Nutrition

Nutrition

Nutrition is how food affects the health of the body. Food is essential—it provides vital nutrients for survival, and helps the body function and stay healthy. Food is comprised of macronutrients including protein, carbohydrate and fat that not only offer calories to fuel the body and give it energy but play specific roles in maintaining health. Food also supplies micronutrients (vitamins and minerals) and phytochemicals that don't provide calories but serve a variety of critical functions to ensure the body operates optimally.

Types of Nutrition

To fully understand the phenomenon of nutrition, it’s important to study its types. It’s classified into two main types:

• Autotrophic nutrition
• Heterotrophic nutrition

We all know that plants also feed like humans and animals do. But, it’s important even for a layman to understand the terminology and science behind these various modes of feeding.

Autotrophic nutrition

Autotrophic nutrition is found in autotrophic organisms. These organisms are self-dependent in terms of their food-making process. This process is called photosynthesis. So which creatures do you think are the ones that make their own food? They’re the trees around you or the plants you see every day. Next time you see a tree, just repeat it to yourself that it’s autotrophic because it makes its own food.

Adding to your knowledge, photosynthesis is a process in which plants manufacture their food, food which is not what we eat. Plants munch on sunlight and water. They consume water, carbon dioxide from the atmosphere and sunlight energy to manufacture the sugar and starch, which is the nutrition of plants.

Heterotrophic nutrition

On the other hand, heterotrophic nutrition is found in heterotrophic organisms. These organisms rely on other organisms for their food. Now the organisms on your mind are most likely humans and animals. That’s true but to understand the different ways in which the various heterotrophic organisms derive their nutrition, let’s discuss them one by one:

1. Herbivores- These are the animals who are just like your vegetarian friends who always eat greens and refrain from eating meat. They’re plant lovers!
2. Carnivores- These are the animals that devour other animals. They’re wild and dangerous so just run away when you see them around yourself. They might eat human flesh too if they’re very hungry.
3. Omnivores- These are the organisms who… let’s cut it short. It’s you! Yes you’re an omnivore. You’re called one because you can eat both plants and animals. Even if you don’t eat animals because you’re too kind and emotional, you still are an omnivore because you’ve only chosen to become a vegetarian; however, you’re naturally born with the tendency to eat both animals and plants.
4. Cannibals- Well, this wasn’t the part of the list, but since it’s happening in the world then why not talk about it too? Cannibals are humans who eat other humans. Gross! Right? But it’s possible that somewhere someone drooled while reading this- no pun intended. But I think cannibals don’t need to be added as a new category of heterotrophic creatures. Rather, they’re more like what you call “evolved omnivores” who perhaps have crossed the limits of humanity.

Key Facts and Statistics of Nutrition:

• Our human body mainly needs 7 kinds of nutrients: carbohydrates, protein, fats, minerals, vitamins, fiber, and water.
• Carbohydrates, fat, and, protein are macronutrients needed in larger amounts.
• Minerals and vitamins are micronutrients needed in small amounts.
• All of the nutrients don’t provide energy, but they are still important e.g. fiber and water.
• Protein forms about 16% of an average person’s body weight.
• Water constitutes around 62% of an average person’s body weight.

Why Nutrition Matters?

Nutrition is the study of nutrients in food, how the body uses them, and the relationship between diet, health, and disease.

Nutritionists use ideas from molecular biology, biochemistry, and genetics to understand how nutrients affect the human body.

Nutrition also focuses on how people can use dietary choices to reduce the risk of disease, what happens if a person has too much or too little of a nutrient, and how allergies work.

Nutrients provide nourishment. Proteins, carbohydrates, fat, vitamins, minerals, fiber, and water are all nutrients. If people do not have the right balance of nutrients in their diet, their risk of developing certain health conditions increases.

This article will explain the different nutrients a person needs and why. It will also look at the role of the dietitian and the nutritionist.

Macronutrients

Macronutrients are nutrients that people need in relatively large quantities.

Carbohydrates

Sugar, starch, and fiber are types of carbohydrates.

Sugars are simple carbs. 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 type 2 diabetes and its complications.

Fiber is also a carbohydrate. The body breaks down some types of fiber and uses them for energ; 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.

Learn more here about fiber.

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 the 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 a range of foods throughout the day that provides the essential amino acids.

Learn more here about protein.

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.

In this article, learn more about the different types of fats and where to find them.

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.

Click here to find out how much water a person needs each day and here to learn about the benefits of drinking water.

Micronutrients

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

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 4,700 milligrams (mg) of potassium each day.

Too little can lead to high blood pressure, stroke, and kidney stones.

Too much may be harmful to people with kidney disease.

Avocados, coconut water, bananas, dried fruit, squash, beans, and lentils are good sources.

Learn more here about potassium.

Sodium

Sodium is an electrolyte that helps:

• maintain nerve and muscle function
• regulate fluid levels in the body

Too little can lead to hyponatremia. Symptoms include lethargy, confusion, and fatigue. Learn more here.

Too much can lead to high blood pressure, which increases the risk of cardiovascular disease and stroke.

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.

How much salt does a person need? Find out here.

Calcium

The body needs calcium to form bones and teeth. It also supports the nervous system, cardiovascular health, and other functions.

Too little can cause bones and teeth to weaken. Symptoms of a severe deficiency include tingling in the fingers and changes in heart rhythm, which can be life-threatening.

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.

Find out more about calcium.

Phosphorus

Phosphorus is present in all body cells and contributes to the health of the bones and teeth.

Too little 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.

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.

Why do people need phosphorus? Find out here.

Magnesium

Magnesium contributes to muscle and nerve function. It helps regulate blood pressure and blood sugar levels, and it enables the body to produce proteins, bone, and DNA.

Too little magnesium can eventually lead to weakness, nausea, tiredness, restless legs, sleep conditions, and other symptoms.

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.

Why is magnesium essential? Click here to learn more.

Zinc

Zinc plays a role in the health of body cells, the immune system, wound healing, and the creation of proteins.

Too little can lead to hair loss, skin sores, changes in taste or smell,and diarrhea, but this is rare.

Too much can lead to digestive problems and headaches. Click here to learn more.

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. For more on dietary sources of zinc, click here.

How does zinc benefit a person’s health? Click here to find out.

Iron

Iron is crucial for the formation of red blood cells, which carry oxygen to all parts of the body. It also plays a role in forming connective tissue and creating hormones.

Too little can result in anemia, including digestive issues, weakness, and difficulty thinking. Learn more here about iron deficiency.

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.

Why is iron important? Find out here.

Manganese

The body uses manganese to produce energy, it plays a role in blood clotting, and it supports the immune system.

Too little can result in weak bones in children, skin rashes in men, and mood changes in women.

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.

Find out more here about manganese.

Copper

Copper helps the body make energy and produce connective tissues and blood vessels.

Too little copper can lead to tiredness, patches of light skin, high cholesterol, and connective tissue disorders. This is rare.

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 (mcg) of copper each day.

Why is copper important? Click here to find out.

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.

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.

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: The eight B vitamins and vitamin C

Fat-soluble: Vitamins A, D, E, and K

Learn more about vitamins here.

Water soluble vitamins

People need to consume water-soluble vitamins regularly because the body removes them more quickly, and it cannot store them easily.

Vitamin	Effect of too little	Effect of too much	Sources
B-1 (thiamin)	Beriberi Wernicke-Korsakoff syndrome	Unclear, as the body excretes it in the urine.	Fortified cereals and rice, pork, trout, black beans
B-2 (riboflavin)	Hormonal problems, skin disorders, swelling in the mouth and throat	Unclear, as the body excretes it in the urine.	Beef liver, breakfast cereal, oats, yogurt, mushrooms, almonds
B-3 (niacin)	Pellagra, including skin changes, red tongue, digestive and neurological symptoms	Facial flushing, burning, itching, headaches, rashes, and dizziness	Beef liver, chicken breast, brown rice, fortified cereals, peanuts.
B-5 (pantothenic acid)	Numbness and burning in hands and feet, fatigue, stomach pain	Digestive problems at high doses.	Breakfast cereal, beef liver, shiitake mushroom, sunflower seeds
B-6 (pyridoxamine, pyridoxal)	Anemia, itchy rash, skin changes, swollen tongue	Nerve damage, loss of muscle control	Chickpeas, beef liver, tuna, chicken breast, fortified cereals, potatoes
B-7 (biotin)	Hair loss, rashes around the eyes and other body openings, conjunctivitis	Unclear	Beef liver, egg, salmon, sunflower seeds, sweet potato
B-9 (folic acid, folate)	Weakness, fatigue, difficulty focusing, heart palpitations, shortness of breath	May increase cancer risk	Beef liver, spinach, black-eyed peas, fortified cereal, asparagus
B-12 (cobalamins)	Anemia, fatigue, constipation, weight loss, neurological changes	No adverse effects reported	Clams, beef liver, fortified yeasts, plant milks, and breakfast cereals, some oily fish.
Vitamin C (ascorbic acid)	Scurvy, including fatigue, skin rash, gum inflammation, poor wound healing	Nausea, diarrhea, stomach cramps	Citrus fruits, berries, red and green peppers, kiwi fruit, broccoli, baked potatoes, fortified juices.

Fat-soluble vitamins

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.

Vitamin	Effect of too little	Effect of too much	Sources
Vitamin A (retinoids)	Night blindness	Pressure on the brain, nausea, dizziness, skin irritation, joint and bone pain, orange pigmented skin color	Sweet potato, beef liver, spinach, and other dark leafy greens, carrots, winter squash
Vitamin D	Poor bone formation and weak bones	Anorexia, weight loss, changes in heart rhythm, damage to cardiovascular system and kidneys	Sunlight exposure plus dietary sources: cod liver oil, oily fish, dairy products, fortified juices
Vitamin E	Peripheral neuropathy, retinopathy, reduced immune response	May reduce the ability of blood to clot	Wheatgerm, nuts, seeds, sunflower and safflower oil, spinach
Vitamin K	Bleeding and hemorrhaging in severe cases	No adverse effects but it may interact with blood thinners and other drugs	Leafy, green vegetables, soybeans, edamame, okra, natto

Multivitamins are available for purchase in stores or online, but people should speak to their doctor before taking any supplements, to check that they are suitable for them to use.

Antioxidants

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.

Find out more here about antioxidants.

Here, learn which foods are good sources of antioxidants.

Dietitian vs. nutritionist

A registered dietitian nutritionist (RD or RDN) studies food, nutrition, and dietetics. To become a registered dietitian, a person needs to attend an accredited university, follow an approved curriculum, complete a rigorous internship, pass a licensure exam, and complete 75 or more continuing education hours every 5 years. Dietitians work in private and public healthcare, education, corporate wellness, research, and the food industry.

A nutritionist learns about nutrition through self-study or formal education, but they do not meet the requirements to use the titles RD or RDN. Nutritionists often work in the food industry and in food science and technology.

Nutritional Facts

There is a lot of controversy in nutrition and it often seems like people can't agree on anything.

But there are a few exceptions to this.

Here are the top 10 nutrition facts that everyone actually agrees on (well, almost everyone...) 

1. Added Sugar Is a Disaster

To improve the taste of processed foods, producers often add sugar to them. This type of sugar is known as added sugar.

Common types of added sugar include table sugar (sucrose) and syrups, such as high-fructose corn syrup.

Everyone knows that eating too much added sugar is unhealthy.

While some think sugar is a simple matter of "empty" calories, others believe it increases the risk of diseases that kill millions of people each year.

It is definitely true that added sugar contains empty calories. There are no nutrients in it, other than sugar. As a result, basing your diet on products high in added sugar may contribute to nutrient deficiencies.

But this is just the tip of the iceberg. There are many other risks associated with excessive sugar intake that are now reaching mainstream attention.

Added sugar is being implicated as a leading cause of obesity, heart disease and type 2 diabetes

The high fructose content of added sugar is often blamed.

This is because fructose is metabolized strictly by the liver. High intake has been linked with non-alcoholic fatty liver disease, insulin resistance, elevated triglycerides, abdominal obesity and high cholesterol over time (2Trusted Source, 3Trusted Source, 4Trusted Source, 5).

However, the role of fructose in disease is controversial and scientists do not fully understand how it works 

2. Omega-3 Fats Are Crucial and Most People Don't Get Enough

Omega-3 fatty acids are extremely important for the proper functioning of the human body.

For example, docosahexaenoic acid (DHA), an omega-3 fatty acid derived from animals, makes up about 10–20% of the total fat content in the brain (7Trusted Source).

A low intake of omega-3 is associated with a lower IQ, depression, various mental disorders, heart disease and many other serious diseases (8Trusted Source).

There are three main types of omega-3 fats: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

ALA comes mostly from plant oils, while the best sources of EPA and DHA are fatty fish, fish oils and certain algal oils. Other good sources of EPA and DHA are grass-fed meat and omega-3 enriched or pastured eggs.

The plant form, ALA, needs to be transformed into DHA or EPA to function correctly in the human body. However, this conversion process is inefficient in humans (9Trusted Source).

Therefore, it is best to eat plenty of foods high in DHA and EPA.

3. There Is No Perfect Diet for Everyone

People are all unique. Subtle differences in genetics, body type, physical activity and environment can affect which type of diet you should follow.

Some people do best on a low-carb diet, while others are better off on a vegetarian high-carb diet.

The fact is, what works for one person may not work for the next.

To figure out what you should do, a little experimentation may be needed.

Try a few different things until you find something that you enjoy and think you can stick to. Different strokes for different folks!

4. Artificial Trans Fats Are Very Unhealthy

Trans fats are formed as a side product when vegetable oils are hydrogenated.

Food producers often use hydrogenation to harden vegetable oils for use in products such as margarine.

Because trans fats have been linked with poor health, margarine free of trans fats is becoming increasingly common.

A high intake of trans fats is associated with various chronic diseases, such as abdominal obesity, inflammation and heart disease, to a name a few

5. Eating Vegetables Will Improve Your Health

Vegetables are good for you.

They are rich in vitamins, minerals, fiber, antioxidants and an endless variety of trace nutrients that science has just begun to uncover.

In observational studies, eating vegetables is associated with improved health and a lower risk of disease (13Trusted Source, 14, 15Trusted Source).

I recommend that you eat a variety of vegetables each day. They are healthy, fulfilling and add variety to your diet.

6. It Is Critical to Avoid a Vitamin D Deficiency

Vitamin D is a unique vitamin that actually functions as a hormone in the body.

The skin makes vitamin D when it is exposed to ultraviolet rays from the sun. This is how people got most of their daily requirement throughout evolution.

However, a large part of the world is deficient in this critical nutrient today.

In many places, the sun simply isn't available throughout most of the year.

Even where there is sun, many people tend to stay inside and use sunscreen when they go out. Sunscreen effectively blocks vitamin D generation in the skin.

If you're deficient in vitamin D, then you're actually lacking a major hormone in the body. Deficiency is associated with many serious diseases, including diabetes, cancer, osteoporosis and others (16Trusted Source, 17Trusted Source, 18Trusted Source).

To find out if you are at risk, see a doctor and have your blood levels measured.

Unfortunately, it may be difficult to get enough vitamin D from the diet.

If getting more sun is not an option, taking a vitamin D supplement or a tablespoon of cod liver oil each day is the best way to prevent or reverse a deficiency.

7. Refined Carbohydrates Are Bad for You

There are a lot of differing opinions about carbs and fat.

Some think fat is the root of all evil, while others believe carbs are the key players in obesity and other chronic diseases.

But what pretty much everyone agrees on is that refined carbohydrates are not as healthy as unrefined carbohydrates.

Unrefined carbs are basically whole foods that are rich in carbs. These include whole-grain cereals, beans, vegetables and fruits. Refined carbs, on the other hand, are sugar and refined flour.

Whole foods contain numerous beneficial nutrients and antioxidants.

However, when high-carb foods such as grains are processed, the most nutritious parts are stripped off. What is left are massive amounts of easily digestible starch.

Those who base their diets on refined carbs may be lacking in fiber and many other healthy nutrients. As a result, they are at an increased risk of chronic disease (19Trusted Source).

Eating refined carbs will also cause rapid spikes in blood sugar. While high blood sugar levels are unhealthy for all people, they are a much greater concern in people with diabetes (20Trusted Source).

It is clear that whole grains and unrefined carbohydrates are a lot healthier than their refined, processed counterparts.

8. Supplements Can Never Fully Replace Real Foods

"Nutritionism" is the idea that foods are nothing more than the sum of their individual nutrients.

But it’s also a trap that many nutrition enthusiasts tend to fall into.

Nuts, for example, aren't just shells loaded with polyunsaturated fat. In the same way, fruits aren't just watery bags of sugar.

These are real foods with a massive variety of trace nutrients.

The vitamins and minerals, the ones you can also get from a cheap multivitamin, are just a small part of the total amount of nutrients in foods.

Therefore, supplements cannot match the variety of nutrients you get from real foods.

However, many supplements can be beneficial, especially those that contain nutrients that are generally lacking in the diet, like vitamin D.

But no amount of supplements will ever make up for a bad diet. Not a chance.

9. "Diets" Don't Work — a Lifestyle Change Is Necessary

"Diets" are ineffective. That is a fact.

They may provide short-term results, but as soon as the diet ends and you start eating junk food again, you will gain the weight back. And then some.

This is called yo-yo dieting and is extremely common.

Most people who lose a lot of weight on a diet end up gaining it back whenever they "stop" the diet.

For this reason, the only thing that can give you actual long-term results is to adopt a lifestyle change.

10. Unprocessed Food Is Healthiest

Processed food is generally not as healthy as whole food.

As the food system has become more industrialized, the health of the population has deteriorated.

During food processing, many of the beneficial nutrients in the food are removed.

Not only do food producers remove healthy nutrients like fiber, but they also add other potentially harmful ingredients like added sugar and trans fats.

Additionally, processed foods are loaded with all sorts of artificial chemicals, some of which have a questionable safety profile.

Basically, processed foods have less of the good stuff and a lot more of the bad stuff.

The most important thing you can do to ensure optimal health is to eat real food. If it looks like it was made in a factory, don't eat it!