Oh, I see now. You did give the relevant context, but you didn't put quotation marks around it, so I didn't recognize it as a quotation. A transcript of the talk is here. The key words you missed are the next sentence, "Not really." The Olive Garden is an Italian-style restaurant that is not "really" Italian. He is "Jewish" in a vague sense, but "not really" Jewish. https://www.ted.com/talks/aj_jacobs_how_healthy_living_nearly_killed_me/transcript "As I mentioned last year, I grew up with no religion at all. I'm Jewish, but I'm Jewish in the same way the Olive Garden is Italian. (Laughter) Not really. " The meaning is clear to a U.S. native. In the United States, there are "authentic" ethnic restaurants. A "real Italian" restaurant might be run people who grew up in Italy, know the cuisine, shop for special kinds of vegetables you can't get in supermarkets... and serve food that might not be to U.S. taste. Then, there are other restaurants, like The Olive Garden, that serve food that is "American food that is somewhat in the style of Italian cuisine." In the United States, there are people who call themselves "Jewish" to whom "Jewish" is primarily a cultural and ethnic identity. Perhaps all their grandparents were "observant Jews." They kept the kosher dietary laws, had two separate sets of dishes for milk and meat, went to "Temple" (or "shul" or "synagogue") every Saturday, didn't use electricity during the high holidays, and so forth. They themselves might never have had a "bar mitzvah" (coming of age ritual), might not attend religious services, eat pork and shellfish (prohibited in Jewish dietary law), might say "I have no religion"--and yet would still call themselves "Jewish." And of course there are people who are in between--"Jews" who only attend Temple on the high holy days, as a celebration of pride in heritage rather than a deeply felt religious observance.

It would help if we had the context, or a link to the full passage. In the United States, "The Olive Garden" is a chain of eight hundred restaurants, often in malls, which Wikipedia describes (accurately) as "an American casual dining restaurant chain specializing in Italian-American cuisine." If people were driving around in a mall, looking for someplace to eat, and someone didn't know what "The Olive Garden" was, you might imagine a conversation like this: "So, what kind of food do you feel like?" "Oh, I don't know. Mexican. Chinese. Thai." "Hmmm... Five Guys is hamburgers. Taco Bell is Mexican." "Oh, god no. I hate Taco Bell." "The Olive Garden..." "What's 'The Olive Garden?'" "The Olive Garden is Italian. Not bad. Good prices. Big portions. Oh, wait, over there, 'Mio Posto Ristorante,' that might be more authentic..." "No, that sounds pricey. The Olive Garden is good enough." "Italian-American" means it serves food that is somewhat in the tradition of Italian cuisine but concentrates on familiar, Americanized dishes that everyone knows: spaghetti, ravioli, "chicken parm" (chicken parmesan). The menu would be in English, not Italian.

It's not an authentic Italian menu, so it shouldn't be looked at as a reference for what Italian food is truly like, while sort of fitting mostly within the Italian label more than in others. In the same way, that guy says he isn't a model of Jewish identity, while sort of fitting mostly within the Jewish culture more than in others.