Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you're worried about what the economy might do next and want to add more defensive stocks to your portfolio, the Focus Morningstar Consumer Defensive Index ETF (NYSE: FCD) could save you a lot of trouble. Instead of trying to figure out which companies will perform best, you can use this ETF to invest in a lot of them simultaneously. Its defensive holdings offer products and services that consumers tend to buy in any kind of economy -- e.g., shampoos, cigarettes, and soft drinks.

The basics
ETFs often sport lower expense ratios than their mutual fund cousins. The Focus Morningstar ETF's expense ratio -- its annual fee -- is a very low 0.19%.

This ETF doesn't have a sufficient track record to assess, though, as it's very young. As with most investments, of course, we can't expect outstanding performances in every quarter or year. Investors with conviction need to wait for their holdings to deliver. The fund is very small, too, so if you're thinking of buying, beware of occasionally large spreads between its bid and ask prices. Consider using a limit order if you want to buy in.

With a low turnover rate of 4%, this fund isn't frantically and frequently rejiggering its holdings, as many funds do.

What's in it?
Plenty of defensive consumer companies had strong performances over the past year. Philip Morris International (NYSE: PM), for instance, gained 36%, with many investors favoring it over its domestic cousin, Altria (NYSE: MO). New FDA regulations will make life harder for Altria, making Philip Morris all the more attractive. With the giant Marlboro brand, among others, it boasts big and growing profit margins.

Despite headwinds such as tougher regulations, steep cigarette taxes, and the somewhat fading popularity of smoking, U.S.-focused Altria also did well over the past year, gaining 23%. The company has been cutting costs and boosting its dividend. It has also been diversifying into areas such as smokeless tobacco, cigars, and even wines.

Other companies didn't do as well last year but could see their fortunes change in years to come. Walgreen (NYSE: WAG), down 19%, has been whacked ever since it parted ways with Express Scripts and lost tens of millions of prescriptions and billions of dollars. There's talk that the two might reconcile, though, which could benefit them both. In the meantime, the company recently signaled its confidence via a 29% dividend increase.

Archer Daniels Midland (NYSE: ADM), down 10%, has seen its profit margins squeezed by rising input costs that it hasn't been entirely able to pass on to customers. Making matters worse, experts expect cocoa prices to surge in the near future, which will hurt companies such as ADM.

The big picture
Demand for defensive consumer offerings isn't going away anytime soon -- sort of by definition. A well-chosen ETF can grant you instant diversification across any industry or group of companies -- and make investing in and profiting from it that much easier.

Learn about "4 ETFs You Can Count On." And if you're looking for some great investments beyond ETFs, consider these "5 Stocks Growing Their Dividends by 20% Per Year."