Nutrition is a biological process that utilizes the nutrients provided by food or other sources for the survival and growth of the organism. The arena of scientific pursuits in nutrition as a science very broad. People from a wide variety of fields specializes in specific areas of nutrition that are related to their original field of study may call themselves nutritionists e.g. veterinary scientists, plant scientists, food scientists, physicians, pharmacists, biochemists may all be titled nutritionist after getting some expertise in nutrition though they have very diverse expertise in relation to nutrition. In most countries of the world there are no strict rules for using the title nutritionists.

Human nutritionists study about various aspects of human nutrition and have much more comprehensive knowledge than the other kind of Nutritionists. However, not all graduate programs in human nutrition are designed to prepare specific nutrition care professionals.

Dietitians-Nutritionists are human nutritionists who study broad aspects of human nutrition and are trained to serve as Human Nutrition Care professionals. Dietetics is the oldest human nutrition profession that is regulated in many countries and has well established standards of education and practice. Dietetics as a field of study started as an area of specialization of home economics. Thus still in many countries graduates of home economics with major in dietetics are fit for serving as Dietitian Nutritionists. Dietitian-Nutritionists are provided comprehensive education and training that enables them to work as clinical Nutritionist, Community nutritionist and as in the food service and food production industries.