Nutrition forms the cornerstone of our health and well-being, providing the essential components needed for growth, repair, and the maintenance of bodily functions. To make informed dietary choices, it's crucial to understand the basics of nutrition, including the concepts of energy and energy balance, macronutrients, and micronutrients. This month's newsletter will help you grasp these fundamental concepts.
Energy and Energy Balance
Energy is essential for all bodily functions, from breathing and muscle contraction to blood circulation and organ function. This energy is obtained from the food we eat and is measured in calories.
Energy Balance refers to the relationship between the energy we consume through food and drink and the energy we expend through physical activity and all the metabolic processes required to maintain life. Maintaining energy balance is crucial for sustaining a healthy body weight. There are three possible states of energy balance:
- Energy Equilibrium: Energy intake equals energy expenditure, leading to stable body weight.
- Positive Energy Balance: Energy intake exceeds energy expenditure, resulting in weight gain. This is necessary during growth periods, such as childhood and pregnancy.
- Negative Energy Balance: Energy intake is less than energy expenditure, leading to weight loss. This can be intentional for weight management or unintentional due to illness or malnutrition.
Energy intake and expenditure are influenced by a variety of factors:
- Energy intake is affected by physiological elements such as hunger and satiety hormones, blood sugar levels, and stomach stretch signals. Psychological aspects like emotions, stress, and eating disorders also play a role, alongside social and cultural influences such as family, traditions, and media. Environmental factors, including food availability and portion sizes, and biological factors like age, sex, genetics, and health conditions, further impact how much energy we consume.
- Energy expenditure, on the other hand, is largely determined by basal metabolic rate (BMR), which is influenced by body composition, age, gender, genetics, and health status. Physical activity, including exercise and non-exercise activities, significantly affects energy expenditure. Other contributing factors include the thermic effect of food, environmental conditions like temperature and altitude, psychological stress, and lifestyle choices such as sleep quality and substance use. By understanding these diverse influences, individuals can better manage their energy balance and overall health.
While some proponents of the “carbohydrate-insulin hypothesis” argue that obesity is primarily driven by insulin's role in fat storage and carbohydrate metabolism, it's important to recognise that the energy balance model does not exclude the influence of hormones on eating behaviors and energy expenditure. The energy balance model acknowledges that hormones like insulin, leptin, and ghrelin play critical roles in regulating hunger, satiety, and metabolic rate, thereby affecting both energy intake and expenditure. This integrated perspective highlights that while hormonal regulation is crucial, it operates within the broader context of energy balance where caloric consumption and physical activity remain central to managing body weight.
Macronutrients
Macronutrients are the primary nutrients required by the body in large amounts, providing energy and supporting various bodily functions. The main macronutrients are proteins, carbohydrates, and fats.
Proteins
Proteins are essential for tissue growth and repair, enzyme function, hormone production, cell signalling, and immune function. The body continuously breaks down and builds up new proteins, necessitating adequate dietary protein intake. Main sources of protein include animal products like meat, eggs, and dairy, and plant-based sources such as legumes, nuts, and seeds. Protein needs vary based on size, age, activity level, health status, and goals; they are higher for the purposes of building muscle or preserving muscle mass during a phase of weight loss.
Carbohydrates
Carbohydrates are the body's primary energy source, broken down into glucose for immediate use or stored as glycogen in muscles and the liver. “Carbs” are found in grains, legumes, fruits, vegetables, and dairy products. There are three main types of carbohydrates:
- Sugars: Simple carbohydrates found naturally in fruits, vegetables, and milk, and as added sugars in processed foods.
- Starches: Complex carbohydrates that the body breaks down into sugars, found in bread, cereal, pasta, certain vegetables, and legumes.
- Fibre: Complex carbohydrates that the body cannot digest or absorb, aiding in fullness, gut health, cholesterol management, and blood sugar control. Fibre is found in plant-based foods like fruits, vegetables, nuts, seeds, beans, and whole grains.
Fats
Fats are crucial for energy storage, cell structure, hormone production, vitamin absorption, and immune function. The main dietary fat sources include oils, fatty meat and fish, whole milk products, nuts and seeds, and high-fat fruits like olives, avocados, and coconut. Fats come in two types:
Saturated Fats: Found in animal foods and some plant foods like coconut oil.
Unsaturated Fats:
- Monounsaturated Fats: Found in foods like olive and canola oil, avocados, almonds, and pumpkin seeds.
- Polyunsaturated Fats: Include omega-3 fats, found foods like in fatty fish, walnuts, and flax seeds.
A balanced diet should include a variety of fats, favoring unsaturated fats for their health benefits, while limiting saturated fats which are linked to metabolic issues and cardiovascular disease. Trans fats, found in processed foods, should also be avoided due to their negative health impacts.
Micronutrients
Micronutrients are nutrients that do not provide energy, but are required by the body in smaller amounts for proper functioning and optimal health. They include
- Vitamins: Organic compounds that are crucial for various metabolic processes. They are classified into water-soluble (B vitamins and vitamin C) and fat-soluble vitamins (vitamins A, D, E, K). Each vitamin has unique functions; for example, vitamin C is essential for immune function and collagen synthesis, while vitamin D is vital for calcium absorption and bone health.
- Minerals: Inorganic elements that play roles in building strong bones and teeth, regulating metabolism, and staying properly hydrated. Major minerals (calcium, potassium, sodium) are required in larger amounts, whereas trace minerals (iron, zinc, selenium) are needed in smaller quantities. For instance, calcium is crucial for bone health, while iron is necessary for oxygen transport in the blood.
- Other Nutrients: Beyond vitamins and minerals, there are other beneficial compounds found in plants and fungi that offer unique health benefits:
- Phytonutrients: Natural compounds found in plants that provide significant health benefits and help prevent diseases. Compounds like polyphenols, commonly found in foods like colourful fruits and vegetables, tea, and dark chocolate, possess strong antioxidant and anti-inflammatory properties.
- Myconutrients: Nutrients derived from fungi, including mushrooms. Compounds like triterpenoids, found in reishi mushrooms, boost the immune system, while ergothioneine, an antioxidant, protects against cellular damage.
At Hupe, we provide personalised micronutrient supplements (provided by our partner Bioniq) that are tailored to each person's body based on their goals and their blood testing results. This personalised approach ensures that individuals meet their specific nutritional needs and helps them optimise their health and performance.
Conclusion
Understanding the basics of energy balance, macronutrients, and micronutrients is essential for developing a healthy and sustainable diet. In the next edition of this series, we will delve deeper into the role of genetics in nutrition, the ideal dietary pattern for you, and share some general healthy nutrition habits everyone can adopt for better health and well-being.