What is happening to food and good in American English?

[cbutter2]

For 70 years I have pronounced "food" in a manner rhyming it with crude, lewd, mood. I have begun noticing television commercials as if the word food rhymed with good, could, wood. At the same time, these commercials pronounce "good" as if it rhymed with mud or bud. Is there a vowel shift going on here? I have lived in a variety of regions of the US, but if I ever heard anyone pronounce these words as they do in the commercials. I'm looking for enlightenment. What do I teach my students?

[Skrej]

Interesting. I don't watch TV, so I can't say I've noticed the bit about advertisements. I haven't heard any native speakers do this in person.

My language learners of course frequently mix up those vowels, but I can't say I've heard it from native speakers. I'd like to hear some examples.

Any chance it's just sounding off because they're singing a jingle or some such?

[Tdol]

If it is confined to a few adverts, teach what most people use. If the situation changes, teach what the majority use. McDonald's I'm loving it slogan did have a small amount of crossover, but the form is still far from standard. I doubt it is taught much outside a recognition that it was used in an advertising campaign.

[emsr2d2]

Many TV adverts are available online these days. Could you see if you could find and post some YouTube links to a couple of these ads so we can hear the pronunciation of "food" in them?

[probus]

I have never heard these pronunciations, although I am currently living in the US and watching a lot of American TV these days. I doubt that they are a significant trend.

[Tdol]

They haven't reached CNN, which is my source for AmE pronunciation as it's what I get here.

[andrewg927]

If it is confined to a few adverts, teach what most people use. If the situation changes, teach what the majority use. McDonald's I'm loving it slogan did have a small amount of crossover, but the form is still far from standard. I doubt it is taught much outside a recognition that it was used in an advertising campaign.

Or Colonel Sanders' "Finger lickin' good." Though I can't quite explain whether that phrase is grammatical.

[Piscean]

A reminder of the original question:

I have begun noticing television commercials as if the word food rhymed with good, could, wood. At the same time, these commercials pronounce "good" as if it rhymed with mud or bud. Is there a vowel shift going on here? I have lived in a variety of regions of the US, but if I ever heard anyone pronounce these words as they do in the commercials. I'm looking for enlightenment. What do I teach my students?

[emsr2d2]

I would teach my students my standard, generally-accepted pronunciation (bearing in mind there are some regional differences between the definition of "standard"). For me, that means teaching them "food" with the long "oooo" sound in the middle. I would make sure that they know that it does not rhyme with "good". Bear in mind, though, that I teach BrE pronunciation.

[Tdol]

I wondered if people from outside the US are still interested in what CNN has to say.

I was describing it as a source of how things are said.