HOUSTON -- Local 2 Investigates is going out to dinner -- giving you important information you've never seen before. Tonight, we're putting some Houston sit-down restaurant meals to the test. Are they actually more fattening than fast food?

We have the surprising results. Local 2 investigative reporter Amy Davis counts the calories and measures the fat you may never know you're getting.

The fast-food drive-through gets the bad wrap when it comes to a healthy meal, but at most fast-food restaurants you at least know what you're getting.

Pick up a Big Mac and fries at McDonald's, and the nutrition information -- the number of calories and amount of fat -- is right there on the packaging. The McDonald's Web site even lists the calories and fat for every item on its menu.

However, when it comes to many sit-down restaurants, we found that is next to impossible to find out anything about calories or fat.

That information is not on the menu, not on a handout, not even on many restaurant Web sites.

"It's hard to know," said Roberta Anding, a clinical dietitian who works at Texas Children's Hospital and for the Houston Texans. "The great thing is, when you have the nutrition facts available to you, it can help you make better choices and that's the reason for the information."

Without that information, Anding says, you're left to guess.

So, how would some of your favorite Houston restaurant meals compare to a Big Mac?

Local 2 Investigates put some meals to the test. We bought a salad at Cafe Express, a pasta dish at Bennigan's, and spaghetti at Olive Garden.

We bagged them, labeled them, and shipped the meals off to a food-testing lab. We tested each meal for its total calories and fat.

We compared them all to a Big Mac -- which has 540 calories and 29 grams of fat.

How did the restaurant meals match up?

We tested the grilled chicken and pasta pesto deli salad from Cafe Express.

Our test results show the salad has 660 calories and 33 grams of fat. That's more than 100 additional calories and a few grams more fat than a Big Mac.

"You think of chicken, you think of pasta as a reasonably healthy food," Anding said.

But she says the pesto and oils help the salad end up with 50 percent of the calories coming from fat.

"I think most people would be surprised, again, because of the ingredient list -- chicken, salad, pasta," said Anding. "You wouldn't think of those as high-fat foods, but it's the secret oil that's used in the preparation."

The next meal -- Olive Garden's spaghetti with meat sauce, along with a breadstick. The totals -- 770 calories and 16 grams of fat. That's more calories, but less fat than a Big Mac.

"That actually was a low-fat meal," Anding said. "The meat being used in that product must be lean because it didn't have a real high saturated fat content."

However, Anding says, don't think all spaghetti dishes are the same. When we checked the nutrition information released by Macaroni Grill, we found its spaghetti and meat sauce has 1,110 calories and 63 grams of fat.

"So, part of the dilemma is when I can't access that information, spaghetti is not spaghetti from restaurant to restaurant," said Anding.

We saved the most fattening meal for last. It's the cajun chicken and shrimp pasta from Bennigan's.

The totals -- 1,200 calories and 46 grams of fat. You could eat two Big Macs, or a Big Mac and large fries, and still have fewer calories than the pasta.

"My initial reaction is 'Wow,'" said Anding. "The illusion would be because it's chicken and shrimp, it's low calorie. It's the cream sauce and the large amount that they give you."

Anding says portion control is the key. She says don't be afraid to box up half your meal and you'll save half the calories and fat.

None of the restaurants in our test says it plans to immediately release nutrition information on menu items.

Here is the restaurant's full response to our test.

From Bennigan's:

"We are the first to admit that the majority of loyal customers eat at Bennigan's to feed their guilty pleasures. People who count calories are not our core audience. In fact, our most popular items include dishes like the battered and fried Monte Cristo sandwich and the Death By Chocolate dessert. For more than three decades, Bennigan's has remained the one real escape with license to indulge across the nation and around the world. Sure, we have lighter options on our menu. But even the strictest eaters deserve to have fun once in a while," said Flynn Dekker, Sr. Vice President of Marketing, Metromedia Restaurant Group.

From Cafe Express:

Cafe Express is based on the foundation of fresh, made from scratch food with a gourmet philosophy. Above all is the manner in which our food is prepared and the vast amount of fresh alternatives offered at the Oasis Table; which prove to be very accommodating to those who may be limiting overall fat intake but do not want to sacrifice flavor. We believe that our guests should be given the freedom and flexibility to personalize their food to their individual needs and desires. For instance, requesting the dressing or sauce on the side can easily lower the calories of any dish. The option for customization is one of the many beauties that Cafe Express brings to the table. No tricks, no games- just good food for a contemporary life style.

More On Tuesday At 10 p.m.

Our food test isn't finished.

Do you like fajitas? Tuesday at 10 p.m., we put a popular version to the test. Also, we'll see if an advertised low-fat meal is really low fat, or too good to be true. Don't miss Local 2 News at 10 on Tuesday.