What are proteins and amino acids?
Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs.
Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to one another in long chains. There are 20 different types of amino acids that can be combined to make a protein. The sequence of amino acids determines each protein’s unique 3-dimensional structure and its specific function.
Types and Functions of Proteins
Proteins can be categorized according to their large range of functions in the body. Below are main types of proteins:
Function | Description | Example |
Antibody | Antibodies bind to specific foreign particles, such as viruses and bacteria, to help protect the body. | Immunoglobulin G (IgG) |
Contractile | Proteins that are involved in muscle contraction | Actin, myosin |
DNA associated | Proteins that regulate chromosome structure during cell division and/or play a role in regulating gene expression | histones and cohesin proteins |
Enzyme | Enzymes carry out almost all of the thousands of chemical reactions that take place in cells. They also assist with the formation of new molecules by reading the genetic information stored in DNA. | Phenylalaninehydroxylase |
Hormone proteins | Proteins that co-ordinate bodily functions, for example, insulin controls our blood sugar concentration by regulating the uptake of glucose into cells. | insulin |
Messenger | Messenger proteins, such as some types of hormones, transmit signals to coordinate biological processes between different cells, tissues, and organs. | Growth hormone |
Structural component | These proteins provide structure and support for cells. On a larger scale, they also allow the body to move. | Collagen, elastin |
Transport/storage | These proteins bind and carry atoms and small molecules within cells and throughout the body. | Ferritin |
How much protein do I need ?
The Recommended Dietary Allowance (the amount to meet the nutritional needs of almost all healthy people) is 0.8 grams (g) of protein per kilogram (kg) of body weight. Usually that means having some kind of dairy at each meal plus a piece of meat the size of a deck of cards , or the equivalent amount of plant-based protein at lunch and dinner. For a 60kg weight adult, the protein he needs would be about 50 gm daily.
Keep in mind that these recommendations may change depending on age and health. The recommendation changes for athletes, too. People who exercise frequently or are training for a race need to increase their protein intake to between 1.1 and 1.7 g per kg of body weight daily. Anything over 2 g per kg of weight is considered excessive. Vegans and vegetarians in particular have to make sure they’re sourcing enough of the proteins.
One of the reasons protein is so popular is because of its potential link to weight loss. Over the past two decades, countless studies, including one published in April 2015 in the American Journal of Clinical Nutrition, have shown that protein may help people lose weight or maintain weight loss because: first, consuming more protein has a positive impact on resting metabolism. Second, high-protein foods increase feelings of fullness. As a result, people eating a sufficient amount of protein may take in fewer calories over the course of the day and lose weight if they end up at a calorie deficit.
To be specific, researchers have found diets that contain between 1.2 and 1.6 g of protein per kg of weight each day — and about 25 to 30 g of protein per meal — have been shown to help with body weight management.
Sources of proteins
Good sources of protein include meat, seafood, chicken, eggs, dairy, beans, soy foods, nuts and seeds.
Animal protein sources, such as meat, fish, poultry, eggs and dairy, are similar to the protein found in your body. These are considered to be complete sources of protein because they contain all of the essential amino acids that your body needs to function effectively. Plant sources lack one or more amino acids, which makes it more difficult to get all the amino acids that your body needs. If you are a vegetarian, make sure to eat a variety of vegetables, fruits and multigrain.
Consuming too much protein might lead to health issues such as an increased risk of osteoporosis and a worsening of an existing kidney problem. However, research in this area is mixed and it is likely that other factors may influence outcome, such as whether the protein is of animal or vegetable origin and how balanced the diet is in terms of vitamins and minerals.
Do I need protein powders?
If consuming an adequate amount of protein from food sources in one’s daily diet, it is not necessary to consume additional protein with protein supplements.
There are a few reasons why athletes or ordinary people might want more protein in his or her diet, or from protein powder:
- When you’re growing. A teenager needs more protein to fuel his workouts because his body is still growing and uses more protein in general.
- Bodybuilders: obviously they consume more protein that needs to be supplemented
- When you’re starting a program. If working out is new to you and you’re trying to build muscle, you’ll require more protein than you normally would.
- When you increase your workouts. If you normally work out for half an hour a few times a week, but now you’ve decide to train for a half-marathon, your body will need more protein.
- When you’re recovering from an injury. Athletes with sports injuries frequently need more protein to help them heal.
- If you’re going vegan. People who pursue a vegan or vegetarian lifestyle eliminate a number of common protein sources from their diet, including meat, chicken, and fish, and sometimes dairy and eggs as well.