Nutrition and Dietary Determinants
Trends in Dietary Quality and Energy Intake
The concept of energy balance is essential to understanding the relationship among food consumption, physical activity and body weight. When caloric consumption from food exceeds energy expended in physiologic processes, physical activity, and for children, "normal" growth, excess weight gain occurs. The balance of energy intake and expenditure is so delicate that routinely consuming 10 calories per day in excess of energy expenditure would result in a one-pound weight gain over 12 months. While the concept of energy balance appears straightforward, the environmental stimuli and behavioral patterns that influence food consumption are extremely complex and so well-integrated into our way of life that we may not notice the factors that contribute to increased calorie consumption.
Over the past 20-30 years, the same period in which obesity doubled among U.S. adults, there has been a significant increase in average daily caloric consumption with men consuming, on average, an additional 168 to 268 calories/day, and women an additional 143 to 335 calories/day (Cutler, Shapiro, USDA, ERS, 2004; MMWR 2/6/04). Trends that contributed to increased calorie consumption over this 30-year period include increased consumption of food away from home, particularly fast food, increased portion sizes, increased intake of sweetened beverages, as well as improved methods for documenting food and nutrient intake (Briefel and Johnson, 2004). Studies by the USDA ERS attribute most of these extra calories to increased consumption of between-meal snacks (USDA, ERS, 2004).
Schools + Professionals in Nutrition (SPIN)
Schools + Professionals in Nutrition (SPIN) Program, an outgrowth of the New York State Action for Healthy Kids Team, pairs school professionals with a volunteer nutritional professional who work together to improve nutrition among students in part through helping schools to complete the School Health Index (SHI) and an Action Plan. Matched schools and nutrition professionals have access to resources, support and technical assistance as needed to foster productive partnerships.
There was little measurable change in children's average daily caloric consumption over this period with the exception of an increase among adolescent females (Briefel and Johnson, 2004). Nevertheless, overweight more than tripled among children 6 through 11 years and more than doubled for youth 12 through 19 years (Ogden and Flegel, 2002). Although significant changes in caloric consumption were not documented, trends in dietary behaviors shifted significantly toward consumption of more food away from home, increased snacking, and increased use of sweetened beverages.
Among preschool children, national dietary surveys indicate overall diet quality improved somewhat between 1977 and 1998 with increased intakes of grains, fruits and vegetables and dairy products. At the same time caloric intake increased significantly, with a large proportion of the extra calories accounted for by increases in added sugar and increases in fruit juice consumption. Although the percentage of calories from fat decreased over the same period, the total amount of fat consumed increased contributing to a higher caloric intake (Kranz et al., 2004).
Be a Power Eater: The Good Food for Great Kids Program
Be a Power Eater: The Good Food for Great Kids Program is being launched in all Pre-K through 8th grade Buffalo public schools (approximately 31,000 students). An enhanced fruit and vegetable display will be placed in school lunch lines for a six-week period (January 24-March 4, 2005) where students will receive incentives and rewards for selecting a fruit or vegetable. The program where the opportunity for rewards and prizes increases proportionately to the number of times a student selects an item. The program will focus on changing behavior in children to lessen health trends in poor nutrition and overweight/obesity. The project will evaluate which approaches have the greatest behavioral outcomes, by school and grade, and results will be available by the end of 2005.
The Be a Power Eater program also has a research component. Variations of the basic program will be tried at the 65 schools. The schools are divided into three groups (A, B, C):
- The "A" schools will be involved in the program that includes the main program + 4th grade nutrition curriculum* for two schools.
- The "B" schools will participate in the main program + a school competition where the top 3 schools who have consumed the most fruits and vegetables win a special award + 4th grade nutrition curriculum* for two schools.
- The "C" schools will participate in the main program + a "Promise Contract" where homeroom students will sign a poster in the classroom pledging to eat more healthfully + 4th grade nutrition curriculum* for two schools
*The curriculum will be completed prior to the program start.
According to Gretchen Fierle, the Project Coordinator, "the Healthy Heart Program's funding has allowed us to leverage other funds." Of the $450,000 cost of this project, $101,250 is from the Healthy Heart contract. More than 15 organizations and 12 funding agencies have developed this district-wide initiative. This intervention is the first of its kind in Western New York and no other urban community in the United States has undertaken a program of this magnitude, aligning existing community and media resources to address a community issue.
The recent Feeding Infants and Toddlers Survey (FITS) revealed that the food intake of infants and toddlers generally met or exceeded nutrient recommendations. However, mean energy intake exceeded estimated requirements by 10% for infants 4 to 6 months, 23% for infants 7 to 12 months, and 31% for toddlers 12 to 24 months (Devaney, Ziegler, Pac et al., 2004). The dietary patterns of infants often resembled those of older children and adults. Up to a third of infants between 7 and 24 months of age consumed no discreet servings of fruits or vegetables. French fries were one of the three most commonly consumed vegetables among 9 to 11 month-old infants, and by 15 to 18 months French fries were the most commonly consumed vegetable. Baked desserts, candy, salty snacks and sweetened beverages, including soda and fruits drinks, were also prominent in the diets of infants and toddlers (Fox, Pac et al., 2004). The transition from an infant feeding pattern to a mature eating pattern has traditionally been regarded as a critical period for introducing an array of nutrient-dense foods in support of healthful life-long eating patterns. This important transitional period has been superseded by the early adoption of the "typical American diet," deficient in fruits and vegetables and replete with snack foods, sweetened beverages and desserts.
Parental Influences on Food Choices and Eating Behaviors
Studies show that parental practices and behaviors influence the development of their children's eating and activity behaviors (Davison and Birch, 2001a,b,c; Moore et al., 1991). Most parents of overweight children, even very overweight children, fail to recognize that their child is overweight (Baughcum et al., 2000). Among children with a BMI between the 85th and 95th percentiles, only 3% of parents reported that his/her child was a little overweight. Among children with a BMI > 95th percentiles, only 27% of parents reported that his/her child was a little overweight or overweight. Dennison et al. (2000) found that parents who believe that their child is overweight report limiting how much food their child eats more frequently. Dietz et al. (1983) found that parents of overweight children tended to have difficulty setting limits with respect to food and other areas. In a cross-sectional study, Johnson and Birch (1994) noted that mothers of overweight preschool children tended to be more controlling of their children's food intake, specifically limiting how much food their child ate. However, in a recent longitudinal study, Davison and Birch (2000) reported that overweight girls whose fathers were more restrictive (i.e., limited more frequently the amount of food) tended to gain less weight over time. In sum, these findings suggest that lack of parental limits to food intake may contribute to obesity, while imposition of some limits (in response to parental perception that the child is overweight) may help slow down continued weight gain.
Approximately two-thirds of parents reported using food as a reward and withholding food, usually dessert, as a punishment (Birch, 1980; Dennison et al., 2000a). Yet, as Birch and colleagues (1982) have demonstrated, this has contrary results; rewarding the consumption of a food (a contingency) devalues the food and decreases the liking for that food. Praising children for eating all of a food or for cleaning their plate may actually encourage overeating, which has been associated with obesity (Klesges et. al., 1995). Parental encouragements to eat were associated with an increased likelihood that the child would eat; prompts to eat were associated with children's weight status (Klesges et al., 1986). When young children were allowed to choose freely from a selection of foods, they selected many non-nutritious foods. When children were told that their mother was going to review the foods selected, they chose fewer non-nutritious foods. When mothers modified their children's choices, "they tend[ed] to focus on reducing foods lowest in nutritional value rather than increasing foods highest in nutritional value" (Klesges et al., 1991).
Public/private partnerships to promote healthy eating
The Jefferson County Eat Well Play Hard demonstration project partnered with the Hannaford Market chain and the NYS Apple Grower's Association to implement an apple coupon redemption system during the fall harvest. The project distributed over 6,000 coupons with total sales of apples increasing by 11,000 pounds over the same time period for the previous year.
The Dutchess County Eat Well Play Hard demonstration project partnered with a local McDonalds to modify the Happy Meal Menu. The "Happy Meal Plus" included 1% or fat free milk or a 5 oz. low fat yogurt in place of a soft drink and added a choice of salad or fruit cup. A physical activity toy, such as a beach ball or jump rope was also included. A total of 943 Plus meals were sold during the promotion. Over a two month period, the number of Plus meals sold was 67% above the average sales for the Happy Meal. Sales of low fat milk for the McDonald's store were up by 19% over the same period during the previous year. Children selected the fruit cup 38% of the time; salad was selected 29% of the time.
Fruits and Vegetables
The 2005 U.S. Dietary Guidelines recommend increased amounts of fruits and vegetables for Americans 2 years and older (USDA, 2005). Four and one-half cups (nine servings) of fruits and vegetables are recommended daily for the reference 2,000-calorie level, with higher or lower amounts depending on the calorie level. This results in a range of 2 1/2 to 6 1/2 cups (5 to 13 servings) of fruits and vegetables each day for the 1,200- to 3,200-calorie levels (USDA, 2005). In the fruit group, consumption of whole fruits (fresh, frozen, canned and dried) rather than fruit juice for the majority of the total daily amount is suggested to ensure adequate fiber intake. As different vegetables are rich in different nutrients, a variety of vegetables from the five vegetable subgroups (dark green, orange, legumes [dry beans], starchy and other vegetables) is recommended for adequate nutrient intake.
Previous recommendations were for a minimum of five servings of fruits and vegetables (two servings of fruits and three servings of vegetables) per day (USDA, 2000), which formed the basis for the national Five-A-Day for Better Health program, a public/private partnership of the produce industry and the U.S. Government to promote vegetable and fruit consumption. The increased fruit and vegetable recommendations are based on the demonstrated role of vegetables and fruits in reducing chronic disease risk including selected cancers, cardiovascular disease and hypertension (Block et al., 1992; Bazzano, 2002; Law and Morris, 1998; Appel, Moore, Obarzanek, and Vollmer, 1997).
Despite long-standing recommendations, three quarters of adults (77% in the U.S. and 72% in New York State) report consuming fewer than the minimum five servings daily (BRFSS 2002). Among children, aged 2 to 5 years, only 32% in the U.S. and in one study, 49% consumed at least 2 servings of fruit, much less than the Healthy People 2010 target of 75 % (Figure 17).
Figure 17:Proportion of persons aged 2 years and older who consume at least 2 daily servings of fruit. (HP Objective 19-5)
Source:Dennison BA, et al. Journal of American College of Nutrition 1998; 17: 371-378; Munoz KA, et al. Pediatrics 1997; 100: 323-329
For vegetables, the findings are even lower. Among 2 to 5 year-old children, 21% in the U.S. and 3% in one NY study consumed 3 servings or more of vegetables (Figure 18).
Figure 18:Proportion of persons aged two years and older who consume at least three daily servings of vegetables, with at least one-third of them being dark green or orange vegetables. (HP Objective 19-6).
Source:Dennison BA, et al. Journal of American College of Nutrition 1998; 17: 371-378; Munoz KA, et al. Pediatrics 1997; 100: 323-329.
National studies indicate that the variety of vegetables and fruits consumed by adults and children is extremely limited, with fried potatoes ranking as the most popular vegetable choice of Americans (Guthrie, 2004). Understanding the individual and household characteristics associated with vegetable and fruit variety may be important because an association has been identified between an increased variety of vegetables and a lower body fat (McCrory, 1999). A U.S. Department of Agriculture analysis of household characteristics and foods purchased showed that the presence of children in a household had a negative impact on variety of vegetables purchased. Households with an older head of household, a higher level of educational attainment, and characteristics associated with preparing meals from scratch were also associated with purchasing a greater variety of vegetables (Stewart, Harris, Guthrie, 2004).
Greenmarket 5-A-Day Partnership
Data reported in the 2002 NYC Community Health Survey showed that only 9.5% of NYC residents consumed five or more servings of fruits and vegetables on a given day. In some areas, the figure was as low as 4.7%. Programs that address barriers, such as availability and cost of produce in larger cities, are clearly needed. To address the issue, the Wellness at Work program developed a partnership with Greenmarket, an organization providing farmers' markets across the city. Program staff developed and distributed promotional kits to the farmers' markets, as well as to mobile fruit and vegetable vendors across the city. The kits contained an apron, produce bags, recipe cards and informational sheets, all branded with the 5-A-Day logo. Roughly 175 boxes were sent out throughout the 5 counties in NYC. In addition, staff canvassed the city and gave out an additional 200 boxes.
This initiative marked the first time the 5-A-Day message and program were promoted throughout NYC by the City Health Department. This program helped make initial efforts to develop a database of local fruit and vegetable vendors, which will facilitate future and continued outreach to these groups. Efforts to assess the effects on fruit and vegetable consumption of this simple promotion and collaboration are ongoing.
Individuals are commonly advised to increase vegetable and fruit consumption as a weight control strategy, although a causal relationship between vegetable and fruit consumption and weight loss has not been demonstrated. Plant foods, being high in fiber and water content and low in calories, promote a sense of fullness, and may therefore make it easier for individuals to avoid excessive caloric intake. Rolls et. al., in a review of intervention studies examining vegetable and fruit consumption and weight control concluded that counseling to increase the consumption of vegetables and fruits coupled with efforts to decrease energy intake may be an effective approach to weight management (Rolls, 2004). The Dietary Guidelines Advisory Committee concluded that increased vegetable and fruit consumption without explicit guidance to lose weight does not lead to weight loss (Report of the 2005 Dietary Guidelines Advisory Committee).
Between 1977 and 1996, portion sizes and energy intake increased for specific foods whether consumed in homes, in restaurants or in fast-food outlets (Nielsen and Popkin, 2003). The progressive increase in portion sizes has been documented by examining the portion sizes commonly sold in ready-to-eat form, and the quantities of food consumers report eating (Young and Nestle, 2002; Smiciklas-Wright, Mitchell et al., 2003). In both cases there has been a notable increase in portion size and consequently in energy consumption. Young and Nestle concluded that marketplace food portions have increased significantly since the 1970s with the promotion of larger portion sizes used as a competitive marketing strategy. The trend toward increasing portion size and the consequent caloric content are significant. With the exception of sliced white bread, food portions, as sold, exceeded, sometimes by several hundred percent, the standard portions used in nutrition labeling (Young and Nestle, 2002). Recent studies examining the impact of portion size on food intake have consistently demonstrated that larger portion sizes lead to increased consumption and higher caloric intake (Diliberti, Bordi et al., 2004; Rolls, Roe, Kral et al., 2004; Rolls, Morris and Roe, 2002; Pearcey and De Castro, 2002; McConahy, Smiciklas-Wright, Mitchell, and Picciano, 2004).
Over the past 25 years, a notable change in the American eating pattern is the increased proportion of individuals of every age consuming sweetened beverages, making sugar-sweetened beverages the principle source of added sugar in the American diet (Guthrie, 2000). This trend, combined with increased portion size and increased servings per day, has resulted in a 135% increase in the caloric contribution of sweetened beverages (Nielsen and Popkin, 2004). Concurrent with the increased intake of sweetened beverages has been a decline in milk consumption, with the largest decrease occurring among youth aged 2 through 18 years. The overall shift in beverage consumption resulted in a net caloric increase of 278 calories per day (Nielsen and Popkin, 2004). Other dietary correlates of high-level sweetened beverage intake include consumption of less fruit and more high-fat vegetables by children (Cullen, Ash, Warneke, and de Moor, 2002). Ludwig and colleagues (2001) observed an association between sweetened beverage consumption and children's weight with each 12-oz. sugared soft drink accounting for a 0.18 kg/m2 increase in BMI and a 60% increase in risk of being obese, associations which were not observed with sugar-free beverages. Because sweetened beverages may displace nutrient-dense foods and beverages, or may be associated with less nutritious food choices, the impact of sweetened beverage consumption on overall diet quality bears examination along with its contribution to increased weight.
Low-fat Milk Promotion
Recent evidence indicates that low-fat dairy products and calcium play a role in preventing overweight and chronic diseases such as hypertension and diabetes. Unfortunately, intake of dairy products has declined over the past 20 years. Eat Well Play Hard (EWPH) demonstration projects in three communities have been successful in working with day care providers and schools to promote low-fat and fat free milk:
Dutchess County EWPH worked with the City of Poughkeepsie School District which began purchasing 1% or fat free milk and discontinued the sale and purchase of whole or 2% milk in all 8 of their schools. In addition, two schools purchased milk machines to replace soda and other non-nutritious beverages. These policies affected 11,500 students.
Erie County conducted a Low Fat Milk Campaign and tracked the purchase inventory of milk over time. Of the 14 schools in the project area, four switched completely to 1% or fat free, affecting over 9,000 students. Additionally through these efforts, the Summer Food Program selected 1% or fat free milk as the milk provided for the 220,000 meals served.
Jefferson County efforts resulted in the Fort Drum Military Base switching to low fat dairy products at the day care centers serving 900 children daily, and the replacement of whole or 2% milk with 1% and fat free milk for the 18,000 meals served during the Summer Food and Nutrition program.
The displacement of milk by sweetened beverages in the diets of children, adolescents, and adults may exert an additional influence on weight other than just its caloric contribution. Inadequate calcium and dairy intake have been associated with obesity and increased adiposity. Studies in both children and adults have shown an association between weight status or adiposity and the intake of calcium and dairy products (Zemel, 2002, 2004; Thompson et al., 2004; Carruth, 2001; Skinner, 2003; Davies, 2000; Lin, 2000). At least one intervention study demonstrated greater weight loss with reduced calorie diets that included calcium from dairy products compared to calcium from supplements (Zemel, 2002). Dietary patterns characterized by increased dairy consumption have also demonstrated beneficial effects on hypertension and insulin resistance syndrome (Appel, 1997; Pereira, 2002).
Energy Density and Dietary Variety Influence Caloric Intake
Two relatively new concepts in understanding energy intake are the energy density of food and dietary variety. Foods low in energy density, which are also typically high in fiber and water content, may play a role in weight management by providing adequate or greater quantities of food while delivering less energy (Rolls, 2000). Many foods with low energy density have also been shown to offer greater satiety by inducing a sense of fullness that discourages subsequent intake (Bell, 1998). Predictors of energy density include water, fiber and fat content, with water content exerting the greatest influence by increasing the weight of food without increasing calories (Rolls, 1999). Both animal and human studies have shown that food consumption is increased when a greater variety of foods are offered compared with offering a single food. McCrosy and colleagues (1999) demonstrated that greater dietary variety was associated with increased energy consumption and increased body fatness for all food groups except fruits and vegetables (McCrosy, 1999).
Food Purchased Away from Home
Approximately half of all household food dollars are now spent at food service facilities outside the home. The U.S. Department of Agriculture estimates that between 1992 and 2002 annual expenditures for food away from home grew by approximately 58%; a trend expected to continue. Over the next 20 years growth in the fast food market will be outstripped by the full-service restaurant sales due to modest increases in household income and an increase in households without live-in children (USDA Stewart Demand for Food Away from Home). Because of increased portion sizes and "value" marketing more calories are likely to be consumed when eating away from home. Restaurant menus offer a wide variety of foods of high energy density in large portions, (McCrory et al., 2000), characteristics associated with increased energy consumption. U.S. Department of Agriculture data show that food prepared away from home accounts for approximately a third of daily caloric intake, but less than 0.5 serving of fruit and 1.25 servings of vegetables (Guthrie, 2004). An examination of children's fast food consumption patterns, using national household survey data, showed that on days when fast food was consumed, children aged 4 through 19 years of age had higher energy intakes and poorer diet quality characterized by more total fat, more added sugars and sugar-sweetened beverages, less milk and fewer fruits and non-starchy vegetables (Bowman et al., 2004). Consumption of food away from home, specifically, consuming quick service food two or more times per week, was associated with increased BMI in adolescent girls (Thompson et al., 2004).
Just Ask Us Restaurant Intervention
In 2002-2003, the Wellness at Work Program implemented a restaurant intervention with two major purposes: 1) to educate the public regarding healthy menu modifications in restaurants, and 2) to incorporate healthy nutrition messages into the curriculum of the Bureau of Food Safety and Community Sanitation. The Bureau of Food Safety and Community Sanitation, within the NYC DOHMH, is responsible for training and certifying all food handlers employed by NYC restaurants. The intervention, "Just Ask Us," aimed to provide restaurant patrons with the option to request basic healthy menu modifications such as sauce or dressing on the side, egg substitutes, and no salt added to their meals. The goal was to provide the consumer with ways to dine out and still maintain a healthy diet. The intervention consisted of two components. For food preparers, the intervention allowed for the incorporation of healthy nutrition guidelines into the city-mandated food protection course required for food preparers. Over 400 food handlers complete this class during any given month. For restaurants, implementation trainings were given to staff and promotional materials (menu labels, server pins, window decals, posters, and comment cards) were distributed. The major proposed outcomes of this intervention were to evaluate whether the availability of healthy options influenced decisions to go to a particular restaurant, whether it increased the likelihood that patrons would ask for menu modifications, and if the servers assisted customers with menu modifications. Although evaluation of the program never occurred due to limited funding, several barriers that were encountered will prove useful for future attempts in implementing the program. For example, finding ways to market the restaurants to increase customer traffic and providing rewards to those vendors that successfully implement the program is essential for long-term participation. In conclusion, the program ensured a community level buy-in to disease prevention by linking mandated training to consumer choice.
Associations between Obesity and Hunger/Food Insecurity
In a society plagued by obesity it is hard to understand that obesity and hunger or household food insecurity co-exist. Hunger is defined as the "uneasy or painful sensation caused by a lack of food." Food insecurity is the "limited or uncertain availability of nutritionally adequate and safe foods" (Bickel, Nord, Price, Hamilton and Cook, 2000). Increased risk of obesity and either food insecurity or hunger is associated with low-income. Multiple examinations of population-based data have revealed an association between food insecurity and obesity among low-income women (Olson, 1999; Adams et al., 2003; MMWR, 2003). Food insecurity was identified as a significant predictor of overweight in women after controlling for confounding variables such as income, occupation, regional influences, and household size (Townsend, 2001). Although a causal relationship has not been established, mechanisms proposed to explain the interrelationship of obesity, poverty and food insecurity include the competing demands of food and household heating fuel during cold weather resulting in reduced food expenditures (Bhattacharya, et al., 2003). Drewnowksi and Specter examined how diet quality, energy density, and energy costs may mediate the relationship between obesity and poverty. The inverse relationship between energy density and energy costs may drive limited resource households toward reliance on highly palatable energy-dense foods including refined grains, added sugars and fats and away from less energy-dense and higher-cost fruits and vegetables. In economic models reducing costs led to high-fat energy dense diets similar to those consumed by low-income households (Drewnowski and Specter, 2004).