• Breakfast: Studies have provided good evidence that a healthy breakfast leads to better cognitive performance, especially in children.
• Regular meals: Keeping your blood sugar even by eating regularly — about every four hours — will help keep your mood level all day. Conversely, skipping meals and eating erratically will lead to highs and lows. "Your eating pattern, as well as the quality of food you eat, will have a bigger effect on your mood than any one food," says registered dietitian Elizabeth Somer.
• A balanced diet: When the brain is deficient in nutrients, mood and concentration are the first to go. "If a person has a nutritional imbalance, fixing that imbalance will make a positive difference," says John Fernstrom, professor of psychiatry and pharmacology at the University of Pittsburgh School of Medicine.
• Exercise and rest: "Eating a healthy diet, exercising and getting enough sleep are what make people feel more alert, focused and energetic," says food researcher Marcia Pelchat of the Monell Chemical Senses Center in Philadelphia. "There is no magic food."
• Believe: "There's nothing wrong with the placebo effect," says Tufts University psychologist Robin Kanarek. "If you think eating more fruits and vegetables will make you feel better about yourself, I recommend it."