Nutrition: Carbohydrates

Foundations of Nutrition: Carbohydrates

• The video discusses carbohydrates as the first topic in a nutrition principles series
• The learning objective is to describe carbohydrate composition, roles, effects, and general recommendations

Overview of Carbohydrates

• Carbohydrates, proteins, and fats are the three macronutrients
• Carbohydrates uniquely supply the body with glucose, a major energy source
• Glucose is the brain's preferred energy source
• Insufficient carbohydrate intake can affect energy levels and brain function

Storage and Use of Glucose

• After eating carbohydrates, the body uses glucose for immediate energy or stores it for later
• Glucose is mainly stored in the liver, skeletal muscle, and brain as glycogen
• Glycogen is used during exercise or when carbohydrate intake is insufficient

Categories of Carbohydrates

• The two major categories are simple and complex carbohydrates

Simple Carbohydrates

• Composed of monosaccharides and disaccharides (one or two sugar molecules)
• Broken down, absorbed, and digested quickly, leading to rapid blood glucose spikes
• Advantageous for quick energy, such as in sports or during tests
• Food sources include white bread, pastries, white rice, pasta, desserts, soda, and juice

Complex Carbohydrates

• Composed of oligosaccharides and fiber (three or more sugar molecules)
• Fiber slows digestion
• Absorbed and digested more slowly, leading to slower, lower blood glucose spikes
• The energy provided lasts longer compared to simple carbohydrates
• Offer additional micronutrients (vitamins and minerals)
• Food sources include fruits, vegetables, whole grains (whole wheat bread, pasta, brown rice, quinoa, oats)

Glycemic Index and Blood Sugar Effects

• The effect on blood glucose levels is a key differentiator between simple and complex carbohydrates
• The glycemic index tracks how different foods affect blood glucose levels

Glycemic Index Categories

• High glycemic index foods spike blood sugar rapidly, followed by a quick drop
• Medium glycemic index foods cause a moderate, longer-lasting spike
• Low glycemic index foods provide longer-lasting energy with a lower spike

Carbohydrates and Glycemic Response

• Simple carbohydrates often cause rapid blood sugar spikes, but not always
• Some low glycemic index foods include fruits, vegetables, and apple juice
• High glycemic index foods include simple sugars like Cheerios and donuts, as well as some complex carbohydrates
• Dates, despite being a natural sweetener, spike blood sugar similarly to donuts

General Carbohydrate Recommendations

• These are for healthy individuals

Acceptable Macronutrient Distribution Range (AMDR)

• 45–65% of daily caloric intake should come from carbohydrates
• The recommendation can surprise people due to media-driven fears about carbohydrates
• Eating carbohydrates does not inherently cause weight gain or diabetes

Complex vs Simple Carbohydrates in Recommendations

• Individuals should prioritize complex carbohydrates for their added nutrients like fiber, vitamins, and minerals
• Simple carbohydrates are not inherently bad; they have a place in a healthy diet
• Reduce fear surrounding simple carbohydrates by acknowledging their role in providing immediate energy
• Educate the general public to reduce anxiety while meeting carbohydrate needs

Basic Nutrition Principles: Protein

• Protein is the second macronutrient discussed in the series
• The goal is to describe the composition, roles, and effects of protein and explain general protein recommendations

Overview of Protein

• Protein is composed of amino acids, the building blocks of cells
• Protein builds and maintains muscle mass
• Roles include structural support for cells, organs, and tissues, enabling movement, maintaining pH balance, and creating essential substances like enzymes and hormones

Sources of Protein

• Found in meat, dairy, beans, nuts, and seeds

Complete vs Incomplete Proteins

• Two classifications: complete and incomplete

Complete Proteins

• Complete proteins contain all nine essential amino acids in needed quantities
• Sources include animal products like meat, fish, poultry, milk, cheese, eggs, and butter

Incomplete Proteins

• Incomplete proteins lack or don't have enough of one or more essential amino acids
• All plant-based protein sources are incomplete, except quinoa
• Vegans and vegetarians must combine incomplete protein sources to get all essential amino acids
• Beans and rice are a classic combination

Protein Recommendations for Healthy Individuals

• The acceptable macronutrient distribution range (AMDR) for protein is 10–35% of daily caloric intake
• Consuming protein within this range meets the body's needs

Recommended Dietary Allowance (RDA) for Protein

• Useful for tracking protein intake
• The RDA for protein is 0.8 grams of protein per kilogram of body weight per day
• Much lower than recommendations from fitness influencers, who often suggest 1 gram of protein per pound of body weight

When Protein Needs Increase

• Protein needs increase during illness, injury (burns, broken bones), growth (childhood, pregnancy), and athletic training
• Protein needs can increase up to 2 grams per kilogram per day in these cases, but not always

Excess Protein and Body Processing

• The body does not store excess protein
• Excess protein converts into glucose for energy
• Consume protein at regular intervals

Protein Intake Timing

• Consume 15–40 grams per meal or snack
• Allows protein to be properly utilized

Basic Nutrition Principles: Dietary Fat

• Dietary fat is the third macronutrient
• Describe composition, roles, and effects of lipids, and explain dietary fat recommendations

Overview of Lipids

• Lipids are composed of fatty acids bound to glycerol
• Triglycerides are a source of energy
• Phospholipids contribute to cell structure
• Steroids transport signaling throughout the body

Sterols and Cholesterol

• Sterols are a subclass of steroids, including cholesterol
• Lipids:
  • Insulate
  • Regulate temperature
  • Lubricate tissues and joints
  • Produce hormones
  • Aid in vitamin absorption, especially fat-soluble vitamins

Categories of Dietary Fat

• Saturated and unsaturated fats

Saturated Fat

• Saturated fats are solid at room temperature due to saturated bonds
• They can increase cardiovascular disease risk
• Main sources are animal-based: meat, dairy, butter, and lard
• Coconut oil is a plant-based source

Unsaturated Fat

• Unsaturated fats are liquid at room temperature
• They include omega-3 fatty acids
• Sources
  • Plant-based are nuts, seeds, olives, avocados, vegetable oils
  • Animal-based is fatty fish

Omega-3 Fatty Acids and Heart Health

• Unsaturated fats, especially omega-3s, improves the cardiovascular systems

Dietary Fat Recommendations

• These support healthy fat intake

AMDR for Dietary Fat

• Recommended between 20–35% of daily caloric intake
• Can vary based on individual factors

Dietary Guidelines for Americans

• Saturated fat intake should be less than 10% of total daily calories
• Unsaturated fats should be prioritized

Prioritizing Unsaturated Fats

• Consumption of fatty fish and seeds can provide health benefits

Energy Metabolism and Macronutrients

• Discussing role of macronutrients in energy metabolism
• The goal is to explain the order of energy metabolism and its real-world implications

Purpose of This Lecture

• To connect scientific processes regarding energy metabolism to real-world dietary recommendations and outcomes

Sources of Energy in the Body

• Body primarily uses glucose from carbohydrates
• Energy dips prompt carbohydrate consumption

Glycogen as an Energy Source

• Glycogen is the stored form of glucose
• Body converts glycogen to glucose for energy

Fat and Protein as Energy Sources

• Fat is broken down through lipolysis
• Protein is broken down through proteolysis
• Gluconeogenesis converts fat and protein into glucose
• People on low-carb diets may prioritize fat and protein consumption for energy production, rather than other roles

Prolonged Fasting and Ketosis

• Body relies on stored fat for energy if carbohydrates, protein, and fat are not available, and glycogen stores have been depleted
• Breakdown of fat done through lipolysis, into ketones
• Ketosis is hard to achieve

Real-World Implications of Energy Metabolism

• These can be seen through low carbohydrate diets and nutrient availability

Low-Carbohydrate Diets and Nutrient Availability

• Limited carbs means fat and protein are used for energy first
• Enough fat and protein may not be available to perform essential roles in the body

Caloric Deficit and Metabolic Adaptation

• The body sees a deficit as starvation
• The body becomes more efficient and lowers the metabolism

Extreme Dieting and Long-Term Health Consequences

• The body cuts out non-essential functions

Yo-Yo Dieting and Weight Cycling

• Dieting can lead to dissatisfaction, prompting another round of diets
• Repeating can harm weight regulation and quality of life

Dietary Guidelines and the Plate Method

• Content ties together dietary recommendations for macronutrients, hydration, and overall nutrition
• The learning objective is to give an overview of the Dietary Guidelines for Americans and explain cohesive nutrition guidelines using the plate method

Overview of the Dietary Guidelines for Americans

• Provides advice on what to eat and drink to meet nutrient needs, promote health, and prevent disease

Updating the Guidelines

• Updated, new set of dietary guidelines every five years to reflect the most recent nutrition research

Intended Audience for the Guidelines

• For professional audience
• Simplified and presented guidelines in a way that is easier for the general public to understand and implement

Development Process of Dietary Guidelines

• Committee Review of Key Resources
• Guideline Development
• Scientific Expert Review
• Approval and Public Release
• Recommendations based on life stage, nutrients, and other factors
• Follow a healthy dietary pattern at every life stage
• Customize nutrient-dense food and beverage choices based on personal preferences, cultural traditions, and budgetary considerations
• Focus on meeting food group needs with nutrient-dense foods and beverages while staying within calorie limits
• Limit intake of beverages high in added sugars, saturated fat, sodium, and limit alcoholic beverages

Simplifying Nutrition Recommendations Using the Plate Method

• Plate method:
  • Half the plate: Fruits and vegetables
  • One-fourth of the plate: Protein
  • One-fourth of the plate: Carbohydrates
  • Fat sources: Used to add flavor

Hydration

• Discussing hydration, listing factors that contribute to hydration status and hydration recommendations

Overview of Water and Its Role in the Body

• Water composes of a major component of the body.
• Key functions of the body
  • Contributing to body fluids
  • Removing waste and toxins
  • Maintaining homeostasis
  • Aiding in digestion
  • Participating in chemical reactions
  • Lubricating tissues
  • Transporting substances.

Electrolytes and Hydration Balance

• Hydration affected by the electrolyte balance.
• Main electrolytes are,
  • Sodium
  • Chloride
  • Magnesium
  • Calcium
  • Potassium.

Factors Influencing Hydration Status

• Major factor includes
  • Activity level.
  • Illness.
  • Altitude.
  • Temperature.
  • Caffeine Intake.

Various levels of Hydration

- Activity Level ->  Active individuals need more electrolytes to maintain hydration.
- Caffeine Intake ->  Regularly should increase fluid to maintain hydration.

Dehydration

• Most common and main concern when the body lacks fluids, higher concentrates electrolytes.
• Causes dizziness, lightheadedness
• If left untreated life threatening

Hyponatremia

• Overhydration, common in active athletes.
• Too much water dilutes elytes which causes extreme health complication.

Hydration Recommendations

• Water Intake:
  • Women -> 2.7 liters/day (~11.5 cups).
  • Men -> 3.7 liters/day (~15.5 cups).
• "Total water" includes fluid from water, food and other beverages.
• Urine Color as a Hydration Indicator Recommend color urine.

Key levels of Hydration

Proper hydration - light lemonade Excess Water - clear urine. Lack of hydration - dark Apple juice.

Basic summary info

• Infants
• Young children
• Older adults
• Athelets
• High risk for hydration

Micronutrients

• There are principles of micro nutrients.
• Main goal is difference between vitamins and minerals

Vitamins

• Needs to meet 4 criteria to be considered

What are some key elements?

• Organic Compound
• Body must make it
• Must naturally flow in food
• Body needs for life process

What are the types of vitamins?

• Fat soluble- A, D, E, K. body best absorbs with certain foods
• water Soluble- body absorbs anytime

What are basic mineral concepts?

• Like Vitamins needs a criteria
• Are non organic

WHat are the types of Minerals?

• Major- must have 100mg intake
• Trace- require less than 100mg intake

What are some keys for minerals??

• Eat more, dont focus on supplements unless critical

Dietary Recommendations for Micronutrients

• Eating lots of different food source aids great health
• Key supplements, mostly dont do it for some

What are food type of nutrients?

• Focus on main food groups + Carb + Fat + Protein
• Try different fruits and vegies