Sensibility shift could drive these stocks lower

Although stocks rallied on Tuesday for a fourth straight session of gains, investors couldn't help but notice some very noticeable losers in the market.

Both Coca-Cola and McDonald's fell after both companies released earnings that disappointed Wall Street, with Coke shareholders suffering through the company's biggest one-day decline in six years.

Although currency headwinds surely played a part in the weakness, on CNBC's "Power Lunch" Jack Ablin of BMO Private Bank said he couldn't help but wonder if the weakness was about something else.

Read More Coca-Cola warns of currency headwinds

He thinks both companies may be on the wrong side of what he calls a "sensibility shift;" a theme CNBC's Jim Cramer often cites on "Mad Money."

Both pros note that young people value healthy eating more than generations past and therefore shun sugary drinks such as soda pop as well as burgers and fries.

In turn, they wonder if weakness in McDonald's and Coca-Cola reflects the shift; and although both companies offer healthier food alternatives, neither is viewed as a healthy choice by young people.

Read More McDonald's sees fewer customers; revenue misses

David MacEwen of American Century Investments added that understanding the theme is particularly important for investors because companies on the wrong side of a sensibility shift may go lower despite broad economic improvement.

And as millennials take on bigger roles in society, Ablin added the shift should become more pronounced.