Healthy choices. My father taught me a great dietary system. He said "eat like a king in the morning, a prince in the afternoon, and a pauper at night." dinner should be your lightest meal. Don't starve yourself, that slows metabolism, eat healthy snacks between meals. Exercise to build muscle. Hydrate! b vitamins, coq10 (gives your muscles energy) and green tea or mate tea.
Speed metabolism. Weight training builds lean muscle which is metabolically active around the clock, day and night. While some studies suggest that cardiovascular exercise may stimulate the metabolism for as much as 48 hours after the exercise, it may be much less time. Both are best in combination. As well, eating a small healthy meal of lean protein and complex carbs every 2-3 hours speeds the metabolism.