Surprised to see this hasn’t been mentioned before. If somebody did say it and I skipped over it I apologize. So here goes …
I know the OP is in Canada, so this may not be fully applicable to his question / situation.
In the US at least, the price of food and fuel is explicitly NOT included in the Consumer Price Index=CPI. Despite the name “Consumer” in the index and despite the fact, as mentioned by many folks above, that groceries and gasoline are very, very visible parts of individual households’ weekly consumption. And very significant parts of the weekly budget for those for whom money is tight. Which is a vast and shamefully large percentage of our people.
Why this obvious omission? Because those two items have very volatile pricing. If they were included in the CPI at a share appropriate to the spending mix of the very budget-conscious lower middle class we’d see inflation rates jumping around anywhere between WAG -2% to +5% annualized every single month! That data would have so much noise the signal would be obscured.
Better in the experts’ view to leave those out. If, say, oil and hence retail gasoline prices are heading steadily upwards, pretty soon that will feed forward into the prices of lots of other stuff that is included in the CPI basket. Ditto when food and/or fuel prices fall; soon enough that gets reflected in the rest of the basket.
So the CPI does reflect the longer term trend in fuel and food prices in these things albeit with a lag.
Unrelated to the above, this post from earlier in this thread is very insightful and deserves a shout-out:
Thank you Sam.