Metabolism and Weight Control: What Really Works? Metabolism is the process by which the body produces and uses energy. Food goes through different nutrients in our body. For example, the process of consuming carbohydrates, fats, proteins, vitamins and minerals from these foods is called metabolism.   When the metabolism works at a slow pace, despite eating less, problems like weight gain, hair loss, low hemoglobin, insomnia, fatigue, etc. are seen. When the metabolism works fast, the body digests food quickly, energy is always high, fear is less, weight is under control and overall health is good. How to increase metabolism