Resumen
The third world countries are not just suffering from food shortage, they are also plagued by malnutrition which stems from poverty coupled with inadequate informations about the nutritional contents of foods consume by most of her populace. Yam is a stable food consume by millions of Nigerians and the decision of which species to consume is often based on palatability and availability. Proximate analysis was carried out on D. rotundata., D. cayenensis and D. alata to compare their protein, carbohydrate, moisture, crude fibre, fat and ash content. The result reveals that Carbohydrate content of D. cayenensis (50.60%) was higher when compared to D. rotundata (48.8%) and D. alata (36.02%). Also, the crude fibre of D. alata (5.26%) was significantly higher compared to D. cayenensis (4.86%) and D. rotundata (4.75%), similar result was obtained for the protein content of D. alata; which was 3.46% compared to D. cayanensis (2.13%) and D. rotundata (1.61%) respectively. This research concludes that the proximate composition of the Dioscorea species studied varied significantly. Yam consumers and nutritionist are advised to select their yam species in view of the various proximate constituents to achieve a well balance diet in terms of food and composite flour. The cultivation of the D. alata species should be encouraged because of its low Carbohydrate and high protein contents, thus making it suitable for diabetic patients or people suffering from related illnesses.