Veteran Hedgeye Restaurants analyst Howard Penney has a long track record successfully covering shares of McDonald’s (MCD). Over the years, he’s been a bigtime bull as well as bear. Unfortunately for investors long Micky D’s, the bear is back. According to Penney, the fast food giant has gotten “back to bad habits.” And that could mean as much as 30% downside for MCD shares.

Right now, Penney is warning that McDonald’s menu and in-store management is getting too “complex” – one of the major causes of McDonald’s last downturn in 2014.

Quoting from the book, The Founder’s Mentality, he notes that “complexity is the silent killer of growth.” This complexity has led to a slowdown in one of McDonald’s bread and butter strengths – drive-thru speed.

“Speed comes a close second to value in terms of brand equity for McDonald’s,” Penney explains in the above clip. “Menu complexities are particularly challenging as it relates to the drive-thru where 75 percent of sales originate. And we’ve already seen a slowdown in drive-thru times.”

Watch the full clip above for more.

Penney: This ‘Silent Killer’ Threatens McDonald's Stock - investing ideas