Protein

Protein in Foods

Top contributors of protein in the North American diet:

• Beef

• Poultry

• Milk

• Eggs

• Cheese

Worldwide meat consumption has been increasing, especially in developing countries

Overview of Protein

• Form important structures in the body, make up a key part of blood, help regulate body functions, can fuel body cells

• The body is made up of thousands of proteins

• Contains nitrogen, carbon, hydrogen, and oxygen

• North Americans generally consume more than they need to maintain health

  Functions:

• Regulate and maintains body functions

Amino Acids—Building Blocks of Proteins

• Provides an essential form of nitrogen (in the form of amino acids)

• Proteins (peptides) are complex molecules made from smaller units called amino acids.

• 20 different amino acids make up all proteins 9 essential amino acids

• Not synthesized, must be consumed from diet 11 nonessential amino acids

• Can be synthesized in the body

• Typically supply 4 calories per gram

• Amino acids with a branching carbon backbone include: leucine, isoleucine, and valine; all are essential amino acids.

• Used by muscles for energy needs

Some people use Branched Chain Amino Acids as an Ergogenic Aid in Athletes; Ergogenic aid: is a substance used to enhance physical performance beyond the gains obtained from physical training alone

Using amino acid supplements is not considered safe

• Overwhelms absorptive mechanisms in the small intestine

• Excess amino acids cause toxicity

• methionine, cysteine, and histidine most likely to cause toxicity

Branch Chain Amino Acids (BCAAs) in Foods:

• Whey/Milk

• Beef

• Chicken

• Fish

• Soy Proteins

• Eggs

• Baked Beans

• Whole Wheat

• Brown Rice

• Nuts

• Pumpkin Seed

Protein Quality of Foods

Animal and plant proteins can differ greatly in the proportions of essential and nonessential amino acids.

• Animal protein generally contains all 9 essential amino acids

• Plant proteins in grains are often low in one or more of the 9 essential amino acids

High-quality (complete) proteins: contain ample amounts of all 9 essential amino acids

Lower-quality (incomplete) proteins: low in or lacking one or more essential amino acids, the all-or-none principle in protein synthesis.

Plant sources of quality proteins:

• Legumes, beans, peas, and peanuts

• Nuts and seeds

• Per gram, many are a great source of nutrients

• Also, contain phytochemicals

All contribute to protein, vitamins, and fiber in the meal

Protein Needs

The Recommended Dietary Allowance (RDA) for protein is a modest 0.8 grams of protein per kilogram of body weight. The RDA is the amount of a nutrient you need to meet your basic nutritional requirements.

• Protein can be harmful if your body is low in plant foods (fiber), vitamins, phytochemicals

• If your body is consuming high saturated fat and cholesterol it can be harmful

• Excessive intake of processed red meat is linked with colon cancer

• Too much protein burdens the kidney

• Eating access protein may increase calcium loss in the urine

Eating access protein Increases urine production which increases the risk of dehydration

Protein Recommendations:

• Incorporate seafood as the protein food choice in meals twice per week in place of meat, poultry, or eggs.

• Use legumes or nuts and seeds in mixed dishes instead of some meat or poultry.

• Shift to nutrient-dense options, including lean and lower sodium options, to improve the nutritional quality of protein food choices and support healthy eating patterns.