If you want to lose big, think small.

That's the expert advice coming just as many people are making a New Year's resolution to become a healthier version of themselves - through better eating, better exercising or better lifestyle habits.

Weight loss, or getting into shape, is one of the most popular resolutions made as the calendar turns to a new year. It also is one of the most daunting personal goals to achieve, and many people end up going about it the wrong way, say experts.

But there are ways to make the process a little easier (really) and improve your odds of making your weight loss plan a long-term success.

The first is understanding whether you really need to lose weight. "Typically, when I have a patient that asks me that question, it's asking yourself if you're comfortable at the weight you're at," said Karen Travers, a registered dietician at Sturdy Memorial Hospital in Attleboro.

"Just asking if you recognize that you need to do that is the first step. Then, it's where do you think you'd feel better?"

A measure of whether you're truly healthy, or at least in a healthy range, isn't just about what the scale says.

One popular tool, recommended on the U.S. Department of Agriculture's helpful Web site, www.nutrition.gov, is the Body Mass Index (BMI) calculator.

BMI can indicate a person's body fat, calculated on your height and weight. While it does not measure body fat directly, the Centers for Disease Control says research shows it is a good screening method for weight categories that could lead to health problems.

You also can use your BMI to calculate how many calories you need, depending on your daily exercise, to maintain, lose or gain weight through the nutrition Web site.

But Travers cautions that aiming for a weight based on BMI, or any other method, may be too much.

"If you focus on the numbers, on BMI or what (is) determined an ideal range, that puts a focus on a number that, for many people, is unachievable or disheartening," she said.

"They come up with a goal that becomes oppressive to them."

Instead, Travers suggests thinking in "small steps" and advises clients to start with changing their behaviors. The key, she said, is to develop a plan that works for you - instead of following something outlined in a magazine or book. Here are some suggestions she has for developing that plan:

Evaluate your habits - Look at what you are doing in terms of eating and exercise, compared to what is suggested.

Make one change a time - Instead of switching to a meal plan that could be based on how many calories you need, think of something smaller. "It's whatever is easiest," Travers said. "If they don't drink milk, they can decide to have a glass at dinner every day. Once they do that, they say, 'OK, that wasn't so hard.'"

Think about portion size - Many experts say this is a big cause of the obesity problem in the United States. Many people might not even know how much they're really eating, and people of different sizes need different amounts of foods from every food group. A 128-pound woman needs about 5 ounces of protein a day, and one big slice of turkey in a sandwich counts as 2 ounces, and 35-year-old man, weighing 180 pounds, needs about 6.5 ounces, based on their calorie needs.

Think about calories - Travers said that this puts things into perspective. "If you're aiming for 1,600 calories a day, one cookie could be 500 calories," she said. "You can raise your level of consciousness about what you eat." Also, it might be easier to give up that cookie if you know it counts as one-third of your total for the day.

Measure your waist - A healthy waist size for a 5'4" woman is around 32 inches, but the average size of an American woman's waist is 36.5 inches, according to Glamour magazine. A waist larger than 35 inches, at any height, poses medical risks, the magazine reports. "If your waist is larger than recommended, you're at a greater for risk for diabetes or heart disease," Travers said.

If you "slip up," move on quickly - Travers said not to get too upset if you slack on your exercise or diet; just start again the next day. "Anything you do today is going to be better than having done nothing," she said.

"I just try to encourage people that any change is a step in the right direction," Travers said. "The alternative is to fall into despair and that doesn't do anything to improve your health."

For more tips on losing weight, visit www.nutrition.gov or www.glamour.com.