Nutritional Science Overview Quiz

Nutritional Science Study Notes

• Nutritional science is the study of nutrients and their impact on human health.
• Key reference books include Krause and Mahan's Food & The Nutrition Care Process (15th ed.), and others by Raymond, J.L. and Morrow, K. (2020), Brown, J. and Lechtenberg, E. (2016), and Rolfes, R S. Pinna, K. and Whitney E. (2017).

Chapter Overview

• Principles of human nutrition
• Energy intake and energy balance
• Food building blocks: Macro & Micronutrients
• Nutrients for healthy blood and bone development
• Introduction to food planning & dietary guidelines (e.g. MyPlate, optimal diet, healthy eating index)
• Common trends in dietary intake and diet planning
• Eating disorders

Our Need for Food

• Food significantly impacts our daily lives, affecting how we look, feel, and function.
• Food provides nutrients.
• Nutrients are chemical substances that support growth, tissue maintenance and repair.

Principles of Human Nutrition

• Food is essential for human survival and for supporting growth and health
• Foods provide energy (calories) and nutrients.
• Health problems from nutrition originate within body cells.
• Poor nutrition can result from both inadequate and excessive nutrient intake.
• Humans have adaptive mechanisms for managing fluctuating food intake.
• Malnutrition stems from poor diets, disease, genetic factors, or a combination of these.
• Inadequate nutrition can influence the development of chronic diseases like diabetes or heart disease.
• A balanced, adequate, and varied diet is beneficial for optimal health.

Introducing Nutrients

• Food is a mixture of chemical substances, including nutrients.
• Six categories of nutrients are carbohydrates, lipids, proteins, vitamins, minerals, and water.

Describing Nutrients

• Nutrients are classified as organic/inorganic, essential/non-essential, macronutrients/micronutrients, and energy-yielding/non-energy-yielding.
• Macronutrients (carbohydrates, fats, and proteins) provide energy and are needed in larger amounts.
• Micronutrients (vitamins and minerals) are needed in smaller amounts and have important functions.

Energy Yielding Nutrients

• Macronutrients provide energy in an adult diet (2000 kcal):
  • Carbohydrates: 45-65%
  • Fats: 20-35%
  • Protein: 10-35%

Understanding Nutrients

• Carbohydrates provide a source of energy.
• Proteins are made up of amino acids and have structural and functional roles.
• Fats are important for the absorption of fat-soluble vitamins and provide energy.
• Vitamins and minerals regulate various biological functions.
• Water is essential for numerous bodily functions.

Energy Balance

• Energy balance is the difference between energy intake and energy expenditure.
• Energy intake and energy expenditure are determined by the types and quantities of food and drinks and physical activity.
• Positive Energy Balance: Intake > Output = Weight gain
• Negative Energy Balance: Intake < Output = Weight Loss
• Energy needed for daily function can be obtained from carbohydrates, protein and fat.
• Oxidation of different nutrients provide different amount of energy: Carbohydrates 4 kcal/g Fats 9 kcal/g Proteins 4 kcal/g Alcohol 7 kcal/g

Carbohydrates

• Carbohydrates are the main component of human diets globally.
• Carbohydrates are the primary source of readily available energy in the body.
• Carbohydrates are composed of carbon, hydrogen, and oxygen.
• The brain uses carbohydrates as its primary energy source.
• The different types of carbohydrates are Monosaccharides, disaccharides, and polysaccharides.

Lipids

• Lipids are composed of carbon, hydrogen, and oxygen.
• Important for the absorption of fat-soluble vitamins.
• Lipids include fatty acids, triglycerides, phospholipids, and sterols.
• Fatty acids are classified based on the number of carbon atoms and the presence of double bonds (saturated/unsaturated).
• Polyunsaturated fatty acids (omega-3 and omega-6) are essential fatty acids.

Proteins

• The quality of protein depends on essential amino acids.
• Protein from animal sources is generally higher quality than proteins from plant sources.

Vitamins

• Vitamins are micronutrients.
• They are categorized as water-soluble or fat-soluble.
• Different vitamins have distinct roles in many bodily functions

Minerals

• Minerals are micronutrients, with various roles in the body.
• Minerals include elements essential for numerous functions, including maintaining fluid balance, nerve transmission, and muscle contraction.

Dietary Guidelines

• Dietary guidelines are established to provide dietary recommendations tailored to specific populations
• The recommend appropriate amount of nutrients in the diet.
• The recommendations vary based on age, sex, and activity level.
• Specific recommendations may also be included to prevent or treat specific diseases

MyPlate

• MyPlate is a visual guide for healthy eating, emphasizing portion sizes and proper food groups.
• Its a helpful tool for meal planning.

Dietary Guidelines for Dietary Fat Intake

• Acceptable Macronutrient Distributions (AMDR) for fat range from 20-35% of total daily energy intake for adults, but vary for children
• Saturated fatty acids (SFA) should be less than 10%
• Monounsaturated fatty acids (MUFA) should be about 12%
• Polyunsaturated fatty acids (PUFA) intake should not exceed 10%
• Trans fats should be as low as possible

Lipid Transport

• Lipids are not water-soluble and require lipoproteins to travel in the blood.
• Lipoproteins are clusters of lipids associated with proteins which help transport lipids through the blood. Different types of lipoproteins exist, each with their specific functions.

Health Effects

• Abnormal blood lipid profiles can cause CVD.
• Saturated fats in animal products may increase LDL cholesterol, a risk factor for CVD
• Dietary cholesterol also increases blood cholesterol levels and increases the risk of heart disease
• Omega-3 fatty acids may have protective effects against heart disease and stroke, reducing LDL levels.

Protein Recommendation

• The recommended daily protein intake for adults is 0.8 grams of protein per kilogram of body weight.
• Protein needs vary based on factors like age, growth, and activity level.

Minerals and Trace Elements

• Minerals and trace elements are essential for normal bodily function, with various roles.
• Minerals and trace elements are often involved in tissue structure, enzymes, fluid balance, cellular function, and neurotransmission.

Nutrients for Healthy Blood

• Vitamins and minerals play critical roles in maintaining healthy blood function, including DNA synthesis and red blood cell formation.
• Deficiency in certain vitamins e.g. folate or B12, can cause anemia
• Iron, present in most meat (especially red meat), is essential for blood hemoglobin and oxygen transport.

Nutrients for Bone Health

• Calcium and phosphorus are crucial for bone health, contributing to strong, healthy bones and preventing related risk like osteoporosis and bone loss
• Vitamin D is essential for calcium absorption and bone development.
• Vitamin K plays a role in calcium binding and bone formation
• Other minerals important components in bone development and maintainance are magnesium, zinc, copper.

Electrolytes and Regulation of Fluid Balance

• Sodium, potassium, and chloride are electrolytes, key to fluid balance and the function of nerves and muscles.
• Recommended amounts of sodium will vary from population to population in relation to health status.

Dietary Guidelines

• Recommendations are provided by USDA/National experts of nutrition
• The guidelines vary based on population (adults, children, pregnant women)
• Specific recommendations are offered to prevent and mitigate particular health related issues

Eating Disorders

• Eating disorders, such as anorexia nervosa, bulimia nervosa, and binge eating disorder, involve severe disturbances in eating habits and related thoughts, beliefs, and behaviors
• These behaviors often become preoccupied with food and body weight with the major health risk for the individual.

Nutritional Assessment and Screening

• Nutritional screenings and assessments are often conducted to evaluate an individual or a patient's nutritional status.
• Assessments can be completed by multiple health professionals

Methods of Nutritional Assessment

• Anthropometry
• Biochemical tests
• Clinical evaluation
• Dietary assessment

Evaluation of Head Circumference Measurement

• WHO and CDC growth charts provide reference values for head circumference as they aid in detecting early signs of underlying developmental conditions

Body Weight

• Weight measurement, both in individuals who can stand and those who can not, helps in the identification of appropriate nutritional interventions.
• BMI (Body Mass Index) is a calculation based on weight relative to height.

Body Fat Distribution

• Body fat distribution (android/gynoid) is important in assessing health risks because of association with health complications like diabetes, and heart disease.

Biochemical Tests

• Biochemical tests are laboratory procedures that provide information about nutritional status; including levels of particular nutrients or metabolites in body fluids (blood, urine, etc).
• Several tests are used, and can help detect early signs of deficiency from macro or micro nutrients

Dietary Methods

• Dietary methods assess habitual food and nutrient intake, used by healthcare professionals when conducting nutritional assessments.
• Direct observation of eating patterns is one approach
• Dietary records, questions and questionnaires may also help assess the diet of an individual.

Why Measure Diet?

• The ultimate goal is improved human health.
• Investigating relationships between diet and common health problems (like heart disease or cancer) are important.

Approaches to Measuring Diet

• Employing dietary measurement techniques ensures proper information is obtained and analyzed in context to potential outcomes or nutritional interventions
• Dietary assessment methods include tracking food consumption; both using diaries or records, questionnaires, and recalling usual or average intake over a period of time

24-Hour Recall

• A 24-hour recall involves detailing a person's food and drink intake over a 24-hour period to establish the diet in that time frame

Food Record, or Diary

• A food diary requires detailed food record, noting the type of food or meal items, amounts and times throughout a specific duration

Anemia

• Anemia is a condition in which the blood has lower than normal quantities of red blood cells (RBCs) or hemoglobin
• It can be caused by deficiency in crucial vitamins like folate and B12.
• Several conditions can lead to iron deficiency.
• Causes include poor nutrition and medical conditions

Indicators of Iron Status

• Hemoglobin levels alone cannot fully indicate iron status due to other factors.
• Ferritin levels reflect stored iron in the body, and decrease are an early sign of iron deficiency

Iron Deficiency

• Iron deficiency can take place in stages with the first stage involving decreased iron stores, the second showing deficit with no overt effects, and the third showing significant impairment (anemia).

Types of Anemia

• Anemia is categorized into macrocytic and microcytic types, based on the size of the red blood cells.
• Macrocytic anemia results from deficiency in crucial vitamins, whilst microcytic anemia is more closely linked to iron deficiency

Iron Deficiency Anemia

• It's the most prevalent nutritional deficiency.
• It is a major public health issue, particularly affecting pregnant women and young children.

Categories at Risk of Iron Deficiency

• Infants and older children
• Pregnant women
• Women of Childbearing age

Micronutrients and Anemia

• Micronutrients such as vitamin B9, B12, Zinc and Copper, are often impacted by and have impacts on anemia, in addition to each other

Zinc in Relation to Anemia

• Zinc is an essential trace element
• It plays crucial parts in enzyme activity and important components of protein functions relating to cell membranes and nucleic acids, growth, and immune function.
• Insufficient zinc can affect red blood cell (RBC) development, associated with anemia.
• Zinc intake can affect iron and copper absorption

B-Vitamins

• Folate and vitamin B12 are crucial for DNA synthesis and red blood cell (RBC) production.
• Deficiency in either can lead to different types of anemia.

Vitamin A

• Vitamin A is not directly related to anemia but indirectly has been associated with impaired absorption, storage and/or transportation of iron in the body and thus plays a role in anemia

Dietary Iron

• Iron exists in two forms: Heme iron (readily absorbed) and non-heme iron (less readily absorbed).

Dietary Treatment of Iron Deficiency Anemia

• Iron is necessary to replace losses in the body
• Iron requirements are varied from population, age, and health status

Absorption

• The absorption process depends on factors like consumption of ascorbic/citric acids, and presence of other compound that can hinder absorption, like phytates, polyphenols, calcium, or phosophate.

Other Components of TLC Diet

• Monounsaturated fats (MUFA) and polyunsaturated fats (PUFA) are encouraged, as they impact LDL cholesterol, and can help lower it.
• There are different recommended amounts of CHO and Proteins in different population groups

TLC and Metabolic Syndrome

• The criteria for Metabolic syndrome can be diagnosed when the patient has abnormal levels of both anthropometry (physical measurements) and biochemistry.

Physical Activity

• Regular physical activity can moderate the risks associated with several CVD related problems

Dietary Approaches to Stop Hypertension (DASH)

• The DASH diet is a dietary pattern rich in fruits, vegetables, and low-fat dairy products and is often associated with better outcomes when it comes to Hypertension.
• It lowers levels of sodium and contains lots of potassium.

Weight

• Overweight and obesity increase the risk of CVD.
• The distribution of body fat, specifically abdominal fat, further enhances the risk for CVD and often associated with other health problems like hypertension.

Hypertension

• High blood pressure (HTN) or Hypertension is a major health concern that correlates negatively with various physical and mental health outcomes.
• It can be caused from various issues including aging, genetics, obesity and insufficient sodium intake
• Diet and lifestyle adjustments may help manage HTN

Cardiovascular Diseases (CVD)

• CVDs, including heart disease and stroke, are leading causes of death in many regions.
• Atherosclerosis, the hardening and narrowing of arteries, is a major underlying cause of several CVD conditions
• Several factors and conditions increase the risk for and contribute to CVD

Understanding CVD

• Coronary Heart Disease (CHD) results from atherosclerosis in the coronary arteries, which supply blood to the heart muscle.
• Blocked blood vessels can lead to strokes, which are caused by reduced/no blood flow to specific sections of the brain
• Both heart attacks and strokes can cause injury, disability or death
• Several health behaviors can influence the risk for and severity of CVD.

Outcomes

• Regular physical activity, balanced nutrition, and not smoking have been confirmed to lower the risks of CVD
• Atherosclerosis results from the build-up of plaque in the inner layers of arteries, potentially leading to blockages and narrowings in arteries
• These blockages can cause conditions such as heart attack or stroke

Development of Atherosclerosis

• Atherosclerosis starts to develop very early in life/childhood but doesn't usually result in overt symptoms for many decades.
• Initially, the inner surface of arteries can be injured; potentially from poor nutrition, or elevated levels of cholesterol.
• LDL's oxidation may be a critical step in triggering inflammation, which activates the process that cause plaque formation to occur.
• Atherosclerosis progresses as the inner layers of the artery have increasing amounts of plaque, which can become unstable and cause problems when the plaque breaks off or ruptures.

Factors Leading to Atherosclerosis

• Smoking is one significant risk factor
• Stress/tension, and hypertension increase the risk of developing/worsening and severity of atherosclerosis.
• Abnormal lipid profiles (dyslipidemia) can put an individual at increased risk for developing atherosclerotic processes
• Age/gender factors also play a role in development of atherosclerosis

Dyslipidemia (Abnormal Lipid Profile)

• Dyslipidemia refers to an abnormality in the profile of serum lipoproteins that transport lipids throughout the body.
• Abnormal lipid profiles e.g, elevated LDL cholesterol or low HDL cholesterol can be a risk factor for developing atherosclerosis

High Serum Triglycerides

• Elevated serum triglycerides are a risk factor for CVD
• Management involves lifestyle changes which include specific nutrition and/or drug therapy

TLC Recommendations

• TLC (Therapeutic Lifestyle Changes) Diet recommendations for dyslipidemia include adjustments to reduce saturated fat, cholesterol, and dietary totals.
• Intake of plant stanols/sterols
• Foods rich in fiber, and regular physical activity

Plant Sterols/Stanols

• Plant sterols/stanols are naturally occurring substances in plants, that help block absorption of cholestrol in the body and thus help lower the levels of LDL cholesterol.

TLC and Metabolic Syndrome

• Metabolic syndrome includes several symptoms where there is high blood pressure (HTN), abnormally high blood glucose levels, and low blood cholesterol (dyslipidemia)
• The presence of abdominal fat is an indicator of metabolic issues.
• Dietary management is typically used alongside suggested lifestyle changes, like adding more physical activity, and reducing the intakes of several nutrients like sodium and saturated fat.

Diabetes Mellitus (DM)

• Diabetes is a chronic and progressive metabolic disorder characterized by elevated blood glucose concentrations.

Outcomes

• Identify what DM is and its relation to various bodily functions and conditions
• Recognize the difference between different types of diabetes (Type 1 vs Type 2)
• Understand the implications of poor/inappropriate dietary management or treatment of the condition

Background/Facts

• Diabetes ranks high among leading causes of death, particularly in developing countries
• Prevalence of diabetes rapidly increasing in low to middle income countries
• Diabetes is a major cause of certain physical impairments, and thus, requires immediate/long-term management and treatment

Overview DM

• Diabetes is characterized by disordered insulin metabolism.
• Insulin facilitates the uptake and utilization of glucose in muscle and adipose cells.
• Lack of proper insulin, or inability to respond to insulin, causes hyperglycemia, increased glucose levels in blood.

Symptoms DM

• Polyuria (frequent urination)- resulting from high levels of blood glucose in the blood
• Polydipsia (excessive thirst)- resulting from body fluid loss in response to frequent urination
• Polyphagia (excessive hunger)- resulting from cells that are not receiving sufficient glucose, for energy
• Weight loss or gain , and other symptoms

Diagnosis DM

• Diagnosis of DM is based on plasma glucose (blood sugar) levels measured under fasting conditions, or at random times, or after glucose loading test.

Prediabetes

• Prediabetes is a condition where blood glucose levels are higher than normal, but not high enough to be diagnosed as diabetes.

Types of Diabetes Mellitus

• Type 1 Diabetes: Usually begins in childhood, caused by an autoimmune attack on pancreatic beta cells (which produce insulin)
• Type 2 Diabetes: Typically occurs later in life and involves insulin resistance and / or deficiency in insulin production.

Type 1 Diabetes Mellitus

• Typically develops in childhood or adolescence.
• Characterized by an autoimmune attack on the pancreatic beta cells.
• Individuals with Type 1 diabetes require insulin therapy to manage the condition.

Type 2 Diabetes Mellitus

• Most common type of diabetes, often occurring in later adulthood.
• Often associated with lifestyle factors like obesity and physical inactivity
• Characterized by insulin resistance, meaning cells do not respond efficiently to insulin

Type 2 Diabetes in Children and Adolescents

• Prevalence has increased in recent decades.
• Often associated with overweight/obesity
• Treatment involves lifestyle changes like improved diet and increased physical activity

What about Gestational Diabetes?

• Gestational diabetes is only observed during pregnancy.
• It can result from hormonal shifts that cause insulin resistance as well as other factors
• Elevated blood sugars during pregnancy if left untreated, can result in several adverse outcomes to mother and child.

Acute Complications DM

• Untreated diabetes can lead to serious complications.
• Diabetic ketoacidosis (DKA) is caused by a severe lack of insulin, characterized by high levels of ketones in the blood, leading to metabolic acidosis
• Hyperosmolar hyperglycemic syndrome (HHS) characterized by extremely high blood glucose levels with dehydration and lack of insulin

Hypoglycemia

• Low blood glucose (hypoglycemia) can be a serious complication of diabetes.
• Symptoms include sweating, palpitations, shakiness, hunger, dizziness, and irritability
• Usually it is due to medical conditions like uncontrolled/increased insulin intake or other factors like delayed meal consumption

Chronic Complications DM

• Prolonged exposure to high blood sugars can cause damage to blood vessels, nerves, eyes, kidneys, and other tissues.
• Macrovascular complications of DM can lead to heart disease, stroke, or other issues.
• Microvascular damage can lead to kidney or eye damage

Treatment of Diabetes Mellitus

• Treatments involve personalized strategies to manage blood glucose regularly.
• Medications and lifestyle changes are usually recommended to individuals with DM
• Monitoring blood sugar levels and ensuring appropriate insulin intake are essential

Dietary Therapy

• Nutrition and food recommendations are crucial for managing diabetes
• Dietary modifications should consider individual situations, and include careful planning and monitoring of carbohydrates, fats, sugars, and also protein intake and portion management
• The recommendations vary by the type of diabetes and other factors like patient activity, health status, etc.

Nutrition Labeling

• Nutrition labels provide important information about the nutritional content of food
• Labels should include information on calories, serving sizes, nutrients, vitamins and minerals , health claims , and other regulatory and important dietary information, and can allow people to read these labels to inform their nutritional choices
• Dietary guidelines help consumers identify appropriate nutritional intake

Health Claims

• Voluntary information on food packages
• Examples of health claims relate food consumption and a variety of conditions like CHD, certain cancers, and osteoporosis.

Background/Facts for specific types of Cancer

• Prevalence of certain types of cancer and risk of particular cancers with different factors and behaviors

Malnutrition in Cancer Patients

• Specific causes of malnutrition include Direct effect of tumour tissue, therapy related issues (e.g. nausea, vomiting, poor appetite, reduced intake) physiological changes and metabolic issues.
• Weight loss can correlate negatively with cancer outcome

Cancer Cachexia

• Malnutrition is closely related to cancers
• Weight loss is associated with impaired outcomes/survival.
• Nutritional support methods can help improve protein and energy intake to minimize risks associated with the condition.

Estimation of Basal Metabolic Rate

• The Harris-Benedict equation can be used to estimate basal metabolic rate (BMR) to determine how much energy a person is expected to use when at rest.
• BMR estimates differ for males and females and depend on some factors like weight (kg), height (cm), and age (years).

American Cancer Society Guidelines

• The guidelines provide recommendations on diet and physical activity that are critical factors for reducing/preventing certain cancers
• They emphasize the importance of maintaining a healthy weight, engaging in moderate-to-vigorous physical activity, consuming a healthy and balanced diet, lowering risk associated with red/processed meats or other foods considered potentially associated with increased risks with certain cancers or conditions

Test your knowledge on the key concepts of Nutritional Science. This quiz covers dietary guidelines, nutrient categories, and the roles different nutrients play in human life. Evaluate your understanding of macronutrients, micronutrients, and their impact on health.