Experts recommend you write down your measurements before you start any diet or fitness plan and then refer back to see how you're doing. Among the factors to measure:

• Weight. Weigh yourself first thing in the morning before you put on your clothes and shoes. Weigh yourself once a month instead of daily or weekly to give your body time to respond to your weight-loss program.
• Resting heart rate. It should be between 50 and 100 beats per minute.
• Circumference. Write down the numbers for your waist, hips, thighs and chest. Record new measurements every four weeks, and wear tight-fitting clothes each time you measure yourself.
• Body mass index. BMI is a measure of weight for height that indicates whether you might be considered overweight. To calculate your BMI, divide your weight in pounds by the product of your height in inches times your height in inches. Then multiply that by 703. The U.S. Centers for Disease Control and Prevention offers an online calculator at www.cdc.gov/nccdphp/dnpa/bmi/calc-bmi.htm. Normal is between 18.5 and 24.9.

For more information: About.com/health/