Incentives, time use and BMI: The roles of eating, grazing and goods.

In the 2006-2007 American Time Use Survey and its Eating and Health Module over half of adults report grazing (secondary eating/drinking) on a typical day, with grazing time almost equaling primary eating/drinking time. An economic model predicts that higher wage rates (price of time) will lead to substitution of grazing for primary eating/drinking, especially by raising the number of grazing intervals relative to meals. This prediction is confirmed in these data. Eating meals more frequently is associated with lower BMI and better self-reported health, as is grazing more frequently. Food purchases are positively related to time spent eating-substitution of goods for time is difficult-but are lower when eating time is spread over more meals.