There are many good restaurant investments out there, but it's hard to find the best ones. A risk that faces all restaurants is changes in consumer preferences, which is why investing in a diversified restaurant group is often a safer investment for the long term. Yet it can be hard to choose where to invest since there are so many options such as DineEquity, Yum! Brands, and Brinker International. 

I submit that a good strategy is to invest in restaurant groups that aren't even restaurant groups yet. Yes, I'm suggesting investing in the hottest restaurant groups -- not of 2013 -- but of 2023.

Why diversification matters
Darden Restaurants (DRI -0.76%) is about as diverse as they come. Its three main concepts are Olive Garden, Red Lobster, and Longhorn Steakhouse, but it also runs several other chains through its specialty restaurant group. This wide range of options keeps things running smoothly even during difficult market times. For example, last quarter, same-store sales were only up 1.1% at Olive Garden but increased 3.5% at Longhorn.

Darden has achieved balance, and this is one of the main reasons the company performs well -- even during recessions. Below is a chart with the recession highlighted.

DRI Revenue TTM Chart

Darden revenue trailing-12 months data by YCharts

Unfortunately, Ruby Tuesday's (RT) diversification plans didn't pan out. At one point, the company had Ruby Tuesday's for American food, Wok Hay for Asian cuisine, Marlin and Rays for seafood, and newly acquired Lime Fresh for Mexican dining. All of this came crashing down in January when the company decided to close down Wok Hay and Marlin and Rays.

Poor financial results and mounting debt problems have led Ruby Tuesday to this point: Betting all of the chips on a sinking-ship concept. Last year, the company had to close eight Ruby Tuesday locations, and sales fell 3.1% at continuing locations. Keeping the company alive, in the meantime is the large amount of property it owns. The company has been able to sell this property off little by little -- $13.6 million worth last quarter -- to address debt and cash needs.

An investment in Darden is a relatively safe one, but it won't give investors a big growth story. The company plans to open 80 new units this year -- mainly Longhorn Steakhouse and Yardhouse -- but that's only 3.7% growth from the current level. Are there investments that give you a diversified safety net and growth?

Hottest restaurant groups of 2023
While not holding a crystal ball, my bold and unapologetic restaurant group predictions are Buffalo Wild Wings (BWLD) and Chipotle Mexican Grill (CMG -1.34%). Both companies aren't currently restaurant groups but are clearly progressing toward it.

Much ado has been made of Chipotle's ShopHouse Southeast Asian Kitchen concept since it opened in 2011. Management has been quick to point out that its growth strategy remains centered on the Chipotle brand. But while ShopHouse is still in the experimental stage, it's clearly moving forward. 

The company plans to operate eight locations by mid-2014 -- doubling the current count. The timing is excellent, as American consumers grow in their love for Asian food. But challenges remain. Specifically, a customized burrito assembly line works pretty well for Chipotle since most folks know what they want on a burrito. It may be less conducive to ShopHouse as people struggle to know which meat goes with which sauce and which rice goes with that authentic Hanoi Vietnam flavor.

Challenges and all, this concept is moving forward. Stephen Anderson of investing firm Miller Tabak believes that ShopHouse has potential to balloon into a chain of 300-400 units in the next 10 years. That would be a major success for Chipotle and just the second restaurant concept for this hot new restaurant group. What other concepts could the company dish up?

Perhaps just a ripple on investors radar in the second quarter of 2012, Buffalo Wild announced it was looking to acquire a new restaurant concept. In March, it made an investment in a three-location pizza chain called PizzaRev. In August, the craft-your-own-pizza chain disclosed that Buffalo Wild Wings is the company's first franchisee, and will open a location in early 2014 in the Minneapolis area.
 
I see this just as an experimental period for Buffalo Wild Wings. It wants to determine how effectively it can operate the pizza chain and how profitable the venture will be. The potential is huge. Fast-casual pizza is littered with competitors like Blaze Pizza and Live Basil, all trying to grab their slice of the growing pie (ahem), yet no fast-casual pizza chain currently has more than 30 locations.
 
And this is where Buffalo Wild Wings' huge advantage factors in. With the soon-to-be 1,000 Wild Wings locations, the company already has a restaurant infrastructure in place to grow PizzaRev. Any other pizza chain's growth will be limited to how fast the company grows its network. Considering Buffalo's $56 million cash on hand and no debt, I wouldn't be surprised if PizzaRev was bought out before 2015 followed by a quick expansion. 

Conclusion 
Many investors focus on how far Chipotle Mexican Grill and Buffalo Wild Wings can grow their respective flagship concepts, but these companies are moving toward something bigger. The current growth of these restaurants makes them compelling investments. The opportunities that await only make them more appealing.