Dietary Protein

단백질보충제 Dietary protein provides organic nitrogen and the essential amino acids. Current dietary protein RDAs are set to prevent deficiency in healthy individuals.


High-protein diets may reduce hunger, as they promote the release of satiety hormones such as cholecystokinin and peptide YY. Additionally, higher protein intakes may lead to lower blood urea nitrogen concentrations.


Proteins are complex molecules made up of amino acids (Figure 3-1; the letters are abbreviations for the 20 different amino acids). The amino acid side chains have various characteristics, some polar, some non-polar or hydrophobic, and some positively or negatively charged.

The core of the protein is a polypeptide chain that consists of amino acid residues linked together by peptide bonds. The peptide bonds form a local secondary structure that is stabilized by hydrogen bonds. The structure is generally a series of twisted or bent regions known as helixes or sheets.

Proteins perform many important functions in the body. For example, they provide structural support for cells and tissues, transport certain substances in the blood and across cell membranes, and manufacture enzymes. They also produce antibodies that recognize and help destroy antigens, such as bacteria and viruses. Proteins are found in a wide variety of foods, including meats, fish, dairy products, beans, nuts, seeds and whole grains. The quality of proteins varies, with animal foods providing higher quality protein than plant foods. Foods that contain complete proteins, meaning they supply all of the essential amino acids, are called high quality proteins.


Meat is animal flesh that has been sliced and prepared for human consumption. It can include all edible internal organs, tongues and even brains (although these are typically not eaten). There are different specialized terms used to identify the meat of different animals.

Red meat is a source of complete protein (containing all nine essential amino acids) iron, zinc, selenium, Vitamin B12 and calcium. It is also a high-energy food that can provide up to 340 calories per serving.

When consumed in moderation, consuming lean meats is part of a healthful diet. However, people who eat too much meat may be at increased risk of heart disease and cancer.

Cultivated meat is made from cells that have been stimulated to differentiate into skeletal muscle, fat and connective tissue using various stimuli, such as hormones or scaffolding structures. These cells are then harvested, and ground into a product such as beef or chicken. The process of culturing is still being refined, and it is estimated that a commercially available product could be on the market by 2022.


Fish are a low-fat protein that’s loaded with nutrients. They’re a good source of omega-3 fatty acids, as well as B vitamins and calcium. Plus, they’re a great source of lean protein, which helps build and maintain muscles.

The dietary intake of fish has a major impact on hormonal and metabolic homeostasis. They are a unique source of nutrients with significant endocrine functions, such as iodine, selenium, vitamin D, omega-3 fatty acids, taurine and carnitine. Furthermore, they have a high biological value and provide satiety, help control appetite and produce smaller glycemic excursions after meals.

Studies show that eating fish (preferably fatty) two or more times a week provides many health benefits, including heart-healthy omega-3 fats and vitamins D and B2. Fish also can reduce your risk of autoimmune diseases. However, people should choose fish that are low in contaminants, since certain types of fish contain PCBs, a group of chemicals linked to cancer and other serious illnesses.


Vegetables are rich in nutrients and can provide you with important vitamins, minerals, and antioxidants. They are also low in calories and can help you maintain a healthy weight. For example, carrots are high in vitamin A and can improve eye health, while bell peppers contain vitamin C, folate, and potassium.

It is important to eat a variety of vegetables each day as they are full of vitamins and minerals. The most popular vegetables include carrots, sweet potatoes, kale, collard greens, broccoli, and all lettuces. Other vegetables include asparagus, bok choy, cauliflower, beets, and turnips.

The definition of vegetable can differ depending on where you are from and the language you speak. For example, some people may call rice a vegetable while others might consider it a grain. Research shows that consuming adequate amounts of fruits and vegetables can benefit your health by helping you control your weight, improve heart health, reduce your risk of some cancers, and prevent disease. Nutrition education has shown to be a successful tool for improving fruit and vegetable intake.


Dairy products provide protein and calcium, two important nutrients for healthy bones. All fluid milk, yogurt, and cheese are part of the dairy group, as well as unsweetened, calcium-fortified soy milks and yoghurts. Products sold as “milks” made from almond, rice, coconut, and oat do not count as part of the dairy group even though they may have calcium since they are not processed like dairy milk.

Eating more low-fat or fat-free dairy foods, especially those that are fortified with calcium (milk, yogurt, and cheese) can help most people meet their nutrient goals. Replacing fluid milk with sugar sweetened beverages would decrease diet quality and leave individuals further from meeting nutrient goals.

Despite the dairy industry’s best marketing efforts, some research suggests that high-dairy intake can contribute to a number of health problems including heart disease and bone fractures. Also, the production of dairy products – particularly with hormones and antibiotics – has significant environmental and animal welfare impacts. Switching to plant-based proteins is a more sustainable option.