Rates of obesity in children continue to rise in the United States and abroad [1–4]. Even among preschool-aged children the prevalence of obesity is alarmingly high, with 26.2% of children aged 2 through 5 years in the United States classified as either overweight or obese [2]. Even in childhood, obesity is associated with a variety of adverse health consequences that can include Type II diabetes mellitus [5, 6], hypertension and hyperlipidemia [6, 7], asthma and sleep apnea [8], early maturation [9], lower self-esteem,[10] and psychosocial stress [11, 12]. Additional research has identified the preschool period as a critical time for growth, development, and risk of later obesity [13–15].

While there are genetic factors related to childhood obesity, diet and physical activity-related causes are modifiable and have therefore been targets of obesity prevention efforts and research. Associations between dietary intake and obesity have been examined in numerous studies [16–21]. Intake of sugar sweetened beverages and high fructose corn syrup [22, 23] may be contributors to the obesity epidemic, as the increases in consumption show a pattern consistent with the rise in obesity [16–19]. Other studies corroborate this finding and report that sweetened beverage consumption, including soft drinks and fruit juice, has increased in all children, including toddlers [23, 24], and is related to childhood obesity [25]. Studies examining the relationship between fruit juice intake and childhood obesity have shown mixed results [26–28].

Adult behaviors may interfere with a child's ability to respect hunger and satiety cues. There is some evidence that restrictive feeding and forcing children to eat are related to childhood obesity [29–34]. Moreover, using food as a reward may also have a negative effect on children's weight status [35, 36]. Additionally, there is strong evidence that breastfeeding has a protective effect against later childhood and adolescent obesity [37–40].

Strong evidence also links childhood obesity to television viewing both through observational studies and randomized controlled trials [41–47]. Even among preschool-aged children television viewing is associated with risk of obesity [41, 44–47]. Little is known about the contribution of computer use and its relationship to obesity in young children; one recent study found an association between computer use and adiposity in preschool-aged children [47]. In addition to television and other screen time, researchers have associated physical activity with obesity in young children, with low levels of physical activity observed among preschool-aged children [48], and in particular, preschool-aged girls [49]. Burdette and Whitaker found that play, which can involve any type of physical movement, is on the decline among children of all ages and may contribute to increases in sedentary activity and obesity [50].

Children under the age of five years have recently been a focus of obesity prevention efforts [51, 52]. In the United States and in many other countries, a large percentage of young children are in some form of child care, and the amount of time children spend in child care each week has increased in recent years [53–57]. In the United States, the 2001 National Household Education Survey found that 74% of children ages three to six are in some form of non-parental care and 56% are in center-based child care [58]. Similarly, approximately two thirds of infants are cared for by someone other than a parent, while half attend center-based care [59]. Child care facilities may serve as home-away-from-home settings, where children adopt early nutrition, physical activity, and television viewing behaviors. These behaviors are often a result of interactions with parents and other caregivers [60]. Young children in particular are more likely to be influenced by adults in an eating environment [61]. Moreover, preschool-aged children may consume 50% to 100% of their Recommended Dietary Allowances in child care settings [62], placing a great deal of responsibility on the child care facility to provide nutritionally adequate, healthful food.

Child care facilities are in a unique position to support and facilitate healthful eating and promote physical activity for young children, and a small number of studies have targeted child care settings for nutrition promotion [63–67] and obesity prevention [68–72]. While individual and environmental intervention efforts represent one approach to improving health outcomes of children in child care, broad-sweeping state policy changes may play a complementary or perhaps primary role in childhood obesity prevention.

In the United States, regulation of child care facilities is the responsibility of the individual state and the District of Columbia, and each has an agency responsible for oversight and enforcement of these regulations [73]. As a result, regulations for child care facilities vary considerably by state. A recent report of state regulations by the National Association of Child Care Resource & Referral Agencies (NACCRRA) scored states on a variety of health and safety benchmarks including: staff to child ratios, Sudden Infant Death Syndrome (SIDS) prevention, hand washing and diapering, playground surfaces, and emergency preparedness [74]. Nutrition and physical activity, however, were not included in this report. We conducted a review of state nutrition and physical activity regulations related to childhood obesity for child care facilities in the United States and present results of a state-by-state comparison. Although one publication reported tallies of a small number of state regulations related to nutrition and physical activity [75], no comprehensive review has examined obesity-related regulations for child care facilities.

In this review of state regulations for child care facilities in the United States, we found that most states had few nutrition and physical activity regulations related to obesity for child care centers and family child care homes. Tennessee had 6 of the 8 obesity regulations for child care centers, and Delaware, Georgia, Indiana, and Nevada had 5 of the 8 regulations. On the other hand, the District of Columbia, Idaho, Nebraska and Washington had none of the 8. For family child care homes, Georgia and Nevada had 5 of the 8 regulations; Arizona, Mississippi, North Carolina, Oregon, Tennessee, Texas, Vermont, and West Virginia had 4 of the 8 regulations. California, the District of Columbia, Idaho, Iowa, Kansas, and Nebraska did not have any of the regulations for family child care homes.

In addition to the overall dearth of nutrition and physical activity regulations related to obesity, the regulations that do exist may be difficult to interpret by child care providers. The regulation related to water, for example, generally did not specify where and how water should be provided to children, only that it should be freely available. Other regulations may be difficult to decipher as well. A number of states prohibited forcing children to eat. This regulation, however, was mostly associated with discipline, and may not be applied to adult-child interactions during meals and snacks (e.g., requiring children to "clean their plates" or take a "no thank you" bite). This regulation may have a greater impact if states explicitly stated that this regulation applied to all eating occasions. The screen time and the physical activity regulations, however, may be easier to interpret and implement because they offer more precise guidelines.

We also examined regulations related to vending machines in child care facilities. We did not report results on vending machines because there is limited data linking vending machines to obesity in children. We did, however, find that only 4 states (8%) restricted or prohibited vending machines at the child care center. Two of these states, Mississippi and Georgia, also regulated vending machines in family child care homes. Alabama and Georgia prohibited vending machines in any areas used by children, while Louisiana required them to be outside of children's play areas. Mississippi required food in the vending machine to meet nutritional guidelines. We present this information on vending machines as a supplement to our review of nutrition and physical activity regulations related to obesity for child care facilities.

Given the overall absence of regulations or lack of clear and specific nutrition and physical activity regulations related to childhood obesity, a number of states could enhance their regulations for child care facilities. Reviewing and revising regulations on a regular basis helps ensure that regulations reflect current best practices related to childhood obesity. As additional evidence becomes available, states should revise regulations for both child care centers and family child care homes to reflect this new information. In this review, we found that 8 states had regulations dating back to the 1980s or 1990s. In a recent publication, Story et al. [75] contend that inadequate nutrition and physical activity regulations represent a missed opportunity for childhood obesity prevention. Moreover, they argue that simple, easy to follow nutrition and physical activity regulations, such as prohibiting sugar-sweetened beverages and requiring physical activity daily may help promote healthy weight in young children in child care [75]. If widely implemented, enhancing state regulations could be one way of improving weight-related nutrition and physical activity behaviors in preschool-aged children in the United States.

Generally, regulations for family child care homes tended to be less stringent than centers. In a few instances, however, regulations for family child care homes were more robust than child care centers. For example, Washington required homes but not centers to offer water at frequent intervals to children, and Arizona limited sugar sweetened beverages and foods of low nutritional value in family child care homes, but not in child care centers. Additionally, Oregon limited screen time in family child care homes but not centers. Although family child care homes are generally considered a more informal child care setting, states should provide the same regulations for both family child care homes and centers. This helps to ensure consistent quality of care, and minimizes variation among child care providers within a given state.

A limitation of this review is the ever-evolving nature of state regulations. States may have revised regulations for child care centers or family child care homes since our last review, or may be in the process of updating their regulations. Given the current national call-to-action to address childhood obesity in both schools and child care settings, states may be more likely than ever before to enact nutrition and physical activity regulations to help prevent obesity. In addition, cities or other geographic areas within a state have the power to regulate child care facilities in their jurisdiction. New York City, for example, recently enacted nutrition and physical activity regulations in Article 47 of the New York City health code that were more stringent than those for New York State. New York City is leading the way for other cities who may want to enact new regulations for child care facilities that go beyond their state regulations.

In this review of US state regulations for child care we found that most states had few regulations related to obesity for child care centers and family child care homes. This is the first comprehensive review of nutrition and physical activity regulations related to childhood obesity for child care facilities, and further exploration is needed. Recently, researchers have attempted to classify and categorize state level policy related to physical education and nutrition services in school settings [85, 86], but the researchers did not extend the scope of their work to include state regulations governing child-care facilities. A logical next step would be to conduct a similar study classifying obesity regulations for child care facilities in the United States. In addition, existing child care regulations could be compared to federal recommendations to assess how states regulations compare to national standards.

The mere existence of a regulation, however, does not necessarily ensure compliance or enforcement. Frequency of compliance checks vary from state to state. For child care centers, 29 states visit centers one time per year, 16 states visit 2 times per year, and 6 states visit 3 or more times per year for routine inspections. For family child care homes, states assess compliance less frequently (range: every 6 months to 10 years). Some states do not require routine inspections of family child care homes unless a formal complaint is filed. Future studies should explore not only the presence of a regulation but also implementation, compliance, enforcement, and unintended consequences of the regulation, as well as the overall effect on child health outcomes. This review and report of state nutrition and physical activity regulations for child care facilities in the United States represents the first step in policy-level approaches to address childhood obesity. Results of this review, coupled with a growing interest in obesity prevention in child care settings, may inspire states to improve and enhance their nutrition and physical activity regulations related to obesity and could spark additional research in this area to help evaluate the impact of these regulations.