Proteins are the building blocks of life. The body needs protein to repair and maintain itself. In short, we can't do anything without protein. Every cell of the human body contains protein in their structure. It is present in the skin, hair, nails, teeth, muscles, bones, ligaments, tendons and organs of the body.
Proteins form an essential part of a balanced diet. During digestion, the proteins from the food are broken down into their constituent amino acids. These amino acids are absorbed by the blood and are transported to the liver, where further synthesis of proteins takes place and they are stored as fat or glycogen in the body.
Every person needs one gram of protein per kilogram of his/her bodyweight. For example, if a person weighs 80 kilograms, then his everyday diet should contain 9 grams of protein. It is estimated that 1 gram of protein contains 4 calories of energy. One should consume diets rich in protein such as pulses, eggs, milk and milk. However, overconsumption of proteins is harmful as it can strain the liver and kidney due to excessive protein catabolism.
Proteins also play a major role in the body's defense mechanism. In fact, antibodies are made up of proteins and are responsible for protecting the body against the harmful organisms such as bacteria, fungi, virus and protozoa. An individual with a compromised immune system refers to a person whose body fails to produce adequate antibodies. Such people need to consume adequate amount of protein supplements to boost their immune system levels.
Protein is an essential component of the diet and helps your body repair muscle, grow tissue, regulate hormones, control metabolism, defend against illness, and more.
Protein is what makes up your ligaments, tendons, muscles, hair, nails, skin, teeth, tissue, organs, and bones. About half of the non-water mass of your body is made up of protein.
Since most of the body's
proteins are continually broken down, the body needs to manufacture
thousands of proteins every day to replace them.
The more
active you are the faster your proteins break down, and more protein
you need to replenish them.
Individuals typically need 1 gram of protein daily for each kilogram of their body weight. For example, a 180-pound man would need at least 80 grams of protein a day to meet his body's needs; a 140-pound woman would need a minimum of 60 grams.
Protein cannot be stored for later use, like fat or carbohydrates can, so the body needs daily replenishments.
Just what is protein? Protein consists of smaller units of amino acids. These amino acids, formed of carbon, nitrogen, hydrogen, and oxygen atoms, are literally the building blocks of the human body. From these amino acids, your body can make hundreds of different proteins that perform different functions.
On its own, the body can manufacture 14 of the 22 amino acids it needs. But the other 9 cannot be made by the body and must be obtained from the diet. These eight amino acids are called "essential amino acids".
Amino acids are classified into three groups:
Essential
Nonessential
Conditional
Essential amino acids cannot be made by the body, and must be supplied by food. They do not need to be eaten at one meal. The balance over the whole day is more important. The nine essential amino acids are:
Histidine
Isoleucine
Leucine
Lycine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine
Nonessential amino acids are made by the body from essential amino acids or in the normal breakdown of proteins. They include:
Alanine
Asparagine
Aspartic acid
Glutamic acid
Conditional amino acids are usually not essential, except in times of illness and stress. They include:
Arginine
Cysteine
Glutamine
Glycine
Ornithine
Proline
Serine
Tyrosine
Protein foods are no longer described as being "complete proteins" or "incomplete proteins."
The body uses the amino acids obtained from dietary protein or amino acid supplements to build the body's proteins, which become the structural foundation of the body and the molecules that sustain life.
Amino acids not synthesized into protein become converted to calories or energy. However, converting protein to calories or energy requires your body to strip the amino acids of their nitrogen atoms, creating nitrogen waste.
This nitrogen waste from the metabolized protein arrives at your kidneys as a toxic "urea," and must be filtered out.
For example, a hen egg, the highest protein food, makes only 48 percent of its protein available to the body. The rest of the egg converts to calories and produces nitrogen waste in the process.
For individuals with reduced kidney function, the amount of nitrogen waste produced from protein digestion can actually harm their kidneys.
According to the National Kidney Foundation, 20 million people have reduced kidney function and don't even know it. Not only does the toxic nitrogen waste considerably strain kidneys, but in high amounts can cause weak kidneys to further decline.
Therefore, to maintain optimum health and fitness, you must include enough dietary protein to keep up with losses. Since the diet alone often does not accomplish this, supplementing with an optimum protein source is recommended. It is for this reason that Master Amino Acid Pattern (MAP) was created. It is the optimum protein therapy.
Daily protein/amino acid intake is required to maintain or normalize cellular turnover and optimize the body's protein synthesis. Without sufficient protein, the body either lets cells die or breaks down other muscles and tissues to get the protein it needs for repair and other functions.
The body may actually "eat itself" to acquire the necessary amino acids, or borrow the amino acids from the immune system or body functions to meet its protein needs. If you workout and don't have enough protein to rebuild your body, instead of getting stronger, you will become weaker and be subject to injury.
Whether due to restricted diets, illness, skipping meals, poor diet choices, and so on, inadequate protein/amino acid intake can compromise your health and affect the following body functions:
Bone cell synthesis
Red blood cell production
Heart cell turnover rate
Neurotransmitters/mood
Sense of well-being/stamina
Immune function/antibodies
Enzymes/hormones
Skin elasticity/muscle tone
Organ function/pH balance
Mobility/joint integrity
Many people are unknowingly protein deficient. Protein levels may actually be normal in standard blood panels, but in deeper tests of the serum, many individuals have deficient amino acid levels. Even marginal deficiencies can magnify the effect of every disease. Most vegetarians are protein deficient.
Although you get much protein through your daily diet, the body cannot, unfortunately, digest and use all of it.
A nutritional label may indicate 10 grams of protein in a food, but your body won't assimilate all 10 grams. Most likely you'll assimilate only 10-20% and convert the rest to calories.
Why? Because in order for protein synthesis to take place, all 8 of the essential amino acids must be present. All 8 must be at the cell at the same time; otherwise protein cannot be made.
Protein cannot be stored, so these essential amino acids must either be in place or the body will burn the protein as energy, or store it as fat.
Another factor determining the amount of protein synthesis that takes place is the proportion and ratio of these amino acids. For each living creature, the proportion and ratio for maximum protein synthesis varies.
Many individuals need protein well beyond the regular requirements. People that exercise frequently have increased muscle breakdown and body wear, and need more protein to rebuild their bodies and prevent injury.
The American Dietetic Association says that when athletes do heavy strength and resistance training, they need more than twice the amount of protein as normal to rebuild and repair their bodies.
Not just athletic individuals need more protein. Middle aged and elderly people have extended body breakdown too. The hydrochloric acid in their stomachs, which activates the pepsin enzyme that digests protein, drops to half its regular level as individuals enter middle age. So the protein they eat may never be digested and their bodies break down for lack of it. Much of aging is probably due to this factor alone.
Children and adolescents also need more protein because their bodies are constantly growing. They have an increased need for new cells, new tissue, and other building materials.
Dieters who starve their bodies, menopausal women with imbalanced hormones, patients recovering from surgery or illness, individuals looking to support healthy kidney function, and others who want to maintain their immune system all have greater needs for protein.
Protein deficiency is a state of malnutrition in which insufficient amounts of protein is taken in for the body to utilize in order to produce energy. This condition is largely responsible for the high incidence of starvation and disease in many Third World countries, causing death to millions of people each year. Sadly, many children under the age of five make up the majority of victims. However, protein deficiency also occurs in developed countries, primarily due to poverty. Certain individuals may also become prone to protein deficiency, such as crash dieters and vegetarians who neglect to properly balance their diet.
Protein is necessary for the body to synthesize 13 amino acids and to break down polypeptide molecules into the nine essential amino acids that the body cannot manufacture on its own. Collectively, these acids constantly work to replenish tissue in the body, so they play an important role in the maintenance of healthy bones, muscles, and organs. The body also uses protein to produce hemoglobin in red blood cells, the vehicle by which oxygen is transported to muscles and organs. In addition, without sufficient protein, the lungs and immune system would cease to function properly.
The body interprets a state of protein deficiency as a signal to enter into starvation mode. As a result, the body attempts to compensate for the deficiency by pulling out stores of protein in the body for recycling. The first source the body will turn to make a protein withdrawal is the muscles, which leads to a condition known as muscle wasting. In fact, weakness resulting from a loss in muscle mass is one of the first symptoms of protein deficiency.
Other symptoms of protein deficiency include weight loss, diarrhea, and an accumulation of fluids (edema) in the legs and abdomen. Initial outward signs include hair loss, scaly skin, and lethargy due to a lack of energy. If the deficiency continues, organs will begin to malfunction. For instance, since protein utilization is involved in the transport of lipoproteins and cholesterol, a lack thereof will lead to steatosis hepatitis, or fatty liver disease. In addition, the body will be unable to maintain normal levels of leukocytes, leaving the body deficient in white blood cells and the immune system unable to fight infections.
Generally speaking, children require 1 grams of protein for every kilograms of body weight and adults a total of approximately 60 grams of protein per day. However, pregnant or nursing women may require more. Aside from meat, eggs, and dairy, particularly good sources of protein include whole grains, beans, nuts, sunflower seeds, brown rice, potatoes, spinach, and broccoli.
When we eat foods that contain protein, the body breaks it down into amino acids. These amino acids are necessary for building muscle and blood. There are 22 amino acids, which are divided into two categories, including essential amino acids and non-essential amino acids. The body can make some of the essential acids on it's own, but certain amino acids must come from eating foods containing protein.
There are many health benefits of protein. Eating enough protein is essential to maintain a healthy body. If the body sustains an injury, such as a cut, protein helps with tissue repair. Along with carbohydrates, protein provides energy for the body which helps keep us from becoming fatigued. Another one of the benefits of protein is helping the body fight off illness and disease and keeping the immune system functioning properly.
The muscles in our bodies are partly made up of protein. One of the benefits of protein is maintaining healthy muscles. Protein also helps build skin, hair, nails and cartilage. Because the body does not store protein, it's important to eat healthy protein everyday.
Proteins are considered incomplete or complete proteins. Complete proteins contain all the essential amino acids, while incomplete proteins don't. Good sources of complete proteins come from animals. For instance, eggs, milk, chicken and fish all contain complete proteins. Healthy food choices for incomplete proteins include, nuts, such as almonds, beans and whole grains.
To get the proper health benefits of protein, most people need about 1 grams of protein per kilogram of body weight each day. When additional demands are made on the body, such as in pregnancy or while recovering from an injury, more protein is needed to help the body. Children and teenagers also need additional protein to help with growth.
Without protein, the body would not be able to function properly. Various conditions could develop such as anemia and hypotension. Problems with circulation and healing from an injury would also occur. Because protein helps muscle, without it muscle mass may decrease and weakness can occur.
Although there are benefits of protein, too much of a good thing can be bad. Eating a high protein diet can cause problems if too few carbohydrates are eaten. When high levels of protein are eaten in combination with too few carbohydrates, the body can form ketones and releases them into the blood. This causes ketosis, which may lead to fatigue and nausea and is not a healthy state for the body to be in.
Maybe you've wondered how much protein you need each day. In general, it's recommended that 10–35% of your daily calories come from protein. Below are the Recommended Dietary Allowances (RDA) for different age groups.
|
Recommended Dietary Allowance for Protein |
|
|
|
Grams of protein
|
|
Children ages 1 – 3 |
13 |
|
Children ages 4 – 8 |
19 |
|
Children ages 9 – 13 |
34 |
|
Girls ages 14 – 18 |
46 |
|
Boys ages 14 – 18 |
52 |
|
Women ages 19 – 70+ |
46 |
|
Men ages 19 – 70+ |
56 |
Here are examples of amounts of protein in food:
1 cup of milk has 8 grams of protein
A 3-ounce piece of meat has about 21 grams of protein
1 cup of dry beans has about 16 grams of protein
Main article: High Protein Foods
When proteins are digested, amino acids are left. The human body needs a number of amino acids to break down food. Amino acids need to be eaten in large enough amounts for optimal health.
Amino acids are found in animal sources such as meats, milk, fish, soy, and eggs, as well as in plant sources such as beans, legumes, and nut butters. You do not need to eat animal products to get all the protein you need in your diet.
A nutritionally balanced diet provides enough protein. Healthy people rarely need protein supplements.
Vegetarians are able to get enough essential amino by eating a variety of plant proteins.
The amount of recommended daily protein depends upon your age and health. Two to three servings of protein-rich food will meet the daily needs of most adults.
The following are the recommended serving sizes for protein:
2 to 3 ounces of cooked lean meat, poultry, or fish (a portion about the size of a deck of playing cards)
1/2 cup of cooked dried beans
1 egg, 2 tablespoons of peanut butter, or 1 ounce of cheese
For recommended serving sizes of protein for children and adolescents, see age-appropriate diet for children.
Choose:
Turkey or chicken with the skin removed, or bison (also called buffalo meat)
Lean cuts of beef or pork, such as round, top sirloin, or tenderloin (trim away any visible fat)
Fish or shellfish
Other good sources of protein include:
Pinto beans, black beans, kidney beans, lentils, split peas, or garbanzo beans
Nuts and seeds, including almonds, hazelnuts, mixed nuts, peanuts, peanut butter, sunflower seeds, or walnuts (just watch how much you eat, because nuts are high in fat)
Tofu, tempeh, and other soy protein products
Low-fat dairy products
Do not eat more than four eggs per week. Although they are a good source of protein and are low in saturated fat, eggs are very high in cholesterol. Try recipes with egg whites only.
Protein isn't particularly dangerous, but an over-consumption of protein may be associated with:
Weight gain. Excess calories from excess protein may be stored as body fat.
Intestinal irritation. Too much protein has been linked to constipation, diarrhea and/or excessive gas.
Dehydration. Experts advise drinking a half gallon of water per 100 grams of protein.
Seizures. Seizures have been linked to excess protein intake – but only if insufficient amounts of water are consumed.
Increase in liver enzymes.
Nutritional deficiencies. Just focusing on protein intake causes some high-protein dieters to overlook other nutrients. Ensure that your diet is balanced and nutritious.
Risk of heart disease. This is a bit misleading. A healthy high-protein diet is not associated with heart disease. But if you are getting all of your protein from unhealthy sources that are loaded in unhealthy fats, obviously the risk for heart disease will increase.
Kidney problems. Some believe that high protein and low carbohydrate diets – when done long term – can possibly cause kidney issues, but more research is needed.
Other side effects. A diet high in meat can contribute to high cholesterol levels or other diseases such as gout. A high-protein diet may also put a strain on the kidneys.
While this list may seem alarming, it's important to remember that many of these side effects are only associated with highly excessive protein diets coupled with unbalanced nutrition and/or dehydration. And this list pales in comparison to the side effects of protein deficiency, which includes general illness, loss of hair, loss of sleep, poor coordination, vision problems, etc.
The average person needs about .4 grams of protein per pound of body weight. Active individuals may require .6 grams. People that exercise frequently and at a high intensity require about a gram per pound of body weight.
With protein you don't want too little or too much – but an amount that's just right.