Has snacking by adults changed in the past 30 years?

Yes. Between 1977-1978 and 2007-2008, significant increases (p<0.01) have occurred in both the mean frequency of snacking (up from 1.0 to 2.2 snacks in a day) and the percentage of adults snacking on any given day (up from 59 percent to 90 percent), as shown in figure 1. On any given day in 1977-1978, most adults (73 percent) snacked only once or not at all. In 2007-2008, about two-thirds of adults (65 percent) snacked two or more times in a day.

Figure 1

Percentages of adults age 20 years and over consuming specified number of snacks in a day, 1977-78 and 2007-2008. NOTE: Due to a change in collection of water intake data, this time comparison excludes occasions that were identified as a “snack” (more...)

How many calories do adults obtain from snacks in a day?

Based on the WWEIA 2007-2008 survey, foods and beverages consumed at snacking occasions now contribute a daily average of 586 calories for men and 421 calories for women. Adults age 60 years and over consume fewer calories overall, and calories consumed at snacking occasions are lower for people in this age group than for younger groups (see figure 2). In addition, the proportion of daily calories provided by snacks is significantly smaller for older women (but not men) than for their younger counterparts (p<.01).

Figure 2

Mean calorie intake in a day from snacks and other eating occasions, adults, by age group, WWEIA, NHANES 2007-2008.

What proportion of adults’ daily calorie intakes come from snacks?

On average, 24 percent of adults’ total daily calories are consumed at snacking occasions. However, for some individuals, snacks provide a substantially larger proportion of daily calorie intake. Nearly 1 in 6 adults (16 percent) obtain over 40 percent of their total daily calories from foods and beverage they report as being consumed as snacks (see table 1).

Table 1

Percentages of adults age 20 years and over with specified level of total calorie intake from snacks, WWEIA, NHANES 2007-2008.

How much of their daily intake of nutrients and other food components do adults obtain from snacks?

Relative to their caloric contribution (marked by line X in figure 3 below), snacks provide higher proportions of adults’ daily intakes of alcohol, carbohydrate, and total sugars (a subgroup of carbohydrate); similar proportions of vitamin C, vitamin E, calcium, and magnesium; and lower proportions of most other nutrients.

Figure 3

Snacks’ contributions to intakes of nutrients and other food components by adults age 20 years and over, WWEIA, NHANES 2007-2008. NOTES: Line X marks the proportion of total energy, or calories, that snacks provide. Bars that extend beyond line (more...)

Is higher snacking frequency associated with higher total calorie intake?

Yes. Higher snacking frequency is associated with higher total calorie intake, as shown in figure 4. Adults who have 4 or more snacks in a day consume almost one and one-half times as many calories as do adults who report no snacks.

Figure 4

Mean calorie intake by snacking frequency, adults 20 years of age and older, WWEIA, NHANES 2007-2008. NOTES: Adjusted to remove the effects of age, race/ethnicity, percentage of poverty threshold, presence/absence of three-meal pattern, physical activity, (more...)

Does mean daily snacking frequency differ by weight status?

No. The mean number of snacks consumed in a day does not differ significantly by weight status (see definition on page 6) for either men or women (see figure 5).

Figure 5

Mean snacking frequency by weight status, adults 20 years of age and older, WWEIA, NHANES 2007-2008. NOTES: Adjusted to remove the effects of race/ethnicity, percentage of poverty threshold, presence/absence of three-meal pattern, and physical activity (more...)

What foods and beverages contribute the most calories at snacks?

Together, the food groupings listed in table 2 below account for approximately three-fourths of the total calories consumed at snacks by men and women age 20 years and older. Some of these food groups are good sources of nutrients – for example, milk and milk drinks, nuts and seeds, and fruits and fruit juices. However, many of adults’ food and beverage choices at snacks are energy-dense (high in fat and/or sugars) but nutrient-poor.

Table 2

Contribution of selected foods and beverages to total snack calories, WWEIA, NHANES 2007-2008.

Definitions

BMI (body mass index)

Based on an individual’s height and weight, this number is a reliable indicator of body fatness for most people (8). Calculated by dividing a person’s weight (in kilograms) by the square of his/her height (in meters). The equation for calculating BMI based on weight in pounds and height in inches is the following: weight (lb) / [height (in)]² × 703

Poverty thresholds

Percentage of poverty level is based on family income, family size, and composition using U.S. Census Bureau poverty thresholds. The poverty threshold categories are related to Federal Nutrition Assistance Programs. See www.fns.usda.gov.

Snack, snacking occasion

Snacking occasions were reported as distinct eating occasions during the dietary interview and consisted of one or more food and beverage items, including plain water. Survey respondents selected the name of all eating occasions from a fixed list that was provided during the interview. All reports of “snack,” “drink,” or “extended consumption” (items that were consumed over a long period of time) were included as snacking occasions. Spanish language interviewers used Spanish language snacking occasion names: “merienda,” “entre comida,” “bocadillo,” “tentempie,” and “bebida.” Water was the only item reported for approximately 23 percent of snacking occasions. Because of a change in the method of collecting data on water consumption, it is not possible to include water-only occasions in the time comparison of snacking frequency between 1977-1978 and 2007-2008, but such occasions were included in all other analyses.

Three-meal pattern

This pattern was present when an individual’s dietary intake included at least one eating occasion from each of three categories (including both English and equivalent Spanish names for these meals): (1) breakfast, desayuno, or almuerzo; (2) lunch, brunch, or comida; and (3) dinner, supper, or cena.

Weight status

Adults were assigned to weight status categories based upon their calculated body mass index (BMI; see definition above). As defined by the National Institutes of Health (9), weight status categories and their associated BMI ranges are the following: Underweight, <18.5; normal weight, 18.5-24.9; overweight, 25.0-29.9; and obese, 30.0 and over.

Data Source

Estimates in this report are based on one day of dietary intake data collected in What We Eat in America (WWEIA), the dietary intake interview component of the National Health and Nutrition Examination Survey (NHANES), in 2007-2008. A total of 5,420 men and women age 20 years and older provided complete and reliable dietary intake data. Pregnant and lactating females (n=86) were excluded, yielding a final sample of 5,334 adults (2,662 males and 2,672 females). Results presented for 1977-78 are based on Nationwide Food Consumption Survey data from 16,683 adults (6,963 males and 9,720 females). Sample weights were applied in all analyses to produce nationally representative estimates.

During the 24-hour dietary recall, the name of each eating occasion was reported by the respondent. Nutrient intakes were based only on intakes of foods and beverages and do not include nutrient contributions from supplements.

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