Today we will learn the basics of nutrition so we can build the base and learn to design menus with the correct characteristics. We have to start by differentiating the food groups from the nutrients, since these are often confused. Food groups are made up of foods that share nutritional characteristics and are divided into:
fruits
vegetables
grains
foods of animal origin
legumes
dairy products
fats and oils
sugars
Nutrients, on the contrary, are compounds that are found in food and provide our cells with energy to carry out all their functions. The nutrients are:
carbohydrates
protein
fats
vitamins
minerals
water (there are different positions on whether or not it is considered a nutrient, I mention it to point out that all foods contain a percentage of water)
Each food belongs to a food group and is composed of different nutrients, let's see some examples:
An apple belongs to the food group of fruits, and of the nutrients it provides carbohydrates, vitamins and minerals.
Beans belong to the group of legumes, and provide carbohydrates, protein, vitamins and minerals.
Eggs belong to the group of foods of animal origin, and provide protein, fat, vitamins and minerals.
Which nutrients does each food group contain?
Below we will break down the nutrients that each food group provides:
Fruits: carbohydrates, vitamins, minerals and water.
Vegetables: carbohydrates, protein (minimum quantity), vitamins, minerals and water.
Cereals: the group of cereals is divided into cereals with fat and cereals without fat. Tortillas, bread, oatmeal, rice, and pasta make up the group of fat-free cereals, while granola, donuts, among others, are in the group of fatty cereals. They contain carbohydrates, proteins, fats (some), vitamins and minerals.
Foods of animal origin: protein, fat, vitamins and minerals.
Legumes: carbohydrates, proteins, fats, vitamins and minerals.
Dairy: carbohydrates, fats, proteins, vitamins and minerals.
Fats and oils: the group of fats and oils is divided into fats that provide protein and those that do not. For example, avocado is a fat without protein and walnut is a fat with protein. They provide: Fats, protein (some), vitamins and minerals.
Sugars: provide only carbohydrates.
It is important to mention that all foods contain different amounts of water.
What are the functions of each of the nutrients?
Now, let's discuss what the functions of each nutrient are:
Carbohydrates
They form the main source of energy for cells. Within the group of carbohydrates there are different types:
Monosaccharides: glucose, fructose, galactose
Disaccharides: sucrose, lactose, maltose
Polysaccharides: starch, cellulose
Fiber is a carbohydrate that comes from plants, unlike the rest of carbohydrates, it is not absorbed but it supports digestion. Fiber is divided into soluble and insoluble. Soluble fiber helps lower cholesterol and controls blood glucose levels as well as weight by giving you a feeling of satiety and helping to prevent constipation and diarrhea. Examples of foods that provide soluble fiber are fruits, vegetables, and legumes. Insoluble fiber promotes movement and adds bulk to the stool. This type of fiber helps fight constipation and is found in the skin of fruits and vegetables, as well as in the bran of whole grains.
Proteins
They are responsible for the construction, maintenance and repair of body tissue and provide structural support. They are also an essential component in the immune system, as well as in the formation of hormones. Proteins can come from animal and plant origin. For example, eggs, tuna, red meat, chicken and seafood are proteins of animal origin. Legumes (beans, lentils, chickpeas) and the group of cereals such as oats, quinoa, rice, provide protein of plant origin.
It is important to differentiate that proteins of animal origin provide more protein than that of plant origin, in addition to being absorbed faster.
Fats
Among their functions, they provide energy, are part of the cell membranes, help the formation of hormones, serve as an insulator from the cold and help the absorption of some vitamins. So, we have to stop blaming fats or seeing them as bad since they are essential for many functions. Fats are also divided into several categories depending on their chemical structure: saturated, unsaturated and trans fat. Saturated fats are found in animal products like butter, cheese, milk, and cream. Unsaturated fats are divided into monounsaturated and polyunsaturated fats.
One of the most important polyunsaturated fatty acids for the body is omega-3. The three most important omega-3 fatty acids are:
ALA (alpha-linolenic acid)
EPA (eicosapentaenoic acid)
DHA (docosahexaenoic acid)
ALA is mainly found in vegetable oils like flaxseed and canola oil. EPA and DHA are found in fish and shellfish.
Vitamins
Vitamins, like minerals, are considered micronutrients since they provide a lower amount of nutrients compared to macronutrients (carbohydrates, protein and fat). Vitamins are found naturally in plants and animals. They are divided into water-soluble and fat-soluble. Water soluble vitamins dissolve in water and are eliminated from the body. Within the water-soluble category are the B complex vitamins (including folic acid and biotin) and vitamin C. Fat-soluble vitamins are stored in the body's fat and include vitamin A, D, E, and K.
Minerals
Minerals, unlike vitamins, are not produced in the body but are necessary for body functions to be performed properly. Our body requires minerals in specific amounts and they are divided into macro and trace minerals.
Macrominerals are required in large quantities and consist of calcium, chlorine, magnesium, phosphorus, potassium and sodium. Microminerals are required in the body in trace amounts. The trace minerals are arsenic, boron, chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybdenum, nickel, selenium, silicon, tin, zinc and vanadium.
Now that we understand better how food groups and nutrients are classified, we can move on to understand how to better constitute main meals: breakfast, lunch and dinner. There are different approaches and food guides worldwide, for example in Mexico there is the Plate of Good Eating and in the United States My Plate.
Personally, I like to follow the Healthy Eating Plate developed by the Harvard School of Public Health, which balances meals with four (4) parts: vegetables in higher proportion, protein and cereals in the same proportion and fruit in a small amount. Low calorie drinks, water and a small amount of healthy oils and fats complement nutrition. By having this variety on the plate, we ensure a good supply of all nutrients: proteins, carbohydrates, fats, vitamins and minerals.
On many occasions we cook our meals and omit one or more food groups, that is why keeping this guide in mind will help us make better decisions when choosing what to eat.