Protein is an essential part of the human diet. It's found in a variety of foods like eggs dairy seafood legumes meats nuts and seeds Regardless of the source the protein that we eat gets broken down and reformed into new proteins in our bodies These proteins do everything from fighting infections to helping cells divide. You name it They're doing it at its simplest a protein is a chain of amino acids bound to one another by peptide Bonds like a string of beads These strings get twisted and folded into a final protein shape When we eat protein, it gets broken down into its individual amino acids Most amino acids have a central carbon atom bonded to one amino or nitrogen-containing group and one Carboxylic acid group. That's why it's called an amino acid The carbon also has one hydrogen atom and a sidechain which is unique to each amino acid The exception to this is prolene, which is a tiny little ring structure instead Although there are hundreds of amino acids in nature humans only use about 20 of them to make basically every type of protein they include alanine arginine asparagine aspartic acid cysteine glutamic acid glutamine glycine histidine isoleucine leucine lysine methionine phenylalanine prolene serine threonine tryptophan tyrosine and valine Huh? That's twenty One way to divide them is by defining which ones our bodies can make and which ones we can't There are five amino acids alanine asparagine aspartic acid glutamic acid and serine that we can get from foods But we can also make ourselves These are called non-essential amino acids Then there are six that we call conditionally essential because healthy bodies can make them under normal circumstances arginine cysteine glutamine glycine proline and tyrosine But we can't make them in cases like starvation or certain inborn errors of metabolism Finally there are nine of them that we can only get from food histidine isoleucine leucine lysine methionine phenylalanine threonine Tryptophan and valine we call these the essential amino acids Dietary protein provides the essential amino acids that are needed to make our own proteins hormones and other important molecules a circle of life of sorts but to do so We need to break the dietary protein down first through a process called proteolysis when we first eat a protein containing food proteolysis begins when the food reaches the stomach First hydrochloric acid denatures the protein unfolding it and making the amino acid chain more accessible to enzymatic action Then pepsin which is a itself made by gastric chief cells enters the picture pepsin cludes any available protein into smaller oligopeptide chains Which move into the duodenum where a second set of digestive enzymes made by the pancreas further chopped the oligopeptides into tripeptides dipeptides and individual amino acids These can all be taken up to the intestinal cells where died and tripeptides are then converted into amino acids Some amino acids remain in these cells and are used to synthesize intestinal enzymes and new cells But most enter the bloodstream and are transported to other parts of the body in general animal-based protein foods like eggs Dairy seafood and meat provide all nine essential amino acids in adequate amounts Soy foods are unique in that they are plant-based and also provide all nine essential amino acids in adequate amounts most other plant foods including whole grains legumes nuts and seeds Have high amounts of some amino acids and low amounts of others Hearing this it might be easy to assume that animal-based foods provide more protein than plant-based ones But as it turns out a cup of tofu has the same number of grams of protein as three ounces of steak chicken or fish and half a cup of lentils has more grams of protein than an egg and Not all plant foods are low in the same amino acids so eating a variety of plant-based foods can provide all nine of the essentials for Example pairing protein sources like rice and beans or hummus and pita bread or oatmeal topped with almond butter However, in terms of volume it may be necessary to eat more plant-based foods to get a similar amount of protein and amino acid profile provided by animal-based proteins generally speaking daily protein requirements are based on studies that estimate the minimum amount of protein needed to avoid a progressive nitrogen loss the World Health Organization guidelines and the u.s Recommended dietary allowance each estimate that daily protein requirements for healthy adults are about point eight grams per kilogram of body weight Protein recommendations per day vary by age as well children one to three years of age are recommended to get 13 grams for ages 4 to 8 19 grams are recommended and Between ages 9 and 13 34 grams are recommended whether a person is male or female also impacts protein needs Females ages 14 and above are recommended to get 46 grams of protein per day males aged 14 to 18 needs slightly more about 52 grams per day and Males 19 and older are recommended to get 56 grams per day some groups like pregnant and breastfeeding women as well as athletes have elevated needs and Older adults may also benefit from eating more protein Getting the right amount of protein per day can be achieved in multiple ways for example one serving of Greek yogurt with breakfast a salad topped with three ounces of chicken for lunch and Three to four ounces of fish at dinner provides about 64 grams of protein getting the same amount of protein could also be achieved by eating a cup of tofu scramble and a slice of peanut butter toast for Breakfast a cup of shelled edamame with lunch and one cup of lentils and brown rice at dinner Which also offers about 64 grams of protein in total? Now the fact is that it's still unclear. What an optimal amount of protein is and the research is ongoing in Clinical settings. There are certain individuals who may be at risk for a protein deficiency including patients with malnutrition Trauma and burn injuries as well as various conditions impacting nutrient absorption like inflammatory bowel disease These individuals may have increased protein needs compared to the general population Except for certain circumstances like kidney disease there usually isn't a health risk associated with eating a lot of protein Because our bodies are able to process it Alright is a quick recap Protein is a cornerstone of the human diet and a major component of our bodies There are five non-essential six conditionally essential and nine essential amino acids We need to get essential amine acids from our diet Protein needs vary depending on lifecycle stage level of physical activity and health status Some health conditions may put people at risk for protein deficiency or increased protein needs Everyone whether omnivorous vegetarian or vegan can get enough protein by eating a variety of foods