Varies with the type
Of food. After consuming a typical solid meal, there is a lag time of 20 to 30 minutes in which there is minimal gastric emptying.
This is followed by a phase in which the rate of emptying is roughly linear. In contrast, liquids are generally transported out of the stomach at an exponential rate.
See this site:http://www.Vivo.Colostate.Edu/hbooks/pathphys/digestion/stomach/emptying.Html.