Nutrition | February 20, 2017 | Author: Naturopath
The proteins we eat help build our muscles, bones, skin, cartilage, and blood. They provide us with energy, and are needed for the structure and function of hormones, enzymes, antibodies, and tissues. Along with fat and carbohydrates, protein is a macronutrient, meaning the body requires it in large amounts for energy. When we eat protein, the body breaks it down into small molecules that are attached to one another to form a long chain. These molecules, called amino acids, are the building blocks that make up protein.
There are 20 amino acids. Our bodies can make all but 9 of the 20 amino acids. As a result, they must come from the food we eat, and are therefore called essential amino acids. They include phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.
Animal sources of protein, including meat, poultry, fish, eggs and cheese, contain all of the essential amino acids, and as such are considered to be complete proteins. Plant foods, such as fruits, vegetables, legumes, grains, nuts and seeds, are referred to as incomplete proteins. Although they also contain protein, some may lack one or more essential amino acids. Unlike carbohydrate and fats, the body does not store protein. Thus, it is important that we consume adequate protein. Each amino acid has specific functions in the body, such as making certain hormones and neurotransmitters. Consume too little, and your body will start breaking down muscle in order to get the amino acids it needs.
In general, it is recommended that 10-35 percent of your daily energy intake comes from protein. According to the National Health and Medical Research Council (NHMRC), the recommended amount you should eat every day is:
In Australia and most developed countries, most people consume adequate protein to prevent deficiency. However, you may need extra if you are:
Vegetarian or vegan. A large study (EPIC-Oxford) compared the nutrient intakes of about 30,000 meat-eaters, 10,000 no meat except fish-eaters, 20,000 vegetarians, and about 2,500 vegans. Overall, meat-eaters were found to consume higher amount of protein than the other dietary groups, and the lowest protein intake was among the vegans. However, most dietary groups consumed over the minimum protein requirements.
Over the age of 70. Elderly persons are at risk of developing protein-energy malnutrition, a disorder caused by an intake of poor quality dietary protein or by inadequate dietary intake of protein, due to increased demands because of disease, decreased appetite, and lack of variety in their diet.
Furthermore, body composition changes as people get older, manifested in decreased skeletal muscle. The American College of Sports Medicine suggests that in order to maintain muscle mass, you need to increase the protein in your diets as early as around 50 years of age.
Active. If you do a lot of high-intensity workouts, the Australian Institute of Sport recommends increasing your protein intake in order to help with recovery and performance.
Pregnant or breastfeeding. Extra protein is required for pregnancy and lactation, with increasing amounts recommended for each trimester.
Trying to lose weight. Protein is considered to be the most satiating macronutrient. Increased satiety helps to decrease energy (calories) intake, which is necessary for successful weight loss. Research suggests that high-protein diets are effective for both short and long-term weight loss.
More is not necessarily better! The increased acid load in high-protein diets may put a strain on the kidneys.
It is advisable that patients with pre-existing kidney disease should consume low-to-moderate protein diets. It has also been suggested that the high fat content of animal proteins (e.g. red meats, eggs and dairy products) may put consumers of high-protein diets at higher risk for heart disease.
Eating red meat, especially processed red meat, is linked to an increased risk of not only heart disease but also type 2 diabetes and cancer.
Protein quality matters more than protein quantity.
Although most plant-based foods are incomplete, meaning they do not contain the nine essential amino acids we need, there are a number of plant-based foods that do provide complete proteins.
Amino acids can be taken individually or in different combinations as supplements. Getting them from your diet is best, but for certain conditions taking amino acid supplement can be beneficial.
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