Hi a warm welcome to the site. Yes many variations that go by the name level 3 xx
The framework, nutritional guidance materials and local initiatives will depend on your home nation eg. if you're volunteering in England the framework you'll need to relate requirements to is
EYFS 2014.
Researching healthy lifestyles, food and drink via the framework, your setting's policies & procedures, information gained from a handbook, local and national initiatives will provide you with the knowledge you need to define & explain the importance.
Your nursery will be able to give you copies of their policies regarding the setting's provision for food and can let you know any local initiatives they're involved with.
National initiatives include:
The eat better, start better programme
The school's Fruit and Vegetable scheme
Feeding young imaginations
The Children's food campaign
Cool Milk
Change4Life
The nursery milk scheme
Eat Smart, Play Smart
For links to Wales, Scotland and NI publications please see this page -
UK home nation framework
The
EYE handbook on amazon.co.uk has supportive reading in unit 2
As far as how much to write, after researching your subject thoroughly you'll find you have the ability to respond to the criteria more directly and maybe use fewer words. However the breadth of research could also mean you have a lot of reading/sourcing to conduct so responses will be deeper, if you feel you've covered what's being asked check with your tutor.
Hth, very best wishes with your study