If you’re looking to eat for health, it’s really important to understand what makes up the food you eat. You’ve probably heard that your body needs nutrients to survive. Food is a source of nutrients, and different foods have different nutritional content. In this post, I will give you lots of information about the six classes of nutrients, where we find them, and why we need them.
We need the macronutrients in relatively large quantities to maintain health. Three of the macronutrients–carbohydrates, protein and fat–are sources of calories for the body. Those calories are a source of energy and fuel us throughout the day. Let’s take a look at each of the macronutrients.
As mentioned, carbohydrates are a source of energy and provide 4 calories per gram. We can further break down carbohydrates into simple sugars and complex carbohydrates. The simple carbohydrates are made up of one (monosaccharides) or two (disaccharides) sugar units, while complex carbohydrates are made up of three or more monosaccharides linked together. Starch and fiber are considered complex carbohydrates.
Carbohydrates are found in lots of different foods. Some examples are grains, fruit, vegetables, dairy products, and legumes. They are also of course found in sweets like candy, cookies and cake. Some carbohydrate-containing foods, like bread, are often demonized. If you’d like to read further about bread as a source of carbohydrate, check out my blog post that answers the question “Is rye bread healthy?”
In terms of why we need carbohydrates, there are many reasons. Lots of people have the impression that carbohydrate-containing foods are not healthy. In fact, as I have explained, they do lots for our health. Carbohydrates are a source of energy and fuel us throughout the day, including when we exercise. Fiber is an important type of carbohydrate that aids with maintenance of a healthy weight, digestion, and controlling cholesterol. In addition, the foods that contain carbohydrates often are sources of many other nutrients, including vitamins and minerals.
Protein also provides energy, with 4 calories per gram like carbohydrates. Proteins are made up of amino acids. Nine of these amino acids are considered essential, meaning we must obtain them from the diet.
Protein is found both in animal- and plant-source foods. Dairy, including milk, yogurt and cheese, is a source of protein. Meat, poultry and fish also contain protein. These animal-source foods contain all of the essential amino acids. Plant-source foods that contain protein include legumes, nuts and grains. Generally, these foods do not contain all of the essential amino acids, so it is necessary to consume different types of plant-based foods to be sure you get them all from the diet. Beans and rice together, for example, constitute a complete protein source.
Protein serves lots of different functions in the body. Proteins are needed as enzymes for chemical reactions, and also help to transport substances in the blood. They are also important for immune health.
Fat has more calories per gram than protein and carbohydrate, at 9 calories per gram. We can think about fat as being saturated or unsaturated depending on their chemical makeup. Some fats, namely omega-3 and omega-6, are considered essential, meaning we must obtain them from the diet.
Fat is found widely in animal- and plant-source foods. Meat, fish and poultry contain fat, both saturated and unsaturated. Dairy contains primarily saturated fat. Plant-source foods like avocado and nuts contain quite a bit of fat, and this is mainly unsaturated. Similarly, oils are sources of fat, and the type of fat differs depending on the source.
Fats serve many different functions and are an important part of the diet. Fats form part of cell membranes, and also protect the organs. They also insulate the body.
Water makes up most of the body and is part of every tissue and organ. It does not provide any calories, unlike the other macronutrients.
Water is part of most foods. We find water in larger amounts in foods like fruits and vegetables. We also consume water when we drink it alone, as well as when it is used to make tea, coffee, herbal tea and more.
Water has lots of different functions. It helps to regulate body temperature and is also important for removal of waste products. In addition, it is needed for transport of nutrients and oxygen in the body and for lubrication of the joints.
Vitamins are nutrients that we need in small amounts than the macronutrients and that do not provide any calories. Vitamins can be considered either water- or fat-soluble, with the former not stored in large amounts in the body, unlike the latter.
Different types of vitamins are found in different foods. Fruit and vegetables are rich in different types of vitamins such as vitamin A and vitamin C. Grains are rich in B vitamins, dairy contains vitamin A and may be fortified with vitamin D, and meat contains vitamin B12, to name a few examples.
Vitamins have so many different functions in the body. They are needed for transforming food into energy, for immune function, for healthy bones, and for eyesight, among many, many other functions.
Minerals are also needed in small amounts compared to the macronutrients and do not provide any calories.
Minerals are found in lots of foods. Sodium is a mineral that is found in large amounts in packaged foods, while potassium is another mineral that is naturally found in whole foods. Minerals like calcium are found in foods like dairy, while iron is found in foods like meat, as well as plant-based foods such as beans. Vegetarian alternatives to meat generally contain iron, as well as other nutrients.
Minerals have many different functions. They help maintain the body’s structure and also are used in chemical reactions in the body. They are also important for immune function and to maintain fluid balance.
It’s important to be familiar with the different components of foods as you are planning your diet so you can get the right nutrients to meet your needs. Remember that a healthy diet can look different depending on your food preferences as long as you are getting everything you need nutritionally.