BOSTON -- You know you should watch the fat and calories in your diet. Now by sending a simple text message, your cell phone can be the latest tool to help you keep your nutritional information in check.

Launched this week by Diet.com of Brookline, the service is called Nutrition On the Go. With a simple text message, you can access the nutritional information on thousands of restaurant foods and drinks, helping you decide if you should order that blueberry muffin or stick to just a nonfat latte.

"It's a brand new text messaging service where you can get nutrition info for 1,700 restaurants and 36,000 menu items at restaurants nationwide," said Diet.com marketing director Meredith Oliver. "Starbucks, we have Dunkin' Donuts. We have Bruegger's Bagels, McDonalds, Burger King. Mostly a lot of chains are in the system right now."

According to Diet.com, if you're at McDonalds and want to choose between the Southwest salad or the grilled chicken sandwich, type in the numbers 3-4-3-8-1, or "D-I-E-T ONE." Then type in the restaurant name, along with the menu item. Diet.com said they will text you back with the fat, calories, carbohydrates and protein analysis of the item in less than one minute.

Oliver said Diet.com compiles its data from the USDA Web site, as well as from the restaurants themselves. She said the service is free from Diet.com, but charges depend upon your cell phone text messaging plan. Oliver hopes it will help people make more informed food choices.

"They do want to eat healthy, but they don't necessarily have the information that they need at their fingertips," said Oliver. "This is going to enable people to make the smarter decision."