You know what women in fast-food restaurants do not want to talk about? Calories. That was the lesson recently, out on Court Street in downtown Brooklyn, a busy thoroughfare that resembles the Spice Bazaar in Istanbul, except with fewer spices and more varieties of animal fat and ketchup. There you can find a McDonald s, a Popeyes, a Checkers, a Dunkin Donuts, and in one plaza presumably designed to drum up business for a nearby hospital KFC, Pizza Hut, Nathan s, Tim Hortons, and H agen Dazs.

The question of the day was: Do you pay attention to New York City s recently instituted calorie labels? Required in all fast-food restaurants locally since mid-2008, the calorie labels are set to roll out nationwide in the next few years, as part of President Obama s new health care law despite a lack of evidence that they ll do any good.

It turns out, you see, that people really like food. And their brains will do a lot of gymnastics to justify shoving more pie into its designated hole.

At this point, New Yorkers are familiar with the dark-white on light-gray numbers hidden in the nooks and crannies of fast-food menu boards, with cable-guy-will-be-here estimate ranges such as 490-2,220 (KFC four-piece individual meal), 270-1,030 (H agen Dazs cup/cone), or 1863-1890 (French impressionism). But when asked directly if they pay attention to the counts, the women were not talking. Please, no, said one smartly dressed (and perfectly svelte) older woman sitting down with a hotdog and fries from Nathan s, covering her face as if she d just walked into a Dateline sting.

The men were a bit more forthcoming. Yeah, for the most part, said Ben, 24, client at Popeyes. But sometimes I go by my taste buds. Ben, being a guy, was even willing to hand over his lunch receipt: chicken wrap, apple pie, fries about 960 calories. Ben s taste buds must have ordered dessert.

The question facing health officials is: Can government really overpower Ben s taste buds in the pudding-wrestling match between restraint and indulgence that overtakes his and every American s mind come meal time? Two recent studies of New Yorkers habits before and after the introduction of calorie labeling offer less-than-encouraging results.

One study, out last fall, suggests that people either ignore the labels or use them like teenage boys use the movie and TV rating systems to make sure they ll be getting enough of the good stuff. Researchers from New York University and Yale looked at a sample of 1,156 adults at fast-food restaurants in low-income, minority communities in New York City and compared their habits before and after calorie labeling to similar customers in Newark, N.J., a city that had not instituted calorie labeling. While many people claimed to be paying attention to the new information in New York, the researchers found that there was no change in the amount of calories purchased. In fact, there was even a slight uptick.

the reductions were almost entirely in food ordered (drinks were unaffected); 2) the reductions were greater for patrons from high-income and high-education zip codes, and 3) the reductions disappeared entirely around the holidays.

Starting from the fact that these calorie reductions were tiny to begin with (even if they were consistent at all chain restaurants, they d only add up to about 30 calories a day for the average person), it s particularly disturbing that the effects may be smallest for the people who need to reduce their weight the most: the urban poor. Starbucks has a very different clientele from McDonald's, Burger King, Wendy s and KFC it s probably no coincidence that one clientele responded to health information and the other didn t. (For its part, the National Restaurant Association actually supports the calorie postings on the grounds that they supersede the state patchwork.)

The holiday effect is perhaps even more important. One of the main findings of research into how and why we eat is that we re very good at coming up with excuses to eat more. Exercised today? You re entitled to another helping of cake. The food you re eating is labeled low fat ? Time to wolf down 10 more of whatever it is. Your favorite fast-food place has introduced a salad? A study last year in the Journal of Consumer Research showed that when you see a salad on the menu, you give yourself license to get something more indulgent.

If you were good at Starbucks, in other words, you ll probably be bad later. Our brains find calories rewarding. And we like to do rewarding things.

So, what are policy makers to do? Well, they can start by realizing how people actually tend to take their cues about food.

Seventy-eight-year-old Richard Kersche, who sat alone, savoring a French cruller and coffee from Tim Hortons, summed it up nicely. I don t count calories, to tell the truth, Kersche said. You can eat all kinds of goodies, but if you have too many, you defeat yourself and have to buy new pants.

But how do you know what s too many without help from the New York City Department of Health and Mental Hygiene or the federal government? Says Kersche: I know I ve had too much when I have trouble bending down to tie my shoes.

Ryan Sager writes the blog Neuroworld at TrueSlant.com.