association Between Attention-Deficit/Hyperactivity Disorder and Binge Eating Among Bariatric Surgery Candidates?

Background: Addictive-like eating and attention-deficit/hyperactivity disorder (ADHD) are both common among persons seeking treatment for severe obesity. Given that ADHD and addictive-like eating, especially binge eating (BE) and food addiction (FA), are both strongly associated with personality dimensions and emotion dysregulation, it is possible emotional and personality characteristics contribute to the link between addictive-like eating behaviors and ADHD in people with severe obesity. This study aimed to investigate the psychological factors associated with BE and FA in bariatric surgery candidates, and to explore the mediational role of emotional factors (emotion dysregulation and alexithymia) and personality dimensions in the association between ADHD and BE. Method: Two hundred and eighty-two (n = 282) bariatric surgery candidates were recruited during the systematic preoperative psychiatric assessment (University Hospital of Tours, France). We assessed significant BE (Binge Eating Scale), probable adult ADHD (Wender Utah Render Scale and Adult ADHD Self-Report Scale), FA (Yale Food Addiction Scale 2.0, YFAS 2.0), emotion dysregulation (Difficulties in Emotion Regulation Scale-16), alexithymia (Toronto Alexithymia Scale-20) and personality dimensions (Big Five Inventory). Mediation analyses were performed using the PROCESS macro for IBM SPSS Statistics 22. Results: Prevalence of probable adult ADHD, significant BE and FA were 8.2, 19.1, and 26.6%, respectively. Participants who screened positive for addictive-like eating showed higher prevalence of probable adult ADHD, as well as higher scores on adult and childhood ADHD symptoms. They also reported lower conscientiousness, but higher emotion dysregulation, higher alexithymia, and higher neuroticism. Only BE (as opposed to FA) was also associated with lower scores on agreeableness and openness. Analysis of the association between adult ADHD and BE suggests that emotion dysregulation, conscientiousness, agreeableness, and neuroticism are total mediators and alexithymia a partial mediator. Conclusion: Our findings suggest a significant association between ADHD and addictive-like eating among bariatric surgery candidates, and also suggest a significant role of emotion dysregulation and personality dimensions in this association. For individuals with ADHD and obesity, eating may be a way to cope with negative emotions, potentially increasing the risk for addictive-like eating behavior.

Analysis of the Impact of Selected Vitamins Deficiencies on the Risk of Disability in Older People.

Vitamin deficiencies have a serious impact on healthy aging in older people. Many age-related disorders have a direct or indirect impact on nutrition, both in terms of nutrient assimilation and food access, which may result in vitamin deficiencies and may lead to or worsen disabilities. Frailty is characterized by reduced functional abilities, with a key role of malnutrition in its pathogenesis. Aging is associated with various changes in body composition that lead to sarcopenia. Frailty, aging, and sarcopenia all favor malnutrition, and poor nutritional status is a major cause of geriatric morbidity and mortality. In the present narrative review, we focused on vitamins with a significant risk of deficiency in high-income countries: D, C, and B (B6/B9/B12). We also focused on vitamin E as the main lipophilic antioxidant, synergistic to vitamin C. We first discuss the role and needs of these vitamins, the prevalence of deficiencies, and their causes and consequences. We then look at how these vitamins are involved in the biological pathways associated with sarcopenia and frailty. Lastly, we discuss the critical early diagnosis and management of these deficiencies and summarize potential ways of screening malnutrition. A focused nutritional approach might improve the diagnosis of nutritional deficiencies and the initiation of appropriate clinical interventions for reducing the risk of frailty. Further comprehensive research programs on nutritional interventions are needed, with a view to lowering deficiencies in older people and thus decreasing the risk of frailty and sarcopenia.

Stable Isotope Abundance and Fractionation in Human Diseases.

The natural abundance of heavy stable isotopes (13C, 15N, 18O, etc.) is now of considerable importance in many research fields, including human physiology. In fact, it varies between tissues and metabolites due to isotope effects in biological processes, that is, isotope discriminations between heavy and light isotopic forms during enzyme or transporter activity. The metabolic deregulation associated with many diseases leads to alterations in metabolic fluxes, resulting in changes in isotope abundance that can be identified easily with current isotope ratio technologies. In this review, we summarize the current knowledge on changes in natural isotope composition in samples (including various tissues, hair, plasma, saliva) found in patients compared to controls, caused by human diseases. We discuss the metabolic origin of such isotope fractionations and highlight the potential of using isotopes at natural abundance for medical diagnosis and/or prognostic.

Plasma amino acid pools in the umbilical cord artery show lower 15N natural isotope abundance relative to the maternal venous pools.

15N natural isotope abundance (NIA) is systematically higher in infants' hair than in that of their mothers at birth. This study aimed to investigate this difference in plasma pools. We compared 15N NIA values for plasma amino acid (AA) pools (free + protein-bound) in the umbilical cord artery (UCA) and vein (UCV) and in the maternal vein (MV) at birth. This preliminary study included 7 mother-infant dyads. Whole plasma was treated (HCl) to hydrolyze protein. Following derivatization, AAs were separated using gas chromatography and compound-specific 15N NIA values were measured on-line using an isotope ratio monitoring mass spectrometer. 15N NIA plasma AA pools in the UCA and UCV were highly correlated to the MV, r 2 > 0.89 and r 2 > 0.88 (both P < 10-4) respectively. The full model found a significant effect of sampling compartment (P = 0.02) and AA type (P < 0.0001) on 15N NIA plasma AA values. 15N NIA plasma AA was 0.74 ‰ higher (P = 0.01) in the MV than in the UCA. This study indicates that a decrease in 15N NIA for plasma AA pools occurs in the fetal-placental unit. Trial registration: ClinicalTrials.gov identifier: NCT00607061.

Effect of Organic Food Intake on Nitrogen Stable Isotopes.

Food choices affect the isotopic composition of the body with each food item leaving its distinct isotopic imprint. The common view is that the natural abundance of the stable isotopes of nitrogen (expressed as δ15N) is higher in animals than in plants that constitute our contemporary diets. Higher δ15N is thus increasingly viewed as a biomarker for meat and fish intake. Here we show that organic compared to conventional farming increases plant δ15N to an extent that can appreciably impact the performance of δ15N as a biomarker. The error that can arise when organic plants are consumed was modelled for the entire range of proportions of plant versus animal protein intake, and accounting for various intakes of organic and conventionally grown crops. This mass balance model allows the interpretation of differences in δ15N in light of organic food consumption. Our approach shows that the relationship between δ15N and meat and fish intake is highly contextual and susceptible to variation at the population, community or group level. We recommend that fertilization practices and organic plant consumption must not be overlooked when using δ15N as a biomarker for meat and fish intake or to assess compliance to nutritional interventions.

The Modified Yale Food Addiction Scale 2.0: Validation Among Non-Clinical and Clinical French-Speaking Samples and Comparison With the Full Yale Food Addiction Scale 2.0.

OBJECTIVES: The modified Yale Food Addiction Scale 2.0 (mYFAS 2.0) was designed to assess food addiction using a shorter version than the YFAS 2.0. We lack data about the psychometric properties of the mYFAS 2.0 in patients with obesity, as well as studies comparing the psychometric properties of the mYFAS 2.0 versus the full YFAS 2.0. This study aimed to validate the French-language mYFAS 2.0 in a non-clinical population (study 1, n = 250), to determine the yet unknown psychometric properties of this scale in patients with obesity (study 2, n = 345), and to compare the full YFAS 2.0 and the mYFAS 2.0 in terms of food addiction (FA) prevalence and symptoms detection in both populations. METHOD: Study 1 included 250 non-clinical individuals (non-underweight and non-obese persons screened negative for eating disorders). Study 2 included 345 bariatric surgery candidates recruited in three centers (Québec, Canada; Reims and Tours, France). The mYFAS 2.0 structure was investigated using confirmatory factorial analyses with tetrachoric correlations. Convergent validity was tested using the full YFAS 2.0, the Binge Eating Scale (both studies), the revised 18-item Three Factor Eating Questionnaire (study 1), the Beck Depression Inventory (study 2), and the body mass index (BMI; both studies). RESULTS: The mYFAS 2.0 was unidimensional, and had adequate (study 1: KR-20 = .78) and acceptable (study 2: KR-20 = .73) internal consistency. In study 1, the mYFAS 2.0 had good convergent validity with the YFAS 2.0, BMI, binge eating, cognitive restraint, uncontrolled eating and emotional eating; in study 2, the mYFAS 2.0 had good convergent validity with the YFAS 2.0, binge eating, depression, but not BMI. Participants endorsed fewer symptoms with the mYFAS 2.0 than with the YFAS 2.0; FA prevalences were similar between questionnaires in the non-clinical, but not in the clinical sample. A FA 'diagnosis' and risk of binge eating disorder were associated but did not completely overlap. CONCLUSIONS: The mYFAS 2.0 has close psychometric properties to the YFAS 2.0 in non-clinical and clinical samples. However, the use of the mYFAS 2.0 in bariatric surgery candidates might lead to a significant underestimation of FA prevalence and number of FA symptoms.

Negative Affectivity and Emotion Dysregulation as Mediators between ADHD and Disordered Eating: A Systematic Review.

Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with disordered eating, especially addictive-like eating behavior (i.e., binge eating, food addiction, loss of control overeating). The exact mechanisms underlying this association are unclear. ADHD and addictive-like eating behavior are both associated with negative affectivity and emotion dysregulation, which we hypothesized are mediators of this relationship. The purpose of this systematic review was to review the evidence related to this hypothesis from studies assessing the relationship between childhood or adulthood ADHD symptomatology, negative affectivity, emotion dysregulation and addictive-like eating behavior. The systematic review followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) recommendations. The literature search was conducted in PubMed and PsycINFO (publication date: January 2015 to August 2020; date of search: 2nd September 2020). Out of 403 potentially relevant articles, 41 were retained; 38 publications reported that ADHD and disordered eating or addictive-like eating behavior were significantly associated, including 8 articles that suggested a mediator role of negative affectivity or emotion dysregulation. Sixteen publications reported that the association between ADHD symptomatology and disordered eating or addictive-like eating behavior differed according to gender, eating behavior and ADHD symptoms (hyperactivity, impulsivity and inattention). We discuss the practical implications of these findings and directions future research.

Maternal obesity does not influence human milk protein 15N natural isotope abundance.

Obesity increases protein metabolism with a potential effect on nitrogen isotope fractionation. The aim of this study was to test the influence of obesity on human milk extracted protein 15N natural isotope abundance (NIA) at one month post-partum and to compare human milk extracted protein 15N NIA and bulk infant hair 15N NIA. This cross-sectional observational study involved 16 obese mothers (body mass index (BMI) ≥ 30 kg m-2 before pregnancy) matched with 16 normal-weight mothers (18.5 kg m-2 ≤ BMI < 25 kg m-2) for age and pregnancy characteristics. Human milk extracted protein and bulk infant hair 15N NIA were determined by isotope ratio monitoring by mass spectrometry interfaced to an elemental analyser (IRM-EA/MS). No significant difference was found in human milk protein 15N NIA values between obese and normal-weight mothers (8.93 ± 0.48 ‰ vs. 8.95 ± 0.27 ‰). However, human milk protein 15N NIA was significantly lower than bulk infant hair 15N NIA: 8.94 ± 0.38 ‰ vs. 9.66 ± 0.69 ‰, respectively. On the basis of these results, it is concluded that human milk protein 15N NIA measured at one month post-partum is not influenced by maternal obesity. These findings suggest that 15N NIA may be exploited to study metabolism without considering maternal obesity as a confounder.

NUTRI-REAPED study: nutritional assessment of French critically ill children and nutrition practice survey in French-speaking pediatric intensive care units.

BACKGROUND: Impaired nutritional status is adversely associated with suboptimal outcomes in critically ill children. Undernutrition at pediatric intensive care unit (PICU) admission ranges from 15 to 65%. A lack of knowledge of the nutritional status of children in French PICUs prevents us from specifically targeting education. This study aims to describe the nutritional status of children in French PICUs and to assess nutritional practices and physicians' knowledge of nutrition, in order to focus NutriSIP (the French-speaking PICU nutrition group) future education programs. A prospective observational multicenter point prevalence study was conducted in French PICUs, recruiting all children admitted over three different weeks. Anthropometric measurements were taken (weight, height/length, mid-upper arm, and head circumferences), in order to calculate nutritional indices. Nutritional status was defined according to WHO Body Mass Index z-score and dynamic assessment based on growth faltering detection. Concurrently, PICU physicians and PICU nurses from seven French-speaking countries completed a survey to ascertain knowledge about local nutritional care practices and overall nutrition knowledge. PICU physicians' responses were compared to PICU nurses' responses (previously published). RESULTS: Four hundred and thirty-two children were included in the observational study from 27 French PICUs. Undernutrition was diagnosed in 18.5% of them, young age and underlying chronic condition being the two independent risk factors. Faltering growth was diagnosed in 4.8% and overweight in 7.4%. Subjective nutritional assessment was not accurate. Thirty-eight French-speaking PICUs completed the survey. These showed nutritional practices frequently did not comply with international guidelines, especially regarding nutritional goals, and the reasons for withholding enteral nutrition. Comparison between physicians' and nurses' responses to the survey showed large discrepancies. CONCLUSION: Undernutrition is frequent at admission in French PICUs. Nutritional status should be assessed using a holistic approach, because of the potential impact on outcome. French-speaking PICU healthcare professionals need further nutrition education, in order to improve nutritional practices to comply with international recommendations. This study will serve as a baseline to focus NutriSIP teaching programs in the future.

Adulthood and childhood ADHD in patients consulting for obesity is associated with food addiction and binge eating, but not sleep apnea syndrome.

INTRODUCTION: The exact mechanisms underlying the established association between ADHD and obesity remain unclear. Food addiction and binge eating may contribute to this link. We examined for the first time the association between childhood/adult ADHD and food addiction/binge eating in patients with obesity, as well as the association between ADHD and sleep apnea syndrome. METHODS: We included 105 obese patients from the Nutrition Department of the University Hospital of Tours (France) between January and December 2014. We assessed categorical diagnoses of childhood/adulthood ADHD (semi-structured interview DIVA 2.0), food addiction (Yale Food Addiction Scale 2.0), binge eating (Binge Eating Scale), obstructive sleep apnea (clinical assessment), and BMI (clinical assessment). RESULTS: Patients with adult ADHD were at significantly higher risk of food addiction than patients without adult ADHD (28.6% vs. 9.1%; p = .016). Adult and childhood ADHD were significantly associated with self-reported food addiction, food addiction scores and binge eating scores, with a larger effect size for adult (ORs: 4.00 [1.29-12.40], 1.37 [1.14-1.65] and 1.08 [1.03-1.14], respectively) than childhood (ORs: 3.32 [1.08-10.23], 1.29 [1.08-1.55] and 1.06 [1.01-1.11], respectively) ADHD. ADHD diagnosis was not significantly correlated to obstructive sleep apnea. Mean age of onset of ADHD preceded mean age of onset of obesity. CONCLUSION: ADHD diagnosis is associated with food addiction and binge eating, with a larger effect size for adult than childhood ADHD. Our results provide a strong rationale for further longitudinal research on the link between ADHD, food addiction, binge eating and obesity, paving the way for evidence-based therapeutic interventions for these patients.

Protein restricted diet during gestation and/or lactation in mice affects 15N natural isotopic abundance of organs in the offspring: Effect of diet 15N content and growth.

OBJECTIVES AND STUDY: This study aimed at measuring the effect in normal to restricted protein diets with specific 15N natural isotopic abundance (NIA) given during gestation and/or lactation on the 15N NIA of fur, liver and muscle in dams and their offspring from birth to adulthood. The secondary aim was to study the effect of growth on the same parameters. METHODS: Female Balb/c mice were fed normal protein diet containing 22% protein or isocaloric low protein diet containing 10% protein throughout gestation. Dam's diets were either maintained or switched to the other diet until weaning at 30 days. All animals were fed standard chow thereafter. Offspring were sacrificed at 1, 11, 30, 60, 480 days and a group of dams at d1. Growth was modeled as an exponential function on the group followed up until 480 days. Fur, liver and muscle were sampled at sacrifice and analyzed for bulk 15N NIA. Fixed effects and interactions between fixed effects and random elements were tested by three-way ANOVA. RESULTS: Higher 15N NIA in the diet resulted in higher organ 15N NIA. Switching from one diet to another changed 15N NIA in each organ. Although dam and offspring shared the same isotopic environment during gestation, 15N NIA at day 1 was higher in dams. Growth rate did not differ between groups after 10 days and decreased between 1 and 5 months. 15N NIA differed between organs and was affected by growth and gestation/lactation. CONCLUSION: Dietary 15N NIA is a major determinant of the 15N NIA of organs. 15N NIA depended on organ and age (i.e. growth) suggesting an effect of metabolism and/or dilution space. Post-natal normal-protein diet of lactating dams could reverse the effect of a protein-restricted diet during gestation on the offspring growth. Measuring 15N NIA in various matrices may open a field of application particularly useful in studying the pre- and post-natal origins of health and disease.