While you can't change who you are (not easily, at least), you can outsmart your inner eater.

How many times have you been skydiving?

Our image of adrenaline junkies usually involves people with the kinds of bodies that look amazing in jumpsuits and wet suits. However, an analysis by the National Institute on Aging (NIA) of more than 50 years of data from almost 2,000 people found that excitement seekers are more likely to be overweight or even obese. That's probably because when they're not jumping out of airplanes, they can always get a small rush by sneaking out for a midday margarita or blowing off the treadmill to go to a rock concert.

Change your behavior: To tip the scales in their favor, excitement seekers don't need to order plain, sauce-less, steamed everything when they go out to eat, says Keri Gans, RD, a nutrition counselor and author of The Small Change Diet. Instead, Gans suggests finding healthier ways to take risks—like ordering your dish punishingly spicy or sharing the most exotic, unpronounceable item on the menu with friends. If you happen to be one of those people who can sneak out of work for a mountain bike ride or a climb (Coloradoans, we're talking to you), go for it. You'll want to keep exercising as you get older, because the NIA study found that compared with other personality types, those with this excitement-seeking trait are vulnerable to greater weight gain over time.

Are you a blurter, an interrupter—excuse me, we weren't finished—or a spur-of-the-moment decider?

It's no surprise that impulsive people are impulsive eaters and thus more likely to be overweight, but it is a bit of a shock to hear how those pounds can add up: The NIA study, which was published in the Journal of Personality and Social Psychology, found that those who scored in the top 10 percent on impulsivity in personality tests weighed an average 22 pounds more than those in the bottom 10 percent.

Change your behavior: Identify the things you're powerless to resist: The office candy jar, the croissants at your local café, the pizza place on the drive home—and then do whatever it takes to avoid temptation, Gans says. Switch up your routine. If this isn't realistic, Gans suggests creating distractions. Find a health-conscious coworker (not another candy junkie) who's leaving the office at the same time you are and strike up a conversation to keep your eyes and mind off the jar of temptations. Or pick up some healthy takeout before you pass the pizza place. Whenever you can, eliminate the opportunity to make last-minute decisions that involve food.

Do you often forget you have plans with a friend...until she calls you from outside the movie theater?

This won't come as a surprise to the frazzled among us: The NIA researchers agreed with other study authors that orderly neatniks tend to be leaner than other people—in their analysis, by about 10 pounds. These are usually the same folks who embrace the structure of diets and are obsessed with counting calories. Then there are the disorganized masses. Gans has many overcommitted clients who tell her they're so busy that they barely eat a thing all day—and they can't understand why they're gaining weight. She helps them recognize unhealthy patterns, like skipping lunch, drinking a beer in a post-meeting debrief and then snacking indiscriminately on whatever's in the fridge at home. That's 150 calories for the beer, 350 for some hummus and crackers, 250 for frozen yogurt, 150 for a cereal bar...and none of it adds up to real satisfaction, Gans says.

Change your behavior: Gans says that the trick for these personality types is getting them to eat even when they think they don't have time. She recommends that they stock their homes and offices with portable, nutritious, filling snacks, so they always have something on hand to prevent them from getting too hungry and making bad choices. Her tried-and-true favorites: 23 almonds or 49 pistachios in individual-serving-size bags, six-packs of yogurt and low-fat string cheese.

Do friends or family members refer to you as "Little Miss Sunshine"?

We know that bringing joy to others can enlarge the spirit, but research seems to say it can also make our hips bigger. The NIA study found a correlation between warmth and gregariousness and a higher BMI—especially in women. Another study published earlier this year in the Journal of Personality and Social Psychology suggested that people with sweet dispositions showed a strong preference for sweet treats. Finally, a study from Case Western Reserve University found that when good-natured people pleasers found themselves in social situations, they were likely to overindulge in foods they’d normally avoid if they believed it would make others feel more comfortable. All of this means that cheerful, sweet people pleasers may face extra weight challenges.

Change your behavior: Good news, sweetheart: Gans says that you won't do any damage by eating an ounce of chocolate a day (that's three chocolate kisses). Really adore sweets? Get creative by microwaving semi-healthy S'mores (substitute half a banana for the marshmallow) or enjoy sundaes with frozen yogurt, fruit and nuts. Share the love by making an extra one for your cubicle-mate. If your healthy eating plans are derailed by a friend who had a bad day and wants to split a pint of ice cream, Gans suggests a different kind of deliciousness: Take her out for a pedicure instead.

It's 2 a.m. Are you a) sleeping b) finishing the book you're reading, the book you're writing or the Hogwarts-shaped cake you made for your kid's birthday?

We know that not getting enough sleep throws off our metabolism, interferes with our ability to know when we're full and causes us to seek comfort and stimulation in fatty, sugary snacks. The obvious solution for the sleep deprived is to get more rest. But night owls who do their best work after hours (and the overextended who need to squeeze in a few more hours of work, sewing kids' costumes or catching up on Mad Men) need to be a little more creative.

Change your behavior: Gans says that the biggest challenge is to recognize when to eat meals and when to stop snacking. She usually sees people putting off eating for most of the day because they're not hungry at normal meal times and then taking part in an all-night snack-a-thon. She recommends three regular meals, starting with breakfast every morning—even if your morning is 11 a.m. and you're not starving, have a granola bar, a cup of yogurt or a piece of fruit. Don't worry about eating dinner later than other people, she says, because it's not when but how much you eat that determines weight gain. If you know you're going to be up for a while after your last meal, double up on fiber (whole wheat pasta, barley, legumes), which will help you stay full.