Q.Nutrition is ________________Substance. a. Biological b. Chemical c. Energy d. Mechanical
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Nutrition and Diet: The Fuel and the Plan
Think about what happens when you skip breakfast before a long day. By mid-morning, you feel sluggish, can't concentrate, and might get a headache. That's your body telling you it's running on empty. Now think about a day when you eat a proper meal — you feel alert, energetic, and ready to work. This everyday experience is the simplest way to understand nutrition: it's what your body does with the food you give it.
Nutrition is the process by which your body takes in food, breaks it down, and uses the resulting substances for growth, repair, energy, and maintenance of all its functions. It's not just about eating — it's about what happens after you eat. Every bite you take gets converted into the raw materials your body needs to keep your heart beating, your brain thinking, and your cells working.
Diet, on the other hand, is simply the pattern of what you eat and drink — the sum total of your food choices. Everyone has a diet, whether they think about it or not. A diet can be balanced or unbalanced, healthy or unhealthy, but it's always there.
The word "diet" often gets associated with weight loss, but in its original and correct meaning, it simply refers to the food you habitually consume. A "diet" is not something you go on temporarily — it's what you eat every day.
Why Nutrition Matters
Your body is like a machine that never stops running. Even when you're sleeping, your heart pumps, your lungs breathe, and your cells repair themselves. All of this requires energy and materials. Food provides both.
The nutrients in food fall into two broad categories:
- Macronutrients — needed in large amounts: carbohydrates, proteins, and fats. These provide energy and the building blocks for your body.
- Micronutrients — needed in tiny amounts: vitamins and minerals. These don't provide energy directly, but they are essential for the chemical reactions that keep you alive.
Water is often considered a separate, essential nutrient — you can survive weeks without food, but only days without water.
The Concept of a Balanced Diet
A balanced diet is one that provides all the nutrients your body needs in the right proportions. It's not about eating "perfect" foods — it's about variety and moderation. No single food contains everything your body needs, which is why eating a range of foods is important.
- Carbohydrates (from grains, fruits, vegetables) are your body's primary fuel source.
- Proteins (from pulses, milk, eggs, meat) are needed for growth and repair of tissues.
- Fats (from oils, nuts, dairy) provide concentrated energy and help absorb certain vitamins.
- Vitamins and minerals (from fruits, vegetables, dairy) regulate body processes.
- Fibre (from whole grains, vegetables, fruits) aids digestion and prevents constipation.
A balanced diet doesn't mean cutting out entire food groups. It means getting enough of each nutrient without going overboard on any one thing.
Diet and Lifestyle Connection …
The textbook's own definition of nutrition centres on the chemical substances in food — it explicitly calls these substances 'nutrients' and defines nutrition as their scientific study.
Why the other options are wrong
- (a) Biological: nutrition is studied scientifically, but the textbook's own phrase for what food breaks down into is specifically 'chemical substances', not a generic 'biological' label. …
The textbook's own words are the giveaway: "These chemical substances which are present in food are called nutrients" — nutrition is the study of these chemical substances.
Section 5.1.1 defines food as any substance that nourishes the body, and nutrition as "the science of food and a study of the process that includes everything that happens to food from the time it is eaten until it is used" — specifically, "the scientific study of foods and the nutrients therein; their action and interaction and balance, in health and diseases." It goes on to say that when food enters the body, it breaks down and the b …
- CBSE 2026Set 75/SRP1Q/41 markMCQQ.Given below are the food groups in List-I with their functions in List-II. List-I (Food Group):(a) Protein(b) Carbohydrates(c) Fats(d) Roughage List-II (Functions):(i) These are the main sources of energy(ii) It is a negligible source of energy(iii) Repair body cells(iv) It helps in transporting fat-soluble vitamins Match the items of List-I with List-II and choose the correct option from the following: | Option |(a) |(b) |(c) |(d) | | --- | --- | --- | --- | --- | | (A) |(i) |(ii) |(iii) |(iv) | | (B) |(iv) |(iii) |(i) |(ii) | | (C) |(iii) |(iv) |(i) |(ii) | | (D) |(iii) |(i) |(iv) |(ii) |
›Reveal solutionSolution
Proteins are for cell repair, carbohydrates are the main energy source, fats aid in vitamin transport, and roughage provides negligible energy. The correct option is (D).
Concept and Intuition
Our bodies are complex machines that require various nutrients to function correctly. These nutrients can be broadly categorized by their primary roles: providing energy, building and repairing tissues, regulating body processes, and aiding digestion. Understanding the fundamental role of each food group is key to matching them with their functions.
- Macronutrients (Carbohydrates, Fats, Proteins): These are needed in large quantities and provide energy.
- Carbohydrates are the body's preferred and most immediate source of energy.
- Fats are a concentrated energy source and play crucial roles in hormone production and vitamin absorption.
- Proteins are the building blocks, essential for growth, repair, and maintenance of virtually all body tissues.
- Roughage (Dietary Fiber): While not providing energy, roughage is vital for digestive health, adding bulk to stool and facilitating its passage.
Let's match each food group to its specific function based on these principles.
Step-by-step Matching
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Matching Protein:
- Proteins are often called the "building blocks" of the body. They are crucial for the growth, maintenance, and repair of tissues, muscles, organs, and cells. They also form enzymes and hormones.
- Looking at List-II, function (iii) "Repair body cells" directly aligns with the primary role of protein.
- So, (a) Protein → (iii) Repair body cells.
-
Matching Carbohydrates:
- Carbohydrates are the body's primary and most readily available source of energy. They are broken down into glucose, which fuels cellular activities, especially for the brain and muscles.
- Function (i) "These are the main sources of energy" perfectly describes carbohydrates.
- So, (b) Carbohydrates → (i) These are the main sources of energy.
-
Matching Fats:
- Fats are a concentrated source of energy, but they also have other vital roles. They insulate the body, protect organs, and are essential for the absorption of fat-soluble vitamins (Vitamins A, D, E, and K). …
- Macronutrients (Carbohydrates, Fats, Proteins): These are needed in large quantities and provide energy.
- CBSE 2024Set 75/RQPS/41 markMCQQ.Body Mass Index is one of the common way of assessing healthy body weight. Which of the following BMI range is considered for healthy weight? (A) 25.0 – 29.0 (B) 30.0 – 34.9 (C) 18.5 – 24.9 (D) 35.0 – 39.9
›Reveal solutionSolution
A Body Mass Index between 18.5 and 24.9 is the healthy-weight range for adults. The answer is (C) 18.5 - 24.9.
Body Mass Index, or BMI, is a widely used screening tool that relates a person's weight to their height to classify them as underweight, healthy weight, overweight or obese. It is calculated by dividing weight in kilograms by the square of height in metres, giving a value in kg/m squared. For example, a person of 70 kg and 1.75 m has a BMI of 70 divided by (1.75 times 1.75), which is about 22.9 — within the healthy range.
Using the standard adult classification, the ranges are:
- Underweight: below 18.5 — possibly too little weight for the height, with a risk of nutritional deficiency.
- Healthy (normal) weight: 18.5 to 24.9 — the range linked with the lowest weight-related health risk.
- Overweight: 25.0 to 29.9 — excess weight that raises health risks.
- Obese: 30.0 and above — associated with the highest risk of conditions such as type-2 diabetes, high blood pressure and heart disease. …
- CBSE 2023Set 75/EF1GH/41 markMCQQ.Role of water in human body is to _____(a) regulate body temperature(b) give energy(c) repair cell(d) protect from disease
›Reveal solutionSolution
Water's key role highlighted in the nutrition unit is regulating body temperature, chiefly through sweat evaporation during exertion.
Water makes up a large share of body mass and performs several functions, but the one most emphasised in the context of sport and physical activity is thermoregulation: as muscles work, they generate heat, and the body relies on water-based sweat, which evaporates from the skin, to dissipate that heat and keep core temperature within a safe range. Without adequate water, an athlete's ability to regulate temperature breaks down quickly, leading to heat exhaustion. Water does not …
- CBSE 2019Set 75/BVM/41 markQ.Write briefly about ``Micronutrients''.(OR)Suggest two reasons, why our body requires food-supplements.
›Reveal solutionSolution
Part (a): micronutrients are vitamins and minerals needed in small amounts for vital body functions.
Part (b): the body needs food supplements to fill diet gaps and to meet the extra demands of training, growth or recovery.
Part (a) — Micronutrients
Micronutrients are the nutrients required by the body in very small quantities — measured in milligrams or micrograms. They are of two kinds: vitamins (e.g. A, B-complex, C, D) and minerals (e.g. calcium, iron, iodine, zinc). Although they provide no energy, they are essential because they regulate metabolic processes, support growth and development, strengthen immunity, and prevent deficiency diseases — for example, Vitamin A protects vision, Vitamin C aids immunity, and iron forms haemoglobin. The prefix "micro" refers to the small amount needed, not to small importance.
Part (b) — Why the body requires food supplements
- To fill nutritional deficiencies/gaps in the diet. An ordinary diet may not always supply adequate amounts of every nutrient — for example iron, calcium, protein or vitamins may fall short. Food supplements make up this shortfall and help prevent deficiency diseases such as anaemia or weak bones. …
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