Like their younger counterparts, more and more seniors are becoming obese, and at the same time, seniors are living longer. Indeed, many seniors will live 20 to 30 years in retirement. Because medical costs are escalating, many retirees are increasingly worried about whether they have sufficient resources to keep their golden years golden.

Financial experts at Ameriprise Financial predict that a couple turning 65 in 2010 will need $250,000 for health care expenses in retirement. And the government forecasts a healthcare inflation rate of 6 percent annually for the rest of the decade. Moreover, the Medicare trust fund is projected to be insolvent by 2019.

Will these worrisome findings trigger changes in lifestyle? Will we decide to become fit to reduce medical expenses? Or will we instead go broke by remaining fat?

A significant percent (some experts place the estimate at 80 percent) of the medical expenses we incur are a function of lifestyle choices, such as eating too much, smoking, not exercising consistently and abusing drugs and alcohol. The implication is clear: we can prevent the majority of medical illnesses and associated costs by adopting healthful lifestyles.

If we can no longer afford expensive care or prescription drugs to deal with our medical conditions, we certainly will have a strong incentive to stay as fit as possible.

Before I decided to lose weight and get fit, my medical insurer had a file on me that was at least five inches thick. Much of what I was treated for, such as gallbladder surgery or chest pain, was a function of lifestyle. I ate too much, so I weighed too much. I seldom exercised, and I enjoyed nightly cocktails. One overnight stay in the hospital for chest pain cost several thousand dollars.

Today I keep my weight in the normal range, I exercise each day and I limit alcohol to an occasional glass of wine. As a consequence, except for an occasional sinus infection, my medical expenses are minimal. I want to keep them this way, partly to preserve my good health but also to preserve my nest egg. The strategy is win-win: I keep my savings account fat by keeping my body trim.