This is the first study, that we are aware of, that has shown that total apple product consumption, whole apples, and apple sauce and apple juice were associated with higher diet qualities than those seen in non-consumers of the same food groups. It is also the first study to show that total apple consumption and whole apple consumption is associated with a lower prevalence of obesity and a lower likelihood of obesity.

Recently, it was shown that more than three-quarters (77.1 %) of all children 2–19 years consumed any fruit on a given day [8]. There is a clear difference in age, with younger children 2–5 years consuming more than older children 12–19 years [8]. Fruit consumption among children 2–18 years appears to have increased during the time of this study (2003 to 2010) [9] from 0.55 in 2003–2004 to 0.62 in 2009–2010 cup equivalents/1,000 kcal (kcals) because of significant increases in whole fruit intake. Similar results have been shown for children 2–17 years [10]. Fruit juice consumption declined over this period, going from 0.31 to 0.22 cup equivalents/1,000 kcals [9]. Despite these encouraging numbers, fruit is still under-consumed by children [11–14].

Consumption of total apple products and whole apples clearly has a significant impact on overall diet quality, suggesting that fruit intake and in particular apple products, should be encouraged. This complements other studies that have shown that consumption of individual types of whole fruit, including grapefruit [50], mangos [51], pears [52], and avocados [53], and 100 % fruit juice [6, 54] was associated with a higher HEI score than non-consumers. In this study, total apple products, apples, and apple sauce were all associated with intakes of greater intakes of total and whole fruit, whereas, consumption of 100 % fruit juice was not. This differs from other studies that have examined the diet quality of 100 % fruit juice consumers [6, 54], perhaps because of the number of 100 % apple juice consumers was relatively small compared with the total number of children consuming 100 % of any type of fruit juice. In addition, the higher diet quality for consumers of all apple products was also driven by higher component scores for whole grains and fewer empty calories consumed.

Determining the effect of fruit consumption on weight is difficult, since most studies have considered fruit and vegetables together [22, 23]; further, most studies have been conducted in adults. Although the association of fruit and vegetables consumption and weight or weight loss is inconsistent [22], the recommendation is to increase fruit and vegetable consumption in the diet to help manage weight [1, 18]. The single study that has examined apple intake and weight loss was a randomized controlled trial of overweight adult females (n = 411) who consumed three apples (300 g), three pears (300 g), or oat cookies (60 g) per day for 12 weeks. Groups consuming either apples or pears lost 1.21 kg, compared with the group consuming cookies that lost only 0.88 kg [24].

Ours is the only epidemiologic study that has examined apple products and weight, and the only study in children. This study showed that only total apple products and whole apples were associated with lower BMI z-scores and that consumers were less likely to be obese. Consumption of neither apple sauce nor 100 % apple juice showed any association with weight. The lack of an association between 100 % apple juice with weight is of particular import since although the majority of studies of fruit juice consumption have shown no association with weight [55, 56], one study has shown that apple juice consumption was associated with increased BMI and ponderal index in children [57]. However, that was a small regional study and the data were subsequently disputed [58]. It’s not clear why total apple products and whole apples and not apple sauce or 100 % apple juice would be inversely associated with BMI z-score, but it may be related to satiety factors, at least acutely, associated with whole fruit rather than a semi-solid food like apple sauce or a liquid like 100 % apple juice [59, 60].

The strengths of this study were that it included a large sample size with a nationally representative sample of children. The NHANES has carefully controlled protocols and screens 24-h dietary recalls confirming they are valid and complete; the NHANES also uses the multiple pass method to obtain dietary intake, which is the best dietary assessment method available for large scale epidemiologic studies. Twenty-four hour dietary recalls, used in this study do have several inherent limitations: they are memory dependent, and under- and over-reporting may occur. In proxy-assisted recalls of children, parents may know what their children consume at home [61, 62], but they may not know what their children consume outside the home, for example in school or day care [63]. Finally, cause-and-effect relationships cannot be determined from a cross-sectional study.

In conclusion, the consumption of total apple products, whole apples, apple sauce, and 100 % apple juice contributed to the fruit recommendations of children and was associated with better diet quality, and in the case of total apple products and whole apples with a decreased risk of obesity in children. Apple products should be encouraged as part of a healthy diet [64] to help children meet the recommendations for fruit.