01/22/2013 05:42 pm ET Updated Mar 24, 2013

When to Lie About Your Weight

When should women lie about their weight?

First of all, I'm answering as myself, a real woman who lives in the real world, and then I'll answer as a health care provider. My personal policy is to never come clean and be exact about my weight. I mean really, is it necessary for friends to know? Well, yes, if you've lost weight, and then when you say, I lost 25 pounds and I now weigh 135, they quickly do the math and realize that you were topping out at 160 or more. Yikes. Is that too much honesty?

In most cases, when someone really, really needs to know a woman's 100 percent accurate, the whole truth and nothing but the truth, actual, honest-to-goodness weight (like at your health care provider's office), then we never, ever rely on someone's complete honesty.

That's why in every clinic and office around the country, we have very unforgiving and heartbreakingly accurate scales. And now, for even more accuracy and help in determining whether a person's weight is healthy, we use a calculation using height and weight to determine Body Mass Index, also known as BMI, to determine if a woman is at a healthy weight, overweight or obese. Using the BMI helps us counsel women about risks of diabetes and heart disease.

Having said that, there are a few things to remember. In almost every situation, fudging a little (pun intended), plus or minus 5-10 pounds will not make any difference. And there is no harm in putting in the wrong weight into the gym machines as long as you're staying within a 10 pound variance.

When You Should Be Honest About Your Weight:

• When lives are on the line: Yes, when you're bungee jumping and skydiving.

• Flying in bush planes in remote areas, when there are other passengers and/or cargo.

This helps the pilot know how much fuel they'll need. It helps to be honest, but in a mission critical situation, and the pilot is skeptical, they'll ask you to take a little step onto their heartbreakingly accurate scale. One Bush Pilot I spoke to in Homer, Alaska, who was a mom herself, told me that it wasn't just women who lie about their weight, men do too. Their company policy is to have everyone step on the scale before boarding the plane. Imagine if United or Southwest asked you to do that!

What We Tell Ourselves:

• Let's face it, many of us like to think of ourselves as slimmer than we are. Many of my patients are shocked when they see the actual numbers on the scale. They usually underestimate by five to seven pounds. Some underestimate by 20 or more.

• Many women, myself included, have a distorted body image. We can look in the mirror from certain angles in low lighting, wearing all black and actually believe that we're 15 pounds lighter.

• How often have you struggled to zip up pants and wondered if they shrunk in the dryer or at the dry cleaner?

Denial Ain't Just a River in Egypt

• Many of my patients are in denial about their weight and don't think that the statistics about obesity, diabetes and risks of serious health issues actually apply to them. It's normal and natural to have a "blind spot" when it comes to the scale and to think that those 20-30 or more extra pounds are just temporary bloating.

• It's also normal to see the number and become overwhelmed, not want to deal with it and just throw in the towel.

The Truth Hurts, But Will Set You Free

• However, this is a case, where lying to yourself doesn't help and can actually hurt you. Yes, the truth is often painful, and yet by hiding our heads in the sand, lying to ourselves and not acknowledging the truth can lead to serious consequences like diabetes and a heart attack.

• Now that we're a few weeks into the new year and those resolutions are fading, it's time to get on the scale and take a look.

• Then take a deep breath and go to a BMI calculator to find out what your Body Mass Index is. This one is from the National Institutes of Health.

BMI results:
• Underweight = < 18.5
• Normal weight = 18.5-24.9
• Overweight = 25-29.9
• Obesity = BMI of 30 or greater

If your BMI is 25 or higher, it may be time to decrease portions and get back to the gym, where you'll find me on the elliptical. I'm the one in all black.

For more by Barbara Dehn, click here.

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