All tissues and cells need protein. Proteins are very important for muscle building and keep hair, nails, skin and eyesight healthy. Proteins are used for transporting iron and oxygen in the blood and for the manufacturing of hormones, enzymes, stimulation of the immune system and other compounds that provide fuel for your body.
Protein is considered to be the most filling nutrient according to the energy it gives. Since protein stimulates the fat burning hormone, glucagon, protein is considered good for weight loss. 10-20% of your daily calorie intake should be from protein.
Proteins are converted in the body into 22 building blocks called amino acids and divided into complete and incomplete proteins.
Protein deficiency is relatively rare in developed countries but people who are on a strict diet can be at risk. Symptoms of protein deficiency can be decreased muscle mass, fatigue, anemia, impaired immune function, decreased metabolism, reduced fertility, hair loss, premature aging, mood swings and memory problems.
Too much protein can harm your body. If you eat too much protein the excess will be stored as body fat. Over-consumption of protein can also cause constipation, diarrhea, excessive gas, dehydration, dizziness and bad breath.
The recommended daily allowances (RDA) set by the Food and Nutrition Board, is 0.36 grams of protein for every pound of body weight.
Dietary Reference Intakes (DRIs) – Estimated Average Requirements for Groups:
|Life Stage Group||Protein Grams per Day|
|Children 1-3 years||11|
|Children 4-8 years||15|
|Males 9-13 years||27|
|Males 19-30 years||46|
|Males 31-50 years||46|
|Males 51-70 years||46|
|Males > 70 years||46|
|Females 9-13 years||28|
|Females 14-18 years||38|
|Females 19-30 years||38|
|Females 31-50 years||38|
|Females 51-70 years||38|
|Females > 70 years||38|
|Pregnancy 14-18 years||50|
|Pregnancy 31-50 years||50|
|Lactation 14-18 years||60|
|Lactation 19-30 years||60|
|Lactation 31-50 years||60|
Source: Food and Nutrition Board, Institute of Medicine, National Academies