Snacking increased among U.S. adults between 1977 and 2006.

This study built on limited knowledge about patterns and trends of adult snacking in the US. We selected adults aged 19 y and older (n = 44,754) between 1977-1978 and 2003-2006 with results weighted and adjusted for sample design effects. Differences testing, by a Student's t test, used STATA 10 (P < or = 0.01). We defined a snacking event as intake of foods over a 15-min period and excluded food defined as snacks but eaten at a meal. Dietary data were obtained from the first 2 d for the 1977-1978 Nationwide Food Consumption Survey (NFCS 77) and the 1989-1991 Continuing Survey of Food Intake by Individuals (CSFII 89); and 2-d dietary data from the 1994-1996 CSFII (CSFII 96) and the NHANES from 2 consecutive surveys: NHANES 2003-2004 and NHANES 2005-2006 (NHANES 03-06). Results showed that snacking prevalence increased significantly from 71 to 97% in 2003-2006 with increases in both the 1989-1994 and the 1994-2006 periods. In all adults, snacking occasions increased 0.97 events over this time period (P < 0.01) and the contribution of snacks to total energy intake increased from 18 to 24% (P < 0.01). The energy density of snacks (food plus beverages) also increased progressively over the time period studied. Important changes in snacking food sources were found among desserts, salty snacks, candies, and sweetened beverages. More research is needed to gain a better understanding of the implications for overall energy intake and energy imbalance.