This chapter discusses the role of carbohydrates in nutrition, with particular emphasis on grains and their importance as a source of protein, fiber, and micronutrients. It also explores the negative effects that gluten, a storage protein found in grains, can have on some individuals, leading to disorders such as celiac disease, wheat ataxia, wheat allergy, and dermatitis herpetiformis. The primary treatment for such conditions is to remove gluten from the diet, but this can lead to a reduction in fiber intake and an increase in fat intake. The chapter then looks at the important role gluten plays in dough rheology, particularly in baking, and considers the challenges faced by those who must follow a gluten-free diet. Finally, it examines the potential of pseudocereals such as quinoa, amaranth, and buckwheat as substitutes for gluten-containing grains with their potential usage in the food industry and daily nutrition routines.