Food prices have hit the highest annual increase in almost 20 years, and they're expected to go even higher. Here are some insider tips on how to spot real bargains and keep your grocery bill under control.

A supermarket flier can be a good starting point for bargains, but Tod Marks of Consumer Reports says you have to know how to spot genuine sale items.

He says while supermarket fliers are powerful selling tools, you have to be weary about what they are advertising.

"The items featured prominently on the front page are almost always on sale, but you've got to be really careful about the prices of goods on the interior pages," he warned.

"That's because manufacturers sometimes simply pay for the privilege of advertising, and there's no sale price involved."

Here's how to navigate to save: Don't assume items at the end of aisles are always on sale. They're put there to get shoppers to buy more of them.

And while single-serving packages are usually more expensive, keep in mind that buying bigger quantities isn't always cheaper.

In fact, a study showed that 25 per cent of the time, the smaller size actually cost less.

Let's take tuna fish for example. The larger size cost $5.05 a pound, but the smaller size actually cost only $4.25 cents a pound.

And depending on where you find an item, it can cost more or less. For example, cheese at the deli counter might be pricier than cheese in the dairy case one-week, then less expensive the next.

"You'll almost always pay more for convenience," said Marks.

For example, Marks showed CTV a watermelon that costs 99 cents a pound, versus $2.99 for the previously already cut variety.

Try to use a preferred-shopper store card in order to get discounts automatically, no coupons needed. With the cost of food going up and up and up, a little extra effort could take your food dollars a lot further.

Stores often have savings coupons right in the aisles ready for the taking, that can save you money in addition to sale prices or discounts for cardholders.

With a report from CTV British Columbia's Chris Olsen