Basic concepts

Calcium and phosphorus are major mineral components of bones and teeth, where they provide strength and structural support. Calcium also participates in muscle contraction, nerve transmission and blood clotting, while phosphorus is involved in energy compounds such as ATP. Vitamin D helps the intestine absorb calcium and supports proper bone mineralisation.

Spoilage may produce noticeable changes in smell, colour, texture, taste, or appearance. A sour or putrid odour, mould growth, sliminess, gas formation, or unusual discoloration should be treated as a warning. Such food may contain harmful microorganisms or toxins, so tasting it to test safety is not advisable.

The calories and nutrient values on a nutrition label usually refer to one stated serving, not necessarily to the entire packet. Knowing serving size allows a person to calculate actual intake when two or more servings are eaten. It also helps with portion control and fair comparison between products.

Carbohydrates are the body’s preferred and readily available energy source, while fats provide concentrated energy and act as an important reserve. Vitamins and minerals regulate body processes, and water supports hydration and transport, but these three do not supply energy in the usual nutritional sense.

Protein-rich foods are called body-building foods because proteins supply amino acids needed for growth, development and repair of body tissues. Pulses, milk, eggs, fish, meat, soybeans and nuts are examples. Protein does not replace all other nutrients; a healthy diet must still include energy foods, protective foods and water.

Protective foods, especially fruits and vegetables, supply vitamins, minerals and often useful fibre. These nutrients support immunity, vision, blood formation, bone health and normal body functions, thereby helping protect against deficiency disorders. They do not consist only of one nutrient, but vitamins and minerals are their key protective components.

Pulses such as lentils, chickpeas, beans and peas are important sources of plant-based protein. They also provide complex carbohydrates, fibre, iron and other nutrients. Combining cereals with pulses can improve the overall quality of protein in a meal, making pulses especially valuable in affordable vegetarian diets.

Milk and milk products provide high-quality protein and calcium. Protein supports growth and tissue repair, while calcium is needed for strong bones and teeth, muscle contraction and other body functions. Their nutritional value varies by product, and some products may contain added sugar or fat, so appropriate portions are important.

Green leafy vegetables such as spinach, amaranth and fenugreek can supply iron, folate, vitamin A precursors, vitamin C, fibre and other protective nutrients. The exact amount depends on the vegetable and preparation method. They are valuable in a balanced diet, although plant iron may be absorbed better when eaten with vitamin-C-rich foods.

Nutrition education develops understanding, skills and motivation for making appropriate food choices. It explains the functions of nutrients, balanced meals, hygiene, portion control and healthy habits, then encourages people to apply this knowledge in daily life. Its broader aim is to support improved nutritional status and health, not merely to provide facts.

Taking regular and balanced meals helps distribute energy and nutrients across the day. It encourages variety, supports concentration and activity, and reduces the likelihood of excessive hunger followed by overeating. Good food habits also include safe food handling, adequate water, moderation and attention to individual health needs rather than relying on one type of food.

Skipping meals may reduce total energy and nutrient intake, especially when the missed food is not replaced with a balanced meal later. It can also cause tiredness, poor concentration, irritability and excessive hunger, which may encourage overeating of less nutritious foods. Effects vary, but regular suitable meals generally support better nutrition.

Breakfast can provide energy and nutrients after the overnight fasting period and may support concentration, learning and physical activity. A nutritious breakfast may include a cereal or other energy food, a protein-rich item, fruit or vegetables and water. Its quality matters; a sugary snack alone is not necessarily a balanced breakfast.

Food labels commonly provide the ingredient list, nutrition information, serving size, allergen declarations, dates, storage instructions and manufacturer details. Reading them helps consumers compare products, identify nutrients such as sugar, salt and fat, notice possible allergens and make informed choices according to health needs and preferences.

Proper storage protects food from microorganisms, insects, moisture, oxygen, unpleasant odours and cross-contamination. Using clean containers, covering food, separating raw and cooked items, and maintaining suitable temperatures can slow spoilage and preserve safety and quality. Storage cannot make already spoiled food safe, so dates, appearance and smell should also be considered.

Fried foods can absorb substantial oil, increasing their fat and energy content. Frequent intake of energy-dense fried foods may contribute to excess calorie consumption and, depending on the overall diet, unhealthy weight gain or other health risks. Fried food is not automatically devoid of nutrients, but moderation, healthier cooking methods and a varied diet are advisable.

A nutrient-dense food supplies substantial vitamins, minerals, protein, fibre or other beneficial nutrients in relation to the energy it provides. Fruits, vegetables, pulses and many whole foods can be nutrient-dense. Cost, size or greasiness alone does not determine nutrient density, so option C is correct.

When energy intake remains higher than energy expenditure, the body may store part of the surplus, often as body fat. Over time this positive energy balance can contribute to weight gain, although individual responses vary. It is not a food-safety problem or an automatic cause of dehydration. Therefore option B is correct.

If energy intake remains below the body’s needs, stored energy may be used. Prolonged deficiency can lead to weight loss, tiredness, reduced physical capacity, poor concentration and, in severe cases, impaired growth or immunity. The exact effect depends on age, health and diet quality. Hence option A is correct.

Calcium is a major mineral in bones and teeth, where it helps provide structure and strength. It also participates in muscle contraction, nerve signalling and blood clotting, but bone and dental health is the most familiar primary role in this question. Haemoglobin transports oxygen and nutrients provide energy. Hence option B is correct.

Overnutrition means consuming energy or one or more nutrients in excess of the body’s needs. Persistent excess energy may be stored as fat and may increase the risk of overweight and related health problems. It is different from undernutrition, water deficiency or a single isolated nutrient deficiency. Thus option C is correct.

Malnutrition is a broad term describing an imbalance, deficiency or excess of energy and nutrients. It includes undernutrition, such as wasting or micronutrient deficiency, and overnutrition, such as overweight caused by sustained excess energy. Clean food, exercise and water alone are not categories of malnutrition. Therefore option A is correct.

Iodized salt is salt fortified with a small, regulated amount of iodine. Iodine is needed to make thyroid hormones, which support growth, brain development and metabolism. Regular use in the recommended amount helps prevent iodine-deficiency disorders, although excessive salt intake should still be avoided. Therefore option B is correct.

Food preservation aims to delay spoilage and extend the safe storage life of food. Methods such as refrigeration, drying, canning, pickling and fermentation control microorganisms, enzymes or moisture. Preservation can also reduce seasonal waste and improve availability, although hygienic processing and appropriate storage remain essential.

A healthy diet message should be clear, accurate, culturally suitable, and practical enough to use in daily life. Simple wording and familiar examples help people understand what to do, while specific achievable actions improve adherence. The message must remain scientifically correct and avoid exaggerated promises or confusing restrictions.