Some sleep problems may start at the table, says Elizabeth Somer, a registered dietitian and the nutrition correspondent for ABC's Good Morning America. Dietary habits, she asserts, can interfere with falling asleep and staying asleep, as well as the quality of sleep.

Spicy or gas-forming foods can cause heartburn or indigestion that disrupts sleep. Eating too fast can have the same effect. Monosodium glutamate (MSG), a flavor enhancer, may promote unusually vivid and disturbing dreams. Most people know that caffeine near bedtime can disrupt sleep. A single cup of coffee, tea, or caffeinated cola in early afternoon, Somer says, is all it takes to leave a caffeine-sensitive person wide awake at bedtime. Caffeine also acts as a diuretic and may prompt middle of the night trips to the bathroom. Alcohol near bedtime disrupts sleep, too, diminishing deep sleep and inducing frequent awakenings.

Some people awaken in the night needing a snack before they can return to sleep. The problem is not exclusive to small children. Cutting back too severely on calories in the daytime may foster this problem. You may be attempting to run on empty through the night's long fast. Protein-rich foods such as chicken or fish at dinner, plus a low-protein, high-carbohydrate bedtime snack such as air-popped popcorn or toast with jam, Somer suggests, may help break this cycle. Other tactics: even if you wake up hungry, don't eat. Read a book or drink some water instead.

Somer also addresses disturbed sleep and daytime fatigue in premenstrual syndrome, or PMS, and seasonal affective disorder, or SAD. Though cravings for sweets are prominent in both PMS and SAD, eating simple sugars may aggravate these disorders, she says. Complex carbohydrates such as sweet potatoes, corn, and whole-grain pastas and breads, however, may be helpful. In one study, women with PMS reported less fatigue, anger, and tension after eating a bowl of cornflakes than after eating a candy bar.

Somer's "Feeling Good Diet" aims to foster daytime alertness. The most important rule: eat breakfast. Your mother was right, Somer says. One in four persons starts the day without this meal. Skipping breakfast slows metabolism and leaves people feeling tired, sluggish, even cold, she reports. Even if you eat a relatively good lunch, you will not regain the energy you missed by not having breakfast. She includes suggestions for fast but healthy breakfasts, as well as recipes.

This book is a revised and updated edition of Somer's 1995 book. It provides a smorgasbord of information on the food and mood connection. Somer describes the action of brain chemicals involved in mood regulation, defining complex scientific terms in conversational language. She also provides charts and drawings to make the chemical pathways comprehensible. This presentation is a refreshing contrast to the jargon-laden prose in Lights Out, another nutrition book reviewed here this month.