The described effects of H. pylori on leptin and ghrelin, and postulated subsequent effects on satiety, energy expenditure, weight, and height. Although leptin and ghrelin have other important paracrine, autocrine, and endocrine effects, here we concentrate on actions that affect body habitus. The observed effects of H. pylori on leptin and ghrelin are based on observational and interventional (H. pylori eradication) human studies. Other observational human studies support the portrayed effects of H. pylori on weight and height.