A slow metabolism is recognized as the inefficiency of fat burn in your body resulting in fat preservation. This leads to gradual weight gain and increased body fat.
How much fat your body stores is regulated by a complex and powerful hormonal system. In normal circumstances, your hormonal system works at keeping your body fat mass within a reasonable range. In addition to regulating appetite and caloric intake, these hormones regulate how much fat you burn even when you are not doing anything (Basal Metabolic Rate). These major hormones include:
• Leptin: Produced in the fat tissues, it has two major roles: Suppressing appetite and speeding up metabolism. It promotes fat burn, facilitating weight loss.
• Thyroid Hormone: Produced by the thyroid gland, is the most potent hormone that makes you burn unnecessary fat and speed up your metabolism.
• Ghrelin: Predominantly produced by the stomach, it has two major roles: Stimulating appetite and increasing cravings. It slows down metabolism and fat burn, as opposed to Thyroid Hormone and Leptin.
Other important hormones that regulate appetite and metabolism include growth hormone, insulin, cortisol, and sex hormones such as estrogen, testosterone, etc…