Synonyms in Task 1 are a lot less important than they are in Task 2.
In Task 1, it is often impossible to avoid repeating keywords, so don't try to use obscure synonyms that will lose points.
Instead of looking for a synonym for 'eat' and 'consume', it's better to use the same word but in a different form. For examples:
'The charts give information about the diet of two groups of students.'
- The charts show how much junk food two groups of students ate over a 3-year period.
- We can see that students consumed a lot of pizzas during term time.
- It is clear that a lot of pizzas were eaten after midnight.
- The number of pizzas consumed at lunchtime increased during the exam period.
- The consumption of pizzas increased as final exams approached.
REMEMBER - not all synonyms work in all contexts. In this example,
- Students are not the same as pupils.
- Diet is not the same as nutrition.
- Illness is not the same as disease.
- Fruit and vegetables are not organic food.
- A cluster is not the same as a group.
- Ingest is not the same as eat.