Bob Seger prepared for his current U.S. tour by shedding the pounds after ballooning in weight.

Bob admits he tipped the scales at 247 pounds and decided he was too out of shape to hit the road - so it was time to diet.

Seger tells Rolling Stone magazine he signed up to diet plan Nutrisystem and has been steadily losing weight ever since.

He says, "I was huge. Now I'm down to 220 (pounds)... I'm going to keep going until I reach my target weight of 205."

Now, he has to focus on cutting back on smoking and drinking coffee.

Bob adds, "It can't help my voice. The coffee and milk doesn't help either. They're all drying agents. I'm really trying to cut down."

We'll see the new Slim Bob at the Palace in May.