Nutrient Profile of Some Local Leafy Vegetables Consumed By Ethnic Groups in Bangladesh

Good health needs a balanced diet. Therefore, it is important to identify the food sources of various nutrients that are required for the maintenance of good health and make it available to the mass population. Information about the composition of food is essential for dietary recommendation and supplementation of food. Reliable data on the nutrient composition of foods consumed by people are critical in many areas such as health assessments, formulation of appropriate institutional and therapeutic diets, nutritional education, training and research, plant breeding and food manufacturing. A food composition database (FCD) provides essential information on the nutritive value of foods. It provides values for energy and nutrients (e.g. protein, Fat, Carbohydrate, vitamins and minerals) and other important food components or bioactive compounds that are important for human nutrition. On the whole FCD provides the basis for planning food, nutrition and health related policy tools. The earliest known food composition table was produced in 1818 (Somogyi, 1974). The current knowledge of nutrition is still incomplete, and studies are still required, often at ever increasing level of sophistication, into the composition of foods and the role of these components and their interactions in health and diseases (Greenfield and Southgate, 2003a).

Macronutrients "carbohydrate, protein, and fat" are essential for health, growth, heating, and immune function. Too little or too much of any of these macronutrients may result in poor health and a variety of diseases.
Protein Proteins are complex molecules and the body needs time to break them down. This is why they are a slower and longer-lasting source of energy than carbohydrates. According to the Dietary Reference Intakes (RDI) published by the Unites States Department of Agriculture (USDA), adults need to eat about 56grams of protein per day Adults who are physically very active or trying to build muscle need slightly more. Children also need more. If more protein is consumed than is needed, the body stores its components as fat, which can be broken down and used for energy as need arises. Proteins are broken down during digestion, which exposes them to acid in the stomach and to degradation by the action of enzymes called proteases. Some ingested amino acids are converted to carbohydrates (gluconeogenesis), which is also used under starvation conditions to generate glucose from the body's own proteins, particularly those found in muscle.

Protein supports the growth and maintenance of the body. The amino acids that make up proteins are used for building DNA, cell membranes, hormones, receptors, brain chemicals, and many other molecules in the body. Protein is also the second largest source of stored energy (second to fat cells) because of the large amount of muscle that is a steady source of amino acids. Besides providing energy to the body, dietary protein is also required for growth—especially by children, teenagers, and pregnant women, tissue repair, immune system function, hormone and enzyme production. When eaten, the proteins contained in foods are broken down into amino acids, an important dietary source of nitrogen. To make the proteins that it needs (protein biosynthesis), the body also needs them. There are 20 amino acids and the body can make some of them from components within the body, but it cannot synthesize nine of them, accordingly called the "essential amino acids" since they must be provided in the diet. They include: histidine, isoleucine, leucine, methionine, phenylalanine, threonine, tryptophan, and valine. Protein that comes from animal sources are called "complete proteins" because they contains all of the essential amino acids while protein from plants, legumes, grains, nuts, seeds and vegetables are called "incomplete proteins" because they are lucking one or more essential amino acid(s).