10 Healthy Habits of the 'Naturally' Thin

Anna Medaris Miller

No fair.

We all know the type: the slender colleague who's never known a love handle, the childhood friend who's still rocking her high school pants size, the fit neighbor who just doesn't get your weight-control struggles. While genes, income, health conditions and a host of other factors help dictate who joins the ranks of the two-thirds of Americans who are overweight or obese, even for part of their lives, the folks who don't slide into those categories share some common healthy habits that anyone can steal. U.S. News asked them -- and the researchers who study them -- their secrets. Here's what they said:

1. They don't diet.

At Cornell University's Food and Brand Lab, researchers compared people who stay "mindlessly slim" to those who've also maintained healthy weights, but more rigidly. (Notably, the vast majority of the lifetime-healthy-weighters were of the mindless variety.) One of the biggest differences? The folks for whom slimness comes easy don't diet. "Oftentimes, people associate thinness with strict diet," says lead researcher Anna-Leena Vuorinen, a research scientist at VTT Technical Research Centre of Finland and former visiting scholar at the Food and Brand Lab. "However, highly restrictive behaviors are neither effective nor sustained long-term." They're also linked to food cravings, binge eating and some eating disorder symptoms -- not successful weight loss, she adds.

2. They listen to their bodies.

If they don't diet, what do they do? They eat when they're hungry. Fancy that! According to the Food and Brand Lab's findings, 23 percent of people who are mindlessly slim reported listening to "inner cues" as a top weight-control strategy, while only 3 percent of rigid dieters did. Ashleigh Dixon, a 25-year-old communications professional in the District of Columbia, counts herself among the slim-with-apparent-ease crowd. "I pay attention to my diet," she says, "but I do not obsess over it."

3. They eat real food.

For meals, Dixon sticks to lean meats such as chicken, turkey and fish. For snacks, it's usually whole foods such as strawberries or nuts. "I ensure I have a good balance of all the major food groups," she says. Mindlessly slim folks in the Food and Brand Lab's registry also seem to value real food: Fifteen percent reported eating high-quality, unprocessed foods as a top strategy to control weight, while only 3 percent of stricter dieters did. "Eat as many fresh fruits and vegetables as you can throughout the day," advises Melissa Buches, a naturopathic physician in Seattle who weighs the same now at age 47 as she did at 17.

4. They cook.

Home-cooking proved to be another big difference between the mindlessly slim and the rigidly so: Nineteen percent of the former reported using this strategy as a top way to control weight, while none of the latter did. Indeed, other research out of the Johns Hopkins Bloomberg School of Public Health has found that people who cook at home six or seven nights a week eat healthier and consume fewer calories than those less acquainted with their kitchens.

5. They dine out in good conscience.

Even when home chefs leave their kitchens to eat out, they consume fewer calories and avoid fast food more than frequent out-of-the-house diners, the Johns Hopkins study found. For Chris Tucker, a 54-year-old in the District of Columbia whose weight has stayed within a 10-pound range for more than 20 years, that means choosing the second-most healthy menu item. "That way," he says, "you don't feel deprived but you can feel great about avoiding high-calorie foods."

6. They eat breakfast.

Whether people who are slim for life do so with or without effort, nearly all of them -- a whopping 96 percent -- believe in breakfast, the Food and Brand Lab has found. "Skipping breakfast may lead to overeating and weight gain," says Vuorinen, noting that most participants reported loading up on fruit, vegetables and dairy products in the a.m. "Always eat breakfast, and make sure that breakfast is high in protein," adds Buches, who recommends eggs or Greek yogurt. The nutrient will give your brain a boost, balance your blood sugar and energy, and keep your metabolism revved up throughout the day, she says.

7. They exercise.

"Exercise daily -- period," Buches says. People who've been a healthy weight their whole lives are apparently listening. The majority of participants in the Food and Brand Lab's recent analysis, for instance, report exercise as one of the main tools that's kept their weight steady. Forty-two percent of those in the Lab's wider registry work out five to seven days a week. While fitness frequency is important, mixing up your routine is key, too, both Buches and Dixon say. "I make a conscious effort to exercise regularly," Dixon says, "with a mix of cardio exercises and strength-training activities to maintain my metabolism and stay fit."

8. They fidget.

Even when they're not hitting the gym, people who are able to better stave off weight gain seem to burn more calories throughout the day doing all kinds of less-conscious movement, be it walking to work, typing, gardening or simply fidgeting, research from the Mayo Clinic and Arizona State University suggests. Those movements can add up to 1,000 calories a day -- the amount in a Big Mac and shake, study lead and endocrinologist Dr. James Levine explained to a group of journalists in February. "This is a massive public health opportunity to get up and move," he said.

9. They weigh themselves -- or not.

About half of the people in the Food and Brand Lab's healthy weight registry weigh themselves weekly; 29 percent never do. While keeping close tabs on your weight isn't helpful for everyone, some research suggests that weighing yourself regularly can help you lose weight and keep it off -- especially if you're a man. "Self-weighing gives immediate feedback and might help one to regulate eating and exercise to prevent weight gain," Vuorinen speculates.

10. They indulge (guilt-free).

Dixon has a sweet tooth and she's not afraid to admit it -- or indulge it, usually with chocolate or ice cream. "After all, we should reward ourselves for working hard," she reasons. Science supports her. In one 2012 study, for instance, dieters who included a treat like chocolate mousse with their breakfasts kept weight off better, felt less hungry and had fewer cravings than their counterparts whose breakfasts weren't so sweet. Mindlessly slim folks in the Food and Brand Lab's registry, meanwhile, are less likely to report feeling guilty after overeating. For Tucker, "cheat days" aren't something to plan for, but rather to embrace when the occasion arises. "Just give yourself peace of mind by knowing you'll work out harder for the next day -- or two," he says.