Caraway, cayenne pepper, fennel, ginger and bitter greens, such as kale, collards, radicchio and arugula, are several natural stimulants that increase appetite when added to meals, according to HowStuffWorks. It also helps to drink at least eight glasses of water daily.
Bitter greens help improve a person's appetite by stimulating digestion and increasing production of digestive juices and enzymes, explains HowStuffWorks. Mustard, watercress, dandelions, sorrel and mizuna are several other bitter greens. To boost metabolism and appetite, an individual may add cayenne pepper to soups, deviled eggs and potato salad. Chewing on gingersnaps or drinking ginger ale are also good ways to improve appetite. Additionally, drinking peppermint tea made from a mixture of 1 tablespoon peppermint leaves and one pint jar of boiling water can stir a person's appetite.