Here are the suggested answers to fill in the blanks:

1. A healthy (referring to the adjective form)
2. A then (for the sequence of actions)
3. B while (to indicate the duration)
4. A healthy (as it describes the routine)
5. B about (to indicate excitement regarding something)

So the complete text would read:

"The Thomson family has been trying to eat (1) **healthy** meals for a very long time, but found it difficult to keep it up. Mr and Mrs Thomson work long hours at the hospital and feel exhausted (2) **when** they arrive home. They also have three young children who needed a lot of care. David is eight years old, their daughter - Ann is six and the baby is one. It is difficult for the family to cook healthy meals every day. (3) **For** months, Mrs Thomson has been ordering food during the week, which is delivered after they arrive from work. This is a (4) **healthy** routine, and the Thomsons know this fact very well and have started to worry that their children will get so used to eating fast food; it will be difficult for them to change this habit. For the past two weeks, they have been eating healthy homemade meals and feel very excited (5) **about** it."