You may have swapped out empty carbs for kale and quinoa, but it's no longer simply about which foods you eat. "Consume the right nutrients at the right time intervals and you'll reap rewards," says Haylie Pomroy, author of The Fast Metabolism Diet and a nutritionist whose clients include Robert Downey Jr. and Jennifer Lopez. "When you eat helps dictate whether you store calories as fat or burn them off," says JJ Virgin, author of The Virgin Diet. Here, your ideal schedule.

START EARLY. Dehydration can slow your metabolism and raise stress hormones, explains Virgin, who recommends drinking 16 ounces first thing and sipping throughout the day. The one exception is mealtime, for which she suggests no more than 8 ounces: "If you drink too much during the meal, you dilute your stomach acid and impair digestion."

What to eat: A protein-based breakfast that also includes carbs and healthy fats. Pomroy recommends a wrap (three egg whites plus one whole egg, spinach, hot chilies, half an avocado, and black beans in a whole-grain tortilla), plus a cup of strawberries.
Why you need it now: Eating a protein-dense meal within an hour of waking can jump-start your metabolism, help suppress the stress hormone cortisol, and prevent cravings later in the day, according to John Berardi, Ph.D., the founder of Precision Nutrition in Toronto.

What to eat: A protein-rich combination of fiber and healthy fat. Think hummus and sliced bell peppers or 15 pecans and a small banana.
Why you need it now: Fiber feeds the good bacteria in your gut, detoxifies you, lowers cholesterol, and increases satiety by slowing down stomach emptying. Virgin recommends clients work up to a daily intake of 50 grams a day.

What to eat: Equal parts protein and veggies, such as spinach salad with grilled salmon, a half-cup of chickpeas, cherry tomatoes, onions, mushrooms, and vinaigrette dressing, or a Mexican salad with greens, fajita vegetables, grilled chicken, black beans, guacamole, and salsa. Have an apple or a tangerine for dessert.
Why you need it now: Protein and vegetables are a midday dream team—the pairing spikes metabolism and fat burn. Avoid grain-based carbs between breakfast and dinner to absorb other nutrients more efficiently.

What to eat: A combo of healthy fats and protein; for example, three ounces of turkey jerky and a handful of almonds.
Why you need it now: A pre-workout snack of fat and protein helps break down amino acids, which are then used to build lean muscle. Just be sure to fuel up 30 minutes to an hour before exercise, so your digestive system doesn't sap your body's energy levels.

BREAK A SWEAT. A new study from UCLA's Brain Research Institute using mice found that afternoon exercise was most beneficial in regulating the body's circadian rhythms, which affect metabolic function. Late afternoon is also when cardiovascular and muscle strength are greatest.

What to eat: A high-protein, high-carb meal that's low in fat. Some good options: six to eight ounces of filet mignon, a small sweet potato sprinkled with cinnamon, and a cup of sautéed spinach with olive oil, or ground turkey in a whole-wheat tortilla with black beans, salsa, avocado, and arugula.
Why you need it now: "After a high-intensity workout, there is a magical period of heightened carb tolerance," Berardi explains. "Carbs are stored as energy and used to promote recovery, and you almost exclusively burn fat." Grab dinner shortly after exercising, as this fat-incinerating window lasts between one and three hours.