And now we move onto modern health in america and something new from coca-cola. The soft drink giant. Under mounting pressure about sugary soft drinks and the consequences for health, coke ads are about to sing a new tune. And here's abc's senior national correspondent jim avila on that. Ice cold coke. Reporter: Coca-cola in 1961, advertising the original coke as a diet beverage. There's no waistline worry with coke. Reporter: But now, most studies say that's not true. be part of the obesity solution, not the problem. More than 650 beverages, we now offer over 180 low and no calorie choices. Reporter: Coke buying a cable ad blitz tonight, reacting to a full-fledged assault on sugary sodas that include proposed taxes and an often mocked new york city effort to eliminate large sizes. Oh, no! I'm on the run from johnny law! Reporter: But many feel it's no joke. After all, the average american gets 45 gallons of suge gay soft drinks a year. That's 1 1/2 barrels of soda pop. In fact, sodas are the single largest source of calories in the american diet. Even that small can has the equivalent of ten sugar cubes in it. The regular soda, some 27 sugar cubes. And that big gulp? 38 sugar cubes. Critics argue they're not just ordinary calories, either. They're empty of nutrition and don't tell the body its full. Beverages, we drink the calories and consume more foods on top of those calories. Reporter: Coke's new commercial promotes exercise programs to work off what you drink. But for the world's largest soda maker today, it's no coke and a smile.