What is the relationship between snacking and nutrient intake?

A limited body of evidence supports a positive relationship between snacking and nutrient intakes in children, adolescents, adults and older adults.

Evidence Summary Overview

This conclusion is based on the review of seven studies, three of which include children or adolescents (Macdiarmid et al, 2009; Maffeis et al, 2008; Sebastian et al, 2007) and four of which examine adults or older adults (Kerver et al, 2006; Ovaskainen et al, 2006; Stockman et al, 2005; Zizza et al, 2007). Not all nutrients are evaluated in all studies. In general, snacking is associated with higher intakes of macronutrients and dietary folate, vitamin C, calcium, magnesium, iron, potassium, and dietary fiber as well as total sugars and saturated fatty acids. Snacking by some adolescents and adults is associated with lower intakes of protein, fat, cholesterol, and iron, however

Evidence summary paragraphs (7):

Kerver et al, 2006 (positive quality), conducted a cross-sectional study to test the hypothesis that specific meal and snack patterns are associated with selected nutrient intakes in 15,978 US adults (≥20 years old). Using the 24-hour dietary recall from the Third National Health and Nutrition Examination Survey (NHANES), meal and snack patterns were described in relation to nutrient intakes. Meal patterns were further categorized into five most commonly reported meal and snack combinations by population percentages of breakfast (B), lunch (L), dinner (D) and snacks (S). The majority of subjects reported consuming two or more snacks (62.3%), while 25.2% of the population reported consuming one snack, and 12.5% reported consuming no snacks. Those reporting no snacks consumed the least amount of protein and total fat. Those consuming B, L, D, and ≥2 S had the highest energy and carbohydrate (CHO) and lowest fat intakes. The groups reporting B, L, D, and 1 S and B, L, D, and ≥ 2 S had the highest intakes of all micronutrients [folic acid (322±4.69ug), vitamin C (116±3.12mg), calcium (942±13.5mg), magnesium (339±3.01mg), iron (17.5±0.29mg), potassium (3,177±23.4mg), and fiber (18.6±0.2g)], except cholesterol, vitamin B₆, and sodium, which were consumed in the highest amounts by the B, L, D, group (cholesterol=323±10.2mg; vitamin B₆=2.10±0.05mg; and sodium=3,946±48.4mg). These findings suggest that meal and snack patterns may be markers for nutrient intakes and therefore diet quality.

Macdiarmid et al, 2009 (positive quality), used cross-sectional data (N=156) from the National Survey of Sugar Intake among children in Scotland to investigate the meal and snacking patterns of school-aged children (five-17 years old). Meals and snacks were defined by a food-based classification system based on “core” (foods normally eating as part of a traditional meal) and “non core” (foods and drinks easily consumed without a meal). A meal was defined as an event containing one or more “core” foods with or without “non-core” foods or drinks, while a snack was defined as an event containing only “non core” foods or drinks. Seventy-eight percent of children had an average of between 2.5 and 3.5 meals per day and 98% of children ate one or more snacks. Boys ate similar number of snacks than girls, and children in the lowest socio-economic group ate fewer snacks than those in the highest socio-economic group. The number of meals and snacks eaten did not differ by age or body mass index (BMI) group. The median (inter-quartile range) number of items eaten within a snacking event was two (one to two) and in a meal was four (three to five) items two (one to two) “core” and two (one to three) “non-core”items. The average daily intake of saturated fatty acid (SFA) and non-milk extrinsic sugars (NMES) (% food energy) was higher from snacks than meals, but there was no difference in total fat. Snacks accounted for approximately a fifth of the total daily energy intake and total fat intake, a quarter of SFA intake and almost 40% of NMES intake. The only difference by sex, age, BMI, and SIMD group was that girls derived a higher proportion of their daily intake of total fat from snacks than boys: 19.8(17.0-22.5) for boys, and 23.7 (21.0-26.3) for girls. To investigate whether the number of snacks eaten was related to nutrient intake, children were grouped as infrequent (average of less than two snacks per day) or frequent snackers (average of more than two snacks per day). Frequent snackers had a higher daily intake of NMES (% food energy), but there was no statistical difference (SD) in percentage food energy from SFA or total fat, or total daily energy intake. Frequent snackers had more total eating events per day and fewer meals than infrequent snackers. The proportion of subjects eating breakfast did not differ between snacker groups. The number of meals, snacks and total eating events per day and daily energy and nutrient intake (total fat, SFA and NMES) on weekdays did not differ between term-time and school holidays. The number of snacks eaten on weekdays and weekend days did not differ significantly. In conclusion, children tended to follow a traditional pattern of three meals a day, which was consistent between age and BMI subgroups and between term-time and holidays.

Maffeis et al, 2008 (positive quality), conducted a prospective study to assess the type and number of snacks consumed weekly by a sample (N=1,837) of 8- to 10-year-old children from Italy. A questionnaire on the frequency of a child’s snacking (food and drink) weekly was filled out by a pediatrician. Energy and nutrient intakes were calculated by multiplying the frequency of weekly consumption by the nutrient composition of the portion size for each specific snack listed. Children consumed on average four snacks per day [mean values (SE) were: boys: 3.9 (0.07); girls: 3.8 (0.07), P¼0.27]. The favorite snacks were: Fruit juice, fruit, bread with cold cuts, milk, tea, soft drinks, brioche, crackers, yogurt, bread, and cookies. Children preferred salty snacks to sweet snacks; they consumed 8.4 (0.16) servings per week of savory snacks vs. 7.2 (0.13) servings per week of sweet snacks (P<0.001). Energy intake and macronutrient composition was not statistically different between boys and girls. Macronutrient composition of snack serving was: 8.3 (0.1)% of protein, 64 (0.28)% of CHO, and 27.7 (0.25)% of fat from total energy.

Ovaskainen et al, 2006 (positive quality), used a random sample from a cross-sectional population survey (FINRISK 2002) in Finland, to assess prominence of snacks in energy intake. Dietary data were collected for 2,007 adults by using a computer-assisted 48-hour dietary recall in the national FINDIET. The interviewer selected the meal name from the following alternatives: breakfast, lunch, dinner, drink, evening snack, other snack and other eating event. To simplify the variety of meal, meal type was divided into two categories: main meals and snacks. Daily energy was mostly derived from main meals comprising traditional mixed dishes, milk and bread. However, a snack-dominating meal pattern was observed in 19% of men and 24% of women. This meal pattern was associated with urbanization in both genders and with physical work in men. Higher sucrose intake and lower intake of micronutrients (not statistically different) were typical of the snack-dominating meal pattern compared to the others. In this population sodium content of the diet was lower for those with a snack-dominating meal pattern than the main-meal dominating diet group.

Sebastian et al, 2007 (positive quality), conducted a cross-sectional study to determine how snacking level impacts intake of nutrients and food groups. Dietary data based on 24-hour recall from 4,357 adolescents, 12 to 19 years of age participating in the NHANES 2001-2004 were analyzed. Food energy, CHO, total sugars, and vitamin C intake were positively associated, whereas protein and fat intake were negatively associated, with snacking frequency. Fruit intake increased, whereas solid fat intake decreased, as snacking incidence rose. Increasing snacking frequency was also associated with a greater likelihood of meeting milk and oil recommendations for boys and meeting fruit recommendations for both genders. Non-Hispanic black adolescents were less likely to meet their milk recommendations at low and high snacking levels and more likely to meet their fruit recommendations at high levels only. Foods consumed as snacks provided 12-39% of the day’s total number of portions of the five MyPyramid food groups, 35% of total discretionary calorie intake, and 43% of total added sugar intake.

Stockman et al, 2005 (positive quality), conducted a retrospective cohort study to determine and compare the distribution of energy and nutrient intakes among meals and snacks, and related eating occasion frequency to the BMI of 180 healthy adolescents males (14 to 18 years old) recruited from local school and community groups in Canada. Anthropometric information and 24-hour dietary recall on three consecutive days, including two weekdays and one weekend day, were evaluated. Also, subjects were instructed to self-report the type of every eating occasion, such as breakfast, lunch, dinner, and snacks. Snacks tended to contribute fewer nutrients than meals; however, only cholesterol and iron intakes were statistically lower at snacks relative to all meals. Overall, the average daily number of snacks consumed was 1.63, with 77% of subjects consuming an average of at least one snack per day.

Zizza et al, 2007 (positive quality), used cross-sectional data from the NHANES 1999-2002 to compare the diets of snackers and nonsnackers, and to evaluate the influence of snacking on energy intakes and energy density in older adults. This study included 2,002 adults aged 65 years and older, and one day 24-hour dietary data was analyzed to classify eating occasions. The prevalence of snacking was high (84%) among this age group, and snackers had significantly higher daily intakes of energy, protein, CHO, and total fat. Alcohol intakes were not significantly different. In this population, snacks contributed almost a quarter of the energy and CHO intakes and a fifth of the daily fat intake. Also, snacking contributed 14% of daily protein intakes. Snackers had, on average, two and a half snacking occasions per day, with each snacking occasion contributing 150kcal. The average energy contribution of meals was not different between snackers and nonsnackers. The energy density of meals is significantly greater for snackers than for non-snackers. In conclusion, results from this study demonstrate that snacking is an important dietary behavior among older adults.