There are three sources of energy our body draws on: carbohydrate, fat, and protein. It seems lately that protein has become the obsession for those looking to lose weight or change their body. While protein is important, just like anything else, it is best consumed in moderation.
Proteins are made up of amino acids linked together by peptide bonds. There are two types of amino acids: essential and nonessential. Essential amino acids cannot be manufactured in the body, or are manufactured in insufficient amounts. As a result, essential amino acids must be obtained from the food supply or some other outside source.
After digestion and absorption by the intestines, the fate of amino acids depends on the body’s needs, which can range from tissue replacement or addition, to a need for energy. Once proteins go through the digestion and chemical processes in the body, the resulting free-form amino acids have three possible fates: they can be used to build and repair tissues or structures (synthesis), immediate energy, or potential energy (fat storage).
If protein intake exceeds the need for synthesis, and energy needs are met, protein is stored as fat. Among Americans, protein and caloric intakes are typically well above requirements, allowing protein to contribute significantly to fat stores, according to American Dietetic Association. A high-protein diet is generally defined as one that consists of more than 35% of total caloric intake from protein, or three times the Recommended Dietary Allowance (RDA) for athletes. Prolonged consumption of a high-protein diet is typically associated with a higher intake of saturated fat and lower fiber intake. Both of these are risk factors for heart disease and some types of cancer. Furthermore, the kidneys need to work harder to eliminate the increased urea produced. Protein requires approximately seven times the water for metabolism than carbohydrate or fat according to Smolin and Grosvenor in Saunders College Publication. Low-carbohydrate consumption and high-protein diets typically accompany each other, especially for weight loss. This can lead to decreased glycogen stores, inhibition of performance, and possible dehydration.
Tomorrow’s post will include complete protein food sources, factors affecting protein requirements, protein’s effect on satiety, as well as intake recommendations.