While trading stocks based on speculative employment figures doesn't make for a sound long-term Foolish investment strategy, paying attention to where jobs are being added and taken away can guide investors toward sectors that may stand strong during dismal economic times. After all, rising unemployment is a key indicator of a recession, so keeping a close eye on industries that aren't rapidly losing jobs could provide a great starting point of where to invest when the economy isn't in its healthiest stage.

The March employment report was pretty grim, with 80,000 jobs lost during the month. As one would expect, job losses occurred in the construction, manufacturing, and employment services, while health care, food services, and mining continued hiring. While unemployment levels are sitting at a five-year high, there's a positive twist to this story. Avoiding the industries that are losing jobs, and focusing on those gaining jobs, or at least remaining stable, can be helpful when deciding where to invest.

Health care heats up
For example, the health-care sector added 23,000 jobs in March, with hospitals introducing 14,000 new roles. It's not just a monthly gain, either -- the health-care industry has added 363,000 jobs in the past 12 months. That's pretty impressive in today's market.

Accordingly, the health-care industry looks like a great place for long-term investing, with a recent study by the Centers for Medicare and Medicaid Services (CMS) estimating that both public and private health-care expenses are expected to outpace the economy for the next 10 years, with an average annual increase of 6.8% in health-care spending vs. a 4.9% increase in the GDP.

This expected growth is good news for companies like Quest Diagnostics (NYSE: DGX) and UnitedHealth Group (NYSE: UNH), who are both close to 52-week lows. While these companies probably aren't the best of friends after Quest lost its contract with UnitedHealth to rival LabCorp (NYSE: LH), both medical diagnostic testing and managed-care services are strong groups to consider in light of continued expected health-care spending increases. The prices are relatively low compared to historical averages, with a forward P/E ratio of less than 10 for UnitedHealth, and a forward P/E of 14.5 for Quest.

Food services serves up a winner
I was pretty surprised by this myself, but people need to eat, even if in a recession. Food-service roles increased by 23,000 in March, with the industry hiring 288,000 in the past year. While the addition of these jobs doesn't do a lot to boost the economy, since these are lower-paying, high-turnover roles, this is an interesting sector to consider. The National Restaurant Association predicted a 4.4% increase in restaurant sales in 2008, with a 4.3% increase in full-service restaurant sales, a 4.4% increase in quick service restaurant sales, and a 6.8% increase in snack and beverage shops.

So, with a forecasted higher-than-average increase in beverage and snack sales, Starbucks (Nasdaq: SBUX) and McDonald's (NYSE: MCD) are probably your best choices as the economy turns south. (And if you don't like the investing option in food services, then at least you know you have an opportunity to get a second job to pay for that $4 gas we might be seeing this summer.)

Mining some profits?
The mining industry, particularly oil and gas extraction, saw a job increase of 6,000 for the month of March. Natural gas producer Chesapeake Energy (NYSE: CHK) has raised its 2008 and 2009 production forecasts, with plans to increase production by 21% in 2008. Last week, Chesapeake announced plans to expand its Fort Worth office space, further demonstrating expansion prospects.

Coal producers like CONSOL Energy (NYSE: CNX) are also an interesting consideration, as coal prices remain much lower than oil and natural gas and international coal demand increases. CONSOL has already seen huge gains, with a stock price that has more than doubled in the past year and a trailing P/E over 50.

So, even though the unemployment rate is at 5.1% and the economy lost 80,000 jobs last month, all is not lost. For now, health care, food service, and mining are three sectors actually seeing growth and are worth a look in identifying strong investing opportunities.

Quest Diagnostics, Chesapeake Energy, and Starbucks are Inside Value selections. United Health, Lab Corp, and Starbucks are Stock Advisor picks. The Fool owns shares of Starbucks. Looking for more advice in a topsy-turvy market? Give The Motley Fool's newsletters a try via the 30-day free trial.

Fool contributor Colleen Paulson owns shares of Quest Diagnostics but is not invested in any other company mentioned in this article. The Fool's disclosure policy is always optimistic.