Food is the basic need of life because it provides energy for our daily necessary activities. It imparts the nutrition required by our body. Based on the quantity of requirements they fall under 2 categories — macronutrient & micronutrient, both are essential for the body in a particular proportion. Assessing dietary intake of an individual is essential in order to achieve proper growth, development & a good mental condition.
Food provides the energy and building material for the countless substances that are essential for the survival and growth of living things. Nutrients are an integral part of our body as they govern its physiological and biochemical processes. The different characteristics of food such as colour, texture, flavour, etc., plays an important role in selectivity, however once inside the alimentary tract the appeal no longer remains important. The process of digestion splits the food into its basic components and helps them in getting absorbed and transported at the cellular level. Carbohydrate, protein and fat contributes to the total energy pool, the ultimate energy release from the food is used in synthesis, movement and other functions. The involvement of vitamins and minerals act as a co-enzyme, or a co-catalyst and water as a buffer in the whole process.
Nutrients are classified into 2 categories based on the amount required in the body: macro-nutrients and micro-nutrients. Both groups are essential to promote our body growth, development and regulate various body processes.
Based on recent studies the importance of dietary fibre has gained popularity as the 4th macro-nutrient. Now let’s discuss the differences and similarities between macronutrients and micronutrients.
WHAT ARE MACRONUTRIENTS?
MACRONUTRIENTS are the elements present in a larger quantity of our diet (in gram range), it generally includes water, carbohydrates, fats and proteins. Macronutrients (except water) provide us with the calories and energy to maintain our bodily functions, such as growth, repair and development of new tissues. It also conducts nerve impulses and regulate life process.
CARBOHYDRATES are required for energy and they act as the main source of energy (4 kcal/ gram). They form the major part of the stored food in the body for later use of energy and exist mainly in 3 forms: sugar, starch and fibre. Complex carbs come from healthy starches, while simple carbs come from sugars. These sugars (glucose molecules) directly get absorbed into the bloodstream and provide energy by producing ATPs via several biochemical pathways. Hence a sudden spike and drop is often experienced after a meal heavy in carbs. Functioning of the brain depends on only glucose. When in excess, it gets stored in the liver in form of Glycogen. Carbohydrates are also important for fat oxidation and can be converted into protein through metabolism and conversion pathways. The discovery of how carbohydrates provide stability to the digestive system has changed our perspective about the impact of carbohydrates on our health. Another purpose of the carbohydrate was found in ‘glycobiology,' the idea that many carbohydrates together act as communication codes which play a part in detecting the blood type, immune function and many more.
PROTEIN is made up of amino acids which are ‘the building blocks of protein’ and makes up most of the cell structure including the cell membrane. In cases of extreme starvation, the muscles made up of proteins are used to provide energy. It is called muscle wasting. Proteins provide 4 kcal energy per gram. Amino acid balance is very important for the overall health and wellbeing. Not all proteins are equal in terms of composition, some may contain more of one amino acid than another. This is why a variety in protein intake is very important. Taking in different types of animal protein provides us with all the essential proteins.
FATS have the highest caloric value and provide the largest amount of energy when burnt around 9 kcal/gm, it is measured by a calorimeter. It is twice as energy-rich as protein and carbohydrates. Extra fats are stored in adipose tissues and burnt when the body runs out of carbohydrates. They are used in making steroids and hormones to help us avoid excessive hunger. Fats also provide a good buffer for carbohydrates, so it’s good to take them together. Dietary fat is also important for our body to synthesis certain micronutrients, such as fat-soluble vitamins A, E, D and K. Fat intake impacts our health as it is important to maintain omega-3 fatty acid to omega-6 fatty acid ratio. This balance impacts so many aspects of our health. With all macronutrients, it’s important to understand the priority of quality versus quantity, especially for fats.
FIBRE was once the under-appreciated “nutrient.” But based on recent studies, it is considered as the 4th important macro-nutrient. There are two types of fibres — soluble and insoluble, they both impart a variety of health benefits.
The main difference between soluble and insoluble fibre is that the former has the ability to dissolve in water, while the latter does not. This results in both types of fibres being important for maintaining the regular bowel movements. Soluble fibre forms a gel-like substance in the presence of water which helps to move the contents of the bowels. Insoluble fibre does not absorb water, thereby “bulking” up our stool and making it easier to pass. The regular transit of intestinal contents is critical for the detoxification capacity of the body and both types of fibres are essential for this function. Additionally, soluble fibre has the ability to directly bind toxins and inhibit them from being absorbed into the body.
WATER makes a large part of our body weight and also the main component of our body fluids. (Apx. 70%). The body needs more of water than any other nutrient and it can be replenished through foods and liquids that we eat and drink. Water serves as a carrier, distributing nutrients to cells and removing waste products through urine. It is also a compulsory component in the regulation of body temperature and maintaining the ionic balance of the blood. Water is completely essential for maintaining the metabolism of the body and required for lubrication, also acts as a shock absorber.
WHAT ARE MICRONUTRIENTS?
MICRONUTRIENTS are the essential components of our diet that are required in much smaller amounts. There are approximately 53 essential micronutrients. The body doesn’t make any of these on its own, so we have to maintain a proper micronutrient intake. Together, they are extremely important for the proper functioning of the body. Their main function is to conduct chemical reactions in the body. They do not provide any kind of energy to our body.
They are essential for maintaining the normal metabolism, development, regulation of cell function, etc. They work together with other enzymes. They are either fat-soluble or water-soluble. Fat soluble Vitamins can be stored in the adipose tissues of the body when in excess. Water-soluble vitamins are excreted through urine when in excess, thus it needs to be taken daily. Water-soluble vitamins include Vitamin B and C. Green leafy vegetables (GLVs ) are a rich source of Vitamin B, whereas Vitamin C is mostly found in citrus fruits. Fat-soluble vitamins are Vitamin A, D, E and K. Green leafy vegetables, dairy products and plant oils provide these vitamins.
Below table indicates the vitamins with their health benefits/functions and sources
In the body they are found in an ionised form. They are further classified based on the quantity of requirement in macro-minerals and micro-minerals (or trace minerals). Macro-minerals present in the body eg. Ca, K, Fe, Na, Mg, etc. Iron is the main constituent of haemoglobin which is present in the blood. Macro-minerals are needed in large amounts, as compared to micro-minerals. Micro-minerals include Cu, Zn, Cl, Co, Cr, F. They mostly act as co-factors and necessary for the functioning of enzymes in the body, but are needed only in minor quantities. Approx. 4% of the body’s mass consists of minerals.
Below table indicates the mineral with their health benefits and sources
WHAT IF THERE IS AN EXCESS OR INADEQUACY?
It is important to maintain a proper balance of the macro & micronutrients. The deficiency of macronutrients can cause reduced stamina by depletion of the body store. Also, the excess of the same can cause obesity & other chronic degenerative diseases, such as CHD or diabetes. The scarcity of micronutrient such as Vitamin- A, E and Iron can cause night blindness or reproductive damages or anaemia and the excess can cause allergy or intolerance in the body.
The Indian diet has changed drastically over the past few years, and the change wasn’t for the betterment. We now eat more of processed foods and instant ready to eat foods than we did before. Processed and fast foods have a tendency of includeing high levels of macronutrients, often at the expense of micronutrients. During the process of making these foods, they are stripped off the vitamins, minerals, and phytochemical that we require. This means that most boxed foods, cereals, bread, sweets, dairy products and mostly fast food provides you with a high amount of calories but offer a minimal nutrient content.
It is very important to pay attention to what you are consuming. Maintaining the right balance between macro and micronutrients leads to a better overall health and wellness. Use of high-quality vitamin supplements helps boost our possibly lacking micronutrient levels.
1. Robert Luby.(n.d.).Fiber: The Fourth Macronutrient? Retrieved from https://www.citymarket.coop/
2. Food Pyramid.com(n.d.).The 6 Essential Nutrients Retrieved from http://www.foodpyramid.com/6-essential-nutrients
3. What we get from food(n.d.) Retrieved from http://www.fao.org/docrep/
4. Green, R., Milner, J., Joy, E. J., Agrawal, S., & Dangour, A. D. (2016). Dietary patterns in India: a systematic review. The British journal of nutrition, 116(1), 142-8.
5. What Are Macro And Micro-Nutrients?. Retrieved from https://www.healthstatus.com/
6. Warne, R.W.(2014).The Micro and Macro of Nutrients across Biological Scales, Integrative and Comparative Biology, 54(5), 864–872