These breakfast foods, meanwhile, aren't likely to do anything for your mental alertness:

• Croissants (They're too fatty.)
• Bagels with cream cheese ("Cream cheese has almost no protein," Wurtman says.)

How about coffee for mental alertness? Coffee has been shown to increase reaction time, Wurtman says. But again, don't overdo. Drink too much, and you may be too scattered to concentrate on the task at hand.

To avoid a mid-afternoon slump, try adding these foods to your lunch:

• Chicken
• Turkey
• Lean burgers
• No-fat lunch meats
• Hard-boiled eggs (or eggs cooked any way without fat), plain or with no-fat mayo
• Bread, buns, or rolls (with a protein source)
• Greens and other vegetables. While alertness is a brain quality, meals must nourish the rest of the body, too, which means getting the fiber, phytochemicals, and other nutrients found in fruits and veggies.

Here are some lunch no-nos:

• French fries
• Cola and other sodas (A soda contains 16 teaspoons of sugar, and while the caffeine may provide a momentary blast of mental alertness, the sugar "lets you down" rapidly.)

As for dinner, that's generally a time when you want to slow down and relax. This is when carbs are OK, Wurtman says. To help you sleep better, try including the following foods:

• Potatoes
• Pasta
• Couscous
• Vegetables
• Beans and rice

One more nighttime note: If you plan amorous activities, cut out the fried stuff and heavy sauces at dinner, Wurtman says: "You will go from perky to pathetic."

Published June 6, 2003.

Sources: David N. Figlio, PhD, Knight-Ridder professor of economics, University of Florida, Gainesville. Ruth Kava, PhD, RD, director of nutrition at the American Council on Science and Health, New York. Judith Wurtman, PhD, director of a women's health program, MIT Clinical Research Center, Boston. Web site of Wurtman's private weight loss center: www.adaracenter.com. National Bureau of Economic Research web site: www.nber.org/digest/apr03/w9319.html.

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