I also want to know about how to remove items in background without changing bacground and how to add items in that background using GIMP thank you very much for ur help in advance
Broad questions, so broad answers:
Typically you use a "selection" to restrict the effect of your tool to the selected pixels. There are plenty of tools to obtain selections, and it is often easier to obtain the inverse selection (for instance selecting the bowl is easier than selecting the food).
Adding items over the background is not too difficult if you have images that have been taken in similar conditions (light tone and direction). Professional image editors take pictures specifically for that purpose, you'll rarely get a good result using images snatched on the web.
Removing items from the background can be easy (see the
resynthesizeplugin) if the background is a random texture, but here it's a very sharp pattern so you would have to copy it from some other place in the image while adjusting the perspective. It would be easier to remove it entirely (only keep bowl/spoon) and insert a new background (shot with adequate perspective/lighting).