About what percentage of american Jews obey the dietary laws? Are there any polls or surveys on this?
I notice that on shows like “Sienfield” Jewish people eating pork and shellfish with no comment.
are the dietary laws really taken very serious anymore?
Depends. IANAJ, but my understanding is that the Orthodox have always kept the diatary laws (as a generalization, of course. Individual Orthodox undoubtably broke them.) Conservative Judaism (the largest denomination in the US) teaches that the diatary laws are binding, but I’m sure there is wide variation in individual adherance to that teaching. Some Jews only keep kosher at home, some are “semi-kosher” (no pork or shellfish), etc. Reform Judaism officially declared the kashrut (diatary laws) no longer binding. In fact, in the 1870s, the first course served at the first graduating class of Hebrew Union College (the only rabbinical school in the US at the time, and a Reform institution) was shrimp! (The school was embarased and claimed it was an accident.) My understanding is that in recent decades, more and more Reform Jews have come to see the value in traditional Jewish practices, and the keeping of kashrut among Reformed Jews has increased.
Much of this comes from Rabbi Joseph Telushkin’s wonderful 1991 book * Jewish Literacy*, but if I made any errors, I’m sure Zev or Dex will correct me. 
Nope, you seem to have pretty much hit the nail on the head Alan Smithee.
Orthodox Jews, as a general rule, observe the laws of kashrus.
Conservative Jews are supposed to keep the laws of kashrus as well (according to the Conservative position). However, as Alan pointed out (and as was my own experience when my parents were Conservative), many only do so in the home, while eating non-kosher outside the home.
Likewise, Conservative authorities hold of some differences in kashrus than Orthodox Jews. The most famous difference is in the status of the swordfish (Orthodox = not kosher; Conservative [relying a solitary opinion of the Noda B’Yehuda maintaining that it is kosher).
Zev Steinhardt
i unerstand the concept of the kosher laws
what about the milk and meat law…without the time differences is it hard to keep
coffee with milk and a beef sandwich etc
is it related to the caananite baal rite of boiling a kid in its mother’s milk…or is that some made up story.?
To make a long story short, the Talmud derives from the thrice-repeated “Don’t boil a kid…” that cooking, consumption and deriving benefit from meat/milk mixtures are forbidden.
As for the time differences between eating meat and milk, that is largely a matter of local custom, with different Jewish communities observing a wait from as little as one hour to as long as six hours after meat consumption before being allowed to consume dairy.
Zev Steinhardt
cheers zev
iron sharpens iron?
glad of your comments
Zev Steinhardt
OP
All the posts so far have told us about the dietary laws, but nothing about the main thrust of the OP, which is how many keep them. I confess I’m stumped. I can find nothing after about an hour of searching in Google.
I think that it answering the question about what percentage of American Jews keep Kosher is difficult for two reasons. How do you define Kosher and how define American Jews.
There is a large discussion going on among Jews about who should be considered Jewish. The traditional approach is that any person who has a Jewish mother or who has had converted is considered Jewish (though some Jews do not recognize some non-Orthodox conversions). A liberal approach is taken by many Jews (particularly those in the reform movement) that anyone with a Jewish parent (or who has converted) is considered Jewish. Another issue is whether or not to include those who can be considered Jewish by birth (under either definition) but do not practice the religion.
As discussed above, there are levels of dietary observance even among those who keep Kosher in whole or in part.
That all being said, based on my experience in New York, I would estimate that the vast majority of American Jews (defined as those who consider themselves Jewish) do not keep Kosher (defined as consiously trying to eat only food that is considered Kosher by some authority). Of the non-Kosher American Jews, most of them do not have any religious-based dietary restrictions, though a minority refrain from eating pork and/or shellfish for religious reasons. YMMV.
Minor nitpick: Reform Judaism recognizes people as Jews who have only one Jewish parent (regardless of which one) only if the child was brought up with a Jewish upbringing and education.
Zev Steinhardt
Zev,
Does that mean that if a child has a Jewish mother, but was not brought up and educated as Jewish, the Orthodox would recognize the child as Jewish but Reform would consider the child non-Jewish?
[This points out the difficulties of the issue of who is Jewish, which is worth more than a thread of its own.]
That would be correct.
Zev Steinhardt
I’ll see if I can dig up any statistics, but I think they’d be very suspect, for a lot of reasons. Definition of who’s Jewish, for one thing, and definition of what you mean by “kosher” for another.
While Orthodox Jews tend to keep kosher fairly strictly, both in the home and out, Conservative Jews are all over the place. We are Conservative, and we have friends from our synagogue who are very strictly kosher and friends who keep kosher in the home but not when eating out, and then there’s the in-betweens. People who don’t mix meat and milk, but don’t buy kosher meat. People who allow non-kosher food in the house but eat it on paper plates. People who keep strictly kosher on Passover, but not during the year. People who eat shellfish but not pork. And every imaginable grade in between.
So any statistic is going to have a huge order of magnitude of fuzziness. You could make a generalized guess, like 98% of Orthodox affiliated Jews, 40% of Conservative, 2% of Reform, and then work it out and that would probably be as reasonable a guess as any, IMHO.