Many people assume there's some mystifying secret to weight loss. When looking at fit celebrities, and even neighbors or co-workers, men and women commonly ask: "What's their secret?" or "How can I look like that?" While searching for these "secrets," people often overlook the simplicity of adopting healthy lifestyle habits that support a slim waist and healthy weight. While different strategies work for different people, scientific evidence indicates that individuals who effectively maintain a lean shape over time stick to similar eating and activity habits.

Other than a few genetic variations, there aren't many physiological differences between you and your slim neighbor – it all comes down to habits that promote a healthy weight. If you're attempting to lose weight, use your healthy counterparts as inspiration. If they can do it, so can you. Use these 13 healthy habits as a road map to achieving a healthy, lean figure.

1. Eat a smart breakfast. Individuals who start their day off with breakfast have a reduced risk of weight gain. In a study that included 20,000 middle-aged men, researchers found that breakfast consumption was inversely associated with weight gain over 10 years. That might explain why 78 percent of individuals from the National Weight Control Registry report eating breakfast every morning.

Don't settle for a small granola bar to fill you up. Get in the habit of eating a smart breakfast, meaning one that is substantial enough to fuel your energy all morning. Smart breakfast choices include a good balance of healthy fat, lean protein and carbs, like an egg white omelet cooked with olive oil and sauteed spinach.

[Read: High-Protein Breakfast Ideas.]

2. Listen to internal hunger cues. External cues such as social pressures or environments strongly influence when and how people eat. Whether it's a morning meeting with doughnuts, the candy bowl in the conference room or the popcorn in your lap at the movie theater, people don't think twice before indulging. Individuals who have a lean shape are generally able to ignore the convenience factor and base eating decisions on whether they're hungry or not hungry. Try tapping into your internal hunger cues and question whether you're even hungry before putting food in your mouth.

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Flickr / ginnerobot

Fruit makes a good snack

3. Avoid skipping meals. According to a study conducted by researchers at Cornell University, short-term food deprivation can lead people to make unhealthy food choices and increase the attraction of high calorie foods. The researchers found that "hungry" participants who did not eat five hours prior to grocery shopping were more likely to buy higher-calorie foods, compared to those who snacked on crackers before shopping. The results confirm the importance of eating before shopping, but also demonstrate that consuming regular meals can promote healthy food choices later in the day.

4. Eat most meals from home. Eating meals away from home decreases awareness of the calories and ingredients in the meal, as indicated by a 2013 study conducted in popular fast-food restaurants in America. Two-thirds of the 3,385 study participants who ate at a fast-food chain underestimated the calorie content of their meal, with one quarter underestimating by more than 500 calories.

Additional findings in children and adolescents were also published in 2013, demonstrating that eating out at fast food and full-service restaurants increases children and adolescents' daily energy consumption by 126 to 310 calories. That's in addition to increasing total fat, saturated fat, sugar and protein intake.

[Read: Top-Rated Diets Overall.]

5. Load up on plant-based protein. Many individuals who maintain a healthy body weight long-term do so by removing meat from the center of their plate. Studies show that vegetarians tend to have a lower body fat percentage long-term, in addition to lower levels of oxidative stress and cholesterol, compared to their meat-eating counterparts.

Another study evaluated the link between weight change and daily servings of individual foods. Over the course of four years, daily servings of unprocessed red meat and processed meat were associated with respective weight gain of 0.95 and 0.93 pounds, while a daily serving of nuts was associated with 0.57-pound weight loss.

wegmans candy section

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Avoid this aisle

6. Avoid foods with added sugars. A diet low in added sugars translates to fewer empty calories and a lower risk of weight gain. A 2013 report from the Centers for Disease Control and Prevention defines added sugars as sweeteners added to processed and prepared foods such as breads, cakes, jam and ice cream. Some examples of added sugars include white sugar, brown sugar, raw sugar, corn syrup, high fructose corn syrup, molasses and honey. The CDC report stated that an increased intake of added sugars is associated with a decreased intake of essential micronutrients and an increase in body weight. Stick to naturally occurring sugars found in fruit and dairy products and minimize intake of added sugars.

[Read: Ferreting Out the Hidden Sugar in Your Diet.]

7. Creatively add vegetables. Veggies provide a variety of nutrients for very few calories, which makes them a key component to achieving a healthy weight. Incorporating vegetables into snacks and meals leads to a boost in fiber intake, which is associated with increased satiety and weight loss. Creatively add vegetables wherever you can get them into your diet. For breakfast, add diced veggies to eggs and a few scoops of salsa. For lunch and dinner, try making a wrap with collard greens instead of tortillas, or add tomato sauce to a baked potato. Other ideas including seasoning and grilling an entire cauliflower "steak" or incorporating broccoli or kale into a rice dish.

[Read: How to Cook With Collard Greens.]

wheat bread

Flickr-thejoykitchen

Whole wheat is the way to go

8. Choose 100 percent over 50 percent whole grain. Science demonstrates that the proportion of grains consumed in the diet is not as important as type when predicting future weight gain. The study suggests that a high intake of refined grains and sweets may predict weight gain, while consumption of refined white bread is associated with larger increases in waist circumference. Obvious sources of refined grains are white bread and bagels, while less obvious sources are hidden in "whole grain" products that are not 100 percent whole grain. Get in the habit of avoiding all refined grains by choosing 100 percent whole wheat or 100 percent whole grain products. The benefits of increased fiber intake will lead you to a weight-loss transformation.

9. Use smaller containers. Those who carefully control the quantity of food they consume generally eat from smaller serving dishes and containers. A 2012 study demonstrated that students consumed twice as much candy when they ate from two larger candy bowls, compared to the small bowl. The findings imply that eating with larger serving containers – plates, bowls, spoons and packages – stimulates food intake. To help curb overeating, switch to smaller containers.

10. Read ingredients before anything else. Check to see that the claims made on the front of the package are justified by the ingredients that are in the actual food product. Focusing on the quality of food first and the numbers second will ensure consumption of nutrient-dense calories. While calorie content does determine weight loss, fueling your body with quality calories helps promote healthy choices long-term.

[Read: Diet Success Stories: Dieters Reveal How They Hit Their Target Body Weight.]

11. Don't drink calories. Sodas, fruit drinks, specialty coffee drinks, energy drinks – the list of empty calories goes on and on. These popular beverages are exploding with sugar, meaning empty calories that provide no nutritional value. Regular consumption of sugary drinks adds inches to the waistline faster than you can finish a 20-ounce bottle of soda. According to results from 2005 to 2006 NHANES data, 35.7 percent of added sugar in the average U.S. diet comes from soda, energy drinks and sports drinks. An additional 10.5 percent of calories from added sugar are derived from fruit drinks. In total, almost 50 percent of sugar calories in the U.S. come from beverages that lack any nutritional benefits. Get in the habit of drinking water as often as possible, which will minimize your consumption of liquid sugar packets.

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12. Get adequate sleep. Research has shown that sleep habits influence people's dietary habits. A study published in 2011 followed men and women for six years and found that every additional hour of sleep decreased the incidence of obesity by 30 percent. The underlying mechanism that explains the relationship is not known, but experts suspect it involves hunger hormones such as leptin and ghrelin, along with other physiological factors. Aim for seven to eight hours of sleep per night for optimal health.

[Read: Trouble Sleeping? Ask Yourself Why.]

13. Wear a pedometer. Individuals who have a lean shape are often active throughout the entire day, not just during their 30-minute date with the elliptical. In order to achieve optimal health and a slim physique, experts recommend taking at least 10,000 steps per day. Start tracking your steps each day with a pedometer or other devices that increase your awareness of your activity.

Brigid Titgemeier, nutrition assistant at the Cleveland Clinic Wellness Institute, contributed to this article.

Kristin Kirkpatrick, MS, RD, LD, is the manager of Wellness Nutrition Services at the Cleveland Clinic Wellness Institute. She is an experienced presenter, an award-winning dietitian, an author and a regular television guest on both local and national shows, as well a contributor to several national magazines and newspapers. The Huffington Post recently named Kristin "one of 25 diet and nutrition experts you need to follow on Twitter." Kirkpatrick's career began in Washington, D.C., lobbying for Medical Nutrition Therapy reform, and from there she went on to become the Regional Coordinator of the National Heart, Lung and Blood Institute's Hearts N Parks program in Maryland. Follow her on Twitter at @KristinKirkpat.

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