If you're worried about your chances of getting life insurance because of your weight, you're certainly not alone. According to a 2009 report by the Trust for America's Health, adult obesity rates exceed 25 percent of the population in 31 states. Worst off is Mississippi, which breaks the 32 percent mark for adult obesity.

If you're about 10 pounds over your "ideal" weight, your life insurance application won't be affected. But if you're obese, and especially if you have additional medical conditions such as diabetes or high blood pressure, you could have difficulty getting approved for life insurance.

Your weight is judged by how much body fat you're carrying, which is calculated using your height and weight to determine your Body Mass Index (BMI). You are an overweight adult if your BMI is between 25 and 29.9. You are obese if your BMI is 30 or higher, according to the Centers for Disease Control and Prevention (CDC).

The CDC has an online BMI calculator that makes it easy to find out your number.

Obesity does not exist in a vacuum; it can lead to other serious health conditions, which is why it affects your life insurance rates. According to the CDC, being overweight or obese increases your risk of the following conditions:

• Cancer
• Coronary heart disease
• Dyslipidemia (such as high cholesterol)
• Gallbladder disease
• Gynecological problems (such as infertility)
• Hypertension (high blood pressure)
• Liver disease
• Osteoarthritis (a degeneration of cartilage and its underlying bone within a joint)
• Sleep apnea and respiratory problems
• Some cancers (such as endometrial, breast and colon)
• Stroke
• Type 2 diabetes

Life insurers weigh in

Life insurers all have their own underwriting guidelines, but generally speaking, you can get the best rates (often called Preferred Plus) even if your BMI is up to 26 to 28.

A higher BMI will likely push you down into the next rate class, called Preferred, which will cost more.

If your BMI is around 35 to 38, you'll find yourself in the Standard rate class with everyone else of unexceptional health.

These guidelines are not written in stone and there are numerous exceptions and variations among life insurance companies. That's why it's crucial to shop around for the best rates. If you are in a rate class that you find unaffordable, you could also consider lowering your death benefit amount in order to decrease your premium.

In addition, according to life insurance experts, senior citizens (age 65 or 70 and up) are often held to less strict weight standards. Not even the skinny are immune to weight-related underwriting. Many life insurers have weight minimums, too, and charge more when someone is considered underweight.

If you're in a tough spot due to a combination of medical conditions, such as obesity and high blood pressure, don't give up. There are brokers who specialize in finding life insurance for applicants with medical conditions. For more, read how impaired-risk specialists find life insurance for people with medical problems.