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Frequently Asked Questions

Frequently asked questions on the topic of diet and health
Image with FAQ to represent Frequently Asked Questions
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In this section you will find an answer to frequently asked questions on the topic of Diet and Health.

1. What are macronutrients?

Macronutrients are the nutrients we need in larger quantities for energy and tissue maintenance. They include carbohydrates, fats and proteins. Fibre is also considered a macronutrient, although it is not a true nutrient, because it passes the gastrointestinal tract unabsorbed, and it is directly excreted.

2. What are micronutrients?

Micronutrients are the nutrients we need in very small quantities, mostly vitamins and minerals. They are essential nutrients because the body cannot make them, or cannot make them in sufficient quantity and thus, they must come from the diet.

3. What is the function of protein in the diet?

Protein is in every living cell in the body and it is important for a large number of functions in the body. Muscles, bones, connective tissues, blood cells, glands and organs all contain protein so it is an important nutrient for growth and repair. Protein can also be used as a secondary source of energy when insufficient carbohydrate and fat are available to meet the body’s needs. 1g of protein contains 17kJ / 4 kcal of energy.

4. What are dispensable amino acids?

Protein molecules consist of long chains of amino acids chemically combined. There are 20 amino acids commonly found in proteins of which 12 are dispensable. This means they can be synthesised by the body and there for are not essential in the diet. The remaining 8 amino acids are dispensable (essential). These cannot be synthesised by the body and therefore must be supplied by the diet.

5. What is the Biological Value of Protein?

As a measure of protein quality, the biological value of a protein is used. Biological value is the percentage of absorbed protein which is converted into body protein.

If a protein contains the indispensable (essential) amino acids, those which cannot be synthesised by the body and must be supplied by the diet, in the approximate proportion required by humans, it is said to be of high biological value.

If it is comparatively low in one or more of the essential amino acids, it is said to have a low biological value.

6. What is nutritional diseases?

Diet has a profound impact on human life and plays and important role in our health. Nutritional disease include deficiencies or excesses in the diet, obesity and eating disorders, and also chronic diseases such as cardiovascular disease, hypertension cancer and diabetes mellitus. Nutritional diseases also include hereditary metabolic diseases that respond to dietary treatment, the interaction of foods and nutrients with drugs, food allergies and intolerances, as well as developmental abnormalities that can be prevented by diet.

7. What is saturated fat?

Saturated fat contains only single bonds in the carbon chain of the fatty acids. The chain is “saturated” with hydrogen atoms. Each chain is densely compacted and therefore, saturated fat is typically solid at room temperature. Saturated fat have been shown to elevate LDL (bad) cholesterol) in the blood. Saturated fat is found in animal products, such as the streaks of fat in meat; in some plant sources such as palm oil and coconut oil; and in processed foods such as cookies.

8. What is a food allergy?

A food allergy is an adverse reaction to foods with the involvement of the immune system. The immune system of allergic people incorrectly identifies certain food constituents as harmful.

9. What is a food intolerance?

Food intolerance also triggers an adverse reaction in the body. However, food intolerance reactions do not involve the immune system. Food intolerances are usually related to individual differences in how a person digests, absorbs or metabolizes a food. In general, although they can negatively impact health, symptoms of food intolerance are usually less severe.

10. What is a functional food?

According to the International Life Science Institute, a food can be described as functional when it has proved beneficial effects for the human health, beyond the normal nutritional effects. A functional food can improve the health and well-being of the consumer by reducing the risk of disease if it is consumed in usual amounts as part of a normal diet.

© QUB
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Introduction to Food Science

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