I am about to blog one of the most sensitive issues of our time: Fat. So before I dive in, a disclaimer. This is not a post designed to make fun of people who are obese, make them feel bad, or preach to them. Some of the people nearest to my heart in this world struggle with obesity, and I know from them that losing weight and keeping it off is not easy. And with more than a third of Americans qualifying as obese and another third considered overweight, chances are that you fall into these categories yourself or have loved ones who do.

So here goes: Being obese is expensive -- and not just at the doctor's office. We all know that overweight, like other ailments linked to modern living (heart disease, lack of sleep, addiction), costs a hefty (sorry!) amount of healthcare dollars. The diabetes meds, the damage to the circulatory system, the surgeries. Wise Bread has written about this before.

But what about the other costs of living with excess weight? When spending time with loved ones who are carrying around more pounds than they'd like, I've noticed that they end up paying more for a lot of things:

1. Parking. Obesity often means decreased mobility, especially as you age and the knees give out. When you want to take your grandchild to the museum or the ballgame, you're less likely to feel up to grabbing free parking a few blocks away or walking the same distance from public transportation. Yes, everyone tells you the walk would be good for you, but they don't have your knees. Nor do they feel the heat as intensely as you do. Which brings me to ...

2. Air conditioning. I'm not sure if decreased need for home heating in winter cancels this one out, but if you are overweight you will almost certainly spend more on air conditioning. I always knew my home was not well-cooled in summer with a few window boxes, but I never realized how bad it is for some until I saw a relative sitting in his air conditioned car outside my house to cool off.

3. Clothing. Some stores charge more for large sizes, but even worse, many large people find themselves relegated to specialty stores. Specialty = pricey. Unusually tall people or people with unusually large or wide feet find themselves in on this boat too, and it's a boat with an expensive fare. Oh, and the heavier you are, the more expensive shoes you are going to have to get. Otherwise, you'll end up forking out even more in medical bills.

4. Travel. Any obese person who can afford it, or has the miles to upgrade, will tell you they avoid flying coach. Who can blame them? Coach airline seats are already uncomfortable for those within the healthy weight range for their heights! Airlines have toyed with charging weighty passengers more even for coach. And the truly heavy passengers have to shell out twice as much to purchase two airline seats. I'm not going to rule on whether any of this is right or wrong, or get into whose responsibility the problem is. But we can agree on this: Air travel can be more expensive when you're obese. Also, once you pass a certain size, you'll have to buy a larger, more expensive car. That uses more gas.

5. Dieting. OK, this one is obvious but more than $40 billion are spent in this country every year on commercial diet plans. Yes, you can lose weight on your own, and it would seem like consuming fewer calories would cost you LESS money. But studies show that the most effective way to lose and keep it off is Weight Watchers. Which costs a monthly fee.

6. Parenthood. Extra weight lowers the chances of conception, which means that to become a parent while obese, you're more likely to end up paying for IVF or adoption. Even adoption is getting harder for the obese now that China has stipulated a maximum BMI for would-be adoptive parents. (See article in American Baby, june)

At the same time that it makes life cost more, obesity can decrease earnings potential. A New York Times article described one study that reveals that the obese accumulate half as much wealth in a lifetime than those in their healthy weight range.

Employment opportunities decrease. It is definitely wrong to discriminate against the obese, but it definitely happens. Also, decreased mobility and energy may inhibit your ability to keep up with any job with a physical component, such as nursing or waiting tables. You can be kicked out of the military for overweight, too.

While plenty of people seem to have no trouble going about their normal interpersonal lives after becoming obese, some lose self-confidence or become depressed. This will also cut into earnings ability -- if you no longer feel comfortable speaking in front of a crowd, you may have trouble holding onto that job as a corporate marketing executive or motivational speaker.

The moral of the story? There are plenty of reasons to avoid letting extra pounds accumulate, health and quality of life at the head of the pack. But as the summer draws to a close and the more sedentary seasons approach, cost is one more reason to remain vigilant about weight.