Introduction to Nutrition

Introduction to Nutrition

• Nutrition is an interdisciplinary science focused on how food affects health.
• Staying updated on nutrition is encouraged due to its rapidly evolving nature.
• This chapter highlights the principles of nutrition science, food constituents, dietary patterns, food programs, nutritional assessment, and public nutritional health priorities.

Principles of Nutrition Science

• Ten key principles form the basis of nutrition science.
• Food is a basic human need for survival and optimal health.
• Food security means having constant access to safe and nutritious foods, while food insecurity involves limited availability or access.
• Foods provide calories, nutrients, and other vital substances.
• Calories measure the energy transferred from food to the body.
• Nutrients are chemical substances used by the body for growth and health and are divided into six categories.

Six Nutrient Categories

• Carbohydrates: Energy source derived from sugars, starches, and fiber.
• Proteins: Made of amino acids used for tissue building and maintenance.
• Fats (lipids): Provide energy and support functions like hormone synthesis.
• Vitamins: Assist in regulating body processes in foods and components of diet.
• Minerals: Elements with specific bodily functions from Milk, leafy vegetables, meat.
• Water: Essential for various bodily functions from food and fluid.

Essential vs. Nonessential Nutrients

• Essential nutrients must be obtained from the diet due to the body's inability to produce them sufficiently.
• Nonessential nutrients can be synthesized by the body.
• Requirements for essential nutrients depend on age, body size, gender, genetics, growth status, illness, physical activity, medication use, and pregnancy/lactation.
• Dietary Reference Intakes (DRIs) account for these factors influencing nutrient needs.

Dietary Intake Standards

• Dietary Reference Intakes (DRIs) are nutrient intake standards for healthy people.
• Recommended Dietary Allowances (RDAs) meet the needs of most healthy individuals and decrease chronic disease risks.
• Adequate Intakes (AIs) are tentative RDAs based on less conclusive information.
• Estimated Average Requirements (EARs) meet the needs of half the healthy individuals in a group and are used to assess population intake.
• Tolerable Upper Intake Levels (ULs) represent the upper limits of nutrient intake to avoid toxicity.

Nutrition Labels

• Daily Values (DVs) on Nutrition Facts panels identify the amount of a nutrient in a food serving compared to a standard level.
• Carbohydrates are a primary energy source, including simple sugars, complex carbohydrates, fiber, and alcohol sugars.
• Simple carbohydrates are monosaccharides (glucose, fructose, galactose) and disaccharides (sucrose, maltose, lactose).
• Complex carbohydrates include starches, glycogen, and most types of fiber.
• Glycemic index classifies carbohydrates based on their effect on blood glucose levels.
• Recommended carbohydrate intake is 45-65% of total calories, with limited added sugar.

Proteins

• Proteins provide amino acids for building body components and can be a source of energy.
• Essential amino acids must be supplied by the diet.
• Nonessential amino acids can be manufactured by the body.
• Protein sources vary in quality based on amino acid content.
• High-quality proteins include animal products, while plant sources of protein are considered lower quality and can be supplemented using foods like seeds, grains, and dried beans.
• Recommended protein intake should be 10-35% of total energy and protein deficiency can lead to conditions such as kwashiorkor.

Fats (Lipids)

• Fats that are soluble are classified as lipids and includes fats, oils, and cholesterol.
• Triglycerides consist of three fatty acids attached to glycerol.
• Fats provide energy, support hormone synthesis, form cell membranes, transport fat-soluble vitamins, and supply essential fatty acids.
• Essential fatty acids include linoleic acid and alpha-linolenic acid, both of which contain unsaturated fatty acids.
• Derivatives of alpha-linolenic acid such as EPA and DHA and can be from fish.
• The central nervous system is rich fatty acids, they are also part of phospholipds.

Saturated vs Unsaturated Fats

• Saturated fats lack double bonds between carbons and tend to be solid at room temperature, and unsaturated fats have one or more double bonds, double carbon bonds make them less solid.
• Monounsaturated fats contain one double bond, and polyunsaturated fats have multiple double bonds.
• Saturated fats tend to increase LDL cholesterol, while unsaturated fats decrease LDL cholesterol.
• Hydrogenation is the process of adding hydrogen to oils to make them solid, which can create trans fats.
• Trans fats raise LDL cholesterol levels.

Cholesterol

• Cholesterol is found in animal products and is a component of cell membranes, the brain, and nerves.
• It is a precursor to estrogen, testosterone, and vitamin D.
• Dietary cholesterol's impact on blood cholesterol levels varies based on genetics.
• Recommended fat intake is 20-35% of total calories.
• Dietary patterns should emphasize polyunsaturated fats, with low trans fat and increased EPA and DHA intake.

Vitamins and Minerals

• Vitamins are chemical substances that perform specific functions and are classified as fat-soluble or water-soluble.
• Water-soluble vitamins are limitedly not stored in the body and fat soluble vitamins are stored in the body's fat tissues.
• Excessive fat-soluble vitamin intake from supplements can lead to toxicity, but rare for non supplements.
• Vitamins act as coenzymes and perform key functions in metabolism.
• Minerals consist of single atoms carrying a charge and form stable complexes, for electrical power and help to maintain body function, as well electrical power and are essential to functions like energy.

Minerals and Phytochemicals

• Antioxidants from eating healthy plants, help protect against toxins.
• Minerals consist of single atoms with a charge, enabling combinations, function as electrical power and help maintain body function, like heart beat for example .
• Homeostasis
• Recommended intakes of minerals are summarized in Table 1.11.
• Humans require the 15 minerals.
• Functions of the Vitamins are summarized - B Vitamins, Vitamin B, Vitamin C, Vitamin A and Vitamin E.
• Some foods contain naturally occurring toxins to nerves and large doses can interfere with nerve impulses.
• Good sources for Minerals - Meats, Dairy, Vegetables and Fruit.

Water

• Water is 60-70% of body weight, and assists with all sorts of chemical reactions, as well as temperature regulation and is also last not not least, a critical nutrient category.

Nutrition at a Cellular Level

• Health problems in Nutrition tend to originate within the cells, and the functions of the cells are maintained by the nutrients they are receiving.
• Poor nutrition can result from both excess or little nutrients, which often results in disruption from the homeostasis in certain processes and parts.

Adaptive Mechanisms

• Humans have adaptive mechanisms for fluctuation in food in takae.
• Dietary surplus, will mean the addition to tissues and body.
• Body down regulates , downregulates from glycogen and fat stores.
• Malnutrition occurs as a result of of too much excess and lack of everything from adequate availability and ability.

"ripple effects".

• As previously mentioned, good health requires adaptive mechanisms to account for for poor diets, and the ability to use nutrients consumed well overall.

Nutrigenomics

• Nutrigenomics is the study of diet and nutrients to affect the body.
• Genetics contribute to the disease.

Groups at Higher Risk

• Groups of high nutrition need - lactating women, pregnant women, children are more often impacted by lack of nutrition and less.
• Inadequate and insufficient nutrition contribute to the development of various illness for example, heart disease.

Good Dietary Habits and Dietary Patterns

• These habits have been developed to to best be fit for the body and are key characteristic of excellent diet to stay balanced.
• There are many ways to help a body through illness, but the most important is to eat well, and have food and good nutrients.

Diversity and Chronic Disease

• In many cases with disease their is and lack of need for certain food patterns, diversity, and lack of inflammation and oxidative stress, to keep someone healthy when they are well.

Dietary Guidelines

• Diet is really and closely related to all kinds of different connections for certain diseases and illness, it is crucial to try an prevent a poor diet if one can avoid it.
• Good balanced health leads to better results in patients health overall.