The two crises driving public worry these days involve food and fuel. Prices for both are climbing, and people worldwide are growing more disgusted over having to shell out more money.

So how would you like to be part of the solution?

The Web site MSN Money, in its occasional series of financial what-ifs, posed a very interesting question that, when you learn the answer, is one of the most practical ways to conserve precious resources and save everyone a lot of money.

What if nobody in the United States were fat?

Think about that. Two out of three Americans are classified as overweight. They eat excessively or unwisely, or both. They are more prone to illness. The bigger the person, the more resources that person is going to consume.

So what would happen if the average American adult lost, say, 20 pounds?

According to experts, we would save ourselves an astounding $487 billion. If that could be liquefied into cash, that's the equivalent of each U.S. household receiving $4,270.

The savings would be everywhere.

No obesity would mean a sharp drop in the medical conditions often brought on by obesity -- such as diabetes and heart disease. One economic researcher projects that medical insurance costs would drop, and medical professionals could be free to perform a greater amount of preventive care.

It would mean a healthier work force, which would be a more productive work force. One estimate from the director of health economics at the Milken Institute theorizes that workers unburdened by fat and its ill medical effects could boost the Gross Domestic Product by $257 billion.

Of course, with your new, healthier look, you'll need new clothes to better complement your new figure. And, according to a North Carolina State textile apparel professor, if apparel manufacturers didn't have to make plus-size clothing any more, those companies would save themselves money -- and save us money. The largest sizes of clothing tend to cost 10 to 15 percent more.

Vehicles and airlines would be carrying lighter loads, which means burning less fuel. Consumers would get back almost a billion gallons more gas, and airlines would save about $1.9 billion, industry studies have found.

So eat a little less and exercise a little more. Any tiny bit will help you -- and the nation -- become healthier.

There could be one downside for some people, though -- the people employed by America's $55 billion weight-loss industry!