Back in 1990, the Food and Drug Administration required major food producers to label their packages with calorie, fat, carbohydrate, and other nutritional information.

For many of us, this changed the way we bought groceries. In fact, studies show that 75 percent of people read these labels and, of them, 61 percent changed their purchases based on the information they read.

Fast forward to 2007. Knowing that nearly 30 percent of meals are now eaten outside the home, public health experts began to ask: "If labeling packages changes food purchases, could people improve their eating habits at restaurants by having access to nutritional information on menus?"

That is what the King County Board of Health intended to find out when, nearly 3 years ago, we became the second governing body in the country to pass legislation that would require chain restaurants to label menus with nutrition information.

Earlier this year, President Obama signed the health care reform legislation into law, which includes the expansion of menu labeling throughout the nation.

In addition to our local labeling already in place, you will see the expansion of labeling to grocery store delis, convenience stores, vending machines, and buffets.

In the next few years, when you visit these places you'll be able to see the number of calories per serving and serving size - and they'll be clearly marked and easy to find.

More than half of King County residents (54 percent) are overweight or obese. Menu and package labeling provides valuable information, but knowing how much one should eat is also critical.

After all, what good is calorie information if you don't know how many calories you should consume?

To effectively use calorie information:

First, calculate your body mass index, or BMI.

BMI is a measure of body fat based on height and weight that applies to adults. The normal range is 18.5 to 24.9, overweight is 25-29.9, and obese is a BMI of 30 or greater. To calculate your BMI, divide your weight in pounds (lbs) by height in inches (in) squared (height times height) and then multiply by 703.

So, for example, if you are a 5'5" (or 65 inches) and weigh 130 pounds, your BMI would be 21.6.

Calculation: [130 ÷ (65 x 65)] x 703 = 21.6

You can also use an easy BMI calculator online at http://www.nhlbisupport.com/bmi/. BMI calculators for children and teens can be found at http://apps.nccd.cdc.gov/dnpabmi/.

Second, figure out your ideal weight.

Using the example from the last paragraph, in order to be considered a healthy weight a woman who is 5'5'' should weigh between 114-144 lbs. You can look up your ideal weight here: http://www.active.com/fitness/calculators/weight.htm

Now, using what you know about your ideal weight and BMI, this calculator shows you how many calories you should eat each day based on your height, weight, age, and gender: http://caloriecount.about.com/cc/calories-burned.php.

If you are in the overweight or obese category, you can calculate how much you need reduce your daily calorie intake to lose weight and reach your ideal weight. http://caloriecount.about.com/cc/calories-goal.php (As a general rule, you can lose one pound a week by a cutting 3500 calories from your weekly intake, or about 500 calories per day.)

Up until about a year ago, I wasn't eating well and rarely got exercise other than walking from my car to my office and back. I was tiring easily and not fitting into my favorite clothes.

So I made some changes to my lifestyle, small at first. I went walking with a friend for an hour a few days a week, and started eating more salads with salmon and less meatloaf and ice cream.

My staff and colleagues encouraged me to keep up these healthy habits, and by the end of last summer, I was exercising every day and had lost over 20 pounds!

I'm keeping it up (it gets easier, like any new habit that takes shape) and I plan to run/walk the Seattle Rock and Roll 1/2 marathon this summer. I can't wait to line up with 28,000 other participants in Tukwila and feel, with every step, how far I've come.

If you have a weight loss story to share that incorporates using menu labeling, I'd love to hear it! Please send me an email: Julia.patterson@kingcounty.gov and I'll post it (using your first name only) on my website!