Build and maintain more muscle mass with regular strength training
Eat enough calories to avoid chronic under-eating
Prioritize protein at each meal
Stay physically active throughout the day
Add high-intensity interval training if appropriate
Get enough sleep every night
Manage stress consistently
Drink enough water
Eat regular meals if that helps you avoid overeating or energy crashes
Avoid extreme crash diets
Limit long periods of sitting
Include nutrient-dense foods in your diet
Keep alcohol intake moderate
Get checked for thyroid or other medical issues if metabolism feels unusually slow