Research shows that eating a good breakfast is critical to a healthy lifestyle. According to a study in the American Journal of Epidemiology, people who skip breakfast are 4.5 times more likely to be overweight than those who don't.

However, we have busy lives and sometimes a fast-food breakfast may be the only option. With that in mind, here are some choices that won't leave you feeling guilty.

(As a point of reference, a person who needs 2,000 calories per day to maintain weight should aim for a breakfast of approximately 500 calories, with less than 16 grams of fat.)

MCDONALD'S

The classic Egg McMuffin is actually a pretty good deal at only 290 calories. If you must add butter, use only half a pat and spread it on the egg (not the muffin). You'll use less without losing the flavor. Some McDonald's outlets serve their Fruit 'n Yogurt Parfait dessert all day (160 calories).

Fit tip: Stay away from the hotcakes and sausage at 770 calories, the cinnamon roll at 420 and especially the Deluxe Breakfast, which packs 1,220 calories. And avoid hash browns at 140 wasted calories for less than 2 ounces. Spend those calories on something more substantial.

DUNKIN' DONUTS

Yes, it's even better to grab a doughnut than to skip breakfast altogether. Go for either the Black Raspberry or the Bavarian Kreme, 210 calories each. A chocolate-frosted doughnut is just 200, while a plain glazed is 180. Remember: Cake doughnuts have twice as much fat as and up to 170 more calories than yeast doughnuts. Dunkin' Donuts outlets also offer an Egg and Cheese English Muffin, which has less sugar than a doughnut and, with 280 calories and 15 grams of protein, is your most filling choice.

Fit tip: Avoid fancy coffee drinks that pack on calories. Iced coffee (regular or flavored) with skim milk is fine (about 35 calories without sugar, 80 with sugar). Skip the muffins; they have 300 to 600 calories and probably will not keep you full. Also watch the bagels — including reduced-carb with cheese at 380 calories, multigrain at 380 and sourdough at 370 — once you add butter or cream cheese, you're at almost 600 calories. Try the lower-calorie onion bagel at 320 calories. Use lite cream cheese and save 80 calories per serving over regular cream cheese.

STARBUCKS

The fruit cups offer healthy fruits. If you stick to skim milk and Splenda in your coffee, you can get away with coffee and a low-fat muffin for less than 400 calories, a good deal if it holds you until lunch.

Fit tip: Watch out for the baked goods, which can have almost 700 calories. Bagels start at more than 400 calories before you add butter or cream cheese. Croissants have around 330 calories. And be careful of the drinks: A Venti Mocha Frappuccino with whipped cream is 590 calories for 24 ounces.

JACK IN THE BOX

At 290 calories, the Breakfast Jack sandwich (ham, egg and cheese on a bun) is a pretty good choice. You can even get away with the Meaty Breakfast Burrito for 480 calories. It's not the best, but for the amount you get, the calorie cost isn't bad. As always, hold the cheese, sausage or bacon to trim the calories.

Fit tip: Watch out for the Extreme Sausage Sandwich, which breaks the bank at almost 700 calories. And steer clear of the Sausage, Egg & Cheese Biscuit — at almost 750 calories, it can crash your diet before you've finished your morning coffee.

JAMBA JUICE

Smoothies can be pretty healthy and very filling, but avoid those made with ice cream, whole milk or cream, nuts or peanut butter. The Strawberry Nirvana is a great deal at 160 calories for 16 ounces, and the vitamin-packed Powerboost comes in at 280 calories.

Fit tip: Watch out for the Peenya Kowlada at 460 calories, the Chocolate Moo'd at 500 and the Peanut Butter Moo'd at 540 unless they are all you're eating for breakfast, in which case they could be fine. (Hawai'i locations recently began serving several new breakfast items, called "Breakfast Blends": Matcha Momentum, with 360 calories for 24 ounces, and Acai Eye-Opener, with 350 calories at 24 ounces.)

Charles Stuart Platkin is a syndicated health, nutrition and fitness writer. Staff writer Mary Kaye Ritz added Hawai'i information to this report.

Reach Charles Stuart Platkin at info@thedietdetective.com.