Answer:
What needs colons.
1. During exam season, both your anxiety levels and academic performance are influenced by: what you consume.
The colon above is not needed.
2. Jimmy Cole, a professional dietician, says "Your focus should be on high nutrient foods that will provide you with a continuous source of energy over the whole day." "Try to eat porridge and wholemeal toast for breakfast," says Cole: "as these will help to prevent spikes in both your mood and your blood sugar levels."
The colon above is not needed.
3. "In addition," says Cole, "berries of all colours are: awesome.
The colon above is not needed.
You can juice them, make smoothies or jam from them, or just sling them into a salad or a bowl of porridge. Whatever works!"
Explanation:
All the colons used in the passage are not required. The grammatical rule is that a colon comes before an explanation or a list. By the way, a colon is a punctuation mark. For example, one can write thus: "Nutritious Diets before Examinations:" This will then be followed by the list of nutritious diets, with examples to buttress the point. I even used one to list the example I am giving.