This chapter will briefly consider the basics of good nutrition for the general population, the specific requirements for sports performers, and information about the benefits to the body of various food groups. The specific needs of the judoka are considered, in particular, training and competition day nutritional requirements. Discussion extends further on the specific nature of judo, considering issues around weight management, include the advantages and disadvantages of common weight loss techniques. Finally, there will be an explanation of issues around dehydration and effects on sporting performance, glycogen depletion and strategies to recover after a weigh-in.