1.3 Explain the role of essential nutrients for health

This guide will help you answer 1.3 Explain the role of essential nutrients for health.

Essential nutrients are substances the body needs to function properly but cannot produce in sufficient amounts. These nutrients must come from food or supplements. They are critical for energy, growth, repair, and overall health. Without them, the body struggles to maintain physical and mental wellbeing.

There are six main categories of essential nutrients: carbohydrates, proteins, fats, vitamins, minerals, and water. Each plays a unique role in supporting health.

Carbohydrates

Carbohydrates provide the body with glucose, its primary energy source. Glucose comes from sugars and starches, which the body breaks down during digestion. Once broken down, glucose is either used immediately for energy or stored as glycogen in the muscles and liver.

Carbohydrates are found in foods such as:

• Bread, rice, pasta, and cereals
• Fruits and vegetables
• Dairy products like milk and yoghurt

They support brain function, physical activity, and cellular processes. A diet lacking carbohydrates can lead to fatigue, poor concentration, and decreased physical performance. However, too many carbohydrates, particularly from sugary sources, may contribute to weight gain and other health problems.

Proteins

Proteins are the building blocks of the body. They are made up of amino acids, which help build and repair tissues like muscles, skin, and organs. Proteins are also involved in the production of enzymes, hormones, and haemoglobin.

Sources of protein include:

• Meat, fish, and poultry
• Eggs and dairy products
• Plant-based foods like beans, lentils, nuts, and tofu

Protein is especially critical for growth and repair. For example, children, pregnant women, and athletes require higher amounts. A lack of protein can lead to muscle wasting, weakened immunity, and delayed healing. However, oversized portions or high-fat protein sources can increase risks of diseases like heart disease.

Fats

Fats are another energy source. They help the body absorb fat-soluble vitamins (A, D, E, and K) and support brain health. Fats are also necessary for hormone production and insulating the body.

Fats are categorised as:

• Unsaturated fats (considered healthier) – found in fish, nuts, seeds, and olive oil
• Saturated fats – found in animal products and certain processed foods
• Trans fats – often present in fried or baked goods (linked to poor health outcomes)

Including moderate amounts of healthy fats in the diet promotes heart health and supports key body functions. Overconsumption of unhealthy fats can contribute to heart disease, obesity, and other conditions.

Vitamins

Vitamins are organic compounds the body needs in small amounts. Each vitamin has a unique function. They support processes such as vision, immunity, energy production, and skin health.

Vitamins are grouped into:

• Fat-soluble vitamins (A, D, E, K) – stored in fat cells for later use
• Water-soluble vitamins (B vitamins, vitamin C) – not stored and need regular replenishment

Examples of key vitamins:

• Vitamin A – promotes good vision and skin health, found in carrots and spinach
• Vitamin C – helps the immune system and wound healing, found in oranges and strawberries
• Vitamin D – supports bone health by aiding calcium absorption, found in sunlight and oily fish

A vitamin deficiency can lead to health problems. For instance, low vitamin D levels may cause brittle bones, while a vitamin C shortage can lead to scurvy. Eating a balanced diet rich in fruits, vegetables, and fortified foods can help maintain adequate vitamin levels.

Minerals

Minerals are inorganic elements needed for various bodily functions. Like vitamins, each mineral has a specific purpose.

Key examples of minerals include:

• Calcium – strengthens bones and teeth, found in dairy and green leafy vegetables
• Iron – helps produce red blood cells, found in red meat, spinach, and fortified cereals
• Potassium – regulates blood pressure and fluid balance, found in bananas, potatoes, and tomatoes

Minerals contribute to strong bones, nerve function, and energy production. A lack of minerals like calcium and iron can lead to osteoporosis and anaemia. Eating a varied diet helps maintain the right balance of essential minerals.

Water

Water is vital for survival. It makes up about 60% of the human body and supports almost every function. Water:

• Transports nutrients and oxygen
• Regulates body temperature through sweating
• Removes waste products through urine and breath
• Cushions joints and protects organs

You lose water constantly through sweat, urine, and other bodily functions. Replacing this lost water is essential for preventing dehydration. Symptoms of dehydration include dry mouth, fatigue, and confusion. Drinking 6–8 glasses a day is generally recommended, though needs vary depending on factors like activity level and climate.

Keeping a Balance

Each nutrient is important, but balance is key. Overeating one nutrient while neglecting others can cause health problems. For example:

• Too much fat or sugar may lead to obesity and related conditions.
• Too little protein or vitamins can impact growth, immunity, and energy.

Healthy eating guidelines, such as the Eatwell Guide in the UK, recommend balanced meals with proper portions of carbohydrates, protein, fats, vitamins, and minerals. They also highlight the importance of staying hydrated with water.

Nutrients in Disease Prevention

Essential nutrients do more than meet basic needs. They also help prevent long-term diseases:

• Fibre, found in whole grains and fruits, supports digestive health and protects against heart disease.
• Vitamins C and E, known as antioxidants, reduce oxidative stress in the body, lowering the risk of chronic illnesses.
• Omega-3 fats, found in oily fish, benefit heart and brain health.

A nutrient-rich diet reduces the likelihood of developing conditions such as diabetes, osteoporosis, and high blood pressure. It also helps maintain healthy body weight and boosts lifespan.

Special Cases and Individual Needs

Nutrient requirements vary between individuals. Factors like age, gender, activity level, and medical conditions affect needs. For example:

• Babies require breast milk or formula for growth.
• Pregnant women need more folic acid, which prevents certain birth defects.
• Older adults may need extra calcium and vitamin D to maintain bone health.

People with allergies or intolerances might need modified diets. For example, those with coeliac disease must avoid gluten-containing foods. In certain cases, supplements can help fill nutritional gaps.

Final Thoughts

Understanding the role of essential nutrients helps promote better health. A varied, balanced diet that includes all types of nutrients supports energy levels, growth, and disease prevention. It’s not just about eating enough food—it’s about getting the right nutrients in the correct amounts to support physical and mental wellbeing throughout life.