Consuming animal-based products offers high-quality proteins that contain optimal levels and combinations of essential amino acids, crucial for tissue repair and growth. Foods like eggs, milk, fish, and most meats are a source of complete proteins. Legumes and cereals are abundant in proteins; however, they typically lack a full range of essential amino acids. As a result, they are considered incomplete protein sources. Some plant sources like soybeans, quinoa, and amaranth do contain complete...

Lipids are an essential component of a balanced human diet. Triglycerides, which make up the majority of dietary lipids, are found in both saturated fats—commonly present in meat, dairy products, and certain tropical plants like coconut, and hydrogenated oils such as margarine and baking shortenings (trans fats)—and unsaturated fats, which are abundant in seeds, nuts, olive oil, and most vegetable oils. The main sources of cholesterol include egg yolks, various meats and organ meats, shellfish,...

In biological systems, most metabolic pathways are interconnected. The cellular respiration processes that convert glucose to ATP—such as glycolysis, pyruvate oxidation, and the citric acid cycle—tie into those that break down other organic compounds. As a result, various foods—from apples to cheese to guacamole—end up as ATP. In addition to carbohydrates, food also contains proteins and lipids—such as cholesterol and fats. All of these organic compounds are used as energy sources to produce...

Vitamins, derived from the Latin word for life, are essential organic substances required in small quantities for optimal growth and overall well-being. Unlike other organic nutrients, vitamins don't act as sources of energy or building materials but rather facilitate these nutrients' utilization by the body. Vitamins are predominantly coenzymes, assisting enzymes in specific chemical actions, like the oxidation of glucose for energy involving B vitamins. Most vitamins are not produced in our...

Electrolytes are essential minerals and ions primarily obtained from the diet and absorbed through the gastrointestinal tract. Most electrolytes are absorbed in the small intestine. While the absorption of iron and calcium primarily occurs in the duodenum, calcium is also absorbed in the jejunum and ileum. In these regions, passive diffusion contributes to its absorption alongside active transport mechanisms in the duodenum. These ions can exit the enterocytes through specialized active...

Carbohydrates are predominantly obtained from plant sources. With the exception of lactose found in milk and insignificant glycogen amounts in meat, most consumed carbohydrates have plant origins. Monosaccharides and disaccharides, or sugars, can be sourced from fruits, honey, milk, sugar cane, and sugar beets. Grains and vegetables are rich in the polysaccharide starch. Two types of polysaccharides provide fiber: cellulose, which is abundant in many vegetables, forms undigestible roughage or...