In New York City, chain restaurants are now officially required to post calorie counts for the items on their menu boards. I wrote before about the reaction to this when it went into effect, and now violators are being cited, albeit with no real penalties until the summer.

It will be interesting to see if the news that Jamba Juice's 16-ounce Mango Peach Topper smoothie with granola contains 500 calories affects the number of people ordering it for breakfast. In the meantime, nutrition experts (and the restaurant industry, which is still fighting the NYC regulations) have other ideas about how restaurants could encourage diners to make more healthful food choices. Here are a few of them:

People who have survived cancer and are dealing with side effects of treatment, financial worries, and psychological issues surely have other things on their mind than whether or not they're eating enough fruits and vegetables. So it's not terribly shocking that cancer survivors aren't doing much better than the general population at staying at a healthy weight, getting enough exercise, avoiding tobacco use, and eating a healthful diet.

In fact, new information from the American Cancer Society shows that only about 1 in 20 survivors is meeting all three lifestyle recommendations: accumulating 150 minutes of moderate or 60 minutes of vigorous exercise a week, eating five servings of fruits and vegetables every day, and eschewing tobacco. This isn't just an American problem; last week, a study in Cancer revealed that fewer than 22 percent of Canadian cancer survivors were physically active, while more than 18 percent were obese.

There's been a lot of debate over the past several years about whether you can be both fit and fat. That is, can you be overweight but as healthy as a lean person if you exercise regularly? A study released today in the Archives of Internal Medicine suggests that at least as far as heart disease in women goes, body weight and exercise are both important variables.

The discussion is complicated by the fact that the body mass index, the number researchers typically use to gauge overweight and obesity, is not always a perfect measure of body fatness. On one hand, because it simply relates weight to height, it may put musclebound but lean athletes into the "overweight" category. (Here's a study looking at its use in college athletes and nonathletes.) And as I wrote earlier this month, a low BMI may give some thin people a false sense of security, even though their percentage of body fat is high.

My friend was taken aback when she went to her local Starbucks in New York City for breakfast this week. According to the newly posted calorie counts on the menu, the scone she usually gets clocks in at more than 500 calories. She's now switching to a banana for breakfast.

The city has been embroiled in an ongoing legal battle with the New York State Restaurant Association about posting calorie counts in fast food restaurants. (See a collection of posts about the court case and the broader issue by NYU nutrition professor Marion Nestle here.)

Last week's issue of Us Weekly (yes, I subscribe) reported that Mariah Carey dropped 20 pounds by following a diet prescribed by her trainer/nutritionist. One key, the magazine said: a ban on eating carbohydrates and protein in the same meal, on the theory that because these nutrients are absorbed differently in the gut, eating them separately is more efficient and promotes greater weight loss than eating a more balanced meal.

I thought that Mariah probably lost the pounds because her diet (which actually looked pretty good—lots of fruit, veggies, lean protein, and good fats) provided only about 1,000 to 1,500 calories a day, not because the carbs and protein were allowed to schuss through the digestive tract without the benefit of each other's company. But I called nutritionists to find out if there was anything to the idea of separating nutrients by meal (which is actually an old one; William Howard Hay popularized the concept in the U.S. in the early 20th century).

When I'm in a blue funk, going for a run helps me feel a lot better. And prolonged periods of inactivity—say, after a big race—make me anxious, and something close to depressed. There are certainly a host of reasons why exercise seems to improve my mood (the Justin Timberlake on my iPod and the view from the Brooklyn Bridge, for example), but one potential factor is the idea, supported by a growing body of research, that physical exertion itself has a much bigger influence on the brain than previously thought. Just this week, a survey of existing research published by the Cochrane Library concluded that the same aerobic exercise that is good for your heart also improves cognitive function—specifically, motor function, auditory attention, and memory—in healthy older adults.

That's only one piece of what has become a burgeoning field. In Spark: The Revolutionary New Science of Exercise and the Brain, published earlier this year, psychiatrist John Ratey explores the neuroscience behind potential beneficial effects of aerobic exercise on anxiety, stress, depression, learning, aging, and even attention deficit disorder. (Research hasn't as fully explored the effects of anaerobic exercise or more passive activities like stretching and yoga.) "Even people who are overweight and who start exercising see improvements in mood and cognition in as little as 12 weeks," he says. One study found that exercise improved depression symptoms as well as medication.

A new poll published by Vegetarian Times finds that 3.2 percent of American adults say they're vegetarians. That's slightly up from a 2006 poll, when the number was 2.3 percent. (Both polls were conducted by Harris but on behalf of different organizations). The new poll also finds that about 10 percent of U.S. adults say they follow a "vegetarian inclined" diet. Those folks are also called flexitarians; they mostly eat veggies and plant protein but allow a little meat to cross their plates now and then. (Here's more info on flexitarian eating.)

People who avoid meat largely or in part because of concerns about animal welfare are probably not flexitarians, since that principle is pretty absolutist (thou shalt not kill and all that). But if you're primarily concerned about your own health, being a flexitarian is a great option; research has shown that nutrition is not an all-or-nothing proposition. The study out this week about the DASH diet shows that the closer you stick to an eating pattern that emphasizes fruits, veggies, whole grains, low-fat dairy, and nuts and legumes and goes lighter on red and processed meat, sweetened drinks, and sodium, the better off you are. Yes, the 20 percent of study participants who stuck most closely to the DASH diet saw the most benefits, but those in the 40th to 80th percentiles also saw their risk of heart disease drop. So you can have your occasional burger and your health, too.