Act as a certified nutritionist with 10 years of experience in metabolic health. Provide a comprehensive guide on how to boost metabolism naturally, tailored for [TARGET AUDIENCE: busy professionals, athletes, or seniors]. Include [SPECIFIC METHODS: dietary changes, exercise routines, and lifestyle habits] backed by scientific research. Explain the role of [KEY FACTORS: hydration, sleep, and stress management] in metabolic rate. Offer practical tips and a sample daily plan. Ensure the advice is easy to follow and adaptable for different [DIETARY PREFERENCES: vegan, keto, or gluten-free].