Fundamentals of Human Nutrition/Defining Nutrition

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1.1 Defining Nutrition[edit]

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1.1.1 You Are What You Eat[edit]

Our bodies contain similar nutrients to the food we eat. Therefore, depending on what kind of food we are consuming and the contents of that food, we are affecting our nutrient levels and over all, our health. On average, the human body is 6% minerals, carbohydrates, and other nutrients, 16% fat, 16% protein, and 62% water. Of course these percentages vary for every individual person depending on diet and lifestyle. Our bodies contain similar nutrients to the food we eat. Therefore, depending on what kind of food we are consuming and the contents of that food, we are affecting our nutrient levels and over all, our health. As mentioned above, it is important to eat a wide variety of foods from the five food groups to ensure that you are consuming all the different nutrients that your body needs. Eating one type of food may supply you with excess of a particular nutrient, but your body will be lacking other vital nutrients only obtainable from different foods. The saying, "You are what You Eat," isn't literally true because if you eat a hamburger, that doesn't make you a cow, however, your nutrient levels will equilibrate with that of the hamburger, or cow, that you are eating. Therefore, always make sure that you are putting healthy foods in your body because it doesn't just come in one end and go out the other. The foods you eat alter the nutrients in your body, making it very important to eat foods that will have a positive and beneficial impact on your body and your health. Almost everything is ok, in proportion. If you eat some ice cream or some candy every once in a while, it will not have a significantly detrimental impact on your health. However, if you eat large quantities of high-sugar foods, such as candy, you can continuously tax your system and eventually cause problems that can effect your health forever, such as Type 2 Diabetes. [1] It is important to make a habit of healthy eating. The more often you eat healthy, the easier it will be and the more you will start to enjoy healthy food over un-healthy food. It can be difficult sometimes to choose an apple over a candy bar and you don't always have to, but in the long run, your body will thank you for eating healthy. We often don't think about the nutritional content of our food, but do some research and find out what you're really putting in your body when you eat certain foods. Awareness of the contents of our consumption is the first step in moving towards a healthier diet and therefore, a healthier body.

1.1.2 Malnutrition[edit]

Definition[edit]

According to Marriam-Webster dictionary, malnutrition is defined as "lack of proper nutrition, caused by not having enough to eat, not eating enough of the right things, or being unable to use the food that one does eat". At first thought, it is easy to think of malnutrition as only not having enough food however as the definition so evidently points out, it also incorporates not eating enough of the right things for your body or if your body is unable to use the food you are ingesting for what it needs. It is extremely important to eat a well balanced diet in order to stay in healthy standing as well as giving your body the nutrients it needs to sustain your active life.

Causes, Incidence, and Risk Factors[edit]

There are a number of causes of malnutrition. It may result from an inadequate or unbalanced diet, problems with digestion or absorption, certain medical conditions. Malnutrition can occur if you do not eat enough food. Starvation is a form of malnutrition. You may develop malnutrition if you lack of a single vitamin in the diet. In some cases, malnutrition is very mild and causes no symptoms. However, sometimes it can be so severe that the damage done to the body is permanent, even though you survive. Malnutrition continues to be a significant problem all over the world, especially among children. Poverty, natural disasters, political problems, and war all contribute to conditions -- even epidemics -- of malnutrition and starvation, and not just in developing countries. A study conducted by Action Against Hunger-USA (ACF-USA) among children under five in the Nuer community of Old Fangak, central Upper Nile, found that most of the malnourished children had been sick over an extended period, suffering from diarrhea, respiratory infections and fever, or a combination of several illnesses. Disease and inadequate food intake seemed to have particularly affected children under five years old, the report stated.

1.1.3 Macronutrient basics[edit]

As the name macro suggests carbohydrate, protein, lipids and water make up the bulk of the diet and signify the items the body requires to be consumed in large quantities. In addition, carbohydrate, protein and lipids are the body's main source of energy, with carbohydrate and protein providing 4 kcals/g (16.8 kJ/g) and lipids providing 9 kcals/g (37.8 kJ/g).[2]

Carbohydrates[edit]

The body cells main source of energy, providing 35-70 of the dietary intake, which is acquired through the consumption of sugars and starches[3], which increase the body’s blood glucose levels[4]. The energy supplied by carbohydrate is of particular importance to the brain as the body's only carbohydrate-dependent organ.[5] This category also includes dietary fiber, which are either soluble or insoluble and offer several health benefits. Carbohydrates are divided into two categories simple, which includes items made up of 1 or 2 sugars which increase the blood glucose level quickly and complex, which includes from 3 to >10 sugars and increase the bloods glucose levels more slowly . Typical sources are wheat, rice, potatoes, fruit, sugar beet and whole grains. Carbohydrates are an essential part of the diet and should not be restricted, choosing the complex variety is the healthiest option.[6]

Carbohydrate Associated Disease[edit]

Excessive consumption of refined sugar and simple carbohydrates can contribute to obesity and the onset of type 2 diabetes[7]. Diabetes is dysfunction of the body’s ability to metabolize glucose due to insufficient levels or ineffective use of insulin.[8] Simple carbohydrates in food and drinks are also associated with increased risk of dental caries, (Mobley, Marshall, Milgrom, & Coldwell, 2010). Good start, what might excess sugar intake mean for other macronutrient and micro-nutrient intake?

Protein[edit]

Protein should make up 10-23% of the bodies intake for energy.[9] In addition to providing energy protein also assists with the regeneration and growth of cells, acquired by the consumption of 9 essential amino acids and 11 non-essential amino acids, which are synthesized in the body [10]. Typical sources of essential amino acids are meat, fish, eggs, dairy products and soya, which constitute complete proteins or combinations such as rice and lentils and peanut butter sandwiches.

Protein Associated Diseases[edit]

Protein-energy malnutrition (PEM) is a group of protein deficiency disorders[11], including marasmus, kwashiorkor and a combination condition marasmus-kwashiorkor. Marasmus is a wasting disease characterized by emaciation and is an adaptive response to starvation. Kwashiorkor in contrast, is characterized by a swollen belly, but is also a wasting disease and a mal-adaptive response to starvation.

Lipids[edit]

The lipid macronutrient group is made up of fatty acids, triglycerides, phospholipids, and sterols. Lipids should make up 20-45% of the bodies energy intake[12]. In addition to providing energy lipids also assist the body with the absorption of fat-soluble vitamins.

Fatty Acids
Fatty acids are divided into three categories saturated, which is not essential to the body and monounsaturated and polyunsaturated. There are 2 essential fatty acids that the body can’t produce linoleic acid (omega 6) and linolenic acid (omega 3)[13]. Excellent sources of essential fatty acids are fish and flax seed and canola oil.

Triglycerides

Phospholipids

Sterols
Cholesterol is the most common sterol typical sources are eggs and cheese.

Digestion and Absorption of Lipids

Lipid Associated Diseases[edit]

Hypercholesterolemia
Excessive cholesterol in the blood can lead to coronary heart disease and disease of the arteries. Of major concern is when blood levels are high in LDL cholesterol and trigylcerides, and low levels of HDL cholesterol[14].
Heart Attack

Micronutrient Basics[edit]

Micronutrients are commonly known as vitamins and minerals. They are called micronutrients because the body only requires a very small quantity of vitamins and minerals to assist the body in its normal functions. These nutrients are essential to our bodies, however our bodies are unable to produce micronutrients and they must be sourced from our diets. To gain the essential nutrients we need it is important to eat a well balanced diet that includes a range of colorful fruit and vegetables, nuts and whole grains. That way we gain such vitamins as Vitamins C to aid the immune system, Vitamin E to help fight free radical damage, or minerals such as Iron for red cell production and Calcium for strong healthy bones.

The World Health Organisation calls micronutrients "the 'magic wands' that enable the body to product enzymes, hormones and other substances essential for proper growth and development". The International Atomic Energy Agency (IAEA)[15] has a program called 'Improving Nutrition through Nuclear Sciences', IAEA understands the essential role micronutrients play in our bodies and states "when micronutrients are not sufficient from food in the diet, significant health problems can result" and a significant amount of research has gone into understanding the physiological role and the health consequences of micronutrient deficiencies. Joint experts, the World Health Organisation and the Food and Agricultural Organisation of the United Nations conducted research in 1998 to establish clear parameters of defining micronutrients deficiencies for public health, as well as to develop preventative action and control strategies.[16]

Vitamins[edit]

There are a total of thirteen essential organic vitamins in the body which include Vitamin A,C,D,E,K,B1,B2,B3,B6,B12,pantothenic acid,biotin, and folic acid. These are used on a daily basis for tasks around your body you wouldn't even think of. Certain vitamins are used to see in dim light or make sex hormones and without them, we wouldn't function properly. Vitamins are unique in the fact that they denature by heat, light, and chemical agents. They need to be intact in order for them to work properly.

Fat Soluble Vitamins

The fat-soluble vitamins which mean they are soluble in lipids, include A,D,E, and K. They are dissolved in fat before they are absorbed into the bloodstream where they reach the rest of the body and carry out many different functions. Consuming too many of these vitamins can actual increase the toxicity of your body and become dangerous. However these vitamins are essential and contribute to things such as your eye health, antioxidants to cancer, strong bones, blood clotting and lower risk of heart disease.

Water Soluble Vitamins

Water soluble vitamins are more easily dissolved in water compared to fat-soluble, and are constantly needing them to be replenished in our body since they are eliminated via urine. Therefore, we get a lot of these vitamins through our diet. Water-soluble vitamins include vitamin C as well as the vitamin B complex. Something unique to water-soluble vitamins is the actual vitamins can be lost or destroyed if food isn't prepared properly. For example, keeping milk and grains in sunlight for an extended period of time can denature water-soluble vitamins.

Bellows, L., & Moore, R. (n.d.). Fat-Soluble Vitamins: A, D, E, and K. Retrieved June 5, 2015, from http://www.ext.colostate.edu/pubs/foodnut/09315.html


Vitamins: MedlinePlus Medical Encyclopedia. (2013, February 18). Retrieved June 5, 2015, from http://www.nlm.nih.gov/medlineplus/ency/article/002399.htm

Minerals[edit]

Minerals are inorganic materials that are essential for different functions and growth in your body however they do not give energy. Although there are 16 essential minerals found in the human body, research is constantly trying to prove more exist and are essential. Minerals are contribute to the to things such as bone and teeth production, energy, immune health, nerve and muscle function and more. Unlike vitamins, minerals are inorganic so they are technically indestructible and do not need to be handled with such care as vitamins do however some minerals can bind to certain substances that make it difficult for the body to absorb them. The two types of minerals, major and trace, are described below.

Major Minerals

The major minerals include calcium, magnesium, phosphorus, potassium, chloride and sulfur. These are called "major" minerals not because they are more important than trace minerals but because they are needed in larger amounts than the trace minerals. Major minerals contribute to processes such as proper fluid balance, healthy bones and teeth, nerve and muscle communication, and more.

Trace Minerals

Trace minerals include iron, copper, zinc, manganese, fluoride, selenium, and cobalt. As mentioned earlier, these minerals are not less important than the major minerals but simply need a lesser amount. Trace minerals contribute to things such as red blood cell function, thyroid hormone production, part of enzymes, regulates blood glucose, and many more.


Minerals: MedlinePlus. (n.d.). Retrieved June 5, 2015, from http://www.nlm.nih.gov/medlineplus/minerals.html


Minerals: Their Functions and Sources: Healthwise Medical Information on eMedicineHealth. (n.d.). Retrieved June 5, 2015, from http://www.emedicinehealth.com/minerals_their_functions_and_sources-health/article_em.htm

References[edit]

  1. Whitehead, Ross D., Daniel Re, Dengke Xiao, Gozde Ozakinci, and David I. Perrett. (2012) You Are What You Eat: Within-Subject Increases in Fruit and Vegetable Consumption Confer Beneficial Skin-Color Changes. Retrieved From http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0032988
  2. Wilson, M.G. (2007). Overview of Nutrition. Retrieved from The Merck Manual: http://www.merckmanuals.com/professional/nutritional_disorders/nutrition_general_considerations/overview_of_nutrition.html?qt=&sc=&alt=
  3. USDA. Chapter 11 Macronutrients and Healthful Diets. Retrieved from Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients): http://www.nal.usda.gov/fnic/DRI//DRI_Energy/769-879.pdf
  4. Wilson, M.G. (2007). Overview of Nutrition. Retrieved from The Merck Manual: http://www.merckmanuals.com/professional/nutritional_disorders/nutrition_general_considerations/overview_of_nutrition.html?qt=&sc=&alt=
  5. USDA. (2005) Chapter 6 Dietary Carbohydrates: Sugars and Starches. Retrieved from Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients): http://www.nal.usda.gov/fnic/DRI//DRI_Energy/265-338.pdf
  6. Harvard School of Public Health. (2013). Carbohydrates the bottom line. Retrieved from Harvard School of Public Health: http://www.hsph.harvard.edu/nutritionsource/carbohydrates/?__utma=1.1548129997.1347972122.1347972122.1347981737.2&__utmb=1.1.10.1347981737&__utmc=1&__utmx=-&__utmz=1.1347981737.2.2.utmcsr%3Dhsph.harvard.edu%7Cutmccn%3D%28referral%29%7Cutmcmd%3Dreferral%7C
  7. Vorvick, L. J. (2012). Carbohydrates. Retrieved from Medline Plus: http://www.nlm.nih.gov/medlineplus/ency/article/002469.htm
  8. Diabetes UK. (2013). Type 2 diabetes. Retrieved from Diabetes UK: http://www.diabetes.org.uk/Guide-to-diabetes/Type-2-diabetes/
  9. USDA. (2005) Chapter 10 Protein and Amino Acids. Retrieved from Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients): http://www.nal.usda.gov/fnic/DRI//DRI_Energy/589-768.pdf
  10. Wilson, M.G. (2007). Overview of Nutrition. Retrieved from The Merck Manual: http://www.merckmanuals.com/professional/nutritional_disorders/nutrition_general_considerations/overview_of_nutrition.html?qt=&sc=&alt=
  11. Scheinfeld, N. S. (2013). Protein-Energy Malnutrition. Retrieved from Medscape: http://emedicine.medscape.com/article/1104623-overview
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  13. Wilson, M.G. (2007). Overview of Nutrition. Retrieved from The Merck Manual: http://www.merckmanuals.com/professional/nutritional_disorders/nutrition_general_considerations/overview_of_nutrition.html?qt=&sc=&alt=
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