Quoting from the CRA: "During eligible travel periods in 2018, meal and beverage expenses incurred are deductible at 80%. " Learn more here from the CRA: https://bit.ly/2Ve3BM1
Then follow directives below from TurboTax to help you enter your transport employee expenses.
Where do I claim meal, lodging, and employment expenses as a transport employee? https://turbotax.community.intuit.ca/replies/3266047