When it comes to eating for health and your physique, your diet basically boils down to two key components – micronutrients and macronutrients.
Micronutrients are the compounds and substances your body needs in small (micro) amounts, including vitamins and minerals.
Micronutrients perform a range of functions, including energy, enzyme and hormone production, and supports optimal immune function.
Your body also needs a broad range of vitamins and minerals to support growth and development, bone health and fluid balance, among various other processes.
Important micronutrients like iron help to produce the oxygen-carrying proteins that circulate in our blood stream and deliver vital oxygen to muscle cells, while adequate calcium is required to maintain bone health.
With the exception of vitamin D, the body cannot produce micronutrients, which means we need to get these important compounds from our diet. The best sources of micronutrients include natural, unprocessed whole foods, particularly fresh fruits and vegetables.
As the micronutrient content of each food is different, it is generally best to eat a variety of foods to ensure you get sufficient amounts of all the important vitamins and minerals to cover your recommended daily allowance (RDA).
However, supplements and fortified foods also provide a source of vitamins and minerals to augment a whole food diet.
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The lowdown on deficiencies
A deficiency of one or more these micronutrients can cause illness, impact your health and result in under-recovery from exercise and others forms of stress.
Iron, vitamin A and iodine deficiencies are the most common globally, according to information from the World Health Organization (WHO), particularly among children and pregnant women.
A micronutrient deficiency can cause various diseases and health issues, in addition to less severe issues such as low energy levels, mental and cognitive fog and reduced mental capacity.
This can impact educational outcomes, reduce exercise efficiency and work productivity, and increased your risk for other diseases and health conditions.
Types of micronutrients:
Vitamins and minerals can be divided into four categories:
- Water-soluble vitamins
- Fat-soluble vitamins
- Trace minerals.
These vitamins dissolve in water and are not easily stored in your body. Your body flushes them out with urine when consumed in excess. These vitamins include the B-vitamins and vitamin C.
Your body absorbs these vitamins best when consumed alongside a source of fat. Your body stores fat-soluble vitamins in your liver and fatty tissues for later use. These vitamins include vitamin A, D, E and K.
While your body needs these minerals in small amounts, trace minerals still play important roles in your. Trace minerals include iron, manganese, copper, zinc, iodine, fluoride and selenium.
Your body requires macro-minerals such as calcium, phosphorus, magnesium, potassium and sodium in larger amounts than trace minerals to perform their specific roles in the body.
The macronutrient basics
Macronutrients are the nutrients your body uses in relatively large amounts to meet our daily energy and metabolic requirements, including tissue repair and growth and numerous biochemical processes that create hormones and enzymes, among other important substances.
The various macronutrients also contain different vitamin, mineral and fibre contents, which is another reason to ensure a variety of sources, predominantly from natural whole foods.
Types of micronutrients:
Macronutrients comprise the three major food groups:
Carbohydrates provide the body’s primary, most readily available fuel source. Carbs provide energy for your muscles and the central nervous system during movement and exercise.
Protein provides the body with amino acids, which are vital for tissue repair and growth within muscle, tendons, ligaments and hone, as well as cell membranes, organs, hair, skin, nails, and blood plasma. Proteins also play roles in our metabolic, hormonal and enzyme systems and help maintain acid-alkaline balance in our bodies.
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While dietary fat is often demonised, it is vital for energy, hormone production, and the absorption and transport of fat-soluble vitamins. Fat also serves to protect your organs, and insulates the body.
All about balance
The Institute of Medicine’s Food and Nutrition Board recommends a macronutrient distribution range (AMDR) of 45-65% carbohydrates, 20-35% fat and 10-35% protein.
However, not everyone responds in the same way to specific macronutrient ratios, meal timing or even meal composition, which is individualised advice from a qualified dietitian is always best.
Factors that determine your ideal macronutrient ratio include your metabolic rate, daily activity levels and energy requirements, and your health status, among others.
For instance, highly active individuals typically require more immediate energy from carbohydrates, while someone who is insulin resistant or diabetic generally requires a diet that is lower in carbohydrates. However, a healthful diet should never exclude an entire macronutrient group.
Meeting energy demands
The energy derived from the three macronutrient groups is delivered in the form of calories. The amount of calories available from each macronutrient group are:
- 1g carbohydrate = 4 calories
- 1g protein = 4 calories
- 1g fat = 9 calories
Focus on nutrient density
A sensible approach to eating is to prioritise nutrient-dense foods over energy-dense options. Nutrient density is a measure of the ratio of nutrient content (in grams) to the total energy content (in kilocalories or joules).
Nutrient dense foods will have a high level of nutrients, which include vitamins, minerals, phytonutrients, essential fatty acids and fibre, in relation to the number of calories the food contains, which means you can eat less food and still get all the nutrition your body needs.
These foodstuffs offer many benefits over processed and refined foods that have little or no nutritional value but typically have a high energy content (energy-dense). These benefits include improved overall health, vitality, physical and mental performance and better weight management.