Basics of Nutrition and Diet
What is a calorie?
Official Definition:
The amount of heat required at a pressure of one atmosphere to raise the temperature of one gram of water one degree Celsius.
Our Definition:
Simply a unit of energy sourced from food.
What are Macronutrients?
Official Definition:
A type of food (e.g. fat, protein, carbohydrate) required in large amounts in the diet.
Our Definition:
The building blocks of your diet and food choices.
Macronutrients Calories Per Gram:
Carbohydrate = 4 calories per gram
Protein = 4 calories per gram
Fat = 9 calories per gram
Alcohol = 7 calories per gram
Carbohydrates
Carbohydrates are your body's preferred source of energy.
Simple carbs - found in sugary snacks and drinks, are quickly digested and provide a quick burst of energy but can lead to insulin spikes, blood sugar crashes, and can be a main driver in disease such as diabetes.
Complex carbs - found in whole grains, fruits, and vegetables, break down and digest more slowly, giving you steady, long-lasting energy.
Fiber - a type of complex carb, is crucial for digestion and helps regulate blood sugar. Foods like oats, legumes, and vegetables are rich in fiber and keep you feeling full longer.
Glycemic Index vs. Glycemic Load
The Glycemic Index (GI):
Measures how quickly a carbohydrate-containing food raises your blood sugar levels. Foods with a high GI (like white bread) cause a rapid spike, while low GI foods (like lentils) are digested more slowly, leading to a gradual rise in blood sugar.
Glycemic index calculator: Glycemic Index Calculator (omnicalculator.com)
Glycemic Load (GL):
Goes a step further by considering both the GI and the amount of carbohydrates in a typical serving of the food. It provides a more accurate picture of how a food affects blood sugar. A high-GI food with a small portion size may have a low GL, while a low-GI food eaten in large quantities can still have a high GL.
Glycemic Load Calculator: Glycemic Load Calculator (mdapp.co)
Role of Carbohydrate in the Body
Preferred Energy Source
Fuel for the Brain
Sparing Protein
Supporting Digestion (Fiber)
Regulating Blood Sugar
Stored Energy
Protein
Protein is vital for almost every function in your body. Made up of amino acids, it acts as the building material for your body’s structure and machinery. It helps keep everything working smoothly, from muscle repair to organ function.
https://tilhealthcare.com/amino-acids/
Complete vs. Incomplete Proteins
Complete Proteins:
Contain all nine essential amino acids your body needs but cannot produce on its own. These are typically found in animal products like meat, poultry, fish, eggs, and dairy, as well as some plant-based sources like quinoa and soy.
Incomplete proteins:
Missing one or more of the essential amino acids. These are common in plant-based foods like grains, nuts, seeds, and legumes. However, combining different incomplete protein sources (e.g., rice and beans) can provide all essential amino acids, making a "complete" protein.
Role of Protein in the Body
Building and repairing tissues
Enzyme production
Hormone regulation
Immune function
Transporting nutrients
Maintaining fluid balance
Energy source (not preferred)
Amino Acids
Essential Amino Acids:
9 in total and must be ingested
Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine
Non-essential Amino Acids:
11 in total and your body can produce these
Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine, Proline, Serine, Tyrosine
Sources of Protein
Meat, fish, and eggs
Beans and legumes
Plant-based sources like tofu and lentils
Fats
Fats are an essential macronutrient that provide long-lasting energy, support cell growth, protect organs, and help the body absorb certain vitamins.
Note: Dietary fat is not the same as adipose tissue (the fat on your body)
Types of Fat
Unsaturated Fats – These are the healthy fats found in foods like avocados, nuts, and olive oil, and they can help lower bad cholesterol and support heart health. Two types, mono-/polyunsaturated fats.
Saturated Fats – Found in animal products like butter, cheese, and red meat, these fats, when eaten in excess, can raise bad cholesterol levels and should be eaten in moderation.
Trans Fats – Often found in processed and fried foods, trans fats are harmful, raising bad cholesterol and lowering good cholesterol, and should be avoided as much as possible.
Role of Fat in the Body
Energy Source
Absorption of Vitamins (A, D, E, and K)
Cell Structure
Protecting Organs
Hormone Production
Insulation
What are Micronutrients?
Warning
Vitamin supplements may not be useful, and may in fact harm your health in some circumstances.
What Foods Contain Micronutrients?
All whole and unprocessed foods contain varying degrees of micronutrients
Processed foods may have some naturally or added micronutrients, but may also have none present in ultra-processed foods such as soda or candy
Official Definition:
A chemical element or substance required in trace amounts for the normal growth and development of living organisms.
Our Definition:
Vitamins and minerals required by the body in small quantities, in order to maintain good health which are present in all foods in varying amounts.
Vitamins
Vitamin A (Retinol, Beta Carotene)
Vitamin B1 (Thiamine)
Vitamin B2 (Riboflavin)
Vitamin B3 (Niacin)
Vitamin B5 (Pantothenic Acid)
Vitamin B6 (Pyridoxine)
Vitamin B7 (Biotin)
Vitamin B9 (Folate or Folic Acid)
Vitamin B12 (Cobalamin)
Vitamin C (Ascorbic Acid)
Vitamin D
Vitamin E
Vitamin K
Minerals
Calcium
Iron
Magnesium
Phosphorus
Potassium
Sodium
Zinc
Copper
Iodine
Selenium
Manganese
Chromium
Molybdenum
Fluoride
Role of Micronutrients in the Body
Immune Function
Energy Production
Bone Health
Cell Protection
Blood Health
Hormonal Balance
Nerve and Muscle Function
Wound Healing and Tissue Repair
Reading Nutrition Labels
A nutrition label is a detailed breakdown of the nutritional content of a food product. It provides essential information to help you understand what you’re consuming.
What’s On A Nutrition Label
Serving Size
Servings Per Container
Calories
Total Fat
Cholesterol
Sodium
Total Carbohydrates
Dietary Fiber
Total Sugars
Added Sugars
Protein
Vitamins and Minerals (Required: Vit D, Calcium, Iron, Potassium)
% Daily Value (%DV) - Based on 2,000 calorie diet
How Many Calories do you need?
Your calorie needs refer to the amount of energy your body requires in a single day to maintain essential functions, daily activities, and any extra exercise. Varies depending on factors like age, gender, weight, and activity level.
The total energy you burn in a day is called your Total Daily Energy Expenditure (TDEE).
Aspects of you Total Daily Energy Expenditure (TDEE)
Basal Metabolic Rate (BMR):
The number of calories your body burns at rest to keep essential functions like breathing, circulation, and digestion running. It accounts for the largest portion of your daily energy use, roughly 60-70%.
Non-Exercise Activity Thermogenesis (NEAT):
Calories burned through non-exercise activities like walking, fidgeting, cleaning, or even typing. NEAT varies greatly between individuals and can make up a significant portion of daily calorie expenditure.
Exercise Activity Thermogenesis (EAT):
Calories burned during intentional exercise, such as running, weightlifting, or playing sports. This is typically a smaller portion of your total calorie burn unless you are very physically active.
Thermic Effect of Food (TEF):
Calories burned digesting and metabolizing food. TEF makes up about 10% of your total energy expenditure and varies depending on the type of food (protein has a higher TEF than carbs or fat).
How Do You Calculate Your Calorie Needs?
Step 1: Estimate Your BMR (Basal Metabolic Rate)
To calculate your BMR, you can use the Harris-Benedict equation, which takes into account your gender, weight, height, and age:
For Men:
BMR = 88.36 + (13.4 × weight in kg) + (4.8 × height in cm) – (5.7 × age in years)For Women:
BMR = 447.6 + (9.2 × weight in kg) + (3.1 × height in cm) – (4.3 × age in years)
This gives you an estimate of the calories your body needs at rest to perform essential functions like breathing and digestion.
Step 2: Adjust for Physical Activity
Once you’ve calculated your BMR, multiply it by an activity factor to estimate your total daily calorie expenditure. The activity factors are based on how active you are throughout the day:
Sedentary (little to no exercise): BMR × 1.2
Lightly active (light exercise or activity 1-3 days per week): BMR × 1.375
Moderately active (moderate exercise or activity 3-5 days per week): BMR × 1.55
Very active (hard exercise 6-7 days per week): BMR × 1.725
Extra active (very hard exercise or a physically demanding job): BMR × 1.9
Example Calculation:
For a 40-year-old man, weighing 75 kg, 180 cm tall, who is moderately active:
BMR = 88.36 + (13.4 × 75) + (4.8 × 180) – (5.7 × 40)
BMR = 88.36 + 1005 + 864 – 228 = 1729.36 calories/day at restTotal Daily Calories = 1729.36 × 1.55 = 2679.51 calories/day