Do We Need Full Protein In Our Diet?

Carbohydrates, fat and protein are essential macronutrients and sources of calories in your diet. Proteins are made up of amino acids, and some of the amino acids are considered essential, because your body cannot produce them. You can meet your amino acid needs by eating complete proteins or by eating a variety of foods with incomplete protein. If you have concerns about your diet, a nutritionist can advise you.

Background

You need protein for maintaining your muscle mass and other body tissues, for a strong immune system and for reactions in your body to occur properly. Proteins provide 4 calories per gram, and a balanced diet should get about 10 to 35 percent of its calories from protein, according to the Institute of Medicine. Proteins from animal sources, such as meat, poultry, fish, shellfish, eggs and dairy products, are high-quality, or complete, because they provide each of the nine indispensable, or essential, amino acids.

Essential Amino Acids

The essential amino acids are histidine, leucine, isoleucine, valine, threonine, methionine or cysteine, phenylalanine or tyrosine, tryptophan and lysine, according to the Institute of Medicine. The daily requirement for each of these amino acids is expressed terms of milligrams of amino acid per gram of protein that you eat. The proteins in nuts, seeds, grains, legumes and vegetables are low in at least one of the essential amino acids, but a range of plant-based foods with incomplete proteins can supply the amino acids you need to get from your diet.

Protein Combining

Protein combining, or protein complementation, describes the principle of eating different incomplete proteins in order to get all of the essential amino acids, notes the University of Maryland. To combine proteins, eat multiple kinds of incomplete proteins to form a complete protein. Some examples are a peanut butter sandwich on whole grain bread, beans and rice, a bean burrito and falafel on pita. You do not need to get each amino acid at each meal, but you should get most of them throughout the day.

Other Information

Even if you are avoiding all animal products, you can get complete protein from soy, which is a plant-based food. Soy provides high-quality protein, and examples include soy-based vegetable burgers, tofu, soymilk, soy yogurt and tempeh, according to the University of Michigan. The only natural sources of vitamin B-12 are animal-based products, so if you are following a vegan, or strict vegetarian diet, be sure to get vitamin B-12 from fortified foods, such as cereals, or supplements, according to the Mayo Clinic. Another supplement for vegetarians to consider is a fish oil supplement for heart-healthy, long-chain omega-three fatty acids.