Nutrients are essential elements in body functioning and health. Their roles span growth, repair, body function and health maintenance. There are two categories of nutrients: macronutrients and micronutrients.
This chapter highlights nutritional guidelines from notable dietetic and medical organizations as well as nutritional data such as food composition tables and dietary reference values (DRIs), which serve to compare nutrient contents of various food items or beverages.
Carbohydrates
Carbs are an energy-rich source, provided by starches like potatoes and rice as well as vegetables and fruits. Carbs also include sugars found naturally in fruit or milk products or added into processed food such as soda pop and sweetened cereals.
Simple carbohydrates are rapidly broken down by your body, leading to rapid fluctuations in your blood sugar levels. Examples include table sugar (sucrose) and milk sugar (lactose). Starches require longer for digestion by your body; such as beans, grains (quinoa and brown rice) and vegetables like corn, yams and rutabagas as sources of starches – which make up good sources of carbs!
Proteins
Proteins are vital building blocks of our cells, tissues and organs. They’re used to support muscle growth and repair as well as aiding immunity while transporting essential nutrients around our bodies and acting as energy sources.
One molecule of protein consists of chains of amino acids connected by chemical bonds. These amino acid chains bend and fold to create complex three-dimensional structures necessary for your body’s functions. Most food proteins known as “complete” contain all nine essential amino acids our bodies cannot produce on its own and must obtain from food sources instead.
Animal products (meat, chicken, fish and dairy) provide complete proteins while plant foods like beans, nuts, seeds and grains provide some of the essential amino acids.
Fats
Fats provide energy and are necessary for vitamin absorption. There are four categories of fats: healthy (“good”) fats, saturated fats, trans fats and unsaturated fats. When selecting healthier options such as vegetable sources over animal products (trans or saturated fats).
Monounsaturated and polyunsaturated fats, often called oils, are among the healthiest sources of fats, with liquid at room temperature called oils. You’ll find them in avocados, olive oil and canola oil; avocados; fish; nuts; as well as polyunsaturated fatty acids found in fish oil or nuts and canola oil; they help build cell membranes and nerve sheaths while aiding blood clotting, muscle movement and inflammation; all fats provide 9 calories per gram which doubles those provided by carbohydrates or protein while any unseen ones will convert to body fat if not utilized properly.
Vitamins
Vitamins are organic molecules or groups of closely related molecules that are essential in small quantities for normal physiological function. Our bodies cannot synthesize vitamins themselves and must consume them through food sources instead. Most of the 13 currently recognized vitamins are fat soluble, meaning that their storage occurs mainly within our fatty tissues and livers.
B-group vitamins play a wide range of metabolic roles, from producing energy and producing proteins from carbohydrates to aiding collagen production and helping protect blood vessel linings, as well as increasing heme absorption rates to prevent iron deficiency anemia.
Vitamin A plays an essential role in maintaining the health of skin, eyes and hair. It assists with iron metabolism as well as supporting immune system functioning – benefits found in fruits, vegetables, leafy greens and some fortified foods.
Minerals
Minerals are inorganic substances with specific chemical composition, crystal structure and physical properties. They form through geological processes and may consist of either one chemical element or more often several.
Minerals play a critical role in metabolism, bone health, immune function and nerve signaling – getting too little or too much can have serious repercussions for health.
Hardness, lustre, streak and cleavage can help us identify minerals. Lustre describes how a mineral reflects light. Cleavage refers to how a mineral breaks apart into flat planes or geometric shapes – perfect cleavage in biotite indicates its very pure chemical composition. Colour can also identify minerals but this property is less diagnostic.
