Step-by-step explanation:
(a) fast foods/their/making/children/are/staple diet
children are making fast foods their staple diet .
(b) causing/is/among/a great alarm/health experts/it
It is causing a great alarm among health experts .
(c) need/that/get/healthy food/welto ensure/our children
We need to ensure that our children get healthy food.
The words from the question are jumbled and with their proper connection, they will create meaningful sentences.
With this rearranged sentences we are having issues about the problem with children and fast food that they are eating.