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.

Total water intake and its contributors in infants and young children.

Hydration is a particular concern for infants and young children due to their greater risk of dehydration. However, studies on their water intakes are scarce. The current survey aimed to analyse total water intake (TWI) in non-breastfed children aged 0·5-35 months compared with the adequate intake (AI) for the same age group set by the European Food Safety Authority and to examine the different contributors to TWI as well as beverage consumption patterns. Nationally representative data from the Nutri-Bébé cross-sectional survey were used to assess food, beverage and plain water consumption by age group over three non-consecutive days. With age, median TWI in 1035 children increased from 732 to 1010 ml/d, without differences between sexes, but with a great inter-individual variation, and the percentage of children who did not meet the AI increased from 10 to 88 %. Median weight-related TWI decreased from 136·6 to 69·0 ml/kg per d. Among infants, 90 % had a ratio of water:energy below the AI, similarly for about 75 % of toddlers. Milk and milk products were the main contributors to TWI, while the part of plain water increased gradually to be 25 % in the older toddlers, half of which was tap water. The beverage consumption pattern varied in types and timing, with little consumption of juices and sweetened beverages. Vegetables and fruits accounted for 20 % of TWI after the age of 6 months. These initial results, showing strong discrepancies between actual and recommended water intakes in young children, should help identify ways to increase children's water consumption.

Does the contribution of human milk oligosaccharides to the beneficial effects of breast milk allow us to hope for an improvement in infant formulas?

Human milk is a source of nutrients and contains many distinct bioactive components. Among these, human milk oligosaccharides (HMOs) have attracted considerable attention and are being investigated as a "novel foods". Human milk is unique in its oligosaccharide composition. Recent research has focused on the complexity of HMOs by highlighting their diversity, structural variability, concentration variance, and structure-function relationships. In vitro and in vivo studies have demonstrated that HMOs drive infant gut microbiota, improve intestinal barrier functions, and modulate cell receptor signaling, thereby contributing to the development of infant immunity. These studies, combined with epidemiological data, indicate that some HMO may confer health benefits by preventing infections and diseases such as necrotizing enterocolitis and allergies. However, randomized controlled trials are restricted to structurally simple compounds such as 2' fucosyllactose and lacto-N-neotetraose. More controlled clinical trials are needed to justify routine supplementation of formula. It is felt that a better understanding of the role of HMOs leading to the development of inexpensive methods for large-scale HMO production is needed.

Pollutants in Breast Milk: A Public Health Perspective - A Commentary of the Nutrition Committee of the French Society of Pediatrics.

ABSTRACT: Pregnant and lactating women are continuously and ubiquitously exposed to numerous environmental pollutants from various sources including air, food, water, and occupational and household environments. The available evidence shows that pollutants are present in human milk and one of the emerging questions is what happens when the nursing infant is involuntarily exposed to contaminants through breastfeeding.The available literature does not currently provide a conclusive evidence of any consistent or clinically relevant health consequences in infants exposed to environment chemicals through breast milk. The available data strongly suggest that the benefits of breastfeeding outweigh the potential harmful effects of pollutants contained in human milk. The committee of nutrition of the French Pediatric Society strongly supports breastfeeding but also calls for public health actions to reduce the overall contamination level in the environment, to continue promoting breastfeeding, and to support research in this area.

Mineral and vitamin intake of infants and young children: the Nutri-Bébé 2013 survey.

PURPOSE: Minerals and vitamins are essential for optimal growth and development, particularly during the first years of life. Therefore, regularly evaluating their intake makes sense. For this purpose, we report the data from the Nutri-Bébé 2013 survey in comparison with the European Food Safety Authority Adequate Intake (AI), or Average Requirement, (AR) according to age. METHODS: This observational, nationally representative, cross-sectional survey was conducted in 1035 non-breastfed French children aged 0.5-35 months. Dietary intake was recorded using a food diary on three non-consecutive days, framed by two face-to-face interviews. RESULTS: The intake of zinc, magnesium and water-soluble vitamins most of the time met the recommendations. From the first weeks of life, sodium intake exceeded the AI, with a maximum median intake of 1137 mg/day after the age of 30 months. However, it has decreased since 2005. Calcium median intake often exceeded the AI or AR, reaching a maximum of 780 mg/day between 18 and 23 months. Median vitamin A intake always exceeded the AI or AR but exceeded the recommended upper limit in only a few cases. After 2 years, median iron intake was clearly below the AR, i.e. lower than 6.0 mg/day. Dietary vitamin D intake was below the AI, thereby justifying adequate supplementation. Vitamin E intake was below the AI in 50-75% of toddlers. CONCLUSION: This survey highlights excessive sodium intake as well as a shortfall of iron, vitamin D, and vitamin E intakes. The potential consequences of these discrepancies with respect to health outcomes remain to be assessed.

Food, water, energy, and macronutrient intake of non-breastfed infants and young children (0-3 years).

PURPOSE: The French Nutri-Bébé 2013 study aimed to assess the nutritional intake of infants and young children in comparison with the recommendations of the 2013 European Food Safety Authority (EFSA). METHODS: This cross-sectional study enrolled a random sample of families selected according to the Quota sampling method. A 3-day dietary record was conducted and supervised by two face-to-face interviews. All foods and beverages consumed were qualitatively and quantitatively reported in a diary, and their composition calculated using a food composition database. RESULTS: A total of 1035 non-breastfed children were included. Formula was abandoned early, amounting to approximately 50% of the total food intake at 7 months in 50% of infants and 22% at 1 year. A similar trend was observed for specific complementary foods. After 1 year, 50% of children consumed cow's milk, which was semi-skimmed in 88% of cases. Drinking water intake was low. Protein intake reached 1.4 times the average requirements before 3 months, 2 times at 8-9 months, and > 4 times at 30-35 months. Fat intake was below the EFSA adequate intake (AI) in > 90% of children. Alpha-linolenic acid intake was equal to or greater than the AI in all infants < 3 months, 85% of children at 6 months, 34% at 12-17 months, and 8% >24 months. Regardless of age, docosahexaenoic acid (DHA) intake was less than the AI. CONCLUSION: Strong discrepancies are observed between the actual and recommended intake in young, non-breastfed children namely, a high-protein intake, and a low fat intake, especially DHA.

Physicians advice, parental practice and adherence to doctor's advice: an original survey on infant feeding.

BACKGROUND: Despite several years of guidance on infant feeding, there has been only a slight change in consumer compliance. Therefore, this study aimed to analyse parents feeding practices, explore physicians' advice about infant feeding and subsequent parent's adherence to advice. METHODS: A multicentric cross-sectional qualitative and descriptive self-report online study was conducted in volunteers to participate in the study. RESULTS: Fifty-four physicians (paediatricians and general practitioners) and 600 parents of infants were recruited. Of the infants, 20.2% presented at inclusion with at least one type of functional gastrointestinal disorder. The breastfeeding prevalence was quite low (37.3%). The main initial deviance from guidelines said they observed in infant feeding was the early use of cow's milk. More than two-thirds of infants older than 8 months were drinking cow's milk. The introduction of solid foods was globally in line with recommendations. Most physicians gave advice about the different aspects of infant feeding but were seeking more information, as did the parents. A discrepancy between the physicians' statements and the parents' perceptions was observed. However the majority (95.4%) of parents reported that they followed totally or partially the advice received, especially by abandoning subsequently the use of cow's milk in favour of a formula. The main reason for not adhering to the advice was that they did not consider it suitable for their infant and they preferred to rely on their feelings or recommendations from familiars. CONCLUSIONS: This survey provides good insights into parents' infant feeding practices together with the advice given by their doctor. The gap between practices and current guidelines is notable only for breast-feeding and use of formula. Despite several guidelines professionals and parents seek nutrition information. It highlights the need to deliver consistent, relevant, and less confusing messages about infant feeding.

The French national survey on food consumption of children under 3 years of age - Nutri-Bébé 2013: design, methodology, population sampling and feeding practices.

OBJECTIVE: To update the data on food consumption and practices in children under 3 years of age in metropolitan France. DESIGN: The Nutri-Bébé 2013 cross-sectional study selected a random sample, according to the quota sampling method. After giving their informed consent, parents had to record the food consumption during three non-consecutive days framed by two face-to-face interviews, using for quantitative information different portion size measurement aids. RESULTS: One thousand one hundred and eighty-four children were enrolled. Mothers' mean age was 30·8 (sd 5·4) years; 38 % were primiparous; 89 % lived with a partner; 60 % had an occupation. Of the infants younger than 4 months, 31 % were breast-fed. One thousand and thirty-five children consumed infant formula followed by growing-up milk in 63 % of them; solid foods were introduced at a mean age of 5·4 (sd 2·13) months. From 8 months onwards, 25 % of children consumed the same foods as their parents on a more or less regular basis; 29 % ate in front of a screen, with a daily average screen time of 43·0 (sd 40·4) min. CONCLUSIONS: This robust survey highlights the low prevalence and duration of breast-feeding in France and shows a modest improvement since the previous survey of 2005 in the observance of recommendations concerning other feeding practices. The frequent consumption of adult foods and the screen time are of concern.

Prevalence and Health Outcomes of Functional Gastrointestinal Symptoms in Infants From Birth to 12 Months of Age.

OBJECTIVES: The aim of the study was to review published evidence and the opinion of practising clinicians on the prevalence and long-term health consequences of functional gastrointestinal symptoms in infants younger than 12 months. METHODS: PubMed was searched from inception to November 2014 to find articles reporting the prevalence and long-term health outcomes of infantile colic, regurgitation, functional constipation, functional diarrhoea, and dyschezia in infants younger than <12 months. A questionnaire was sent to practising clinicians worldwide, and a group of 15 international experts met to discuss the likely frequency and longer-term consequences of these symptoms. RESULTS: The literature search identified 30 studies reporting the prevalence of infantile colic (2%-73%), 13 that of regurgitation (3%-87%), 8 that of functional constipation (0.05%-39.3%), 2 that of functional diarrhoea (2%-4.1%), and 3 that of dyschezia (0.9%-5.6%). The studies varied in design, populations investigated, and definition of the symptoms. Questionnaires were received from 369 respondents. The experts agreed that the likely prevalences for colic, regurgitation, and functional constipation were 20%, 30%, and 15%, respectively. The limited data in the literature for functional diarrhoea and dyschezia suggest prevalences <10%. Infantile colic may be associated with future health problems in a subset of infants. CONCLUSIONS: Functional gastrointestinal symptoms appear to occur in a significant proportion of infants younger than 12 months and may have an impact on future health outcomes. Prospective collection of data according to agreed criteria is needed to obtain more accurate estimates of the prevalence and consequences of these symptoms.

Assessment of Dietary Iron Intake and Sources in Early Childhood in a Nationally Representative Cross-Sectional Survey.

BACKGROUND: Iron deficiency has particular importance in early childhood because of its impact on growth and development. Preventive food-based strategies of iron deficiency require knowledge of intakes and sources of iron. OBJECTIVE: This study aimed to assess daily iron intakes (DIIs) in 2013, to compare them with the dietary reference values, to assess their evolution since 1981, and to identify iron food sources among nonbreastfed French children younger than 3 years. DESIGN: This was a nationwide cross-sectional survey conducted in 2013 in France to assess DIIs by means of comparing them with the dietary reference values. Parents' reported diet diaries were collected for 3 nonconsecutive days. PARTICIPANTS/SETTING: Of the 1,184 children enrolled in the study, 1,035 nonbreastfed healthy children aged 0.5 to 35 months stratified into 11 age groups were included after informed consent was obtained from parents and according to a weighted quota sampling method. MAIN OUTCOME MEASURES: DII from the different food sources and trends in their evolution from 1981 to 2013 was assessed. STATISTICAL ANALYSES PERFORMED: Results are expressed as median with interquartile range and range and mean ± SD. Student t test was used with the 2-sided α level of significance set at 5%. RESULTS: Mean ± SD DII was 6.7 ± 2.3 mg/d before 6 months, 8.2 ± 2.7 mg/d from 6 months to 1 year, and 7.0 ± 3.2 mg/d from 1 to 3 years. The prevalence of infants older than 7 months with a DII less than the dietary reference values was 52.5%, and that of young children was 30%. After slightly increasing until 2005, DIIs decreased thereafter. Formulas contributed to most of the DIIs up to 2 years of age. Cereals were the second largest contributor to DIIs, and meat accounted for a small part of iron intake. CONCLUSIONS: A substantial number of children between 6 months and 3 years of age were at risk of insufficient iron intake. This risk increased from 2005 to 2013. The role of formula in ensuring iron intake is highlighted. More research on health outcomes of low iron intakes is needed.

Vegetarian diets and diets which restrict animal-source foods during childhood in high-income countries.

Increasing numbers of populations in the West are restricting their intake of meat and other animal products for reasons relating to health or ethics; in many countries, these restrictions are already common for cultural, religious, or socio-economic reasons. By following their parent's diet, children are exposed in parallel. This narrative review aims at assessing current data regarding vegetarian diets in children from birth to 18 years of age, which include, by increasing degree of restriction, flexitarian, lacto-ovo-vegetarian, lacto-vegetarian, pescatarian, vegan and macrobiotic diets. The 202 references include 45 studies in children. The more restrictive the diet and the younger the child, the greater the risk of nutritional deficiency. Of particular concern are vitamin B12, iron, zinc, calcium, n-3 long-chain polyunsaturated fatty acids, and protein and energy intake, especially in pregnant and nursing women, infants and young children. Providing an adequate lacto-ovo-vegetarian diet is relatively easy, whereas the maintenance of more restrictive diets may be challenging. The benefits and risks of vegetarian diets in adults are relatively well documented, but data for children are scarce. Vegan and macrobiotic diets should be discouraged in pregnant and lactating mothers as well as in young children, who, otherwise, should pay careful attention to ensuring nutritional adequacy, blood testing and appropriate supplementation. The health consequences of a chosen diet should be discussed with parents and adolescents to ensure the best possible adherence to advice and prescriptions. There is a need for well conducted studies in children but also for better knowledge of nutrition in healthcare professionals.Abbreviations: ALA: α-linolenic acid; ARA: arachidonic acid; ASF: animal source foods; BMC: bone mineral content; BMD: bone mineral density; DHA: docosahexaenoic acid; DRV: dietary reference value; EPA: eicosapentaenoic acid; FLD: flexitarian diet; LA: linoleic acid; LC-PUFA: long-chain polyunsaturated fatty acids; LOVD: lacto-ovo-vegetarian diet; LVD: lacto-vegetarian diet; MAD: macrobiotic diet; OMD: omnivorous diet; PSF: plant-source foods; SFA: saturated fatty acids; VGD: vegetarian diets; VND: vegan diet.

Risk Assessment of Micronutrients Deficiency in Vegetarian or Vegan Children: Not So Obvious.

Vegetarian diets have gained in popularity worldwide and therefore an increasing number of children may be exposed to the resulting nutritional consequences. Among them, the risk of micronutrient shortfall is particularly of concern. This narrative review aims to assess and discuss the relevance of micronutrient deficiency risk based on the available data. It mainly draws attention to iron, zinc, iodine, and vitamins B12 and D intake. Diets that are more restrictive in animal source foods, such as vegan diets, have a greater likelihood of nutritional deficiencies. However, the actual risk of micronutrient deficiency in vegetarian children is relatively difficult to assert based on the limitations of evidence due to the lack of well-designed studies. The risk of vitamin B12 deficiency must be considered in newborns from vegan or macrobiotic mothers and children with the most restrictive diet, as well as the risk of iron, zinc, and iodine deficiency, possibly by performing the appropriate tests. A lacto-ovo-vegetarian diet exposes a low risk if it uses a very varied diet with a sufficient intake of dairy products. Vegan and macrobiotic diets should be avoided during pregnancy and childhood. There is a need for education and nutrition guidance and the need for supplementation should be assessed individually.

Children's water intake and hydration: a public health issue.

Optimal hydration is required for all physiologic functions and cognition. Children, especially younger ones, are particularly susceptible to dehydration, given their physiological specificities, in particular, their renal immaturity and relatively large skin surface in early life, but also their dependence on adults and their greater propensity to develop digestive diseases leading to fluid losses. Mild dehydration consequences are dominated by their impact on cognitive functions, whereas more severe dehydration may endanger the health outcome. Studies on this subject in children are scarce; in particular, the long-term consequence on renal function remains questionable. This review considers how children's water intake including fluid intake and water content of food, are worrying. The findings show that, worldwide, most children do not meet adequate water intake recommendations. The main problems likely to explain insufficient water intake are access to safe water, availability of drinking water at school, and healthy-hydration education, which are all points that need to be improved within health policy.

Effectiveness of a starch thickened infant formula with reduced lactose content, probiotics and prebiotics on quality of life and clinical outcome in infants with regurgitation and/or colic.

Background: Regurgitation and colic are quite common in young infants, leading to a reduced quality of life (QoL) and to parental distress. Their management is challenging and aims to effectively reassure and relieve symptoms. This study aimed to assess the effectiveness over 30 days of a starch thickened formula with a reduced lactose content, Limosilactobacillus reuteri (Lactobacillus reuteri) DSM 17938 and FOS/GOS. Methods: A real-world prospective multicenter experimental study was conducted in a before-after design within subject. Full term infants 0-5 months with regurgitation or colic or both symptoms and without intercurrent illness were included after parental informed consent and received the studied formula. The primary endpoint was the improvement in QoL using the QUALIN infant's questionnaire. Secondary endpoints were the symptoms outcome and the formula tolerance. Results: Of the 101 infants included (age: 6.2 ± 4.3 weeks), 33 had regurgitation, 34 colic and 34 had both. At D30, the QoL score was improved in 75% of infants in per protocol analysis (n = 68; +8.2 ± 13.7; p < 0.001), more in those with colic or both symptoms. Meanwhile, in intention to treat analysis (all p < 0.001), the daily number of regurgitations decreased by 61% and the weekly number of days with colic by 63% while the daily cumulative duration of crying decreased by 82 ± 106 mn. These improvements were observed within the first week by 89 and 76% of parents, respectively. Conclusion: The study formula associated with reassurance is shown to be quickly effective in the management of infant's regurgitation or/and colic in routine clinical practice. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT04462640.

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.

Dietary Approaches to Iron Deficiency Prevention in Childhood-A Critical Public Health Issue.

Iron is an essential nutrient, and individual iron status is determined by the regulation of iron absorption, which is driven by iron requirements. Iron deficiency (ID) disproportionately affects infants, children, and adolescents, particularly those who live in areas with unfavorable socioeconomic conditions. The main reason for this is that diet provides insufficient bioavailable iron to meet their needs. The consequences of ID include poor immune function and response to vaccination, and moderate ID anemia is associated with depressed neurodevelopment and impaired cognitive and academic performances. The persistently high prevalence of ID worldwide leads to the need for effective measures of ID prevention. The main strategies include the dietary diversification of foods with more bioavailable iron and/or the use of iron-fortified staple foods such as formula or cereals. However, this strategy may be limited due to its cost, especially in low-income countries where biofortification is a promising approach. Another option is iron supplementation. In terms of health policy, the choice between mass and targeted ID prevention depends on local conditions. In any case, this remains a critical public health issue in many countries that must be taken into consideration, especially in children under 5 years of age.

Protein intake pattern in non-breastfed infants and toddlers: A survey in a nationally representative sample of French children.

BACKGROUND AND AIMS: Protein intake plays a key role in infants and children's growth, but high protein intake may have adverse long-term effects. Data on actual intakes in various populations are scarce. The aims of this study were (i) to assess daily protein intake (DPI) in non-breastfed infants and children aged 0.5-35 months in comparison with the population reference intake (PRI) set by the European Food Safety Authority, and to examine (ii) the various sources of this intake and their consumption patterns, and (iii) time-related changes in DPI over the last 4 decades. METHODS: Data from the Nutri-Bébé cross-sectional survey were used to assess DPI, DPI/kg BW and the protein-energy ratio (E%) by age group. The amounts and quality of each food consumed were recorded over three non-consecutive days and validated by two face-to-face interviews. RESULTS: Overall, this study included 1035 children. Median DPI were consistently above the PRI, reaching 4 times PRI in the older toddlers (41.4 g/d; range 15.1-64.0). Regardless of age, more than 95% of children had a DPI/kg BW above the PRI. Protein intake remained below 14 E% until 6 months of age and increased thereafter from 10% to 75% in children older than one year. Overall, DPI gradually decreased from 1981 to 2013. Milk and dairy products were the main contributors to DPI up to 2 years, while the share of other animal sources became predominant later. Plant contribution remained below 25% of DPI. CONCLUSION: Despite a gradual decrease over the last few decades, DPI have remained well above the PRI. As the predominant contributors to these intakes are animal sources, the potential long term health consequences of such high intake deserve consideration. CLINICAL TRIAL REGISTRY NUMBER: NCT03327415 on ClinicalTrials.gov.

Stress-Induced Premature Senescence Related to Oxidative Stress in the Developmental Programming of Nonalcoholic Fatty Liver Disease in a Rat Model of Intrauterine Growth Restriction.

Metabolic syndrome (MetS) refers to cardiometabolic risk factors, such as visceral obesity, dyslipidemia, hyperglycemia/insulin resistance, arterial hypertension and non-alcoholic fatty liver disease (NAFLD). Individuals born after intrauterine growth restriction (IUGR) are particularly at risk of developing metabolic/hepatic disorders later in life. Oxidative stress and cellular senescence have been associated with MetS and are observed in infants born following IUGR. However, whether these mechanisms could be particularly associated with the development of NAFLD in these individuals is still unknown. IUGR was induced in rats by a maternal low-protein diet during gestation versus. a control (CTRL) diet. In six-month-old offspring, we observed an increased visceral fat mass, glucose intolerance, and hepatic alterations (increased transaminase levels, triglyceride and neutral lipid deposit) in male rats with induced IUGR compared with the CTRL males; no differences were found in females. In IUGR male livers, we identified some markers of stress-induced premature senescence (SIPS) (lipofuscin deposit, increased protein expression of p21WAF, p16INK4a and Acp53, but decreased pRb/Rb ratio, foxo-1 and sirtuin-1 protein and mRNA expression) associated with oxidative stress (higher superoxide anion levels, DNA damages, decreased Cu/Zn SOD, increased catalase protein expression, increased nfe2 and decreased keap1 mRNA expression). Impaired lipogenesis pathways (decreased pAMPK/AMPK ratio, increased pAKT/AKT ratio, SREBP1 and PPARγ protein expression) were also observed in IUGR male livers. At birth, no differences were observed in liver histology, markers of SIPS and oxidative stress between CTRL and IUGR males. These data demonstrate that the livers of IUGR males at adulthood display SIPS and impaired liver structure and function related to oxidative stress and allow the identification of specific therapeutic strategies to limit or prevent adverse consequences of IUGR, particularly metabolic and hepatic disorders.

Religious dietary rules and their potential nutritional and health consequences.

BACKGROUND: The vast majority of the world population declares affiliation to a religion, predominantly Christianity and Islam. Many religions have special dietary rules, which may be more or less strictly adhered to. METHODS: Religious food rules were collected from holy books and religious websites as well as their translation into dietary practices. The literature was searched for potential associations between these rules and potential nutritional consequences. RESULTS: Jewish, Islamic and Indian religions support prolonged breastfeeding. Religious avoidance of alcohol is probably beneficial to health. When strictly applied, a few rules may lead to nutritional inadequacies, mainly in populations living in unfavourable socio-economic or environmental conditions. In Jewish and Muslim observants, animal slaughtering procedures may increase the risk of iron deficiency. Jews may be at risk of excess sodium intake related to home-prepared foods. A vegan diet, as observed by some believers, often by drifting from original precepts, or by some Hindus or Buddhists, may result in vitamin B12, calcium, iron, zinc, selenium and n-3 fatty acids deficiencies. CONCLUSION: When implemented in accordance with the rules, most religious food precepts are not detrimental to health, as suggested by the fact that they have more or less been followed for millennia. Nevertheless, some practices may lead to nutritional inadequacies, such as iron, calcium, vitamin D and vitamin B12 deficiencies. Patients with low socio-economic status, children and women of childbearing age are of particular risk of such deficiencies. Being aware of them should help health professionals to take an individualized approach to decide whether to supplement or not.