The feature 'Recent' shows you the items you've tracked and added to your Diary. This function will it make easier for you to track food you regularly eat as you do not need to enter it again and again but can just choose from a list showing the food you regularly eat. This is an offline function.
In order to find Recent: go to your Diary and choose the meal you would like to track by first clicking on "+" and then choosing the meal in question.
You will then see the Recent section under the search bar on the next page and can track by clicking on the "+" on the item in question.
Additionally, you will find the section Frequent by clicking on the three little dots top right hand. Frequent shows all items that you regularly track.
Please also see this information about the logic behind it.