Food = Nutrients
by Janelle Zakour RD
I have been meaning to write a post about the Caribbean Food Groups for such a long time now. But it did not make any sense to discuss the actual food groups without first going into what food is to begin with.
The most basic definition is that food is nutrients. It is any nutritious substance that we as humans eat or drink. But there are different types of nutrients that come into play.
We can break Food up into:
1. Macronutrients (Carbohydrates, Proteins and Fats - these give us energy) and
2. Micronutrients (Vitamins and Minerals - these do not provide energy but most are Essential meaning that we need to obtain these from the diet).
This is a simplified overview of the role of the 3 Macronutrients.
Carbohydrates (45-65%) are the body’s primary and preferred source of energy. Every cell and tissue in the human body can use glucose (simple form of carbohydrate) for energy. We have different categories of carbohydrates - simple and complex. Simple carbohydrates are quickly digested and provide quick energy. Dietary fibre in complex carbohydrates contribute to the overall health of the colon, increases the satiety factor of a meal and some also play a role in regulating blood sugar levels. Carbs also prevent the body from using protein as an energy source.
Pro tip: Keep it high fibre!
Protein (15-25%) is composed of amino acids that form the building block of tissues. Protein is essential for the growth and repair of our muscles and is also important for making our hormones and enzymes. Every cell in our body contains protein and is used in the information of many molecules essential for life. Protein is also used as an energy source when carbohydrates are limited.
Pro tip: Keep it lean!
Fat (10-35%) is our most energy-dense macronutrient which means that we don’t need a lot of fat in our diet to give us energy. Fat insulates our bodies and keep us warm in colder weather. It helps our bodies store energy and excess fat storage may lead to health complications. Essential fats play an important role in basic metabolism and may prevent heart disease. We also need fats to help the absorption of fat-soluble vitamins (A, D, E and K).
Pro tip: Keep it plant-based!
You’re probably wondering what are those percentage ranges underneath the words Carbohydrates, Proteins and Fats in the table. They are the recommended ranges of calories to be derived for each macronutrient. It is a guide for determining a balanced diet. For instance, a diet that is lower than 45% of overall carbohydrates is considered low-carbohydrate and generally not recommended as it requires cutting back on prescribed servings of staples, legumes, fruits and vegetables.
The Micronutrients are composed of Vitamins and Minerals. This is a very extensive topic so I will summarise as best as possible.
1. Vitamins are categorised based on their solubility.
Water-soluble vitamins involve the 8 B-complex vitamins and vitamin C. Their roles in the body range widely, but most function as coenzymes in numerous metabolic pathways. We can get the range of B-complex Vitamins from a variety of whole grains, root crops, mushrooms, animal products, legumes and leafy greens. Vitamin C is a powerful antioxidant that is vital for the maintenance of connective tissue. The main dietary sources for vitamin C are fruits and vegetables.
All the water-soluble vitamins are easy to get from a balanced diet. However, as vitamin B12 is only found in substantial amounts in the foods from animals group, vegans are at a high risk of deficiency and as a result, may need to take supplements or get regular injections. Optimally, you should get all of these from your diet every day. Keep in mind that your body generally doesn’t store water-soluble vitamins, except for vitamin B12.
There are 4 fat-soluble vitamins in the human diet: A, D, E and K. They are essential for health and play many important roles in the body. Fat-soluble vitamins are most abundant in high-fat foods and are much better absorbed into your bloodstream when you eat them with fat. With the exception of vitamin D (the sunlight vitamin), most of them are easy to get from a diverse diet, especially if you eat plenty of nuts, seeds, vegetables, fish and eggs.
Vitamin A is best known for its vital role in maintaining vision. It's also essential for body growth, immune function and reproductive health. It is found primarily in animal foods like liver, fish liver oil and butter. However, beta-carotene (the precursor to Vitamin A) can be found in orange plant foods.
Vitamin D has many functions and one of the most important is the maintenance of calcium and phosphorus levels in blood. It benefits bone health by promoting the absorption of these minerals. Your body can produce the vitamin D it needs if you regularly expose large parts of your skin to sunlight. However, most people need to get it from their diet or supplements, such as fatty fish, eggs or fish oil.
Vitamin E’s key role is to serve as an antioxidant, protecting cells against free radicals and oxidative damage. The best sources of vitamin E are certain vegetable oils (wheat germ oil), nuts (almonds) and seeds (sunflower).
Vitamin K is vital for blood clotting and supports bone health. Vitamin K1 is abundant in many leafy green vegetables, while vitamin K2 is found in low amounts in animal-sourced foods (butter, egg yolks, liver) and fermented soy foods (natto).
2. Minerals are specific kinds of nutrients that your body needs in order to function properly. The human body requires different amounts of each mineral to stay healthy. Here are just a few of the more common minerals.
Calcium is needed for strong bones and teeth. It also supports proper function of your blood vessels, muscles, nerves, and hormones. Natural sources of calcium include milk, yogurt, cheese, and small fish with bones, beans, and peas. Vegetables such as broccoli, kale, and pakchoi (bokchoy) also provide calcium. Some foods are also fortified with the mineral, including tofu, cereals, and juices.
Iron is an important part of haemoglobin, a protein that carries oxygen to your tissues. Iron is also a part of other proteins and enzymes that keep your body healthy. More than half of the iron in your body is in red blood cells. The best sources of heme-iron are meat, poultry, or fish. Plant-based foods such as beans or lentils are good sources of non-heme iron. Pairing an iron-rich food with vitamin C-rich foods increases the absorption of iron.
Magnesium is needed in the body for hundreds of chemical reactions. These include responses that control blood glucose levels and blood pressure. Proper function of muscles and nerves, brain function, energy metabolism, and protein production are also controlled by magnesium. Roughly 60 percent of the body’s magnesium resides in the bones while nearly 40 percent resides in muscle and soft tissue cells. Good sources of magnesium include: legumes (peas, beans, nuts, seeds), whole grains and green leafy vegetables, such as spinach. You can even get magnesium in dark chocolate!
Potassium is a mineral that functions as an electrolyte. It’s required for muscle contraction, proper heart function, and the transmission of nerve signals. It’s also needed by a few enzymes, including one that helps your body turn carbohydrates into energy. The best sources of potassium are fruits and vegetables, such as bananas, avocado, dark leafy greens, beets, potatoes, and plums. Other good sources include orange juice and nuts.
Zinc plays a role in many aspects of the body’s metabolism. These include protein synthesis, immune system function, wound healing and DNA synthesis. It is also important for proper growth and development during pregnancy, childhood, and adolescence. Zinc is found in animal products like oysters, red meat, and poultry but you can also get zinc in legumes, whole grains and dairy products.
By choosing whole, minimally processed foods on a daily basis, we ensure that we consume a wide range of these micronutrients as well as the countless others that are not listed.
Whitney, Ellie, Sharon Rady Rolfes. ‘Understanding Nutrition’, 11th Edition. Thomson Wadsworth, 2008.