Food, Nutrition, Health and FitnessClass 11 Human Ecology and Family Sciences Part 1 Notes

Introduction

The period of adolescence is marked by a dramatic growth spurt, driven by hormones that affect the entire body. Because of these rapid changes, healthy eating becomes incredibly important. Our need for nutrients increases throughout childhood, reaches its peak during adolescence, and then levels off in adulthood. The old saying, "You are what you eat," holds true. The food we consume provides us with the essential nutrients needed to stay healthy and active.

Nutrition is the science of food, the nutrients within it, and how our bodies use them—from eating and digesting to absorbing and using them for energy and growth. While it's a biological process, nutrition also has social, psychological, and economic aspects.

Health and nutrition are like two sides of the same coin; one cannot exist without the other. Our health depends heavily on our nutrition, which in turn depends on the food we eat. Therefore, food is the single most important factor for maintaining good health and fitness.

Key Definitions

• Food: Anything solid or liquid that, when eaten, digested, and absorbed, provides the body with essential substances called nutrients. Food is a basic necessity of life that supplies energy, enables growth and repair of tissues, protects from disease, and regulates body functions.
• Nutrition: The science of foods, nutrients, and their actions within the body, including ingestion, digestion, absorption, metabolism, and excretion.
• Nutrients: The essential substances in food that the body needs in suitable amounts. They include carbohydrates, proteins, fats, minerals, vitamins, water, and fibre. Nutrients are classified into two main groups based on the quantity we need:
  • Macronutrients: Needed in larger amounts (e.g., carbohydrates, proteins, fats).
  • Micronutrients: Needed in smaller amounts (e.g., vitamins, minerals).

• 1 gram of carbohydrate provides 4 Kcal of energy.
• 1 gram of protein provides 4 Kcal of energy.
• 1 gram of fat provides 9 Kcal of energy.

Balanced Diet

A balanced diet is a diet that includes a variety of foods in the right amounts and proportions to meet the daily requirements for all essential nutrients. A good balanced diet is crucial for promoting and preserving health.

One of the key features of a balanced diet is that it provides a safety margin or reserve of nutrients. This reserve helps the body during short periods of deprivation, such as when we are fasting or if our daily diet temporarily lacks certain nutrients.

Recommended Dietary Allowances (RDA)

The concept of a safety margin is built into the Recommended Dietary Allowances (RDAs). RDAs are not the minimum amount you need to survive; they are guidelines for the amount of nutrients to be consumed daily to keep almost all healthy people well.

The relationship is simple: RDA = Requirement + Margin of Safety

If your diet meets the RDA for all nutrients, it is considered a balanced diet.

Aspects of a Balanced Diet

A truly balanced diet:

• Includes a variety of food items.
• Meets the RDA for all nutrients.
• Includes nutrients in the correct proportions.
• Provides a safety margin for nutrients.
• Promotes and preserves good health.
• Helps maintain an acceptable body weight for your height.

Health and Fitness

According to the World Health Organisation (WHO), health is "the state of complete physical, emotional, and social well-being, not merely the absence of diseases or infirmity." This holistic definition has been used since 1948 and emphasizes that health is more than just not being sick.

• Physical Health: The most easily understood aspect, relating to the body's condition.
• Mental Health: A state of emotional and psychological well-being. It's not just the absence of a mental disorder, but the ability to use one's cognitive and emotional skills, function in society, handle stress, maintain relationships, and recover from difficult situations.

Physical fitness, on the other hand, is more specific. It is defined as the body's ability to function efficiently and effectively in work and leisure, to be healthy, to resist diseases, and to meet emergency situations. Fitness is the result of regular exercise, proper nutrition, and adequate rest.

Using Basic Food Groups For Planning Balanced Diets

One of the easiest ways to plan a balanced diet is to use food groups. A food group is a collection of different foods that share common characteristics, such as their source, function, or the main nutrients they provide. Using food groups ensures variety and helps you get all the necessary nutrients.

In India, the Indian Council of Medical Research (ICMR) suggests a five food group classification system to help with meal planning. This system considers food availability, cost, local meal patterns, and common deficiency diseases.

The Five Food Groups (ICMR)

1. Cereals, Grains and Products:

   • Examples: Rice, Wheat, Ragi, Bajra, Maize, Jowar, Barley.
   • Main Nutrients: Energy, protein, invisible fat, Vitamin B1, Vitamin B2, Folic Acid, Iron, Fibre.

2. Pulses and Legumes:

   • Examples: Bengal gram, Black gram, Green gram, Lentil (dals), Rajmah, Soyabeans, Peas.
   • Main Nutrients: Energy, Protein, invisible fat, Vitamin B1, Vitamin B2, Folic Acid, Calcium, Iron, Fibre.

3. Milk and Meat Products:

   • Examples: Milk, Curd, Cheese, Chicken, Liver, Fish, Egg, Meat.
   • Main Nutrients: Protein, Fat, Vitamin B2, Vitamin B12, Calcium.

4. Fruits and Vegetables:

   • Examples: Mango, Guava, Papaya, Orange; Spinach, Carrots, Brinjal, Beans.
   • Main Nutrients: Carotenoids, Vitamin C, Folic Acid, Calcium, Iron, Fibre.

5. Fats and Sugars:

   • Examples: Butter, Ghee, Cooking oils, Sugar, Jaggery.
   • Main Nutrients: Energy, Fat, Essential Fatty Acids.

Guidelines for Using Food Groups

• Include at least one serving from each food group in every main meal.
• Choose a variety of foods within each group, as their nutrient content can differ.
• For vegetarian meals, combine cereals and pulses (like dal and rice) to improve protein quality.
• Include raw vegetables and fruits in your diet.
• Ensure at least one serving of milk or milk products for calcium.
• Cereals should provide no more than 75% of your total daily calories.

Food Guide Pyramid

The Food Guide Pyramid is a visual tool that illustrates the principles of a balanced diet, showing variety, moderation, and proportion.

• Base (Widest Part): Grains (cereals). This shows they should form the foundation of your diet and be eaten in the largest quantity.
• Second Level: Fruits and Vegetables. These are also important and should be eaten liberally.
• Third Level: Milk and Meat Products. This band is smaller, indicating they should be eaten in moderate amounts.
• Top (Smallest Part): Fats, Oils, and Sweets. This tiny apex shows they should be used sparingly.

Vegetarian Food Guide

People following vegetarian diets can easily use the food guide to ensure they get all necessary nutrients. The principles remain the same, but they must choose specific plant-based alternatives.

• Meat Alternatives: Legumes, seeds, nuts, and tofu can replace meat.
• Iron: Legumes and dark leafy greens are good sources of iron.
• Milk Alternatives: Vegetarians who don't drink cow's milk can use soy milk that has been fortified with calcium, vitamin D, and Vitamin B12.

Dietary Patterns in Adolescence

Adolescence is a time of rapid growth, which means nutritional needs are high. However, this is also a time when many unhealthy eating habits can develop. Understanding these patterns is the first step to ensuring a healthy diet.

Irregular Meals and Skipping Meals

As adolescents gain independence, they tend to miss more meals, especially breakfast. Girls are more likely to skip meals than boys, often in an attempt to control their weight.

Snacking

Snacking is very common among teens and can be a good way to maintain energy levels. A snack can help ensure you get enough essential nutrients, especially if you miss meals. However, relying solely on snacks, especially unhealthy ones, is harmful.

Fast Foods

Fast food is popular with adolescents due to convenience and social trends. While it can be eaten occasionally as part of a balanced diet, it has several nutritional limitations:

• Low in: Calcium, riboflavin, vitamin A (unless milk is included), folic acid, and fibre.
• High in: Fat, sodium, and "empty calories" (energy without many other nutrients).

Dieting

Obesity is a growing problem, and maintaining a healthy weight is important. However, many adolescents, especially girls, diet unnecessarily due to social pressure and the media's portrayal of "thin" as ideal. This can lead to dangerous, unsupervised dieting practices.

Consequences of unhealthy dieting include:

• Cycles of weight loss and regain.
• Increased risk of developing eating disorders and obesity.
• Lowered self-esteem and other psychological problems.
• Increased risk of heart problems.

The best approach is to replace the concept of "dieting" with "healthy eating" as a permanent lifestyle change.

Modifying Diet Related Behaviour

Adolescence is a time of establishing one's own identity, and food choices are often a way to express individuality. This can lead to rejecting healthy home-cooked meals in favour of less healthy options to fit in with peers. Here are some ways to build healthier habits:

• Limit Television Viewing: Limit screen time (TV, video games, computer) to one or two hours a day. Watching TV uses very few calories and often encourages mindless snacking.
• Healthy Eating Habits: Aim for three balanced meals and two nutritious snacks each day. Don't skip meals.
• Smart Snacking: Limit snacks to two a day and choose low-calorie options like fruits or raw vegetables. Avoid high-fat, high-calorie snacks like chips and fried foods.
• Drink Water: Drink four to six glasses of water daily. It has no calories and helps you feel full. Avoid sugary soft drinks and juices.
• Keep a Diet Journal: Tracking your food intake, screen time, and exercise can help you see where you can make improvements.
• Exercise Regularly: Aim for 20-30 minutes of exercise, 3-4 times a week. This can include walking, jogging, sports, or yoga. Simple changes like taking the stairs instead of the elevator also help.

Adolescence and Anaemia

Anaemia, a condition often caused by iron deficiency, affects about two billion people worldwide, primarily women and girls. In India, the problem is significant.

• The National Family Health Survey-3 found that 56% of adolescent girls and 30% of adolescent boys are anaemic.
• Causes in developing countries include poverty, poor diet, and lack of access to healthcare.
• Adolescence is a crucial time to address anaemia, as girls need to build up their iron stores before pregnancy. Information about iron-rich foods and supplements can be effectively shared through schools and media.

Factors Influencing Eating Behaviour

By adolescence, our eating habits are shaped by many complex factors.

• Family: The foundation for eating habits is laid at home. Parents who provide a range of nourishing foods help their children develop healthy tastes.
• Independence and Social Life: As teens become more independent and social, they buy and prepare more of their own food, often eating quickly and away from home.
• Peer Influence: Friends can be a source of support for healthy habits but can also create pressure to eat unhealthy foods or tease those who are overweight.
• Advertising: Teenagers are very vulnerable to advertising, most of which promotes products high in sugar and fat.
• Availability: Ready-to-eat food is available everywhere—from vending machines to fast-food outlets—making it easy to eat often and consume unhealthy items.

Eating Disorders at Adolescence

The rapid physical changes and focus on body image during adolescence make it a high-risk period for eating disorders. These are serious conditions tied to self-esteem and a distorted perception of one's body.

Anorexia Nervosa

This disorder is characterized by an obsessive desire to be thin, leading to self-starvation and extreme weight loss. A person with anorexia often has a distorted body image, believing they are fat even when they are severely underweight.

Bulimia

This disorder involves a cycle of bingeing (overeating large amounts of food) followed by purging (inducing vomiting or using laxatives) to prevent weight gain. It often begins after a series of unsuccessful diets.

Consequences and Prevention

Both anorexia and bulimia have severe health consequences, including:

• Convulsions and renal (kidney) failure.
• Irregular heartbeats.
• Dental erosion.
• In girls, delayed menstruation, stunted growth, and osteoporosis (weakening of bones).

The best defense against these disorders is to learn to appreciate your own uniqueness. Respecting and valuing yourself is a life-saving attitude. Nutritional interventions focus on ensuring a balanced diet, increasing fibre, and using supplements to correct deficiencies.