Goal of Nutrition

When we eat, not only do we satisfy our appetite and enjoy it, but we’re also providing our body with the nutrients it needs to live.

Nutrients are substances the human body requires to carry out various functions and can only get through food.

So, the goals of nutrition are:

Satisfy our energy needs.
Maintain and grow our body structures.
Regulate vital processes for the body to work properly.

To ensure proper nutrition, the first thing is to know how much energy and nutrients your body needs and where to find them.

Energy Needs of the Body

For the human body’s processes to happen, an energy exchange is needed.

Our energy comes from the carbohydrates, fats, and proteins in the food we eat.

An individual’s energy needs are the amount of energy they must consume to balance their calorie expenditure.

We’ll tell you how to calculate the calories you need in this post.

Proteins

They are the main structural elements of the body’s cells and tissues, meaning they’re responsible for building the human body and form the base for bones and muscles.

Proteins are necessary for body growth and development:

Maintain and repair tissues.
Participate in producing metabolic and digestive enzymes.
Are essential components of certain hormones.
Proteins take part in defense mechanisms as they form part of the immune system’s antibodies.
They also play a role in the blood clotting process.

Proteins are made up of amino acids, mainly found in milk and dairy products, eggs, meats, and fish. Legumes, cereals, and nuts also contain proteins, though with lower biological value.

Recommendation: According to WHO, we should get between 12-15% of total diet calories from proteins. However, this value can be higher.

How much protein do you need daily? We explain it here.

Fats

Fats or lipids mainly provide energy to the body and are essential for its proper functioning:

They’re part of the structure of cell membranes.
They transport vitamins A, D, E, and K (fat-soluble) to our cells.
They store a large amount of energy.

However, depending on the type and amount of fat we consume, lipids can be our allies or one of the main health enemies.

That’s why it’s crucial to know the types of fat and how much we should or can consume. We tell you which fats are healthy in this post.

Fats are divided into:

Saturated fatty acids. Mainly come from animal fat (butter, cheese, fatty meat, egg yolk) and some vegetable oils like coconut and palm oil, which in Spain is consumed through industrial pastries. Excessive saturated fat intake raises cholesterol and triglycerides and is a cardiovascular risk factor.
Unsaturated fatty acids. Divided into:
1. Monounsaturated, mainly found in olive oil, nuts, and seeds.
2. Polyunsaturated, including omega-3s, are essential fatty acids because our body can’t synthesize them, so they must come from the diet. Found mainly in oily fish, some vegetables, and enriched foods.

Unsaturated fats help reduce LDL (“bad”) cholesterol levels and increase HDL (“good”) cholesterol.

They’re “heart-healthy” fats and are linked to preventive and therapeutic effects in other diseases like cancer, inflammatory diseases, and skin conditions.

Their intake is especially important for pregnant women, children, and older adults.

Final nutritional goals
Total fats (% energy)	30-35%
Saturated F. A.	7-8%
Monounsaturated F. A.	15-20%
Polyunsaturated F. A.	5%
Cholesterol	less than 300mg/day

Carbohydrates

Carbohydrates are the main dietary energy source worldwide, especially in developing countries. They’re valued for their energy potential, sweetening power, and high fiber content.

Dietary carbohydrates should come from different food sources, prioritizing complex types.

Recommendation: According to WHO, carbohydrates should provide between 50 and 55% of diet energy.

Vitamins

Vitamins are micronutrients that, although needed in small amounts, must be supplied by the diet.

They’re important not only because their deficiency causes diseases, but also because they help prevent highly prevalent chronic diseases like cardiovascular issues, cancer, and even aging processes.

Fat-soluble vitamins	Physiological function	Main food sources
Vitamin A	Important role in vision mechanisms. Participates in steroid metabolism. Involved in cholesterol metabolism. Maintains immune system. Embryo development.	Dairy, liver, eggs, tuna, sardines
Vitamin D	Helps absorb calcium. Participates in bone mineralization.	Fatty fish, cod liver oil, fish, eggs, dairy in small amounts
Vitamin E	Antioxidant action	Vegetable oils, nuts, vegetables, cereals
Vitamin K	Involved in blood clotting mechanism. Regulates mineralization.	Vegetables (spinach, broccoli, cabbage), soybean and olive vegetable oils.

Water-soluble vitamins	Physiological function	Main food sources
Vitamin C	Essential to maintain the structure of the intercellular substance of connective tissue. Prevents formation of nitrosamines, harmful to health.	Fruits (strawberries, currants, lemon, oranges), vegetables (pepper, cabbage, parsley, turnip, radish, broccoli), liver and kidney, milk, meats
Thiamine	Carbohydrate metabolism. Important role in neurotransmission processes.	Cereals, peas and broad beans, green vegetables, fruits, dairy (except butter)
Riboflavin	Enables the energy supply needed for biological processes.	Liver, milk and cheese, eggs, green vegetables, whole cereals
Vitamin B6	Amino acid metabolism.	Red meats, dairy, cereals and bread, nuts, legumes, fruit
Folic Acid	Involved in genetic information transmission. Amino acid metabolism. Prevents megaloblastic anemia. Prevents neural tube defects in fetus.	Liver, dark green vegetables, fruit, cereals and bread, peanuts and hazelnuts, beer
Vitamin B12	Essential for many enzymatic reactions. Converts homocysteine into methionine.	Meats, fish, eggs, and dairy, in smaller amounts

Minerals

Minerals play important regulatory roles in the body.

Minerals	Physiological function	Main food sources
Iron	Oxygen transport from lungs to tissues. Muscle oxygen storage. Release to meet increased metabolic needs.	Meat, fish, dairy, and vegetables to a lesser extent
Zinc	Regulates gene expression. Needed for over 120 enzymes involved in carbohydrate, lipid, and protein metabolism.	Red meats, seafood
Calcium	Key role in the skeletal system. Activates enzymatic systems. Involved in blood clotting. Membrane transport.	Milk and dairy, cereals, fruits, leafy green vegetables
Phosphorus	Replenishes metabolic energy. Regulates many enzymes.	Fish, cereals, nuts
Magnesium	Essential in all biosynthesis processes and neuromuscular activity. Crucial in genetic code transmission.	Nuts, whole cereals, green vegetables, legumes, chocolate

Fiber

Fiber is a group of substances of plant origin, mostly carbohydrates, that don’t dissolve during digestion.

There are two main types:

Insoluble fiber, which absorbs little water forming low-viscosity mixtures, very useful to prevent constipation. Mainly found in cereals.
Soluble fiber, which traps water forming viscous gels. Soluble fiber slows gastric emptying and reduces fat and glucose absorption. Found in fruits and vegetables, bran, barley, and legumes.

Recommendation: It’s recommended to consume between 25 and 30 g of fiber daily as its protective role against high cholesterol, diabetes, obesity, colon diseases, and some cancers is proven. For children, intake of 0.5 g per kg of body weight is recommended.

What are the best fiber-rich foods? We tell you here.

Summary of Nutritional Needs

So, all nutrients have essential functions in the body, many of which directly impact our health.

Some nutrients or food components with functional properties
	Properties
Fiber	Regulates bacterial balance Improves intestinal transit Dilutes carcinogenic agents Increases bile salt excretion Reduces blood cholesterol Regulates blood glucose levels
Antioxidants Vitamin A, E, C Beta-carotenes Flavonoids	Eliminates free radicals (protects against cellular oxidative damage) Inhibits lipid peroxidation
Lactic bacteria	Improves lactose digestibility. Increases calcium absorption. Stimulates immune system
Polyunsaturated fatty acids w-3	Lowers triglycerides and LDL cholesterol levels. Reduces platelet aggregation. Stimulates immune system.
Micronutrients Se, Fe, Cu, Zn, Mn Calcium Iron Folic acid	Act as enzyme cofactors. Stimulate immune system.
Amino acids Tryptophan Tyramine Glutamine Arginine Cysteine	Hypnotic and sedative effect. Memory improvement. Mental fatigue recovery. Immune system stimulation. Slows aging.
Caffeine	Stimulates the central nervous system