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Tatenda Simango
I hope my article on Covid-19 last week provided relevant insights for all of you. This week’s article is going to be on nutrition. However, before we tackle that, there is an outstanding issue that needs to be addressed: the appropriate use of gloves.

Latex gloves are disposable and cannot be used for more than one activity. For example, you must dispose gloves after cleaning a surface or caring for a loved one.

Do not succumb to the temptation of spending a day and using the same pair of gloves for multiple activities. You will end up being a carrier of the Covid-19 SARS-COV2 virus and other infections instead of protecting against them.

This week, we would like to look at nutrition in a broad sense to help families decide on healthy affordable diet options. Nutrition can simply be defined as the process of providing or obtaining the food necessary for health and growth. This is a broad topic, but our focus is on healthy– eating and maintaining a balanced diet.

A balanced diet contains the proper quantities and proportions of the needed nutrients to maintain good health. It must have a balanced and proper proportions of macronutrients (carbohydrates, fats, and proteins), micronutrients (vitamins and minerals) and water.

Macronutrients are essential for proper body functioning and provide the body with most of its energy requirements hence the body requires large amounts of them. Micronutrients are not needed on the same quantities as macronutrients, however, are still equally important. Micronutrients work in tandem with macronutrients to keep the physical and mental wellbeing.

It is therefore important to understand how the different types of macro – and micro- nutrients play a different role in the body and tailor your diet accordingly. The golden rule for consuming a balanced diet: half of your plate should be fruits and vegetables, a quarter whole grains/carbohydrates and a quarter healthy protein.

Carbohydrates (macronutrient) are sugars, starches and fibres that provide the body with energy to support bodily functions and physical activity. They can be classified into two groups: simple and complex carbohydrates. The difference between the two forms is the chemical structure and how quickly they are absorbed and digested.

Simple carbohydrates (or simply sugars) are digested and absorbed more quickly and easily than complex carbohydrates and therefore a rapid source of energy. The most common source of simple carbohydrates in the Zimbabwean diet is sucrose (table sugar), lactose (from dairy foods) and maltose (found in some vegetables and beer).

While all function as relatively quick energy sources, simple carbohydrates cause bursts of energy much more quickly than complex carbohydrates because of the quicker rate at which they are digested and absorbed. Simple carbohydrates can lead to spikes in blood sugar levels and thus sugar highs, while complex carbohydrates provide more sustainable energy.

Fibres and starch are the two types of complex carbohydrates and compared to simple carbohydrates they need more time to be digested and metabolised. Examples of starchy foods include mealie-meal from maize, sorghum, rapoko (used to prepare pap/porridge), samp, rice, sweet potato, cassava, yams (madumbe), potatoes, and pasta.

Fibre is made up of the indigestible parts of plant foods, such as vegetables, fruits, grains and, beans and legumes. It is a complex carbohydrate important for our digestive health and regular bowel movements. Fibre also helps you feel fuller for longer, improves cholesterol and blood sugar levels and assists in preventing some diseases such as diabetes, heart disease and bowel cancer.

Fats are another type of macronutrient needed as part of our diet but not in large amounts. They are an essential part of a healthy diet and should account for about 15 to 20 percent of what you consume. They help improve brain development, overall cell functioning, protecting the body’s organs, temperature regulation and absorption of vitamins found in certain foods. Simply, there are bad fats (saturated) and good fats (unsaturated).

Bad fats tend to be solid at room temperature e.g. butter whereas the good fats are liquid at room temperature, like liquid vegetable oil. Bad fat would increase bad cholesterol in the body and increase the chance of getting heart conditions. Fats can be found in various foods like dairy products, meat, whole eggs, vegetables and nuts.

The final macronutrient is proteins which are is essential for repairing and regenerating body tissues and cells, maintaining a healthy functioning immune system, manufacturing hormones and can also serve as an energy source. This wouldn’t be possible without amino acids, which you can think of as the building blocks for proteins. In total there are 20 types of amino acids, 9 of which are ‘essential’ meaning the body cannot produce them and you can only get them from your diet. They are plant and animal sources of protein.

Plant based sources include legumes, nuts, seeds (sunflower, pumpkin, sesame), fruits, soya beans (chunks), kidney beans, white beans, whole grain and cereal. Animal based protein include meat, dairy products and eggs.

There is a wide variety of micronutrients, with everything from Vitamin A, B, C through to K, and minerals such as iron, magnesium and zinc that are vital for the body. However, no one plant can be certain to contain more micronutrients than another as the level largely depends on the mineral content of the soil each individual plant has grown in. To ensure you’re getting as many of these micronutrients into your diet you should try to eat as varied as possible, incorporating various ‘colours’ into each meal.

Vitamins are micronutrients that help your body grow and work the way it should. Vitamins are an essential part of our immune system as it helps us to regulate and maintain the healthy process of our body. Good sources of vitamins include green leafy vegetables, dairy products, meat, fresh fruits, eggs, whole grain, nuts and fortified cereals.

Vitamin A is essential to the normal structure and function of the skin and mucous membranes such as in the eyes. Therefore, it is vital for vision, embryonic development, growth and cellular differentiation and the immune system. Other sources – carrots, liver, orange-coloured fruits, e.g. mangoes.

Vitamin C has antioxidant properties, potentially protecting cells from oxidative damage caused by free radicals. It is also involved in the synthesis of collagen which is required for the normal structure and function of connective tissues such as skin, cartilage and bones. It is therefore an important nutrient for the healing process.

It is also involved in the normal structure and function of blood vessels and neurological function. It also increases the absorption of non-haem iron (iron from plant sources) in the gut. Other sources – Citrus fruits (lemons/oranges), peppers, tomatoes, ginger.

There are two sources of vitamin D: sunlight (resulting in skin synthesis of vitamin D) and the diet. Skin production is, quantitatively, produced vitamin D as a more important source of vitamin D than what we get from the diet because there are not many rich food sources of vitamin D. However, dietary sources like fish are essential when exposure to sunlight is limited.

Vitamin E is synthesised by plants, it works as an antioxidant and is required to protect cells against oxidative damage from free radicals. Richest sources; vegetable oils, nuts and seeds.

Vitamin K is required for the synthesis of several of proteins required for normal blood clotting and bone structure. Vitamin K is synthesised by bacteria in the large bowel and is also present in both plant and animal foods.

Vitamin B1 (Thiamine) is a co-enzyme for several central energy-yielding metabolic pathways, and therefore is required to release energy from carbohydrates.

Thiamine is also involved in the normal function of the nervous system, skeletal muscles and the heart.

Riboflavin (vitamin B2) functions as a coenzyme in a wide variety of reactions that take place in the body. Riboflavin is required to release energy from protein, carbohydrate and fat. It is also involved in the transport and metabolism of iron in the body and is needed for the normal structure and function of mucous membranes and the skin. Liver, legumes and mushrooms are good sources of the vitamin.

Niacin is required for the release of energy from food. Niacin is also required for the normal function of the skin and mucous membranes and for normal functioning of the nervous system. We get it from wheat, maize, and yeast.

Vitamin B6 breaks down glycogen and has a role in the modification of steroid hormone action. It is also essential for the formation of red blood cells.

Together with folate and vitamin B12, vitamin B6 is required for maintenance of normal blood homocysteine levels. Raised homocysteine is a risk factor for cardiovascular disease. Soya beans provide the vitamin.

Vitamin B12 (Cyanocobalamin) serves in the normal function of the nervous system and for the metabolism of folate. Vitamin B12 is found in almost all foods of animal origin. Green plants provide none.

Folate functions together with vitamin B12 to form healthy red blood cells. It is also required for normal cell division, the normal structure of the nervous system and specifically in the development of the neural tube (which develops into the spinal cord and skull) in the embryo. Source – brown rice, peas, oranges, bananas.

The minerals which are a chemical element required as an essential nutrient by organisms include Calcium, Iron, Magnesium, Potassium, Zinc and Sodium.

These are required in very small (trace) amounts. You can find these minerals in all vegetables, dairy products, meat, grains, table salt, sweet potato, tomato, beans, bananas, avocado and fortified foods.

Water is an essential part of our food. The human being is essentially 80 percent water. Drinking enough water, at least two litres every day is good for overall health. Plain drinking water has zero calories, it can also help with managing body weight and reducing caloric intake when substituted for drinks with calories, like regular carbonated drinks.

The options discussed should help you in deciding which foods to choose in maintaining a balanced, healthy diet. Most of these food stuffs offer a wide range of nutrients thus making them more wholesome. Try fruit to add sweetness, avoid adding refined sugar to cereals. Pure honey can be a good alternative to sweeten tea. Vegetables must not be overcooked to preserve nutrients.

Until next week, stay well and keep safe by washing your hands and staying at home.

Tatenda Simango is a medical practitioner. He can be contacted via email [email protected]