Nutrition Basics

• Nutrition is the science of ingestion, digestion, absorption, metabolism, and biochemical function of nutrients.

Nutrients

• Macronutrients: carbohydrates, fats, and proteins, yield energy.
• Micronutrients: vitamins and minerals, are regulators.
• Water is also a crucial nutrient.
• Essential nutrients must be consumed whereas nonessential nutrients can be made in the body.

Nutrition Consultation

• Process includes building rapport, understanding the client's reasons for consultation, dietary analysis, assessing readiness to change, setting goals, educating on those goals, summarizing, and scheduling the next appointment. A consultation includes discussions on nutrition and physical activity.

Scope of Practice

• Includes anything in the public domain, but excludes medical nutrition therapy or recommendations for supplements

Dietary Reference Intakes (DRIs)

• An umbrella term to plan and assess diets for healthy clients based on sex and age.
• EAR (Estimated Average Requirement) applies to 50% of the population.
• RDA (Recommended Dietary Allowance) covers 98% of the population and is considered the gold standard.
• UL (Upper Level) defines tolerable upper intake levels.
• AI (Adequate Intake).
• AMDR (Acceptable Macronutrient Distribution Range).

AMDR for Macronutrients

• Carbohydrates: 45-65%.
• Fat: 20-35%.
• Protein: 10-35%.

Daily Values

• Used for nutrition labels, based on a 2000 calorie diet, given as a percentage and based on single servings, applicable to the average person.

Dietary Guidelines for Americans

• Evidence-based food and beverage recommendations to promote health, prevent chronic disease, and maintain a healthy weight, updated every 5 years.

Claims on Food Labels

• Nutrient Claim: most reliable, reviewed by the FDA, e.g., "lower in fat".
• Health Claim: reviewed by the FDA, e.g., "may do this," but cannot be definitive.
• Structure-Function Claim: not approved by the FDA, allows broad statements but must disclose that the claim has not been evaluated by the FDA.

Organic Food Labels

• 100% Organic: all ingredients are organic and has the seal.
• Organic: 95% of ingredients are organic, certified, and has the seal.
• Made with Organic: at least 70% certified organic ingredients, no seal, must specify organic ingredients and be certified.
• Organic Ingredients: no specific percent, no seal, can contain GMOs, doesn’t need to comply with the national list and is not certified.

Serving Size vs. Portion Size

• Serving size is the recommended amount; portion size is the amount a person chooses to eat.

Enriched vs. Fortified Foods

• Enriched foods have nutrients added back that were taken out during processing; fortified foods have nutrients added that were never originally present.

Food Label Information

• Includes calories, serving number, sodium, saturated and trans fats, carbohydrates with added sugar, vitamin D, calcium, iron, potassium, and a footnote with ingredients in descending order based on weight.

Digestion and Absorption

• Primary organs: mouth, esophagus, stomach, small intestine (duodenum, jejunum, ileum), large intestine, and rectum.
• Accessory organs: salivary glands, liver, gall bladder, pancreas, teeth.
• Digestion primarily occurs in the small intestine (90%), with 5% in the stomach and 5% in the large intestine.
• Carbohydrate digestion begins in the mouth with amylase.
• Fat digestion begins in the mouth with lipase.
• Protein digestion: mechanical breakdown starts in the mouth, chemical digestion in the stomach with pepsin.

Major Enzymes

• Amylase (for carbohydrates) and Lipase (for fats) both start in the mouth.

Bile Function

• Bile released from gall bladder emulsifies fat for later digestion in the small intestines.

Absorption Mechanisms

• Passive Diffusion: travels down concentration gradient through bilayer.
• Facilitated Diffusion: travels down concentration gradient through protein channel.
• Active Transport: uses ATP to go through protein channel.
• Endocytosis: cell engulfs the substance.

Energy Metabolism

• Three systems: aerobic, anaerobic, and phosphagen.
• Anaerobic system: glycolysis, quick, doesn’t require oxygen.
• Aerobic system: glycolysis, beta oxidation, electron transport chain, citric acid cycle, deamination, slow, requires oxygen.
• Phosphagen: no metabolic pathways, very fast, utilizes muscle glycogen stores, short duration.

Types of Carbohydrates

• Monosaccharide: one sugar (simple): glucose, fructose, galactose.
• Disaccharide: two sugars (simple): maltose, lactose, sucrose.
• Oligosaccharide: 3-10 sugars (complex): corn syrup, maltodextrin.
• Polysaccharide: greater than 10 sugars (complex): starch, glycogen, dietary fiber.

Regulation of Glucose

• Insulin helps cells absorb glucose from the blood stream. The body stores glucose as glycogen in the liver.

Carbohydrate Digestion and Absorption

• Mouth: mastication, amylase.
• Stomach: churning, acid.
• Small intestine: sugar enzymes, most absorption through facilitated diffusion of fructose and active transport of glucose and galactose.
• Large intestine: bacteria.

Fiber

• Types: soluble and insoluble.
• Functional fiber: water soluble, swell, dissolves well, from fruits, oats, beans, dried peas, vegetables, flaxseed, psyllium.
• Dietary fiber: insoluble, don’t swell, from whole wheat products, whole grain cereals, vegetables, brown rice, lentils, psyllium.
• Isolated fiber: fiber extracted from its source.
• Intact fiber: found in its source.

Glycemic Index

• Ranks foods (0-100) based on their potential to raise blood glucose compared to a standard food like glucose.

Sugar Intake

• Limit added sugars because complex carbohydrates provide necessary nutrients and high sugar may displace nutrient-dense foods and also cause crashes in blood glucose.
• Consume less than 10% of daily calories in added sugars.

Carbohydrates and Protein-Sparing

• Carbohydrates are used as an energy source instead of proteins so the body can keep proteins

Sugar Alcohols

• Ends in –ol, is a polyol, natural sweeteners

Carbohydrates and Gut Microbiota

• Gut microbiota: set of microorganisms that colonize our digestive tract and impact our health and may influence athletic performance.
• Positively impacted by: Adequate fiber, Omega-3 fatty acids, Probiotics, Prebiotics
• Negatively impacted by: High protein, High fat (particularly saturated), Low fiber.

Crossover Concept

• Fats primarily used at rest, switch to primarily carbs immediately at exercise with longer duration or higher intensity

Carbohydrates in Sports Drinks

• Should be a concentration of 6-8%.

Carbohydrate Recommendations for Performance

• 4-24 hours prior: 60-70% of diet should be carbohydrates.
• Prior to Exercise: 1-4g/kg BW in carbohydrates (avoid 30 minutes before), can do complex or simple, do more simple the closer you are to exercise, make sure they are low on glycemic index
• During Exercise: 30-60g/hr, do simple, moderate to high glycemic index, 120-240 kcal/hr (up to 90 for endurance athlete).
• After Exercise: 1-1.2 g/kg BW/ hr for 4 hours, medium to high glycemic index, simple, liquid form, mix of CHO and proteins.

Reactive Hypoglycemia in Athletes

• Eating carbohydrates prior to exercise with a high glycemic index can cause a crash during exercise. Prevent by eating foods low on glycemic index (not 30 minutes before due to GI discomfort).

FODMAP Diet

• Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. It can benefit by having lower GI side effects when exercising by avoiding foods with these things (sugar alcohols and short chain carbs).

Carbohydrate Mouth Rinse

• Activates reward system in brain while not using digestive tract.

Special Considerations for Female Athletes

• During luteal phase, increase CHO intake (days 14-28).

Types of Lipids

• Triglycerides (fats and oils): ≈98% of all dietary fat; most common type in humans, Triacylglycerol.
• Phospholipids: glycerol backbone, 2 FAs & phosphate, fat and water soluble, cell membranes; emulsifiers (lecithin); transporters (bile has), e.g., egg yolks, soybeans, and peanuts.
• Sterols: do not contain FAs; ringed molecular structure, same properties as fats, cell membranes, vitamin D, steroid hormones, manufacture bile salts, e.g., plant sterols/stanols, cholesterol.

Structure of Lipids

• Glycerol: forms triglyceride “backbone”, three-carbon molecule.
• Three fatty acids: can be of different lengths.

Fats in the Body

• Source of energy: during rest (60-80%) & exercise (varies).
• Energy reserve (9 kcal/gram): stored in adipocytes, liver, and muscle.
• Protection: cushioning, insulator (thermal/electrical).
• Vitamin Carrier: A,D,E,K.

Saturated vs. Unsaturated Fats

• Saturated: solid at room temperature, straight carbon chain, saturated with hydrogen, bad for you.
• Unsaturated: liquid at room temperature, have kink due to double bond in carbon chain getting rid of hydrogen, better for you.
• Monounsaturated: One kink.
• Polyunsaturated: multiple kinks in chair (omega 3 and 6).
• Trans: have double bond, but are straight.

Essential Fatty Acids

• Polyunsaturated: Omega 3 and omega 6

Recommended intake and food sources

• AMDR: 20-35% of total energy intake or 1 g/kg dailyProblems associated with too low of a fat intake 

• Hunger, have to use CHO during rest, can dip into proteins if they run out of other fuel sources 

• Different types of lipoproteins and what affects their levels in the body 

• High-density lipoproteins (HDL): critical in the process of carrying cholesterol away from body cells to the liver for disposal. (“GOOD”) 

• Very-low-density lipoproteins (VLDL) : carry triglycerides and other lipids made in the liver to the body cells for their use. 

• Low-density lipoproteins (LDL): transport cholesterol and other lipids to the tissues. Made from VLDL after donating triglycerides to body cells. (“BAD”) 

• Liproprotein(a): structurally similar to LDL; linked to atherogenesis and thrombogenesis. 

• Trans fats raise LDL and lower HDL, risk factors and LDL, exercise and HDL 

• Guidelines for lowering blood cholesterol levels 

• Mediterranean diet, exercise, limit trans fats 

• Trans fats and health effects 

• Raise LDL, lower HDL, produce inflammation, increase risk of heart disease 

• DRI recommendations for lipids/Daily Fat Recommendations 

• 20–35% of total calories 

• ~ 10–15% polyunsaturated 

• ~ 15–20% monounsaturated 

• <7; 10% max saturated 

• Avoid trans fats (<1% of total calories) 

• Basics of a Mediterranean Diet 

• fish, fruits, veggies, legumes, grains, legumes, low fat dairy, high fiber, red wine, olive oil, easily digestible 

• Fat recommendations before, during and after exercise 

• Before: Single High-Fat Pre- Competition Meal, Include fats, but keep to a minimum, Facilitate gastric emptying, minimize GI distress. 

• During: avoid fats during exercise 

• After: 20–35% fat content, Focus: Unsaturated fats, Carbohydrates (and protein) should predominate, Consume post-exercise meal ASAP. 

• MCTs-recommendations for physical activity 

• Absorption is faster, Benefits questionable, possible gastric upset 

• WORKSHEETS! 

• Treating Cardiovascular Disease or High Cholesterol 

• 5-6% of total calories from saturated fat, eat lean meats, whole grains, fruits, and vegetables