Eating a meal quickly, as compared to slowly, curtails the release of hormones in the gut that induce feelings of being full. The decreased release of these hormones, can often lead to overeating.
Eating in excess is definitely harmful. Blood sugar levels will rise steeply with a large food intake. If you eat too much meat, this can also lead to the generation of more toxic substances called free radicals, which may cause cancer.
REFERENCES
Kokkinos et al. Eating Slowly Increases the Postprandial Response of the Anorexigenic Gut Hormones, Peptide YY and Glucagon-Like Peptide-1. Journal of Clinical Endocrinology & Metabolism, 2009; DOI: 10.1210/jc.2009-1018
Willie T. Ong, MD. Eat only until you’re half full. MIND YOUR BODY. (The Philippine Star). June 11, 2013