What to eat?

What to eat before exercising:

The truth is, if you're exercising moderately for less than an hour, you really don't need to "fuel up" with extra food for the workout — especially if you're exercising in an effort to lose weight. But if you feel more energized when you've eaten beforehand, I suggest having something small, like a piece of fruit. A banana makes the perfect pre-workout snack because it's easy to digest and provides a good amount of potassium, an electrolyte that gets depleted when you sweat during physical exertion. Give your workout an extra boost by having caffeinated coffee or tea before you hit the gym. Caffeine essentially allows you to push yourself harder for longer while you're exercising and decreases perceived muscle pain during the workout. Drink one cup of coffee (or 2 cups of tea) at least a half hour before your workout to allow the caffeine time to absorb and work its magic.

What to eat before going to bed:

It's smart to avoid eating large, heavy meals late in the evening — they can make you feel uncomfortably full and keep you up tossing and turning — but a light snack (150 calories or less) with the right mix of ingredients can help you get a better night's rest. Among the best natural sedatives is tryptophan, one of the ingredients necessary for the body to make serotonin, a brain chemical that helps you feel calm and drowsy. The trick is to combine tryptophan-containing foods like turkey, milk, cheese, and eggs with carbohydrates, which help transport tryptophan into the brain, where it can make you sleepy. A plain rice cake (those are your carbs) with some low-fat cheese (that's your tryptophan source) is the perfect sleep-inducing snack. Also, sip chamomile tea in the evening: This calming brew appears to act as a mild sedative and may help relieve muscle tension and ease anxiety before hitting the sack.

What to eat before a long car ride:

When you know you're going to have to stay awake and alert for a long drive, it's a good idea to grab a lean caffeinated beverage, like a skim latte or a mug of black tea, to help you stay attentive and focused on the road. Caffeine levels peak 30 to 60 minutes after ingestion, so try to drink yours at least a half hour before you take off. You should also grab a protein-rich snack, since the protein has more staying power than other nutrients and will keep you from getting hungry as the ride drags on. I recommend 1-2 handfuls of almonds or roasted edamame (roasted edamame, which are roasted soybeans, have even more than protein than the nuts).

What to eat before a job interview or big test:

When you're looking for a breakfast meal that can enhance concentration and catapult you to the top of your mental game, think protein! New research shows that protein activates the cells in your brain that keep you alert and focused, so it's definitely key before a stressful exam or interview. For a truly protein-packed meal, enjoy a protein smoothie (blend together a 6-ounce container of flavored Greek yogurt, 3/4 cup skim milk, 1 cup fresh or frozen berries, and a handful of ice cubes). And consider coupling the smoothie with a plate of protein-rich scrambled eggs mixed with chopped tomato and smoked salmon. The omega-3 fats in the salmon don't give you an instant mental boost, but they do improve long-term brain health — so when you land the job after your power interview, your brain will be primed and extra sharp for your first day of work! Remember: Before an important work event, avoid experimenting with any new foods or eating a large fattening meal, gassy vegetables, high-fiber foods (unless you're sure they don't bother you)