Scientific Report of the 2020 Dietary Guidelines Advisory Committee: Evidence on Diet and Health Part Three

Our series on the scientific report of the 2020 Dietary Guidelines Advisory Committee continues with a closer look at diet and health relationships for babies from infancy to 2 years old. Have you caught up on the previous sections yet? Here they are...

1. Executive Summary
2. Setting the Stage and Integrating the Evidence
3. Methodology
4. Evidence on Diet and Health Part One: Current Dietary Intakes Through the Life Course
5. Evidence on Diet and Health Part Two: Pregnancy and Lactation

And now we're tackling Evidence on Diet and Health Part Three: Diet and Health Relationships: Birth to Age 24 Months! Here's what we're going to cover...

• Duration, Frequency, and Volume of Exclusive Human Milk and/or Infant Formula Feeding
• Foods and Beverages Consumed During Infancy and Toddlerhood
• Nutrients from Dietary Supplements During Infancy and Toddlerhood
• USDA Food Patterns for Children Younger Than Age 24 Months

Let's dive right in!In terms of Duration, Frequency, and Volume of Exclusive Human Milk and/or Infant Formula Feeding, the report asserts, "Birth to 24 months of postnatal life is a critical phase of the first 1,000 days of life, and how and what infants are fed contributes to developmental programming. Breastfeeding is the biological norm and provides health benefits for both the mother and the infant." Benefits include...

• Lower risk of communicable diseases during infancy
• Lower risk of non-communicable diseases later in life, including...
  • Ear, gastrointestinal, and respiratory infections
  • Sudden infant death syndrome (SIDS)
  • Asthma
  • Childhood obesity

The report also offers the reminder that "The American Academy of Pediatrics (AAP) recommends exclusive breastfeeding for about the first 6 months of life and continued breastfeeding with complementary foods through at least the first year of life." They observe "marked disparities in infant feeding exist in the United States based on geography, income, education, and race and ethnicity."It appears as though the thesis for this chapter is as follows "Thus, in the first year of life, infants may consume human milk and/or infant formula at varying levels of exclusivity, timing, and duration, which may influence growth and body composition, nutritional status, neurocognitive development, and both short-term and long-term health outcomes, including the risk of diabetes, cardiovascular disease (CVD), and food allergies and atopic diseases. This chapter describes the findings of the reviews conducted to examine these relationships."So let's take a look at those findings!The following questions informed the structure of this section...

1. What is the relationship between the duration, frequency, and volume of exclusive human milk and/or infant formula consumption and overweight and obesity?
2. What is the relationship between the duration, frequency, and volume of exclusive human milk and/or infant formula consumption and long-term health outcomes?
3. What is the relationship between the duration, frequency, and volume of exclusive human milk and/or infant formula consumption and nutrient status?
4. What is the relationship between the duration, frequency, and volume of exclusive human milk and/or infant formula consumption and food allergies and atopic allergic diseases?

The committee concluded "ever, compared with never, consuming human milk is associated with lower risk of overweight and obesity at ages 2 years and older, particularly if the duration of human milk consumption is 6 months or longer" though they warn "Future research studies on infant milk-feeding practices and health outcomes should be designed to reduce bias from confounding factors as much as possible."Now let's talk nutrient status. "For most questions regarding human milk feeding and nutrient status, evidence was scant to nonexistent, leading to conclusions of insufficient evidence and grade not assignable. For questions where evidence was available to address a topic, the number of studies was typically small, did not show consistent associations, and most studies were prone to a substantial risk of bias."Let's move on to the overarching conclusions of this section. "The Committee concluded that ever being breastfed may reduce the risk of overweight or obesity, type 1 diabetes, and asthma, compared to never being breastfed [...] evidence suggested that a longer duration of any breastfeeding is associated with lower risk of type 1 diabetes and asthma, although the optimal duration of breastfeeding with respect to these outcomes is not well understood [... and] exclusivity of breastfeeding was found to be associated with a lower risk of type 1 diabetes" (emphasis ours)."Despite the importance of the questions examined in this chapter for the long-term health of the child, the available evidence for many questions was insufficient to form conclusion statements, highlighting the critical need for additional research."With those conclusion statements behind us, let's move on to the next chapter: Foods and Beverages Consumed During Infancy and Toddlerhood. This one begins with a look at complementary feeding, which often takes place from age 6 months to 24 months and is defined as "the process that starts when human milk or infant formula is complemented by other foods or beverages and typically continues to 24 months of age as the child transitions fully to family foods." How and when foods are introduced, along with what types of foods are offered and in what amounts all may have an impact on "nutritional status, growth and body composition, neurocognitive development, and various health outcomes, both short- term and long-term, including bone health and risk of food allergies and atopic diseases." The Committee often abbreviates complementary foods and beverages to CFB.Here are the questions that guide this section...

1. What is the relationship between complementary feeding and growth, size, and body composition?
2. What is the relationship between complementary feeding and developmental milestones, including neurocognitive development?
3. What is the relationship between complementary feeding and nutrient status?
4. What is the relationship between complementary feeding and bone health?
5. What is the relationship between complementary feeding and food allergies and atopic allergic diseases?
6. What is the relationship between added sugars consumption during infancy and toddlerhood and risk of cardiovascular disease?
7. What is the relationship between types of dietary fats consumed during infancy and toddlerhood and risk of cardiovascular disease?
8. What is the relationship between seafood consumption during infancy and toddlerhood and risk of cardiovascular disease and neurocognitive development?

And here are the main points of the conclusion of this section..."The existing evidence suggests that CFB should not be introduced to infants before 4 months of age, and that introduction at age 4 to 5 months, as compared to 6 months, does not offer long-term advantages or disadvantages.""With regard to the types of CFB needed, the evidence supports guidance to provide foods that are rich in iron and zinc, either intrinsically (e.g., meats) or due to fortification (e.g., iron fortified infant cereal), particularly during the second 6 months of life among breastfed infants.""The evidence also supports the need to provide CFB that contain adequate amounts of polyunsaturated fatty acids, given their critical role in brain development and the link between dietary intake and the child’s fatty acid status.""The evidence indicates that introducing peanut and egg in the first year of life (after age 4 months) may reduce the risk of food allergy to peanuts and eggs.""Avoiding consumption of [sugar-sweetened beverages, a.k.a SSB] by children younger than age 2 years is important."And finally, "As mentioned in the Introduction, the Committee was asked to address several questions related to 'what to feed' infants and young children. The topics reviewed represent only a portion of all the feeding questions that are relevant to infants and toddlers from birth to age 24 months. Questions of 'how to feed' were not among the topics selected to be addressed by the 2020 Committee, but are of critical importance with regard to building healthy eating habits that can be maintained throughout life. These key issues should be taken up by the next Dietary Guidelines Advisory Committee."Next up is Nutrients from Dietary Supplements During Infancy and Toddlerhood! This section focuses on when and why iron, vitamin D, vitamin B12, and omega-3 fatty acid supplements might be advised. Note that we're talking about supplements only, not fortified foods.There were three questions that guided this section's exploration, and I've listed them below...

1. What is the relationship between specific nutrients from supplements and/or fortified foods consumed during infancy and toddlerhood and nutrient status?
2. What is the relationship between specific nutrients from supplements and/or fortified foods consumed during infancy and toddlerhood and growth, size, and body composition?
3. What is the relationship between specific nutrients from supplements and/or fortified foods consumed during infancy and toddlerhood and bone health?

And here are the highlights from the report's conclusions surrounding this section..."The evidence suggesting slower growth among infants given iron supplements suggests that routine iron supplementation of all breastfed infants may not be advisable.""At this time, the current body of evidence does not provide a basis for recommending vitamin D supplementation above 400 IU per day during infancy."And that brings us to chapter 7, USDA Food Patterns for Children Younger Than Age 24 Months, and the last chapter of part D, Evidence on Diet and Health that we're going to address in today's blog post! You've made it pretty darn far! Now let's dig into the overview...The Committee notes "Establishing healthy dietary patterns in early childhood is crucial to support immediate needs for growth and development and to promote lifelong health by helping to reduce the risk of obesity and associated cardiometabolic disorders later in life."This is a period in the lifespan that is marked by a wide variety of feeding patterns and nutrient needs. The Committee has decided that establishing food patterns for babies under 6 months is not necessary. Instead, they started modeling exercises at 6 months, when they recommend that CFB be introduced. This part of the lifespan is less about meeting energy needs with food and more about giving examples about ways to meet nutrient needs. After children are 12 months old, "the Committee focused on food patterns at ages 12 to less than 24 months that would meet nutrient needs of toddlers receiving neither human milk nor infant formula, although potential combinations of foods for toddlers receiving human milk at ages 12 to 24 months also were examined."Now why is this CFB period important? Well,

• "The complementary feeding period is important not only for providing essential nutrients, but also for introducing infants and toddlers to various types and textures of CFB that can be beneficial to health and development."
• "The complementary feeding period also is a time for implementation of responsive feeding practices that can have positive effects on child health and development."

Unlike previous sections, only a single question guides this chapter: "Can USDA Food Patterns be established based on the relationships identified in the systematic reviews? If so, how well do USDA Food Pattern variations meet nutrient recommendations for infants and toddlers? If nutrient needs are not met, is there evidence to support supplementation and/or consumption of fortified foods to meet nutrient adequacy?"The Committee concludes, "The results of modeling exercises for infants and children ages 6 to 24 months illustrate that simply extrapolating down from the patterns for children older than age 2 years is not sufficient to meet the unique nutrient needs during this life stage." In fact, the Committee could not establish a food pattern for babies ages 6-12 months.At age 13-24 months, however, the report details a "recommended Food Pattern for toddlers fed neither human milk nor infant formula that resembles the Pattern established for ages 2 and older. The Pattern allows for a variety of nutrient-rich animal-source foods, including meat, poultry, seafood, eggs, and dairy products, as well as nuts and seeds, fruits, vegetables, and grain products."This Pattern emphasizes...

• Choosing potassium- rich fruits and vegetables
• Prioritizing seafood
• Making whole grains the most common type of grains offered
• Serving oils over solid fats
• Skipping added sugars

NB: "For toddlers fed human milk at ages 12 to 24 months, the Committee was not able to establish a recommended food pattern but provides examples of potential combinations of CFB that come close to meeting almost all nutrient recommendations [...] For toddlers fed lacto-ovo vegetarian diets and fed neither human milk nor infant formula at ages 12 to 24 months, a Pattern was established that includes regular consumption of eggs, dairy products, soy products, and nuts or seeds, in addition to fruits, vegetables, grains, and oils [...] Without supplements and/or fortified products, it is not possible to meet all nutrient goals with a vegan diet at this age."And here's one last thing to remember from this chapter. "These findings are not intended to provide a combination of CFB or food pattern that is right for every infant or toddler, because children develop at different rates, and many different circumstances influence feeding needs and decisions."The chapter ends with recommendations for advice to caregivers, recommendations for federal agencies, and references.You did it! You made it through another round of overviews of the latest scientific report from the Dietary Guidelines Advisory Committee!Remember, you can read the whole scientific report here. This report is now open for public comment, and there will be an online meeting on August 11 to discuss thoughts on the report.