Good nutrition is essential to good health and the prevention of disease. Getting your base nutrition dialled in to your personal needs is the foundation to all health and performance endeavours.
The primary goal of any nutrition strategy is to supply the body with sufficient nutrients for energy, building and repairing body tissue and maintenance of essential metabolic processes. Your base diet, what you eat every day regardless of what else you are up to, should reflect the major factors that influence nutritional needs - gender, age, height, weight, allergies, medical conditions - as well as lifestyle and social factors such as religious beliefs, dietary preferences and food availability.
You can find our more about how to calculate your energy needs in this article. But before you do that, let's have a look at the essential building blocks of what we eat - macronutrients (carbohydrate, fat and protein); micronutrients (vitamins and minerals); and water.
Carbohydrate is one the bodies primary energy sources and its principle role is to provide energy for activity and a constant supply of blood glucose to enable functioning of the brain and the central nervous system.
It's secondary role is to spare protein - when carbohydrate supply is inadequate, protein is broken down into glucose and it the key function of protein - growth and development of muscle - is suppressed.
Lastly, carbohydrate has a role to do with the metabolism of fat. Fat burning occurs more completely and efficiently when sufficient carbohydrate is available. Without adequate supply of carbohydrate, fat breakdown is incomplete, and the resulting ketones can lead to fatigue, nausea and lack of appetite.
The recommended target for carbohydrate intake is 55-60% of calorific requirements for the normal individual. Additionally, to ensure health, no more than 25% of daily calories should be from sugars.
The primary function of fat is a source of energy, secondary to the energy released by carbohydrate in terms of speed of breakdown. Despite containing twice the energy of carbohydrate, fat is slower to metabolise.
However, while the body cannot store large amounts of carbohydrate, fat stockpiles in adipose cells offer the largest and most efficient source of energy in the body, and therefore can provide almost limitless energy.
Additionally, fat has several other key roles including, most importantly, being a source of several key fat soluble vitamins and essential fatty acids which cannot be manufactured by the body. Fat also helps to protect vital organs, acts as a source of insulation and is a lubricant for body tissue.
From a dietary perspective, fat adds moisture to food, making it more palatable and pleasant to consume. For this reason it is often easy to overindulge in high-fat foods.
Normally, fat intake in your diet should provide between 20 to 35% of calories consumed depending on activity levels and intensity.
While carbohydrate and fat are most prominent in the debates on diet, the role of protein is often overlooked. Although protein does have an energy yield that can be used to sustain one’s metabolism should carbohydrate stores become depleted, it’s primary role is to support growth and development of body structures and tissues.
Protein forms a part of every living cell, and differs from fat and carbohydrate in that it also contains nitrogen, in addition to carbon, oxygen and hydrogen and a variety of amino acids.
The amino acids that make up protein are classified as essential and non-essential. Non-essential amino acids can be synthesised in the liver in sufficient quantities to maintain health. Essential amino acids however cannot be manufactured by the body and must be acquired from dietary intake.
The relative amount of each amino acid within any given food affect its quality and utility. That is why having a diet rich in a wide variety of amino acids is important, why enhancing the levels of certain amino acids such as L-leucine can be beneficial and why vegans in particular need to pay particular attention to their protein intake.
Commonly used to describe vitamins and minerals, the term micronutrients refers to the fact that these substances are needed in very small quantities. Although neither is a source of energy, vitamins and minerals are a critical part of your base diet.
Vitamins are essential, non-caloric, organic nutrients required by the body in minute amounts. The key role of vitamins is to facilitate the chemical reactions in the body associated with normal metabolism, growth and development. Each vitamin has a very specific function that cannot be sustained by other components.
Vitamins are classified as either water-soluble or fat-soluble. Water-soluble are found in the watery portion of food, this group of vitamins is absorbed directly into the bloodstream.
Vitamins C and the B complex vitamins are water-soluble vitamins. When consumed in excess, this classification of vitamins is excreted in urine, too much can be toxic.
Vitamins classified as fat soluble are as the name suggests absorbed with fats, and can be stored in the liver or the other fat tissue within the body.
Fat soluble vitamins are A, D, E and K. Excess intake of these vitamins, particularly A and D, can have serious consequences, including liver or kidney damage.
Minerals are inorganic substances and required for promoting growth and maintaining health. Minerals become part of body structures, making up approximately 4% of total body weight and can be found in all tissues and body fluids.
They have two key functions:
- The first is providing structural support, by giving strength to bones, teeth, skin, hair and nails.
- The second is a regulatory function with specific minerals involved with maintaining fluid balance, nerve cell transmission, and muscle contraction.
Minerals are found in all food groups, however either excessive or insufficient mineral intake can cause health problems, calcium and sodium intakes in particular are very important to health and performance.
A simple way to distinguish them is classifying them by the amounts required by the body. Major minerals are required in relatively large amounts by the body, between a few hundred milligrams and a few grams. Trace minerals are needed in much smaller amounts, typically in amounts between micrograms and a few milligrams.
Water constitutes around 60-65% of total body weight in the adult male, and approximately 50-55% of body weight in the adult female, so ensuring adequate hydration is really the most fundamental nutritional requirement.
Water is essential because it:
- Gives shape to cells helping them operate effectively.
- Helps form the structure of large molecules such as glycogen and protein, essential for fuelling our bodies.
- Serves as a lubricant (in part) in various parts of the body such as the joints.
- Has a transport function in the body - taking nutrients to the cells and clearing waste products from vital processes.
- Aids in the regulation of body temperature.
Dehydration occurs when your body loses more fluid than you take in.
When the normal water content of your body is reduced, it disrupts the balance of minerals affecting key metabolic functions.
Climate, the amount of physical exercise you are doing, particularly in hot weather, and your diet can contribute to dehydration. You can also become dehydrated as a result of an illness, such as persistent vomiting and diarrhoea or sweating from a fever.
Dehydration will not only affect your level of performance, it can leave you with a general sense of fatigue, headaches, and loss of appetite or even feel lightheaded and nauseous.
On average, total daily fluid loss is approximately 2.7 litres. As we outlined in this article, you should aim to begin each day in a state of hydration ("euhydration"), not over-hydration or under-hydration.
To achieve this, drinking to thirst is generally sufficient, as is consuming sodium (salt) based on your cravings. Hyperhydration (over hydrating) tends to cause digestive issues so don't waterlog yourself. Hence, why in the Principles of Resilient Nutrition we suggest you only consume water in the first 30 minutes of being awake each day.
Establishing your base
For a complete guide to establishing a healthy, foundational diet you can access the Principles of Resilient Nutrition for free here. If you want help to assess your current diet and work out how to implement a strategy that will help you achieve your health and performance goals you can sign up to our nutrition assessment and planning service here.