Size does matter, but at grocery stores it doesn't always give you the whole picture about what you're purchasing. Some food corporations are camouflaging increased grocery prices by putting less product in smaller packages while charging the same price and hoping consumers won't notice.
Suddenly your brand of yogurt doesn't come in 8-ounce cups anymore. It comes in 6-ounce containers. Jodi Beggs, an economics blogger and founder of the Economists Do it With Models website, calls this the "shrink-ray effect," a term borrowed from website The Consumerist, which describes the silent-but-noticeable way products shrink while grocery prices stay the same.
Shoppers should look past the packaging by looking for a "price per unit" label. For example, the label will tell you a jar of peanut butter costs 17 cents per ounce while the jar of peanut butter on the shelf below it costs 15 cents per ounce.
Ellie Kay, author of "The 60-Minute Money Workout," uses packaging as another indicator. Too much of it means you can find a cheaper version with less wrapping.
She advises grocery shoppers to stop buying snack-sized items such as chips, carrots and fruit snacks.
Making your own "snack bags" at home can cost about 30 percent less than buying products with a lot of packaging, "and it's so easy," Kay says.