Notes on Foods and Nutrition (MDC)

 Multi-Disciplinary Course: Foods and Nutrition

We provide notes on all MDC Papers for Chemistry such as Biochemistry, Biophysics, Environmental Chemistry

Unit 1: Basic Concept in foods and nutrition

Definition of Food: Food is any edible substance that supplies the body with nutrients such as carbohydrates, proteins, fats, vitamins, minerals, fiber, and water, which are necessary for energy, growth, repair of body tissues, and regulation of biological processes.

Definition of food science: Food science is the study of the physical, biological, and chemical properties of food, and the principles involved in its production, processing, preservation, packaging, distribution, safety, and consumption.

Definition of food additive: A food additive is any substance that is added to food to improve its flavor, appearance, texture, shelf life, or to preserve its nutritional value.

Definition of fermented food: Fermented food is any food or beverage that has been produced or transformed through the controlled growth and activity of beneficial microorganisms, such as bacteria, yeasts, or molds.

Definition of Food Fortification: Food fortification is the process of deliberately adding essential nutrients, such as vitamins and minerals, to food to improve its nutritional quality and help prevent or correct nutrient deficiencies in the population.

Definition of Functional Food: Functional food is any food that provides health benefits beyond basic nutrition, such as reducing the risk of disease or promoting optimal physical or mental well-being.

Definition of Nutrition: Nutrition is the science that studies the processes by which living organisms obtain, absorb, utilize, and metabolize food and nutrients to support growth, maintain health, and perform vital functions.

Definition of Health: Health is a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity.

Definition of Nutrients: Nutrients are substances found in food that are essential for the growth, energy production, repair, and proper functioning of the body.

Definition of Nutritional Status: Nutritional status refers to the condition of a person's health as determined by the intake, absorption, and utilization of nutrients, as well as the body's ability to maintain normal physiological functions.

Definition of Optimal Nutrition: Optimal nutrition refers to the intake of the right amount and type of nutrients required by the body to maintain good health, proper growth, energy levels, and to prevent nutrient deficiencies or excesses.

Definition of Security: Security refers to the state of being protected against danger, threats, loss, or harm. It involves measures taken to ensure safety, stability, and protection of individuals, property, information, or resources.

Definition of Nutrition Security: Nutrition security means consistent access to not only enough food but also to food that provides the essential nutrients required for a healthy and active life.

Classification and Function of Foods

I. Physiological Classification of Foods

(According to their role in body functions)

1. Energy-Giving Foods: (Cereals, sugars, oils) Provide energy for body functions and work

2. Body-Building Foods: (Milk, meat, pulses, eggs) Help in growth, repair, and maintenance of body tissues

3. Protective Foods: (Fruits, vegetables, milk) Protect the body from infections, regulate body processes, provide vitamins and minerals

II. Psychological Classification of Foods

(Based on mental and emotional impact)

1. Comfort Foods: (Ice cream, chocolate, tea) Provide emotional satisfaction, relieve stress

.2. Mood-Enhancing Foods: (Nuts, dark chocolate, coffee) Stimulate brain chemicals like serotonin, improve mood

III. Socio-Cultural Classification of Foods

(Based on social, cultural, and traditional importance)

1. Religious or Ritual Foods: (Modak (Ganesh Chaturthi), Seviyan (Eid)) Used in religious ceremonies and cultural traditions

2. Traditional Foods: (Idli, Dosa, Sushi, Biryani) Reflect cultural identity and heritage

3. Status or Luxury Foods: (Caviar, exotic fruits, fine wines) Symbolize wealth, status, and are served at special occasions

Basic Five Food Groups and Their Nutritional Contribution

Food Group	Examples	Nutritional Contribution
1. Cereals and Grains	Rice, wheat, maize, oats, bread	Provide energy (mainly carbohydrates), some protein, B vitamins, fiber
2. Pulses, Meat, Fish & Eggs	Lentils, beans, chicken, fish	Provide protein for body building, iron, B vitamins
3. Milk and Milk Products	Milk, curd, cheese, paneer	Provide calcium for bones, protein, vitamin B12
4. Fruits and Vegetables	Apples, oranges, spinach, carrot	Supply vitamins (A, C), minerals, fiber, antioxidants
5. Fats and Sugars	Butter, oils, sugar, honey	Provide energy, essential fatty acids, taste enhancement

Seven Food Groups and Their Nutritional Contribution

This system is often used in nutritional education, especially in India, to simplify food understanding.

Food Group	Examples	Nutritional Contribution
1. Cereals and Grains	Rice, wheat, maize, millets, bread	Energy (carbohydrates), some protein, B vitamins
2. Pulses and Legumes	Lentils, chickpeas, beans, peas	Plant protein, iron, fiber, B vitamins
3. Milk and Milk Products	Milk, curd, paneer, cheese	Calcium, protein, vitamin D, B12
4. Meat, Fish, Poultry, Eggs	Chicken, fish, mutton, eggs	High-quality protein, iron, vitamin B12, omega-3 fats (fish)
5. Fruits	Mango, banana, orange, apple	Vitamins (A, C), minerals, fiber, antioxidants
6. Vegetables	Spinach, carrots, tomatoes, cabbage	Vitamins (A, C, K), minerals, fiber, antioxidants
7. Fats and Sugars	Butter, oils, ghee, sugar, jaggery	Energy, essential fatty acids, enhance taste

Unit - II : Macro Nutrients

Carbohydrates

Introduction

Carbohydrates are organic compounds made up of carbon (C), hydrogen (H), and oxygen (O), usually in the ratio of 1:2:1. They are the primary source of energy for the body and are essential for proper functioning of cells, especially the brain and muscles.

Classification of Carbohydrates

Type	Sub-Types	Examples
1. Simple Carbohydrates	Monosaccharides	Glucose, Fructose, Galactose
	Disaccharides	Sucrose (sugar), Lactose, Maltose
2. Complex Carbohydrates	Polysaccharides	Starch, Glycogen, Cellulose

Functions of Carbohydrates

1. Provide energy (4 kcal per gram)
2. Spare proteins from being used as an energy source
3. Essential for brain and nerve function
4. Help in the metabolism of fats
5. Certain carbohydrates (fiber) aid digestion and prevent constipation
6. Maintain blood sugar levels

Dietary Sources of Carbohydrates

Type	Sources
Simple Carbohydrates	Sugar, honey, fruits, fruit juices
Complex Carbohydrates	Rice, wheat, maize, oats, millets, potatoes, legumes, vegetables, whole grains
Dietary Fiber	Whole grains, fruits, vegetables, legumes

Daily Requirement of Carbohydrates

·                     Adults: Approximately 45-65% of total daily energy should come from carbohydrates

·                     For an average adult, this equals about 300-400 grams per day, depending on energy needs

·                     Dietary fiber requirement: About 25-40 grams per day

Note: Requirements vary based on age, gender, physical activity level, and health condition.

Proteins

Introduction

Proteins are complex organic compounds made up of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. They are composed of smaller units called amino acids, which are essential for building and repairing body tissues. Proteins are often referred to as the "building blocks" of the body.

Classification of Proteins

Type	Sub-Types/Examples
1. Based on Nutritional Quality	Complete Proteins — Contain all essential amino acids (e.g., milk, eggs, meat, fish)
Incomplete Proteins — Lack one or more essential amino acids (e.g., cereals, pulses)
2. Based on Origin	Animal Proteins — Meat, eggs, milk, fish
Plant Proteins — Pulses, nuts, legumes, cereals
3. Based on Function	Structural Proteins — Collagen, keratin
Functional Proteins — Enzymes, hormones, antibodies

Functions of Proteins

1. Promote growth and repair of body tissues
2. Essential for the formation of enzymes and hormones
3. Help in building antibodies for immunity
4. Provide energy (4 kcal per gram) when needed
5. Maintain muscle mass and body structure
6. Help in transport of nutrients (e.g., hemoglobin transports oxygen)

Dietary Sources of Proteins

Source Type	Examples
Animal Sources	Meat, fish, eggs, milk, cheese, paneer
Plant Sources	Pulses, beans, lentils, soybeans, nuts, seeds, cereals

Daily Requirement of Proteins

• Adults:
  Recommended intake is 0.8 to 1 gram per kg of body weight per day
  Example: For a 60 kg adult, approximately 48-60 grams per day
• Children, pregnant and lactating women:
  Higher requirements due to growth and development needs

Note: Athletes or people with intense physical activity may need more protein.

Lipids

Introduction

Lipids are organic compounds made up of carbon, hydrogen, and oxygen, with a much higher proportion of hydrogen compared to carbohydrates. They are commonly known as fats and oils and are an essential part of the diet, providing energy, essential fatty acids, and aiding in the absorption of fat-soluble vitamins.

Classification of Lipids

Type	Examples
1. Simple Lipids	Fats (triglycerides), Oils, Waxes
2. Compound Lipids	Phospholipids, Glycolipids, Lipoproteins
3. Derived Lipids	Fatty acids, Sterols (e.g., cholesterol), Fat-soluble vitamins (A, D, E, K)

Types of Fatty Acids

• Saturated Fatty Acids (SFA) — Butter, ghee, coconut oil
• Unsaturated Fatty Acids (UFA)
• Monounsaturated Fatty Acids (MUFA) — Olive oil, groundnut oil
• Polyunsaturated Fatty Acids (PUFA) — Sunflower oil, soybean oil, fish oils
• Essential Fatty Acids (EFA) — Linoleic acid, Alpha-linolenic acid (cannot be synthesized by the body, must be obtained from diet)

Functions of Lipids

1. Provide energy (9 kcal per gram), concentrated energy source
2. Act as a storage form of energy in the body
3. Supply essential fatty acids for growth and development
4. Aid in the absorption of fat-soluble vitamins (A, D, E, K)
5. Protect internal organs and provide insulation
6. Maintain cell membrane structure and function

Dietary Sources of Lipids

Source Type	Examples
Animal Sources	Butter, ghee, cream, lard, fish oils
Plant Sources	Groundnut oil, sunflower oil, coconut oil, nuts, seeds, olives, avocados

Daily Requirement of Lipids

• Adults:
  Fats should provide 20-30% of total daily energy intake
  For an average adult, approximately 50-70 grams of visible fat per day, depending on age, sex, and physical activity
• Essential Fatty Acids (EFA):
  At least 3% of total energy should come from EFAs

Note: Excess intake of saturated fats is associated with health risks like obesity, heart disease, and diabetes.