Orlando, Fla. ? When U.S. Rep. Ric Keller falls off the diet wagon — as he often does — his demise is a lunch at Wendy’s: triple cheeseburger, Biggie fries, Frosty.

The damage? A whopping 1,920 calories and more than 90 grams of fat.

Keller doesn’t apologize — except, perhaps, to wincing cardiologists. It is, the Florida Republican says, “a matter of personal responsibility.”

Keller not only takes the blame for his fast-food lust, he thinks everyone else should do likewise. That’s why he’s trying to stop fast-food junkies from suing the industry.

His “Personal Responsibility in Food Consumption Act” — which faces a hearing before a House subcommittee in Washington today — has ignited a debate about who is to blame for America’s widening obesity epidemic, which has grown side-by-side with the popularity of fast food.

Specifically, Keller’s bill would prohibit civil lawsuits against manufacturers, distributors and sellers of food and nonalcoholic beverages for “weight gain, obesity, or a health condition related to weight gain or obesity” as a result of long-term consumption.

Already there have been several lawsuits against the industry, the first launched nearly a year ago when Caesar Barber, a 56-year-old New Yorker, sued McDonald’s, Wendy’s, Kentucky Fried Chicken and Burger King, saying their food made him fat and led to two heart attacks.

Dr. Neal Barnard, president of the Physicians Committee for Responsible Medicine, cited evidence that eating sugar, chocolate, meat or cheese stimulates opiate receptors in the brain.

“I think the idea that, oh, these lawsuits are foolish and it’s just personal responsibility — that’s just a knee-jerk reaction,” Barnard said.

But the addiction theories are still young. And opponents aren’t buying.

“That’s a junk-science argument,” Keller said. “You know, I’m addicted to watching ‘The Bachelor’ every Wednesday night. Can I sue them now?”