What will happen if you eat too much rice and alternative?

Countries that use rice as their main food source will typically have beta-carotene deficiency, which is quite harmful if left untreated. In countries where rice is not a main food source, the only problem with eating too much rice is weight gain (or possibly vitamin/mineral deficiencies, if eating so much rice prevents eating a varied diet). Alternatives include quinoa (pronounced "keen-wah"), which is higher in protein and has a slightly nutty texture. Also, polenta (cornmeal/maize/maizemeal) is a tasty and versitle alternative. Or couscous (a wheatgrain food). Bulghar wheat is also a good alternative (also a wheatgrain food).