Shares of Coca-Cola (KO) slumped Tuesday after the world's largest soft drink company posted results that lagged Wall Street's low expectations. The earnings don't auger well for PepsiCo (PEP), which reports earnings Wednesday.

Net income at the company rose 3.9% to $2.31 billion, or 50 cents per share, fueled by steady growth around the world. Revenue rose 1% to $12.34 billion, or 6% higher on constant currency basis. Excluding one-time items, profit was 51 cents. Wall Street expectations were for earnings of 51 cents per share on revenue of $12.41 billion.

For Coca-Cola investors, who have seen the shares surge 9% this year, there was much to like in the results. Worldwide volume grew 4% in the quarter and has surged 5% year to date. The company saw single-digit growth in many developed markets such as North America, Japan and Europe and double-digit gains in emerging markets, including Thailand (19%) and India (15%). Coca-Cola's quarterly volume even grew 2% in China, where many investors were concerned about growth slowing.
 
Coca-Cola's businesses in nonalcoholic, ready-to-drink beverages posted solid gains, including its sports drinks, energy drinks and packaged water. The company expects beverage volume to grow 4% in the quarter and 5% for the year, which, given the economic headwinds, is pretty impressive. Global sales volume rose 4%.

Given Coca-Cola's decent quarter, the pressure is on PepsiCo, which has lagged its rival in the market for years. Earlier this year, CEO Indra Nooyi revamped her management team, slashed thousands of jobs and reorganized the company so it has a more international focus like its rival. The company has also made a new marketing push.

The company beat Wall Street's low expectations last quarter. Wall Street isn't expecting much this quarter either. Earnings are expected to fall by $1.16 per share, and revenue is expected to slump 3.9% to $16.9 billion.

Both Coca-Cola and PepsiCo are facing pressure from government officials such as New York Mayor Mike Bloomberg who are eager to address the nation's soaring rates of obesity. Though painting soda as the villain in the fight for better health is unfair, this issue isn't going away anytime soon.

Jonathan Berr is long Coca-Cola. Follow him on Twitter@jdberr