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What is Nutrition

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What is Nutrition?

Nutrition is the part of health and development that interprets the nutrients and other food substances to maintain an organism’s growth, reproduction, and disease. It includes ingestion, absorption, biosynthesis, catabolism, excretion, and assimilation.

An organism’s diet is what it eats, which is largely determined by the availability and palatability of foods. Better nutrition is related to the improved infant, child and maternal health, stronger immune systems, safer pregnancy and childbirth, lower risk of non-communicable diseases such as diabetes and cardiovascular disease. Nutrients can be grouped as either macronutrients or micronutrients.

For humans, a healthy diet includes the preparation of food and storage methods that preserve nutrients from oxidation, heat or leaching, and that reduces the risk of foodborne illnesses.

In humans, an unhealthy diet can cause deficiency-related diseases such as anemia, scurvy, blindness, stillbirth, preterm >birth, and cretinism, or nutrient excess health-threatening conditions such as obesity and metabolic syndrome and such common chronic systemic diseases. Lack of nutrition can lead to wasting in acute cases and the stunting of marasmus in chronic malnutrition cases.

People with adequate nutrition are more productive and can create opportunities to gradually break the cycles of poverty and hunger.

Malnutrition, in every form, presents significant threats to human health. Today the world faces a double burden of malnutrition that includes undernutrition and overweight, especially in low- and middle-income countries.

WHO provides scientific advice and decision-making tools to help countries address all forms of malnutrition to support health and well-being for all ages.

This fact file explores the risks posed by all forms of malnutrition, starting from the earliest stages of development, and the responses that the health system can give directly and through its influence on other sectors, particularly the food system.

Poor nutrition can lead to a lack of energy, digestive problems, food allergies, weight gain, depression and anxiety, as well as many of today’s most prevalent chronic diseases like coronary heart disease, cancer, ADHA. Having nutritional knowledge and making informed choices about the foods you eat can help you achieve optimum health over your lifetime.

Nutritionist advises people on what to eat and how to modify their diet to maintain or restore optimal health or help relieve ill health and combat disease.

There is almost daily advice in the media on what to eat, and what not to eat and drink, most of it is confusing and contradictory. Celebrity chefs and fine dining have continued to grow in popularity.

Naturopathic nutrition seeks to uncover and support a disease’s cause, rather than just treating the symptoms as conventional medicine often does. Many people find that improving a poor diet to cure one symptom can often lead to other health benefits such as increased energy levels, skin improvements, and better sleep, amongst many other benefits.

Nutrients Classes

The major classes of human nutrients are macronutrients and micronutrients, such as:

1. Macronutrients

Macronutrients are nutrients that people need in relatively large quantities. These nutrients are carbohydrates, fiber, fats, proteins and water.

(i) Carbohydrates

Sugar, starch, and fiber are types of carbohydrates.

Sugars are simple carbohydrates. The body quickly breaks down and absorbs sugars and processed starch. They can provide rapid energy, but they do not leave a person feeling full. They can also cause a spike in blood sugar levels. Frequent sugar spikes increase the risk of diabetes and its complications.

Fiber is also a carbohydrate. The body breaks down some fiber types and uses them for energy; others are metabolized by gut bacteria, while other types pass through the body.

Fiber and unprocessed starch are complex carbs. It takes the body some time to break down and absorb complex carbs. After eating fiber, a person will feel full for longer. Fiber may also reduce the risk of diabetes, cardiovascular disease, and colorectal cancer. Complex carbs are a more healthful choice than sugars and refined carbs.

(ii) Proteins

Proteins consist of amino acids, which are organic compounds that occur naturally.

There are 20 amino acids. Some of these are essential, which means people need to obtain them from food. The body can make others.

Some foods provide complete protein, which means they contain all the essential amino acids the body needs. Other foods contain various combinations of amino acids.

Most plant-based foods do not contain complete protein, so a person who follows a vegan diet needs to eat various foods throughout the day that provide the essential amino acids.

(iii) Fats

Fats are essential for:

  • lubricating joints
  • helping organs produce hormones
  • enabling the body to absorb certain vitamins
  • reducing inflammation
  • preserving brain health

Too much fat can lead to obesity, high cholesterol, liver disease, and other health problems.

However, the type of fat a person eats makes a difference. Unsaturated fats, such as olive oil, are more healthful than saturated fats, which tend to come from animals.

(iv) Water

The adult human body is up to 60% water, and it needs water for many processes. Water contains no calories, and it does not provide energy.

Many people recommend consuming 2 liters, or 8 glasses, of water a day, but it can also come from dietary sources, such as fruit and vegetables. Adequate hydration will result in pale yellow urine.

Requirements will also depend on an individual’s body size and age, environmental factors, activity levels, health status, and so on.

2. Micronutrients

Micronutrients are essential in small amounts. Manufacturers sometimes add these to foods. They include vitamins and minerals.

(i) Minerals

The body needs carbon, hydrogen, oxygen, and nitrogen. It also needs dietary minerals, such as iron, potassium, and so on.

In most cases, a varied and balanced diet will provide the minerals a person needs. If a deficiency occurs, a doctor may recommend supplements. Here are some of the minerals the body needs to function well.

  • Potassium
    Potassium is an electrolyte. It enables the kidneys, the heart, the muscles, and the nerves to work properly. The 2015-2020 Dietary Guidelines for Americans recommend that adults consume 4700 mg of potassium each day.
    Less potassium can lead to high blood pressure, kidney stones, and stroke. And too much potassium may be harmful to people with kidney disease.
    Avocados, coconut water, bananas, dried fruit, squash, beans, and lentils are good potassium sources.
  • Sodium
    Sodium is an electrolyte that maintains nerve and muscle function and regulates fluid levels in the body.
    Less level of sodium in the body can lead to hyponatremia. Symptoms include lethargy, confusion, and fatigue. And too much can lead to high blood pressure, which increases cardiovascular disease and stroke risk.
    Table salt, which is made up of sodium and chloride, is a popular condiment. However, most people consume too much sodium, as it already occurs naturally in most foods.
    Experts urge people not to add table salt to their diet. Current guidelines recommend consuming no more than 2,300 mg of sodium a day, or around one teaspoon.
    This recommendation includes both naturally-occurring sources, as well as salt a person adds to their food. People with high blood pressure or kidney disease should eat less.
  • Calcium
    The body needs calcium to form bones and teeth. It also supports the nervous system, cardiovascular health, and other functions.
    Less calcium can cause bones and teeth to weaken. Severe deficiency symptoms include tingling in the fingers and changes in heart rhythm, which can be life-threatening. And too much can lead to constipation, kidney stones, and reduced absorption of other minerals.
    Current guidelines for adults recommend consuming 1,000 mg a day and 1,200 mg for women aged 51 and over.
    Good sources include dairy products, tofu, legumes, and green, leafy vegetables.
  • Phosphorus
    Phosphorus is present in all body cells and contributes to the health of the bones and teeth.
    Less phosphorus can lead to bone diseases, affect appetite, muscle strength, and coordination. It can also result in anemia, a higher risk of infection, burning or prickling sensations in the skin, and confusion. And too much in the diet is unlikely to cause health problems though toxicity is possible from supplements, medications, and phosphorus metabolism problems.
    Adults should aim to consume around 700 mg of phosphorus each day. Good sources include dairy products, salmon, lentils, and cashews.
  • Zinc
    Zinc plays a role in the health of body cells, the immune system, wound healing, and proteins’ creation.
    Less zinc level in the body can lead to hair loss, skin sores, taste or smell changes, and diarrhea, but this is rare. And too much can lead to digestive problems and headaches.
    Adult females need 8 mg of zinc a day, and adult males need 11 mg. Dietary sources include oysters, beef, fortified breakfast cereals, and baked beans.
  • Iron
    Iron is crucial for forming red blood cells, which carry oxygen to all parts of the body. It also plays a role in forming connective tissue and creating hormones.
    Less iron can result in anemia, including digestive issues, weakness, and difficulty thinking. And too much can lead to digestive problems, and very high levels can be fatal.
    Good sources include fortified cereals, beef liver, lentils, spinach, and tofu. Adults need 8 mg of iron a day, but females need 18 mg during their reproductive years.
  • Manganese
    The body uses manganese to produce energy. It plays a role in blood clotting, supporting the immune system.
    Less level of manganese can result in weak bones in children, skin rashes in men, and mood changes in women. And too much can lead to tremors, muscle spasms, and other symptoms, but only with very high amounts.
    Mussels, hazelnuts, brown rice, chickpeas, and spinach all provide manganese. Male adults need 2.3 mg of manganese each day, and females need 1.8 mg.
  • Magnesium
    Magnesium contributes to muscle and nerve function. It helps regulate blood pressure and blood sugar levels, enabling the body to produce proteins, bone, and DNA.
    Less magnesium can eventually lead to weakness, nausea, tiredness, restless legs, sleep conditions, and other symptoms. And too much can result in digestive and, eventually, heart problems.
    Nuts, spinach, and beans are good sources of magnesium. Adult females need 320 mg of magnesium each day, and adult males need 420 mg.
  • Copper
    Copper helps the body makes energy and produces connective tissues and blood vessels.
    Less copper can lead to tiredness, patches of light skin, high cholesterol, and connective tissue disorders.
    Too much copper can result in liver damage, abdominal pain, nausea, and diarrhea. Too much copper also reduces the absorption of zinc.
    Good sources include beef liver, oysters, potatoes, mushrooms, sesame seeds, and sunflower seeds. Adults need 900 micrograms of copper each day.
  • Selenium
    Selenium is made up of over 24 selenoproteins, and it plays a crucial role in reproductive and thyroid health. As an antioxidant, it can also prevent cell damage.
    Too much selenium can cause garlic breath, diarrhea, irritability, skin rashes, brittle hair or nails, and other symptoms. And too little can result in heart disease, infertility in men, and arthritis. Adults need 55 mcg of selenium a day.
    Brazil nuts are an excellent source of selenium. Other plant sources include spinach, oatmeal, and baked beans. Tuna, ham, and enriched macaroni are all excellent sources.

(ii) Vitamins

People need small amounts of various vitamins. Some of these, such as vitamin C, are also antioxidants. This means they help protect cells from damage by removing toxic molecules, known as free radicals, from the body. Vitamins can be:

  • Water-soluble: People need to regularly consume water-soluble vitamins because the body removes them more quickly, and it cannot store them easily. The eight B vitamins and vitamin C are water-soluble.
  • Fat-soluble: The body absorbs fat-soluble vitamins through the intestines with the help of fats (lipids). The body can store them and does not remove them quickly.
    People who follow a low-fat diet may not be able to absorb enough of these vitamins. If too many build up, problems can arise. Vitamins A, D, E, and K are fat-soluble vitamins.


Some nutrients also act as antioxidants. These may be vitamins, minerals, proteins, or other types of molecules.

They help the body remove toxic substances known as free radicals or reactive oxygen species. If too many of these substances remain in the body, cell damage and disease can result.

Nutrition Diets

Nutrition is the study of food and how it affects the body. People need to consume a varied diet to obtain a wide range of nutrients.

Some people choose to follow a specific diet, in which they focus on certain foods and avoid others. People who do this may need to plan carefully to ensure they obtain all the necessary vitamins to maintain their health.

A diet rich in plant-based foods limits added animal fats, processed foods, and added sugar and salt is most likely to benefit a person’s health. Below are the different diets, such as:

  • Keto diet: A keto diet is an eating plan that focuses on foods that provide many healthful fats, adequate amounts of protein, and very few carbohydrates. The goal is to get more calories from fat than from carbs.
  • Paleo diet: The paleo diet is an eating plan that mimics how prehistoric humans may have eaten. It involves eating whole foods that people could theoretically hunt or gather.
  • Raw food diet: A raw food diet involves eating mainly unprocessed whole, plant-based, and preferably organic foods. Some sources say that when following this diet, raw food should make up three-quarters of the diet.
  • Vegan diet: A vegan or plant-based diet excludes all animal products, including meat, dairy, and eggs. When people follow it correctly, a vegan diet can be highly nutritious, reduce the risk of chronic diseases, and aid weight loss.
  • Plant-based diet: A plant-based diet is one that focuses on only or most foods from plant sources. This way of eating may have benefits for both a person’s health and the planet.

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