No. Pooping after eating is not necessarily linked to having a fast metabolism. Metabolism refers to the process by which your body converts food into energy and burns the calories you ingest. This process includes all chemical reactions in your body, not just the digestive process.No. Pooping after eating is not necessarily linked to having a fast metabolism. Metabolism refers to the process by which your body converts food into energy and burns the calories you ingest. This process includes all chemical reactions in your body, not just the digestive process.