Table 3.

Characteristics, description and summary of outcomes of articles included in the systematic review (SR) on breakfast and micronutrients intake.

Author	Country, Year and Type of Study	Aim	Sample and Characteristics of Participants £	Data Source and Dietary Assessment of Breakfast (BF)	Principal Outcome about Micronutrients
Affenito, S. et al. 2005 [30]	United States (US) N.A Longitudinal	To examine the association between BF frequency and Ca and fiber intake.	n = 2379 Girls. 9–19 y	National Heart, Lung, and Blood Institute Growth and Health Study 3 day-Food records	Frequent BF consumption was associated with more intake of Ca regardless of the total amount of EI consumed (p < 0.001).
Affenito S. et al. 2013 [41]	US 2004–2005 Cross-sectional	To examine the association of RTEC consumption and dietary nutrients intake.	n = 2298 5–18 y	The third School Nutrition Dietary Assessment Study 1–24 h dietary recall	BF consumption improves the intake of vitA, Ca and Fe (p < 0.05).
Afeiche, M. et al. 2017 [28]	Mexico, 2012 Cross-sectional	To compare BF dietary patterns (DP) with BF skipping and the associations with total-day diet energy and nutrients intake.	n = 3760 4–13 y	Mexican National Health and Nutrition Survey 1–24 h dietary recall	BF skippers consumed less B vitamins (riboflavin, niacin, pyridoxine, folate and cobalamin), Ca, vitD, Fe, Zn, Na, and K than BF consumers. The sweetened beverages and milk and sweetened breads DP had the lowest intakes of Fe, Zn and K at BF.
Albertson A. et al. 2003 [56]	US 1998–1999 Cross-sectional	To assess the relationship between RTEC frequency consumption and nutrients intake in children.	n = 603 4–12 y	American household surveys 14–Food records	RTEC frequency of consumption was not associated to Na, vitE, but it was associated with high intake of vitA, pyridoxine, vitC, thiamin, riboflavin, niacin, folate, Ca, Mg, Fe and Zn (p = 001).
Albertson A. et al. 2008 [57]	US 1987 Longitudinal	To assess the association between RTEC consumption and energy and nutrients intake.	n = 2379 9–10 y	The National Heart, Lung, and Blood Institute Growth Health Study 1–24 h dietary recalls	RTEC consumers did not differ from non-RTEC consumers in Na intake (N.S).
Balvin Frantzen, L. et al. 2013 [58]	US 2001–2004 Longitudinal	To assess the association between frequency of RTEC consumption and nutrients intake.	n = 625 Mean age = 9.13 y	BIENESTAR Study 3–24 h dietary recalls	Baseline data analysis concludes that frequency of RTEC consumption was positively associated with the intake of vitD, vitC, riboflavin, niacine, cobalamin, Ca, Fe, and K. (p < 0.05).
Barr, S. et al. 2014 [42]	Canada 2004 Cross-sectional	To assess the effect of skipping BF, consuming BF and consuming BF with RTEC on intake of nutrients.	n = 12,281 4–18 y	Canadian Community Health Survey, 2004. 1–24 h dietary recall	RTEC consumers had a higher intake of thiamin, pyridoxine, vitD, Ca, Fe, Mg, P, and K than other-BF consumers and non-BF consumers. Both BF consumers and RTEC consumers had higher intakes of vitA, folate and vitC compared with BF skippers. RTEC consumers had higher intakes of riboflavin than non-RTEC consumers and BF skippers. Other-BF consumers had higher intake of niacin than other groups (p < 0.05).
Barr, SI. et al 2018 [43]	Canada 2015 Cross-sectional	To compare daily EI and nutrients intake of BF consumers and BF skippers.	n = 2331 6–12 y n = 2026 13–17 y	Canadian Community Health Survey-Nutrition 1–24 h dietary recall	Children and adolescents who usually consume BF had a higher intake of thiamin, vitC, Fe, and Mg (p < 0.5). In adolescents, BF consumers had a high intake of vitA, riboflavin, cobalamin, vitD and K (p < 0.01), pyridoxine, Ca (p < 0.01), and Zn (p < 0.5).
Barton, B. et al. 2005 [59]	US 1985 Cross-sectional	To assess the association of BF and RTEC consumption with intake of nutrients.	n = 2379 9–19 y	National Heart, Lung and Blood Institute Growth and Health study 3–24 h dietary recalls	RTEC consumption increases the intake of Ca, Fe, folate, vitC, and Zn.
Coulthard, J. et al. 2017 [3]	United Kingdom (UK) 2008–2012 Cross-sectional	To assess differences in nutrients intake between BF skippers and BF consumers.	n = 1686 4–18 y	National Diet and Nutrition Survey 4–Food records	Children and adolescents had significantly higher mean intakes of folate, Ca and I, and significantly lower mean intakes of Na for days on which BF was consumed compared with non-BF days. Frequency of BF consumption was positively associated with folate, Na, Ca, Fe, and I (p < 0.05).
Deshmukh-Taskar, P. et al. 2010 [70]	US 1999–2006 Cross-sectional	To assess the relationship between skipping BF or having lunch with nutrients intake, nutrient adequacy and adiposity.	n = 930 9–13 y n = 1805 14–18 y	NHANES Ω 1–24 h dietary recall	In both children and adolescents, BF skippers had a lower intake of vitA, vitC, riboflavin, cobalamin, folate, Ca, P, Mg, K, and Zn than the other groups (p < 0.05). RTEC consumers had lower Na intake than the other groups (p < 0.05). Thiamine, niacin, pyridoxine and Fe intake was significantly higher in the RTEC consumers group (p < 0.05).
Fayet-Moore, F. et al. 2016 [46]	Australia 2007 Cross-sectional	To assess the impact of BF skipping, BF with RTEC and BF without RTEC on nutrient intake.	n = 4487 2–16 y	Australian National Children’s Nutrition and Physical Activity Survey 2–24 h dietary recall	BF consumers had a higher intake of total Ca, folate, Mg and Zn than BF skippers. RTEC consumers had higher intake of Fe, P, K, I, and Na (p < 0.001). BF consumers, and to a higher degree RTEC consumers, were more likely to meet the EAR of Ca and Fe than BF skippers (p < 0.001).
Fayet-Moore, F. et al. 2017 [45]	Australia 2011–2012 Cross-sectional	To investigate the impact of BF skipping, BF with RTEC and BF without RTEC on daily nutrients intake.	n = 2821 2–18 y	National Nutrition and Physical Activity Survey 1–24 h dietary recall	BF skippers had lower niacin, Fe, thiamin, riboflavin, folate and Ca, intake whereas they had a higher Na intake than BF consumers (p < 0.001).
Fulgoni, VL. et al. 2019 [55]	US 2011–2014 Cross sectional	To compare diet quality and nutrient intake among children consuming an oatmeal-containing BF versus those of children consuming other popular BF.	n = 5876 2–18 y	NHANES Ω 1–24 h dietary recall	Oatmeal consumers had a significantly higher intake of Ca, Fe, Mg, K, folate, vitA, and vitD than BF skippers. In children and adolescents, RTEC consumers had a higher intake of Ca, Fe, Mg, K, vitA, and vitE than those who usually consume “Doughnuts, sweets rolls and pastries”; higher intake of Mg and K than those who usually consume “Pancakes, waffles, French toast” and higher intakes of Ca, Fe and Mg than consumers of “Eggs and omelettes”. RTEC consumers (lower and higher sugar) had a higher intake of Fe and folate than those children and adolescents who usually consume oatmeal BF.
Gibson, S. et al. 1995 [60]	UK N.A Cross-sectional	To examine the relation ship between RTEC frequency of consumption and total daily nutrients intake.	n = 2705 10–15 y	7-day weighed records	Frequency of RTEC consumption in boys and girls was positively associated with Ca, Fe, thiamin, riboflavin, niacin, and pyridoxine intake.
Gibson, S. et al. 1999 [47]	UK N.A Cross-sectional	To examine associations between RTEC consumption and iron intake.	n = 904 1.5–4.5 y	UK National Diet and Nutrition Survey 4 day weighed records	High RTEC consumers had significantly higher Fe intakes than low cereal consumers. (p < 0.0001). They did not have a significantly higher intake of Ca compared to the other groups (p = 0.06).
Gibson, S. et al. 2003 [61]	UK N.A Cross-sectional	To examine the impact of RTEC on micronutrient status.	n = 1688 4–18 y	The National Diet and Nutrition Survey of Young People 7–24 h dietary recalls	The highest tertile of RTEC intake had 20–60% higher intake of iron, B vitamins and vitD, compared with the first tertile. A positive association between Fe, thiamin, riboflavin and folate was observed across tertiles of RTEC consumption (p < 0.001).
Matthys, C. et al. 2007 [65]	Belgium 1997 Cross-sectional	To describe BF consumption patterns and overall nutrients profile.	n = 341 13–18 y	Food Consumption Survey 7–24 h dietary recalls	Good quality of BF was associated with higher intake of Ca, Mg, thiamin, riboflavin and vitC and P compared to low quality of BF consumers (p < 0.001). Specifically, girls with good quality of BF had a significantly higher intake of Ca, P, Fe, Mg, thiamin, riboflavin, and vitC (p < 0.001).
McNulty, H. et al. 1996 [64]	Ireland 1990 Cross-sectional	To establish the contribution of RTEC to the overall nutrients intake.	n = 1015 12–15 y	1–24 h dietary recall	Higher RTEC consumption was associated with higher cobalamin intake, except for boys aged 12 years. Folate intake significantly increased with increasing intake of fortified BF cereals in the younger adolescents (p < 0.05). Ca intake increased with increasing BF cereals intake in all age and sex groups (p < 0.05).
Michels, N. et al. 2015 [48]	Europe 2006–2007 Cross-sectional	To analyze the association of RTEC consumption frequency with dietary intake.	n = 1215 12.5–17.5 y	HELENA Study Ω 1 Food Frequency Questionnaire 2–24 h dietary recalls	Ca, P, K, riboflavin, pantothenic acid, biotin, and VitD intakes were significantly higher in the RTEC consumers group (p < 0.05).
Mielgo-Ayuso, J. et al. 2017 [16]	European countries 2006–2007 Cross-sectional	To examine the association between BF consumption patterns and vitamins intake	n = 1058 12.5–17.5 y	HELENA Study Ω 2–24 h dietary recalls	BF consumption was associated with high intakes of vitD and folate in both sexes, with high intakes of pyridoxine and vitE in girls (p < 0.05).
Mohd Nasir, M.T. et al. 2017 [67]	Malaysia 2013 Cross-sectional	To compare foods consumed at breakfast and nutrient intake for the total day between RTEC consumers and non-RTEC consumers	n = 1819 6–12 y	MyBreakfast study Children 6–9 y: 2 day food records Children 10–12 y: 2–24 h dietary recalls	RTEC consumers had a higher daily intake of vitC, thiamine, riboflavin, niacin, Ca, and Fe (p < 0.05). Non-RTEC consumers had a higher intake of Na than RTEC consumers (p < 0.05). No significant associations in vitA and P were observed between RTEC consumers and non-RTEC consumers.
Morgan, K.J. et al. 1981 [49]	US 1977 Cross-sectional	To assess BF consumption pattern and relate it with nutrients intake	n = 657 5–12 y	7 day food records	BF had a significant contribution to child’s daily nutrients intake. RTEC consumers for 3 or more times per week had higher intake of Fe and B vitamins (p < 0.001) than non-RTEC consumers.
Murakami, K. et al. 2018 [68]	Japan 2012 Cross-sectional	To assess BF consumption and its association with daily dietary intake of nutrients, food groups and overall diet quality.	n = 1444 6–11 y n = 1134 12–17 y	National Health and Nutrition Survey 2012 1 Dietary record	BF consumers had higher intakes of vitK, folate, vitC, Ca, Mg, and P in both age groups. Children who usually consumed BF had a higher intake of vitA, vitK and vitC than BF skippers (p < 0.05). In adolescents, BF consumers had a higher intake of K and Fe than BF skippers (p < 0.05). In both children and adolescents, BF skippers had a lower intake of pyridoxine, folate, pantothenic acid, Ca, Mg, P, and Zn than BF consumers (p < 0.05).
Ortega, RM. Et al. 1996 [62]	Spain N.A Cross-sectional	To analyze the influence of RTEC consumption at BF upon dietary habits.	n = 200 9–13 y	4–24 h dietary recalls	The intake of thiamine, pyridoxine, folate, β-carotene (p < 0.05), riboflavin, and I (p < 0.1) was higher in the group of RTEC consumers.
Ortega, RM. et al. 1998 [63]	Spain N.A Cross-sectional	To assess the association between Ca and milk products consumed at BF with their total daily intake.	n = 200 9–13 y	7–24 h dietary recalls	BF with <20% of total EI included lower quantities of Ca than larger BF (p < 0.05). These adolescents also consumed less Ca over the rest of the day.
Papoutsou, S. et al. 2014 [66]	Cyprus 2007–2008 Cross-sectional	To investigate the association of BF pattern consumption with children’s diet quality in a sample from Cyprus.	n = 1558 4–8 y	IDEFICS Study Ω 1–24 h dietary recall	Milk and pastry consumers had lower intake of Fe, Na, thiamin, riboflavin, and pyridoxine than RTEC consumers. Other—BF, milk and pastry consumers had lower intakes of vitA and vitC. Milk consumers had a lower intake of Mg than the other groups. Milk and pastry consumers had a higher intake of Mg and P (p < 0.05).
Preziosi, P. et al. 1999 [50]	France N.A Cross-sectional	To examine the associations between the intake of different types of BF and dietary intakes.	n = 1108 2–18 y	1–24 h dietary recall	Percent of RDA for Ca, P, magnesium, and Fe were exceeded in non-RTEC and RTEC consumers but was significantly higher in the group of RTEC consumers (p < 0.05). RDA for thiamine and riboflavin were also reached in both groups but RTEC consumers had higher intakes of both nutrients (p < 0.001 and p < 0.01). Percent of RDA for magnesium, Zn, copper, pyridoxine, folate, vitC, vitA, and vitE were also higher in the RTEC group.
Ramsay, SA. Et al. 2018 [51]	US 2005–2012 Cross-sectional	To examine food intake, nutrients intake and overall diet quality among BF consumers and BF skippers.	n = 8590 2–12 y	NHANES Ω 1–24 h dietary recall	BF skippers did not meet the average amount of nutrients of children who consumed BF. BF skippers consumed less vitA, folate, Fe, and Ca than those who consumed BF.
Ruxton, CH. et al. 1996 [29]	UK Scotland 1991–1992 Cross-sectional	To provide new data on the BF habit of children	n = 136 5–9 y	7–24 h dietary recall	The overall diets of children in the high RTEC group were higher in micronutrients than the other groups. Folate and Fe in the low RTEC group were below recommendations.
Vatanparast, H. et al. 2019 [54]	Canada 2015 Cross-sectional	To evaluate how RTEC consumption contributed to daily energy and nutrient intakes and then compare them with non-consumers	n = 3810 6–12 y n = 2379 12–18 y	The Canadian diet, the recent nationally representative dietary survey 1–24 h dietary recall	Children and adolescents who usually consume RTEC had significantly higher intake of pyridoxine, vitD, riboflavin, thiamine, K, Ca, Fe, and Mg than non-RTEC consumers. In children, RTEC consumers had a higher intake of cobalamin and Zn than non-RTEC consumers. In adolescents, RTEC consumers had a lower intake of Na than non-RTEC consumers.
Williams, B.M. et al. 2009 [52]	US 1999–2002 Cross-sectional	To assess if BF dietary patterns are associated with nutrients intake and nutritional adequacy.	n = 1389 2–12 y	NHANES Ω 1–24 h dietary recall	RTEC consumers had a higher intake of vitA, cobalamin, thiamine, riboflavin, folate, and Fe (p ≤ 0.05).
Williams, P. et al. 2007 [53]	Australia 1995 Cross-sectional	To assess the contribution of BF to the nutrition of Australian children and adolescents.	n = 3007 2–18 y	National Health Survey 1–24 h dietary recall 1 FFQ	Higher RTEC consumption was associated with higher cobalamin intake, except for boys aged 12 years. Folate intake significantly increased with increasing intake of RTEC in younger adolescents. (p < 0.05). Ca intake increased with increasing BF cereal intake in all age and sex groups. (p < 0.05).

£ = All the studies included boys and girls in their analysis, except those in which it was specified that only one gender was included. Abbreviations: N.A: Not available; BF: Breakfast; Y = Years; EI: Energy intake; RTEC: Ready to eat cereal; DP: Dietary Pattern; RDA: recommended dietary allowances; vitA: vitamin A; vitC: vitamin C; vitE: vitamin E; vitD: vitamin D; vitK: vitamin K; Mg: magnesium; Zn: zinc; Ca: Calcium; Na: Sodium; K: potassium; Fe: iron; I: Iodine; P: Phosphorus; Ω = IDEFICS—Identification and prevention of dietary- and lifestyle-induced health effects in children and infants; HELENA—Healthy Lifestyle in Europe by Nutrition in Adolescence.; NHANES—National Health and Nutrition Examination Survey; FFQ: Food Frequency Questionnaire.