Total Fat and Fatty Acid Intake among 1–7-Year-Old Children from 33 Countries: Comparison with International Recommendations

This work reviews available data on dietary intakes of total fat, saturated fatty acids (SFA) and individual polyunsaturated fatty acids (PUFA) in children in different countries worldwide and for the first time, compares them with recent international recommendations. Studies published before June 2021 reporting total fat, total SFA and individual PUFA intakes in children aged 1–7 y were included. Observed intakes were evaluated against FAO/WHO and EFSA recommendations. 65 studies from 33 countries were included. Fat intake was too low in 88% of studies in young children (1–3 y). SFA intake was >10%E in 69–73% of children, especially in Europe. Linoleic acid intake was <3%E in 24% of studies in 1–2 y olds and within FAO/WHO recommendations among all other ages. Alpha-linolenic acid intake was <0.5%E in almost half of studies. Docosahexaenoic acid (DHA) or eicosapentaenoic acid + DHA intakes were below recommendations in most studies. In summary, while total fat intake was too low among younger children, SFA intake was above, especially in Europe and n-3 PUFA intake, especially DHA, were below recommendations for all ages. Intake of n-3 PUFA, especially DHA, is generally suboptimal. More data, particularly from developing countries, are required to refine these findings and guide implementation of adapted nutrition policies.


Introduction
Dietary fat has broad physiological functions. It provides essential fatty acids (EFA) required for growth and development and contributes important fat-soluble vitamins (A, D, E, K) to the diet [1]. It acts as a substrate in hormone production [2] and has been shown to play a role in visual and cognitive development [3], cardiovascular health [4], as well as immune function [5]. Additionally, dietary fat enhances the organoleptic properties of food by enhancing the taste, texture, flavour and aroma, and thus affects palatability and acceptability of these foods [6]. Dietary fats may also affect satiety by modulating gastric emptying and intestinal motility [7,8].
Dietary fat is an important source of energy during early life and plays an essential role in supporting rapid growth and development during this period [1]. During childhood, requirements for specific fatty acids such as polyunsaturated fatty acids (PUFA) are higher than at other times in life [9]. Important dietary fatty acids (FA) include the two EFA (linoleic [18:2n-6, LA] and alpha-linolenic acid [18:3n-3, ALA]), as well as the long-chain derivatives of ALA, eicosapentaenoic (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) [1].
Given the critical role of dietary fats in child growth, development and health, various health authorities have generated fatty acid intake recommendations specific for children. These recommendations differ according to children's needs and thus, according to age. Indeed, given that the requirements for fat and certain PUFA are relatively high in children,

Total Fat Intake Recommendations
The DRI used by the two authorities is the AMDR, i.e., the range of total fat intake associated with reduced risk of chronic disease while providing an adequate fat intake. The values are based on evidence that the consumption above or below these ranges may be associated with nutrient inadequacy and increased risk of developing chronic diseases (coronary heart diseases [CHD], obesity, diabetes, and/or cancer). The recommendations are to have a gradual reduction in the fat contribution to the total daily energy intake from 6 months of age depending on the physical activity level of the child, by age 3 years to approximately 30-35% of energy [1] or by age 4 years to 20-35% of energy [18], in line with the upper adult AMDR.

Total Saturated Fatty Acid Intake Recommendations
The FAO/WHO [17] sets a numerical value, as an upper-AMDR in view of limiting the risk of CHD. Currently, it recommends a maximum of 8 E% for total SFA for children (2-18 years); however, new WHO guidelines are in preparation and it seems, from the available draft [21], that the value for children will be aligned to the adult's value of 10%E.
EFSA [18] concluded that SFA can be synthetized by the body and so are not required in the diet. They recognized a positive, dose-dependent relationship between the intake of a mixture of SFA and blood LDL cholesterol concentrations (risk factor for cardiovascular disease) when compared to carbohydrates and finally advised a SFA intake "as low as possible". It should be noted that the value for adults was applied to children without providing a rationale. Knowing that the contribution of SFA to breast milk lipids is considerable (35-40%) [22] and that the WHO recommends continued breastfeeding until 2 years of age [23], more guidance is needed in Europe.
A more flexible approach has been taken by other bodies, such as the Scientific Advisory Committee on Nutrition (SACN). The UK recently released [24] its dietary reference value for SFA, unchanged from the previous one issued in 1994 [25], which was "no more than about 10%". However, this recommendation does not apply before 2 years of age and applies in full from 5 years and into adulthood [25]. A flexible approach was recommended in relation to the timing and extent of dietary change for individual children between 2 and 5 years.  EFSA 2010 [18] 2013 [19] 1-2 y 865.75 1 1-3.  [19,20]. 2 total average daily energy requirement for boys and girls of 1061 kcal for 2-3 year old children (using a low physical activity level of 1.4)(mean of 987 kcal/day for 2 year old boys and girls and 1135 kcal/day for 3 year old boys and girls) [19,20]. 3 total average daily energy requirements for boys and girls of 1329.5 kcal for 3-5 years (using a low physical activity level of 1.4 for 3 years and a moderate level of 1.6 for 4 and 5 years) [20]. 4 total average daily energy requirement for boys and girls aged 5 years, 6 years and 7 years (using a moderate physical activity level of 1.6) [20].

N-6 PUFA-Linoleic and Arachidonic Acid Intake Recommendations
FAO/WHO [17] proposed for LA an estimated average requirement (EAR), i.e., the intake level at which the needs of 50% of the population are met, of 2%E and an AI of 2-3%E after two years of age, based on the fact that the signs of deficiency can be prevented by providing 1-2%E LA in adults. The higher value of the AI (i.e., 3%), as part of a healthy diet, is contributing to long term health by lowering LDL and total cholesterol levels and consequently the risk for CHD. The AI for younger children aged 1-2 years is higher (3-4.5%E). No recommendation was set for ARA.
EFSA [18,19] set an AI for LA, because they estimated there was no evidence to support an EAR. The AI for LA for all populations was based on the lowest estimated mean intakes of the various population groups in Europe, where overt LA deficiency symptoms were not present. For children aged 1-3 years old, they noted that LA intake was generally below the adult AI of 4 E%, but that no signs of LA deficiency were observed if LA intakes were >1 E%, so that intake and status of LA in infants and young children living in Europe were of no concern. The adult AI of 4%E was proposed for children. While acknowledging that ARA was present in human milk, EFSA did not identify clinical effects of supplementing infants or children with ARA [26,27], and thus did not set any recommendation for this fatty acid. This controversial recommendation is not supported by all experts in the field [28].

N-3 PUFA: Alpha-Linolenic Acid and EPA + DHA Intake Recommendations
The FAO/WHO [17] concluded that the ALA minimum dietary requirement for adults (lower AMDR: >0.5%E) does prevent deficiency symptoms, while the highest value (upper AMDR, 2 or 3%E, depending on the age) can be part of a healthy diet. FAO/WHO set an AI for DHA up to the age of 2 years because of its critical role in retinal and brain development and, after the age of 2 years, an AI for EPA + DHA as part of a healthy diet in view of preventing the risk of chronic diseases (total CHD events, stroke). This AI is age adjusted up to the age of 10 years, after which the adult value applies. FAO/WHO also mentions that a specific minimum to prevent n-6 and n-3 PUFA deficiency is unclear.
Similar to LA, EFSA [18,19] found that the mean ALA intakes were below the AI (0.5%E) in some populations of young children in Europe. However, there is no clear relationship between intakes or biomarkers of n-3 PUFA status and clinical outcomes. Thus, EFSA concluded that they could not quantify the risk of inadequate intakes of ALA and DHA in young children living in Europe. Given that DHA is needed for the normal development of the nervous system and the retina, and accumulates in the brain and retina during early childhood, they considered DHA as a conditionally essential FA for infants. The AI of 100 mg DHA per day for the age range 6-24 months was based on "intervention studies with DHA-enriched formula or complementary foods from age 1.5 to 12 months in formerly and continuing breast-fed infants and which was found to be effective for visual function". After the age of 2 years, the same AI as for adults was proposed (250 mg EPA + DHA/day), an amount considered as enough for primary prevention of CHD in healthy subjects [18].

Comparison between FAO/WHO and EFSA Fat Recommendations
The DRIs for fats do not differ much between the two authorities. Nevertheless, compared to FAO/WHO, EFSA has set higher minimum values for LA (4%E vs. 2 or 3%E) and for EPA + DHA for children older than 2 years (250 mg/day vs. 100 mg/day [2-3 years], 125 mg/day [3-5 years] or 175 mg/day [5-7 years]). EFSA has made age-specific recommendations for total fat (until the age of 4 years) and DHA (until the age of 2 years) while FAO/WHO values were age-specific for LA also and evolved until the age of 18 years. Most recommendations are expressed as %E, so the recommended absolute amounts of fat and PUFA increase with age, according to the increasing energy intake. The FAO/WHO also set an upper AMDR for total PUFA (15%E for the age 1-2 years and 11% for 2-18 years) and an AMDR for MUFA (obtained by difference between total fat and all the other FA types). EFSA did not set any DRV for total PUFA or total MUFA. Despite its presence in human milk and its role in building structures of all body cells, no recommendation has been set for the intake of ARA. After initial consideration, several articles were excluded from the final selection: Butte et al., [29] for the USA, Murakami et al., [30] for Japan, Ocké et al., [31] for The Netherlands and Meyer [32] for Australia because more recent data were available from the new national surveys (Bailey [33] for the USA, NHNS-J 2018 for Japan [34], van Rossum for the Netherlands [35] and Meyer [36], Rahmawaty [37]  Fifty of the 65 included studies reported data from high income countries. Thirty-eight of the 65 studies were based on national studies, while 27 were either local or subnational studies (Table S1). Most studies included more than 100 subjects, but in 10 studies, e.g., two of the three studies done in Africa, the number of subjects per age group was less than 100. Data were collected largely in the last 10 years, but for some geographies, e.g., Africa, data were quite old (collected in 1978-1980 for Gambia, in 1998 in one of the two South African studies). While the assessment of fat intake was generally not the objective of the studies, 22 studies mentioned fat as one of their objectives (Table S1). These included 13 studies targeting PUFA, five of them specifically assessing n-3 PUFA. Only 23 studies in total reported DHA intake. The methods used to assess dietary intake were diverse (Table  S2). Twenty-two studies recorded intake using dietary recall (10 used 24 h recall once; six used a 24 h recall at least twice and six used a 24 h dietary recall on whole sample + x days dietary recall on a subsample), 28 used a food record (mostly 3 day or more diary), while the remaining dietary assessment methods were either food frequency questionnaires (7), whole diet collection chemical analysis (one study) or combinations of several methods. Most studies did not inform on whether fortified foods or supplements were included. Nineteen studies reported they included fortified foods and 21 reported they included supplements (Table S3). Most of these supplements were vitamins and minerals, while only a few studies specifically reported that they included PUFA oil or fish oil supplements in their dietary assessment [35,36,[39][40][41][42]. Thirteen of the 31 studies done in 1-2 year-old children indicated that breast milk intake was included as part of the children's intake, and six reported that it was not, while 12 did not provide the information (Table S3). Table 2 reports the observed daily intake of energy, total fat, total SFA, LA and/or total n-6 PUFA, ALA and/or total n-3 PUFA, DHA, EPA + DHA in children 1-7 years old. The last column reports unsaturated FA, which are not in the scope of our review because there was no (ARA, DPA, total n-3 long chain-PUFA [LC-PUFA]) or only limited (total MUFA or total PUFA) intake recommendations. Table 2 values represent means (when not specified) or medians of a variable number of children.                  Table 2. Except for LC n-3 PUFA, when fat and fatty acid intakes were given in absolute amounts, the intake value was calculated in %E using the total daily energy intake found in the same paper or another publication of the same population using a factor of 9 kcal/g fat or fatty acid. 1 All along the table, "~kcal" or "~kJ" means that we converted the energy unit (1 kJ = 0.239006 kcal). 2 All along the table, "~x%E" means that we calculated the %E for fat (or FA) (~x%E = 100 × daily mean (or median) fat (or FA) intake (in g/day) × 9/total daily mean (or median) energy intake (in kcal). 3 The SE were calculated using the reported 95th confidence interval (95% CI = mean ± [1.96 * SE]), all along the tables, for papers that reported the 95% CI. 4 Energy intake values for this study were found in Garriguet, D. [97] 5 The mean of EPA + DHA was not reported while mean EPA and mean DHA were available. All along the table, "~EPA + DHA" means that we calculated the sum based on the average of the two individual FA. 6 Calculated based on daily energy intake of 1141 kcal/day as reported in Butte et al., [29] 7 Calculated based on daily energy intake of 1308 kcal/day as reported in Butte et al., [29] 8 Calculated based on daily energy intake of 1534 kcal/day at 4-5 y as reported in Hamner et al., [98] 9 Calculated based on daily energy intake of 1214 kcal (at 1 year) to 1534 kcal at 4 years as reported in Hamner et al., [98] 10 Calculated based on daily energy intake of 1961 kcal (for 6-11 years-old children) as reported in Murakami & Livingstone [99] 11 In this study (as in 10 other included studies) n-6 PUFA was assessed while LA was not; we reported n-6 PUFA value in the "LA" column; indeed, LA intake constitutes~97% of n-6 PUFA intake [54,73]. Since both values are very close, we used the value for "n-6 PUFA" as estimation for "LA". 12 In this study (as in 3 studies from Japan), n-3 PUFA was assessed while ALA was not. Given the high EPA and DHA intake in Japan, we estimated ALA intake as 60% n-3 PUFA intake, as per (Kakutani et al., [100] and Kusumoto et al., [101]). 13 Energy intake values for this study were calculated from energy intake values from the National Japanese studies: we calculated the average of 2005-2008 studies for males and females separately. 14 In this study (as in 7 other studies) n-3 PUFA was assessed while ALA was not and we reported n-3 PUFA value in the "ALA" column; ALA intake constitutes 87-90% of n-3 PUFA intake [Ramirez Silva ( [54]], Kim [73]). Since both values were very close, we used the value for "n-3 PUFA" as estimation for "ALA". 15 Energy intake values for Australia ANCNPA were found in [102] 16 Long chain n-3 PUFA (EPA, DPA and DHA) in the paper of Meyer 2011 were not considered because they were recalculated and reported in Rahmawaty [37] after identification of errors in LC n-3 PUFA composition of certain foods (e.g., margarines) in the AUSNUT database used for the paper of Meyer [36].

Recommended Cut-Off Values Used as a Basis of Comparison between Effective and Recommended Intake Total Fat
Observed intakes of total fat were compared with the recommended intake using the highest value recommended for the age group. Indeed, the recommendations are to have a gradual reduction in the fat contribution to the diet between the ages of 6 months and 3 or 4 years [1,18]. Infants and children fed human milk (as recommended by the FAO/WHO until the age of 2 years [103]) consume 50%E as fat, while the recommendations for fat between 2 and 18 years are 25-35%E [17]. Thus, taking the upper end of the range, it was decided that the fat adequacy for our assessment would be of minimum 35%E in children 1-3 years (according to EFSA) and between 25 and 35%E in children 3-7 years (according to FAO/WHO).
Total SFA Three thresholds were used for the comparison of children's observed intake with the recommended intake, and these were according to the current 8% limit of FAO/WHO [17] and the 10% limit proposed by FAO/WHO in the latest draft guidelines on saturated fatty acids and trans-fatty acids for adults and children [21]: (1) countries with observed intakes lower than 8%, (2) countries with observed intake between 8 and 10%, (3) countries with observed intakes higher than 10%. Because there is no SFA intake limitation for children less than 2 years, no comparison was made for SFA for this age group.

LA
EFSA AI is at least 4%E, higher than that of the FAO/WHO, because it is mainly based on current intakes in the European population, while lower amounts are still adequate for the prevention of deficiency symptoms [79]. Thus, we used three thresholds for the comparisons between LA observed and recommended intakes: (1) countries with observed intakes lower than 3% (for 1-2 year old children) or lower than 2% (for 2-7 years old children), which correspond to the lower AI values from FAO/WHO for these 2 age groups; (2) countries with intake between 3 and 4% (for 1-2 years old children) or 2 to 4% (for 2-7 years old children), which correspond to the range between the FAO/WHO lower recommended AI value and the EFSA minimum AI; (3) countries with LA intakes higher than 4% (EFSA minimum AI).

ALA
The AI for ALA is similar across ages and for the two authorities (FAO/WHO and EFSA), thus studies were sorted into two groups: those where the mean intake was lower than 0.5%E and those where it was equal to or higher than 0.5%E.

EPA and DHA
FAO/WHO recommendations for EPA and DHA are age-specific, while those of EFSA are not. The intakes of EPA and DHA were compared with FAO/WHO recommendations (using the lower recommended value of the range as a reference for each of our age groups). Minimum reference intakes were: 100 mg (DHA) for children aged 1-2 years, 100 mg EPA+ DHA for those aged 2-3 years, 125 mg for those aged 3-5 years and 175 mg for those aged 5 to 7 years. Intakes were also compared against the EFSA recommendation (250 mg/day after 2 years), which is much higher than that of the FAO/WHO. Table 3 summarizes the cut-off values used for our assessment.  Tables S4-S7 give the numbers extracted from Table 2 and sorted for each of our four age groups (Table S4: intakes in children 1-2 years; Table S5: intakes in children 2-3 years; Table S6: intakes in children 3-5 years; Table S7: intakes in children 5-7 years) that were used for the assessment vs. the authority recommendations. Graphical representations of these intake data for total fat, total SFA, LA, ALA and n-3 LC-PUFA can be found in the Supplementary Figures S1-S5. The results of the assessment vs. the recommendations are given in Table 3, as the proportion of studies where the data were not in line with recommendations for each of the fatty acids and each of the four age groups.

Children 1-2 Years
The intake of total fat was below the lower recommendation in 23 of 26 (88%) studies (range 23 to 36.7%E). LA intake was below the FAO/WHO recommendation of 3%E in 24% of studies and below EFSA AI of <4%E in 59% of studies. ALA intake was below the AI of 0.5%E in 42% of studies. Daily DHA intake ranged between 19.5 to 120 mg and was below the recommendation of 100 mg per day in all of the recovered studies that assessed DHA intake except in one study done in Singapore [69]. Among this age group, two studies, one in China [61] and one in France [78] reported intakes of total fat, LA, ALA and DHA which were all outside (below) the recommendations.

Children 2-3 Years
Total fat intake ranged between 15 and 38.8%E and was below 35%E in 89% of studies. Intake of SFA had a wide range, from 3.6% to 17.2%E, and was above the recommendation of 10%E in 73% of the studies, notably in all the studies from North America, Europe, and Oceania. SFA intake was less than 8%E in only two studies from The Gambia [43] and Bangladesh [60], two countries with very low fat consumption (15%E and 17.2%E, respectively). LA intake was within the FAO/WHO recommendation for all studies and below EFSA AI in 44% of studies. Surprisingly, data from the National Study in Turkey show an exceptionally high LA intake of 9.1%E [14]. ALA intake was below the recommendation in 50% of studies. Daily EPA + DHA intake ranged from 24.7 to 152 mg and was below the FAO/WHO recommendation of 100 mg/day in 7 of the 10 studies for which these data were recovered, except two local studies done in Vancouver (Coastal area in Canada) [49,52] and one subnational study done in urban areas in Spain [89] with daily intakes of 100, 152 and 130 mg, respectively. EPA + DHA consumption was below the EFSA recommendation (250 mg/day) in all studies. Among this age group, two studies, one in Canada [48] and one in Ireland [83] reported intakes which were all outside of the recommendations: intakes of total fat, ALA and DHA were below and saturated fat was above the recommendations, while LA was not reported.

Children 3-5 Years
Total fat intake ranged from 12.9 to 38.8%E. It was below 25%E in 16% of studies and above 35%E in 17% of studies. Total SFA intake ranged from 3.4% to 14.9%E and was above the recommendation of 10%E in 69% of the studies, notably in all studies done in Europe and Oceania. Total SFA intake was less than 8%E in only two studies, one in South Africa [44] (sub-group aged 4-5.9 years from one settlement) and one in Bangladesh [60], two populations where fat consumption was low (23.8%E and 12.9%E, respectively). LA intake was within the FAO recommendation of 2%E in all studies and below the EFSA AI in 41% of studies. Data from the National Study in Turkey show an exceptionally high LA intake of 9.1%E [14]. ALA intake was below the recommendation in 42% of the studies. EPA + DHA intake ranged from 24.7 to 184 mg and was below the FAO/WHO recommendation of 125 mg/day in 9 of the 14 studies done in 11 countries for which these data were recovered. Studies with an intake >125 mg/day were two local studies (one in Vancouver (Coastal area in Canada) [49]; one in Japan [63], one sub-national study in urban areas in Spain) [89] and two national studies (France [79] and Sweden [91] with daily intakes ranging from 130 to 184 mg/day. EPA + DHA intake was below the EFSA recommendations of 250 mg/day in all studies.

Children 5-7 Years
Total fat intake ranged between 17.8 and 42.8%E. It was below 25%E in 9% of studies and above the upper range of the recommendation in 19% of studies. Intake of SFA ranged from 7.9% to 15.4%E and was above the 10%E recommendation in 73% of the studies, notably in all of the studies done in Europe and in Oceania. Total SFA intake was less than 8%E in only a population sub-group (aged 4-5.9 years from one settlement) in a study from South Africa [44], where fat consumption was low (23.8%E). LA intake was within the FAO/WHO recommendation for all studies and below the EFSA AI in 50% of studies. As per the other age groups, data from the National Study in Turkey showed an exceptionally high LA intake of 9.8%E [14]. ALA intake was below the AI in 42% of studies. EPA + DHA intake ranged from 30 to 144 mg and was below the FAO/WHO recommendation of 175 mg per day in all 11 studies for which DHA data was recovered for 5-7 years old children, done in 10 countries. Among this age group, three studies in Europe reported intakes which did not meet the recommendation for total and saturated fat (too high), and ALA and DHA (too low) [79,82,89], despite having intakes of LA within 2-4% of energy.

Summary of Findings
This review provides an overview of the available FAO/WHO and EFSA recommendations for total fat and specific fatty acids and the dietary intakes of children worldwide aged 1-7 years are compared with these recommendations. The 65 studies identified, conducted in 33 countries, show that total fat intake was generally lower than recommended in 1-3 year-old children (88% of studies) and total SFA intake higher than the limit of 10%E in about 70% of children aged 2-7 years. LA intake was below FAO/WHO recommendation (<3E%) in 24% of studies in younger children (1-2 y) and adequate in older children (2-7 years) when assessed against FAO/WHO, while it was lower than EFSA AI in about 50% of studies. ALA intake was below the AI in almost half of the recovered studies and DHA [or EPA+DHA] intake was lower than the FAO/WHO recommendations in most studies and lower than EFSA recommendations in all studies of children more than 2 years.

Methodological Considerations
Data were recovered from many geographic regions, but there is limited information from Africa, South America, and China and we did not find any data from India, the country with the highest number of young children [104]. We did not perform a thorough comparison between countries because the studies differed in their objectives and dietary assessment methodologies. It is well known that all dietary intake assessment methods have their own limitations. Dietary recalls typically rely on memory, while dietary records may potentially be affected by reactivity, but both, at least when weighed records are used and several days are recorded, have the advantage of capturing more detail than food frequency questionnaires [105]. However, both recalls or records may underestimate the intake of food items which are consumed less frequently than others. This is important for FA for which one food item may represent >50% of its intake, such as EPA and DHA, for which fish is the major food source [106]. The method of choice for EPA + DHA intake would be a combination of recalls or records with a validated food frequency questionnaire since in most countries, fish/seafood are typically not consumed very frequently (e.g., daily) [106]. The importance of measurement method is nicely illustrated by the intracountry variability observed in Canadian children for the ALA intake (twice as high in the study of Madden et al., [51] vs. that of Lien et al., [50], which is likely related to methodological differences (chemical analysis of 3 days food collection aliquots vs. parental food records) rather than a real difference in intake per se.
The food databases used to calculate FA intake were not of the same quality, with some, (e.g., the US, French, Australian, and Indonesian databases) being more complete than others with respect to the FA composition of foods. In some national databases, the level of PUFA, in particular, DHA, were not available or were available only for a limited number of foods (e.g., Chinese database), thus, intake may be underestimated in some studies. Also, and partly because of this, only 23 studies reported DHA intake.
Most studies presented results as mean values, although several studies report median. The medians may be more appropriate for some FA such as DHA or the sum of EPA+ DHA, where the intake is not well distributed among the population. Nevertheless, regardless of the variable (mean or median) used, we found that DHA intake was very low.

Contribution of Breastmilk to Fat and Fatty Acid Intake
Thirteen studies among the 1-2 year-old age group included breastmilk intake in their assessment (Table S3). For those studies, intake of total fat and PUFA was still lower than the recommendations. Human milk is a source of LC-PUFA, the levels of which are dependent on multiple maternal factors including diet [107]. Given that in these studies the LC-PUFA content of the milk was not measured and information on maternal factors was not reported, it is difficult to assess the contribution of breastmilk to LC-PUFA intake in this age group. Of the thirteen studies that reported breastmilk intake, two of these studies from Africa discussed the contribution of breastmilk to fat and energy intakes. Prentice et al., [43] reported that breastmilk contributed significantly to fat intake up to 17 months (50%E), which declined thereafter to 30% and 15% at 17 and 24 months, respectively. In a more recent study from South Africa, Steyn et al., [45] reported that breastmilk contributed to 18.7% of total energy intake up to 3 years. Thus, in infancy and early childhood, breastmilk intake can contribute significantly to intake of energy and fat. Therefore, it is possible that the studies that did not include breastmilk intake in their assessment (n = 6) or that did not specify whether breastmilk was included or not (n = 12), underestimated intake of total fat and LC-PUFA.

Total Fat
While total fat intake is too low in 88-89% of studies in the younger age groups (1-3 years), for the older age groups, both low-(poor rural areas in Africa or Asia, or National surveys from South Korea, the Philippines or United Arab Emirates [esp. girls]) and high-(esp. in Mediterranean countries) fat intakes were reported. These results differ from those of previous reviews [14,15], which concluded that total fat intake in children less than 10 years of age was too high in most countries. This difference is because of the large age range used in these studies and the 30%E maximum RNI used (as per 2003 WHO adult recommendation [108]). This relatively low value of 30%E may not be an appropriate comparison to use for children of a young age. The high fat consumption observed in 3-7-year-old children in several Mediterranean countries is in accordance with the findings of Nasreddine [16] in school age children of the Eastern Mediterranean region.
Providing children with adequate dietary fat is of great importance given the essentiality of dietary fat and specific fatty acids for healthy growth and development in early life [1]. Dietary fat is energy dense and thus helps children meet the high energy needs of rapid growth, without ingesting large volumes of food. Given the rising prevalence of childhood obesity, and its high energy density, dietary fat is greatly scrutinized and suspected as a causal factor. Results of a recent Cochrane review commissioned by the WHO suggest that in trials among children aged 2-18 years where a lower fat intake (30%E or less) was provided compared with usual or modified fat intake, small reductions in body mass index, total-and LDL-cholesterol were observed [109]. However, in two of the three identified intervention studies, children were hypercholesterolemic, which limits the applicability of the findings to the general population of healthy children.
In the same review of Naude et al., [109], half of the 21 included cohort studies suggested that increased total fat intake was associated with increased body fatness (body weight and body mass index), nevertheless, some studies showed the opposite, and given the general low quality of recovered studies, no conclusion could be reached. It should be noted that twenty-three of the 24 included studies in Naude et al.'s review were done in children from high income countries. Moreover, given the design of the review (only randomised controlled trials included), some relevant studies were not included, such as the long-term follow-up study of Rolland-Cachera et al., [110]. They demonstrated that fat intake at 2 years of age was negatively associated with body fat-particularly abdominal fat-at the age of 20 years [110]. This is in line with recommendations against restricting fat intake and those supporting a gradual reduction in fat intake over the course of the first 3-4 years of life [1,18].
In our review, we identified excess fat intake in no more than 7 of the 50 studies from high income countries and overall, our findings, which are based on a more globally representative sample of countries, do not suggest a need for children from 1-7 y to reduce their intake of total fat. In line with this, data from the Generation R cohort also show no associations between a higher intake of total fat or SFA, MUFA, or PUFA with growth, adiposity, or cardiometabolic health when fat was consumed at the expense of carbohydrates [111]. Further studies investigating the intake of the other macronutrients by these age groups are required to provide a more holistic overview of their potential influence on body weight regulation. This is particularly important for carbohydrates, where, for example, sugar-sweetened beverages are consumed by up to half of children in this age group in certain countries [112] and are known to contribute significantly to weight gain [113] and incidence of overweight [114].

Total SFA
In nearly all recovered studies (92-98%), SFA intake is higher than the 8%E recommendation [17]. The few exceptions were studies in the Gambia [43] (2-3 years, local study in rural population), Bangladesh [60] (2-5 years, local study in rural population) and South Africa [44] (3-7 years, local study in informal settlement of urban area), three studies also showing a very low total fat intake (12.9 to 23.8%E). This suggests that the 8%E limit for total SFA intake may not be compatible with the achievement of total fat recommendation of at least 35%E in younger children or at least 25%E in older children. In our review, the observed total SFA intake is higher than the 10%E recommendation [21] in 69-73% of studies, notably in all European countries for which we found data, for all ages considered. These findings are in line with earlier reviews, which show mean intakes of SFA higher than 10%E for <10 year old children in Europe using National Survey data [14], in 2-10 year old children worldwide [15] and in young and school-aged children of Eastern Mediterranean countries [16]. The range of SFA intake varied from 3.4-18%E in our review, a narrower range than what was found in adults, where global saturated fat consumption ranged from 2.3-27.5%E [115].
In children, some benefits of reducing intake of SFA have been demonstrated in the context of cardiovascular health. A systematic review and meta-analysis concluded that reducing SFA intake in children aged 2-19 years significantly decreased total and LDLcholesterol, as well as diastolic blood pressure, with no evidence of adverse effects on growth or development [116]. However, the wide age range of participants of the studies included in the review of Te Morenga et al., as well as the fact that five of the eight studies included subjects with hyperlipidemia, make it difficult to translate these findings to healthy toddlers and young children. Although cardiometabolic disease typically presents in later life, atherosclerotic plaques have been shown to appear in childhood [117] and are positively associated with dyslipidemia [118]. Elevated LDL-cholesterol in childhood has been associated with increased CVD risk factors in adulthood [118], however, there is no evidence of an effect of reducing SFA in the younger age group on later CVD risk.
The association between total SFA intake and health is increasingly questioned and a beneficial effect of dairy SFA on the most prevalent chronic diseases in adults, such as diabetes, has been suggested [111,119]. Recently, the SACN updated their recommendations for SFA intake in the UK and concluded that the maximum limit of 10%E for SFA intake does not apply before 2 years and applies, in full, from five years [24]. Thus, younger children may safely consume a higher proportion of their dietary fat as SFA, as a transition from full breast milk feeding to an adult diet. Then, from about 5 years of age, it may be important to keep SFA intake as low as possible to promote lifelong cardiometabolic health. 4.6. Essential Fatty Acids: Linoleic Acid and Alpha-Linolenic Acid LA intake is above the lower FAO/WHO AI for all age ranges in all studies, except in 4 out of 12 studies done in 1-2 year old children (one national survey in France [78] and three local studies in Canada [49], China [61] and Australia [96], for which intake was too low. The EFSA AI for LA, based on LA intake in healthy adults in Europe, is higher than that of FAO/WHO, and LA intake was lower than the EFSA recommendations in about half of the studies for all ages considered, without specificity for geography. Sunflower seed oil contains 80-90% LA and is the most consumed vegetable oil in Turkey [120], which may explain the exceptionally high LA intake in children in this country. However, we did not have access to the original data of this survey to be able to confirm this speculation. At present, the health impact of high LA in early life is unclear. While available preclinical evidence suggests a risk for obesity and worse metabolic outcomes in adulthood in response to high LA (or high LA:ALA ratio) in early life, supportive clinical data are lacking (reviewed in [121]). Future, well-designed studies are warranted to untangle the complex relationship between these FA in early life and their role in long-term health.
ALA intake is lower than the EFSA and FAO/WHO AI in more than half of the studies for all ages considered, without specificity for geography. To the best of our knowledge, no previous reviews have compared LA and ALA intake among children to the new FAO/WHO recommendation, however, Sioen et al., [13] compared intakes in European children of these two essential FA with the EFSA AI and found that in most of studies, LA and ALA intake were lower than the AI (75% of studies in 1-3 years old for both FA; 66% [LA] and 100% [ALA] of studies in 4-9 years old). These findings were based on only 7 studies available at that time in Europe. Our findings for Europe, based on more than 15 studies, most of them published since 2017, are less pessimistic, with LA and ALA intakes being in line with European AI in about 50% of studies.
In the review of Sioen, as in our own review, LA and ALA intake are probably overestimated, because several of the recovered studies assessed n-6 PUFA (and not just LA [12 studies]) or n-3 PUFA (and not just ALA [8 studies]). It is estimated that LA represents 97-99% of the dietary n-6 PUFA, while ALA generally represents~80-90% of the dietary n-3 PUFA [13,54,73]. Thus, the overestimation is higher for ALA than for LA, reinforcing the finding that ALA inadequate intake is more prevalent than that of LA. While LA and ALA are the two EFA needed for normal growth and development of children [122], according to EFSA, intakes of LA above 1% do not show any additional benefits.

Arachidonic Acid
Currently, there is no recommendation for ARA intake in infants older than 6 months, because despite its presence in human milk, and its rapid accretion in body cells in young children, no clinical effect could be observed when infants' diets were supplemented with ARA [26,27]. ARA intake was reported in several studies included in this review [40,43,49,51,52,56,60,61,63,73,[77][78][79]89] and ranged from 10 to 260 mg per day. By comparison, fully breastfed infants aged 0-6 months consume 140 mg/day [19].

EPA and DHA
Intake of EPA and DHA was lower than the recommendation in nearly all studies and for all ages considered, in line with earlier review findings in children [12,13,15] and in adults [115]. N-3 LC-PUFA are highly important for brain maturation and development [3], therefore, this finding is a concern. The exceptions to this were for younger children (1-3 years) in three small studies from coastal areas (Singapore, [69], Vancouver, Canada [49,52]) and for children 3-5 years in five studies (two local (Vancouver [49], Tokyo [63], one subnational (urban areas in Spain) [89] and two national studies (France [79], Sweden [91]), where EPA + DHA intakes were within the FAO/WHO recommendations, but lower than EFSA recommendations.

Distribution of Intakes within the Population
Several studies reported median intakes in addition to the mean intakes. We observed that for intakes of DHA and EPA, means were much higher than medians and differ from medians more than the other PUFA. EPA and DHA intake in populations are generally not normally distributed and skewed to the right due to higher intake of few individuals [36,106]. This is mainly because not all products rich in n-3 fatty acids were consumed by all participants, while the other PUFA are more evenly distributed in foods. Future studies should aim to include median and mean DHA values to allow for a better comparison across studies and geographical regions.  (Table S3) reported n-3 PUFA or fish oil supplement use among their participants. The low proportion of children consuming these supplements (from 0% in Belgium [40] to 3% in Australia [36]) indicates that systematic inclusion of PUFA supplements in the dietary assessment would not greatly alter the global conclusion of our review.
Several studies from North America and Europe, which had as one objective to assess n-3 PUFA intake, used a methodology more adapted to this parameter [35,39,41,50,51,56]: they assessed the diet with FFQ combined with recalls or records; they added to the dietary assessment a FFQ specific for fish intake; they used or developed food composition databases accurate for fatty acids and three of them included fish oil supplements in the assessment [35,39,41]. Surprisingly, results of EPA and DHA intakes obtained by these "best in class" studies were not higher than intake values found in the other studies. Thus, the low values found for EPA and DHA are not likely due to inappropriate methodologies, but rather because of lower consumption of foods containing n-3 LC-PUFA, i.e., mostly fish and shellfish.

N-3 PUFA Supplementation
The fact that dietary intake of EPA + DHA is below recommendations in most studies, begs the question of whether supplementation or food fortification of these fatty acids would be beneficial for these age groups, using, for example, fortified milks. Indeed, Madrigal et al., found a better adherence to n-3 FA recommendations in a group of children consuming adapted milks (including follow-on formula, toddler's milk, growing-up milk, and fortified and enriched milks) [89].
Many observational and intervention studies explored the effects of n-3 LC PUFA among this age group and the vast majority of DHA supplementation trials to-date in children have focused on brain function outcomes, likely due to the known influence of DHA on brain development in early life [123]. A recent systematic review of n-3 PUFA supplementation in relation to cognition in children and adolescents (4-25 y) concluded that it seemed that an increase in the circulating levels of n-3 LCPUFA, reaching >6% EPA + DHA in blood erythrocytes, was required for a positive effect on cognition and that in healthy children, daily supplementation with at least 450 mg DHA + EPA was necessary for this improvement [124].
Another area of research is the influence of n-3 PUFA supplementation on body composition and obesity risk in children, however, few studies exist beyond the pregnancy/lactation period. Even during this period, at present, evidence does not support a benefit of n-3 PUFA supplementation for later obesity risk reduction in infants and young children [125,126]. In older children (7-12 y), dietary intakes of n-3 PUFA are positively related to lean mass accretion [127], but further research is required to determine the impact of n-3 PUFA supplementation at this stage in life on body composition and cardiometabolic health, both in the short-and long-term.

Studies with All Parameters Outside of the Recommended Range
In a few studies, the intakes of all parameters (total fat, SFA, LA, ALA, DHA) were outside the recommended ranges, being lower (or higher for SFA) than the recommendations. It was observed e.g., in a rural population in China [61], in national surveys in France [78], Canada [48] or in Ireland [83]. This highlights that inadequate intake of these fatty acids can occur locally, such as in a poor, rural population in China, but also on a national level, such as those studies conducted in developed countries.

Strengths and Limitations
Unlike previous reviews which tended to focus on one geographic region, a strength of the current work lies in the fact that it provides a global overview of fat intake among children. A second merit is that this review provides information on individual PUFA (LA, ALA, EPA, DHA) and SFA intakes, and not just total fat or total PUFA intakes. Additionally, this review employed a detailed age stratification (1-2, 2-3, 3-5 and 5-7 years), allowing to highlight the low intake of total fat in the younger children (1-3 years), the low LA intake in the younger group (1-2 years) and more specifically, the low intake of EPA + DHA in the younger (1-2 years) and the older (5-7 years) sub-groups. This stratification may help for a more targeted approach to assessing intake and developing interventions for particular age groups. A limitation of the current review is that it did not employ systematic search methods. Also, there is substantial heterogeneity in the methodologies employed by the included studies to assess dietary intake, food databases were not all the same quality and the age grouping differed between countries. Furthermore, about 30% of the included studies were local studies, and it is possible that a high proportion of the volunteer participants were concerned about their diet, which may not be entirely representative of the total population. The interpretations made in this paper are dependent on the available guidelines, which themselves have certain limitations. For example, the FAO/WHO guidelines for total fat, total SFA, LA, ALA, MUFA and total PUFA intake in children cover a wide age range (2-18 years), while the EFSA guideline for SFA is "as low as possible". These vague recommendations, when considered in isolation, make it challenging to compare observed vs. recommended intakes. However, an advantage of the current study is that it takes into consideration both FAO/WHO and EFSA guidelines, as well as recent literature in the field, to generate cut-offs relevant for each fatty acid within each age group, thus providing more precise values against which intakes were compared.

Conclusions
Overall, these findings highlight suboptimal total fat intake among younger children (1-3 y), while fat intakes were either too low, adequate or higher than recommended for >3year-olds (in~12%, 70% and 19% of the studies, respectively). Intake of SFA was generally above recommended maximum values for all ages assessed, particularly in European countries. While intake of LA may be a concern for younger children (1-2 years), it is within the recommended FAO/WHO range after that age. The intake of ALA is below the recommendations in greater than half of all studies for all age ranges considered. The intake of n-3 LC PUFA among children was suboptimal across all age groups in most countries worldwide. Future, well-designed studies are warranted, particularly from Africa, South America, China and India, where there is a scarcity of data. This will help to clarify these findings and to identify the need for specific public health measures to increase intake of important fatty acids in the diets of young children, who make up a significant proportion of the population in these countries and for whom these fatty acids are crucial for growth and development.