Here are a few tips to help you eat the right food whether you're taking your morning walk, a long drive or a relaxing day off.

MORNING WALK

Wake up! Walking is one of the simplest ways of increasing physical activity and losing weight.

Objective: To feel awake, energized, confident and strong.

Pick these foods: Water and 100 percent orange juice or an orange or banana.

Why? "Your cells need water in order to move nutrients in and out for energy and make your exercise productive. Orange juice can also hydrate the body, and, in addition, the carbohydrate gives you a quick burst of energy to fuel the muscles," says Lona Sandon, a professor of nutrition at the University of Texas Southwestern Medical Center at Dallas. A banana does the same but adds fiber. And orange juice, oranges and bananas are also good sources of potassium, which your muscles require to do their work.

When to eat: 30 to 60 minutes before heading out.

How much to eat: 1 to 2 cups of water along with one medium banana are all you need. One cup of orange juice (or an orange) will give you about 120 calories and 30 grams of carbohydrates.

Avoid these foods: Eggs, bacon, cheese, high-fiber foods.

Why? Foods high in protein, fat and fiber need more time to empty from the stomach, and a full stomach can make it difficult to walk briskly. You may even get cramps, says Sandon.

A LONG DRIVE

Some people are naturally alert drivers. Then there are others who act like they have taken a horse tranquilizer as soon as they get behind the wheel.

Objective: To stay awake and alert.

Pick these foods: For a two- to four-hour drive, have a banana, almonds or almond butter spread on a whole-grain cracker, a liter of water and semisweet dark chocolate.

Why? These are quick "picker-uppers" to keep your eyes open, your mind clear and your body feeling refreshed, according to Dr. Susan Lark, author of "Hormone Revolution" (Portola Press, 2007). "Bananas' high potassium content helps maintain nervous system function and combats fatigue. Almonds deliver a power punch to your system in the form of fiber, protein and good fats that ramp up your metabolism without shocking your blood sugar. Cool water helps to clear the brain, flush out toxins caused by stress, and energize you. A square or two of semisweet dark chocolate (at least 70 percent cocoa content) will lift you out of a deep energy and mood funk, and the antioxidants will revitalize you cell by cell."

When to eat: Alertness is all about slow delivery and gradual elevation of blood sugar and brain chemicals. You can pop a few almonds when you start to feel drowsy. Then eat half a banana. Then a square of chocolate. Listen to your body.

How much to eat: Think of these foods as pellets of fuel to use only when your energy starts to wear down. The idea is to stay awake, keep positive and not get ragged from lack of food or too much junk in your system.

Avoid these foods: Simple carbs (bagels, cookies and baked goods) or anything with a lot of sugar, including soda and coffee.

Why? "Although we associate these foods with 'energy,' studies show that the quick spike in blood sugar results in an equally quick dip in mood, alertness and energy. What goes up, as they say, must come down. Salty junk foods, such as chips, will also depress your energy levels. Junk foods are filled with unhealthy fats that bog down your organs and make your energy drag," says Lark. As far as caffeine, it's good to keep you awake, as long as it's not one of the fancy high-calorie versions.

A RELAXING DAY OFF

Days off are times to slow down and take life at your own pace.

Objective: Find foods that will leave you feeling relaxed, lazy, content and happy with your spoiled-cat life.

Pick these foods: Sandon suggests herbal tea, toast or an English muffin with jam, fresh fruit topped with yogurt, and cold water with fresh-squeezed lemon.

Why? The warmth of a noncaffeinated herbal tea can help you relax. Keeping your breakfast light will prevent you from feeling full and sluggish, and since you plan on relaxing most of the day, you can get by with fewer calories. "The carbohydrates will give you just enough energy to lie in that lounge chair while encouraging the hormone serotonin to relax the mind. Keep a thermos of cold water with fresh lemon nearby to stay hydrated," says Sandon.

When to eat: Upon waking, slip into your comfy loungewear and sip your tea slowly throughout the morning, recommends Sandon. Take your time enjoying your fresh fruit and yogurt over a period of 30 minutes to an hour. Sip cold refreshing lemon water throughout the day.

How much to eat: Keep portions small. Have either the English muffin and jam or 1 to 1 1/2 cups of sliced fruit with a cup of yogurt.

Avoid these foods: Espresso, bacon and sausage, alcohol.

Why? The caffeine in the espresso may leave you feeling jittery — just what you were trying to avoid. "Fatty meats such as bacon or sausage can leave an uncomfortable heavy feeling in your stomach because they take longer to digest," says Sandon. Alcohol can cause you to become dehydrated, leaving you feeling nauseated and weak.

Charles Stuart Platkin is a nutrition and public-health advocate, and author of "Breaking the FAT Pattern" (Plume, 2006). Sign up for the free Diet Detective newsletter at www.dietdetective.com.