Food, Nutrition, Health and Fitness Chapter Notes | Home Science for Class 11 - Humanities/Arts PDF Download

Introduction

• Adolescence triggers significant changes, with a dramatic increase in growth rate due to hormonal activity affecting every organ, making healthy eating critical.
• Nutrient needs escalate during childhood, peak in adolescence, and then stabilize or decrease in adulthood.
• The phrase "You are what you eat" underscores the importance of food choices in maintaining health.
• Foods like dal, chapatti, bread, rice, vegetables, milk, and lassi provide essential nutrients to keep the body healthy and active.
• Understanding which foods to consume is vital for sustaining health.
• Nutrition is the science of food, nutrients, and their impact on health, encompassing how food is ingested, digested, absorbed, metabolized, and excreted.

Food, Nutrition, Health and Fitness

• Nutrition and health are inseparable, functioning as two sides of the same coin, with health heavily reliant on nutrition, which in turn depends on food intake.
• Food is the most critical factor for achieving health and fitness.
• Food is defined as any solid or liquid that, when swallowed, digested, and assimilated, provides essential nutrients to the body, maintaining its well-being.
• Food is a basic necessity, supplying energy, supporting growth and repair of tissues and organs, protecting against diseases, and regulating body functions.
• Nutrition involves the study of foods, their nutrients, and their physiological actions, including ingestion, digestion, absorption, metabolism, and excretion, while also encompassing social, psychological, and economic dimensions.
• Nutrients are food constituents required in suitable amounts, including carbohydrates, proteins, fats, minerals, vitamins, water, and fibre, essential for maintaining health.
• Most foods contain multiple nutrients (e.g., milk provides proteins and fats), and nutrients are classified as macronutrients (needed in large amounts) or micronutrients (needed in small amounts).
• Macronutrients include carbohydrates, proteins, fats, fibre, and water, while micronutrients include vitamins and minerals.

Balanced Diet

• A balanced diet includes a variety of foods in adequate amounts and correct proportions to meet daily requirements for all essential nutrients, such as proteins, carbohydrates, fats, vitamins, minerals, water, and fibre.
• It promotes and preserves good health while providing a safety margin or reserve of nutrients to withstand short-term dietary deficiencies.
• The safety margin accounts for fasting days or temporary nutrient shortages in the daily diet.
• If a balanced diet meets the Recommended Dietary Allowances (RDAs), the safety margin is inherently included, as RDAs incorporate extra allowances.
• RDAs are calculated as: Recommended Dietary Allowances = Requirements + Margin of safety.
• A balanced diet ensures the inclusion of a variety of food items, meets RDAs for all nutrients, maintains correct nutrient proportions, provides a safety margin, promotes health, and maintains acceptable body weight for height.

Health and Fitness

• The World Health Organization (WHO) defines health as a state of complete physical, emotional, and social well-being, not merely the absence of disease or infirmity, a definition unchanged since 1948.
• Positive health integrates physical, social, and mental well-being, requiring adequate intake of essential nutrients.
• Physical health is the most straightforward aspect, while mental health is a state of emotional and psychological well-being, enabling individuals to use cognitive and emotional capabilities, function in society, and meet everyday demands.
• Mental health is not solely the absence of mental disorders but is assessed by how effectively a person functions, including feeling capable, handling stress, maintaining relationships, leading an independent life, and recovering from challenges.
• Physical fitness is good bodily health achieved through regular exercise, proper diet, nutrition, and adequate rest, enabling optimal functioning of the heart, blood vessels, lungs, and muscles.
• Physical fitness encompasses general fitness (overall health and well-being) and specific fitness (task-oriented abilities for sports or occupations).
• Historically, fitness was the ability to perform daily activities without undue fatigue, but modern definitions emphasize optimum efficiency due to automation, increased leisure time, and lifestyle changes post-Industrial Revolution.
• Physical fitness is now defined as the body’s ability to function efficiently in work and leisure, remain healthy, resist diseases, and meet emergency situations.
• Fitness includes five categories: aerobic fitness, muscular strength, muscular endurance, flexibility, and body composition.
• Being fit prepares individuals for mental and emotional challenges, providing strength and energy to meet routine physical demands with reserve energy for sudden challenges (e.g., running to catch a bus).
• Health is a state of complete mental, physical, and social well-being, while fitness is the ability to meet physical task demands.
• A well-nourished, fit person has more energy, stamina, self-esteem, and better learning capacity.
• Healthy eating patterns combined with regular exercise help maintain fitness, while unhealthy eating behaviors and undernourishment in teenagers (ages 12–18) can lead to eating disorders.

Using Basic Food Groups for Planning Balanced Diets

• Planning a balanced diet involves dividing foods into groups and ensuring each group is included in meals, simplifying the process.
• A food group consists of foods with common characteristics, such as source, physiological function, or nutrient content.
• Foods are grouped based on predominant nutrients, with classifications varying by country due to factors like availability, cost, meal patterns, and prevalent deficiency diseases.
• India uses a five food group classification for meal planning, as recommended by the Indian Council of Medical Research (ICMR), considering nutrient content and local factors.
• The five food groups are: Cereals, Grains and Products; Pulses and Legumes; Milk and Meat Products; Fruits and Vegetables; and Fats and Sugars.
• Not all foods within a group have identical nutrient content, necessitating variety within each group to ensure all nutrients are provided.
• The table below summarizes the five food groups and their main nutrients:

• Energy contributions: 1 gram of carbohydrate provides 4 kcal, 1 gram of protein provides 4 kcal, and 1 gram of fat provides 9 kcal.
• Guidelines for using food groups include including at least one serving from each group per meal, choosing varied foods within groups, combining cereal-pulse or milk for vegetarian protein quality, including raw fruits and vegetables, ensuring milk for calcium, and limiting cereals to 75% of total calories.
• Balanced diets should include adequate cereals and pulses, liberal fruits and vegetables, moderate animal foods, and sparing fats and sugars.

Food Guide Pyramid

• The food guide pyramid is a graphic tool depicting the daily food guide, emphasizing variety, moderation, and proportion of food groups.
• The pyramid’s broad base represents grains, which should be abundant as the foundation of a healthy diet.
• Fruits and vegetables occupy the next level, indicating a significant but less prominent role.
• Meats and milk products form a smaller band, contributing valuable nutrients like proteins, vitamins, and minerals without excessive fat or cholesterol.
• Fats, oils, and sweets are at the tiny apex, indicating sparing use.
• Alcoholic beverages are excluded, and items like spices, coffee, tea, and diet soft drinks provide minimal nutrients but add flavor when used judiciously.
• The pyramid emphasizes grains, vegetables, and fruits (plant foods), which should constitute 75% of daily servings, providing complex carbohydrates, fibre, vitamins, and minerals with low fat.
• This approach simplifies diet planning for vegetarians.

Vegetarian Food Guide

• Vegetarian diets primarily rely on plant foods: grains, vegetables, legumes, fruits, seeds, and nuts, with some including eggs, milk products, or both.
• Vegetarians can use the daily food guide, selecting meat alternatives like legumes, seeds, nuts, tofu, or eggs, and ensuring iron from legumes and dark leafy greens.
• Those avoiding cow’s milk can use fortified soy milk (with added calcium, vitamin D, and vitamin B12) for similar nutrients.
• The food guide pyramid highlights the five food groups in its lower three sections, each providing unique nutrients, requiring all groups for good health.
• The pyramid serves as a general guide for choosing a healthful diet tailored to individual needs, ensuring nutrient variety and appropriate calorie intake for healthy weight.

Dietary Patterns in Adolescence

• Healthy eating is crucial for adolescent health and well-being, with nutritional needs increasing due to rapid growth and body composition changes during puberty.
• Adequate nutrition supports emotional and physical health, preventing future chronic illnesses like obesity, heart disease, cancer, and diabetes.
• Studies show adolescents often consume less vitamin A, thiamine, iron, and calcium than recommended, while ingesting excessive fat, sugar, protein, and sodium.
• Snacking between meals provides substantial nourishment, with food choice being more critical than timing or location.
• Emphasis should be on fresh vegetables, fruits, and whole-grain products to complement energy- and protein-rich foods commonly chosen by adolescents.
• Common eating habits include skipping meals, frequent fast food consumption, avoiding fruits and vegetables, snacking, and dieting, which need addressing to meet nutritional requirements.
• Irregular meals and skipping meals increase from early to late adolescence due to growing independence and time away from home, with evening meals being the most regularly consumed.
• Girls skip meals (breakfast, lunch, or dinner) more often than boys, often due to dieting or pursuit of thinness, which can lead to overeating later and slow metabolism, contributing to weight gain and poor performance.
• In resource-limited homes, adolescents may face inadequate meal frequency or quantity, leading to nutrient deficiencies.
• Snacking can be beneficial for maintaining energy levels in active adolescents, especially those skipping meals, but relying solely on snacks is harmful.
• Fast food consumption is common in urban areas due to convenience, social appeal, and perceived trendiness, but it is high in fat and empty calories.
• Fast foods lack sufficient calcium, riboflavin, vitamin A, folic acid, and fibre, while being high in fat, sodium, and energy, making them acceptable only as part of a balanced diet.
• Dieting is prevalent due to rising obesity, with 80% of overweight adolescents likely to remain overweight as adults, risking diabetes, high blood pressure, high cholesterol, and sleep apnea.
• Normal-weight adolescents, especially girls, diet due to media-driven thinness ideals, leading to unhealthy weight loss attempts like skipping meals, binge eating, fasting, or using laxatives/diet pills.
• Unsupervised dieting can cause weight cycling, eating disorders, lowered self-esteem, psychological issues, and increased cardiovascular risks.
• Replacing “dieting” with “healthy eating” and adopting regular healthy lifestyle practices can reduce the need for consistent dieting.

Modifying Diet Related Behaviour

• Adolescence is a period of questioning authority and expressing individuality, often through eating behaviors like rejecting healthy home food for less healthy outside options to conform to peers.
• Changing lifestyle and diet patterns is easier when adolescents are motivated to do so.
• Limiting television viewing to 1–2 hours daily (including video games and computer use) reduces erratic eating, as TV watching encourages overeating or undereating and burns few calories.
• Healthy eating habits involve consuming three balanced meals daily plus two nutritious snacks, avoiding meal skipping.
• Snacks should be limited to two daily, using low-calorie options like raw fruits or vegetables, avoiding high-calorie/fat foods like potato chips, biscuits, and fried foods, though occasional treats are acceptable.
• Drinking 4–6 glasses of water daily, especially before meals, promotes fullness without calories, while soft drinks and fruit juices (150–170 calories per serving) should be limited.
• Maintaining a weekly diet journal tracking food/beverage intake, screen time, exercise, and body weight helps monitor habits.
• Exercise is essential, with extracurricular activities like sports maintaining high activity levels.
• Tips to increase physical activity include walking or biking short distances, using stairs instead of elevators, exercising 20–30 minutes 3–4 times weekly (e.g., walking, jogging, swimming, biking), playing sports, or practicing yoga.
• Substance abuse (tobacco, alcohol, marijuana, other drugs) harms adolescent nutrition and health, requiring nutrition intervention, support, and counseling for rehabilitation.
• Rural adolescents often engage in high-energy tasks like agriculture, poultry-keeping, cattle-rearing, or collecting fodder/firewood, increasing their energy and protein needs due to growth and activity.
• Rural adolescents, especially from poorer communities, are at high risk of malnutrition, with girls particularly prone to anemia (low iron), requiring iron-rich foods.
• Wealthy rural adolescents face similar issues as urban peers, with sedentary lifestyles and high-fat/carbohydrate diets.
• Anemia affects two billion people globally, primarily due to iron deficiency, with 56% of adolescent girls and 30% of boys in India being anemic (NFHS-3, 2005–06), a rise from 1991–92.
• Anemia prevalence is high in India due to poverty, inadequate diets, diseases, repetitive pregnancy/lactation, and poor healthcare access.
• Adolescence is ideal for anemia interventions, as girls need iron for growth and pre-pregnancy health, and both genders can access information through schools, activities, and media to promote iron-rich foods and supplements.

Factors Influencing Eating Behaviour

• Adolescent eating habits are shaped by numerous complex influences due to growing independence, social participation, and busy schedules.
• Adolescents increasingly buy and prepare their own food, often eating quickly and away from home.
• Family lays the foundation for eating habits, but external influences like peers, media, and food availability play significant roles.
• Parents should offer nourishing food choices during childhood, allowing teenagers kitchen access (for both boys and girls) to foster healthy habits.
• Peers provide support (e.g., for overweight teens) but can also cause stress through teasing.
• Teenagers are highly susceptible to advertising, particularly TV food commercials promoting high-sugar/fat products, influencing eating habits for over a decade.
• Ready-to-eat food availability (home delivery, vending machines, fast-food outlets, convenience stores, events) encourages frequent eating of less healthy foods, requiring monitoring.

Eating Disorders at Adolescence

• Adolescence involves rapid physical growth and body-image development, making eating disorders a significant concern due to associated self-esteem issues.
• Anorexia nervosa is tied to body image distortion, most common in adolescence when individuals struggle with self-identity and are vulnerable to body image problems.
• Anorexia nervosa example: Sonam, obsessed with a thin body, stops eating despite normal weight, feels fat, has low self-esteem, is depressed, and withdraws socially, risking undernourishment and potentially death.
• Bulimia, another eating disorder, often starts in late adolescence or early adulthood after failed weight-loss diets, involving binge eating followed by purging (vomiting or laxatives).
• Bulimia is more common in females but affects 5–10% males.
• Anorexia and bulimia can cause severe consequences like convulsions, renal failure, irregular heartbeats, dental erosion, delayed menstruation, stunted growth, and osteoporosis in girls.
• Preventing eating disorders involves appreciating one’s uniqueness and valuing oneself to avoid harmful body image pressures.
• Dietary interventions include ensuring balanced diets, increasing dietary fibre, and using nutrient/food supplements to address losses.
• Physical, social, and emotional changes in adolescence profoundly impact nutritional status and eating patterns.
• Learning to apply sound dietary principles helps build a foundation for a healthier life, even if adolescents are not motivated by long-term health goals.