Carbohydrates: A Detailed Overview PDF

Carbohydrates Carbohydrates are essential macronutrients, providing the body with energy. They are composed of carbon, hydrogen, and oxygen atoms and are made by photosynthesis. Their main function is to supply the body with energy. There are 2 types - starch and sugar. Starch produces slower relea...

Carbohydrates Carbohydrates are essential macronutrients, providing the body with energy. They are composed of carbon, hydrogen, and oxygen atoms and are made by photosynthesis. Their main function is to supply the body with energy. There are 2 types - starch and sugar. Starch produces slower releasing energy than sugar and is therefore lower GI (glycaemic index) Carbohydrates are found in a variety of foods, including grains, potatoes, fruits, vegetables, and dairy products. They are classified into three main types: monosaccharides, disaccharides, and polysaccharides. Fibre is a type of polysaccharide, which will be dealt with separately as it is not strictly a nutrient in FPN. 1g of carbohydrate produces 4kcals of energy, the same as protein. Fat produces twice this amount. TJ by Tina Judge Types of Carbohydrates Disaccharides Polysaccharides Starches Made up of two Complex A type of monosaccharide carbohydrates made polysaccharide that is molecules joined up of many a storage form of together. Examples monosaccharide carbohydrates found Monosaccharides include sucrose, molecules linked in plants. Potatoes, lactose, and maltose. together. They are bread, rice and pasta The simplest form of often long chains, and are good sources of carbohydrates, they can be branched or starch. are single sugar straight. molecules. Common examples are glucose, fructose and galactose. How do carbohydrates impact your health? - Richard J. Wood Monosaccharides Glucose Fructose Galactose Glucose is a simple sugar used Fructose is a naturally occurring Galactose is a sugar that by the body for energy. sugar found in fruits and honey. combines with glucose to form lactose. Sources of Monosaccharides Glucose Glucose is a common monosaccharide that is found in many fruits and vegetables, including both fresh and dried forms. It's also present in sugar cane, sugar beet, corn, and honey. Fructose Fructose is another important monosaccharide that can be found in fruits, some vegetables, sugar cane, sugar beet, corn, and honey. Galactose Galactose is a monosaccharide found in milk and milk products, as well as honey. It's also present in avocados. Disaccharides 1 Formation Disaccharides are formed when two monosaccharides combine. 2 Types The three main disaccharides are sucrose, lactose, and maltose. 3 Composition Sucrose is composed of glucose and fructose, lactose is composed of glucose and galactose, and maltose is composed of two glucose molecules. 4 Importance Disaccharides are important sources of energy for the body. Sources of Disaccharides Sucrose Lactose Maltose Sugar cane and sugar beet are Lactose is naturally found in milk Maltose is a disaccharide found major sources of sucrose. and is a key nutrient for infants. in plant foods like sweet Sucrose is a common ingredient It is also found in dairy products potatoes, soybeans, barley, and in processed foods and drinks. like cheese and yoghurt. wheat. It is a product of starch breakdown. Polysaccharides Starch Cellulose Pectin Starch is a complex Cellulose is a complex Pectin is a complex carbohydrate found in plants. carbohydrate found in the cell carbohydrate found in the cell walls of plants. walls of fruits. It is made up of many glucose It is a soluble fibre and is used molecules linked together in a It is made up of many glucose as a gelling agent in jams and long chain. molecules linked together in a jellies. straight chain. Sources of Starch Plants Starch is found in a variety of plants, including wheat, corn, barley, and potatoes. Grains Grains such as oats, rice, and quinoa are rich sources of starch. Legumes Lentils and pulses, like beans and peas, are excellent sources of starch. Faster releasing foods will make you feel hungry sooner than slower releasing starchy foods, so may encourage snacking. Eating sugary foods regularly may contribute to dental caries (meaning fillings). Also there may be a risk of becoming overweight or obese over time due to the high calorie content of sugary foods. A spike in blood sugar can be problematic for type 1 and type 2 diabetics as they may not have enough insulin to metabolise the glucose. How Plants Produce Carbohydrates Photosynthesis Plants use photosynthesis to produce carbohydrates, a process that requires chlorophyll, sunlight, carbon dioxide, and water. Glucose Formation During photosynthesis, glucose is produced, along with oxygen, which is released into the atmosphere. Starch Formation Thousands of glucose molecules link to form starch, a complex carbohydrate stored in plants as grains. Cellulose Formation Thousands of glucose molecules also link to form cellulose, a complex carbohydrate used for plant cell wall structure. Effects of Too Few Carbohydrates Low Blood Sugar Fat Burning Protein Breakdown When carbohydrate intake is low, Without sufficient carbohydrates, If fat stores are depleted, the blood sugar levels drop, leading the body starts to burn fat for body begins to break down to symptoms like hunger, energy, a process that can lead protein for energy, which can be weakness, and dizziness. to weight loss but also potential detrimental to muscle mass and health risks. overall health. Too many carbohydrates Fat storage Weight gain Liver disease Heart disease Excess carbohydrate is Excessive fat storage Excess fat in the liver Excess fat can converted into fat and can lead to weight gain can lead to fatty liver contribute to heart stored under the skin, and obesity. disease and other disease and other around organs, and in health problems. cardiovascular the liver. problems. Slow vs Fast Release Carbohydrates Slow Release Carbohydrates Starch is a slow release carbohydrate. It provides a steady release of glucose energy into the blood. Fast Release Carbohydrates Sugar is a fast release carbohydrate. It causes peaks and troughs in blood sugar levels, making energy levels less stable. Intrinsic Sugars What Are Intrinsic Sugars? Sources of Intrinsic Sugars Intrinsic sugars are naturally occurring sugars Foods such as fruit, some sweet vegetables and found in many foods. They are essential for milk naturally contain intrinsic sugars. energy production and provide sweetness in These sugars are essential nutrients and provide foods. 1. glucose valuable vitamins, minerals and fibre. They are a 2. fructose vital part of a healthy diet. 3. sucrose 4. Lactose - this is also an extrinsic sugar! Extrinsic Sugars Added Sugars Honey Artificial Milk Sugars Sweeteners Extrinsic sugars are Honey is a natural Milk contains naturally added to foods during sweetener produced by Artificial sweeteners are occurring sugars, processing, preparation, bees from nectar. It is synthetic substances primarily lactose. These or at the table. They are made up of a variety of that are used to sugars are classified as not naturally present in sugars, including sweeten foods and extrinsic sugars when the food. fructose, glucose, and drinks without adding they are added to other sucrose. calories. foods. Non-Milk Extrinsic Sugars (NMES)/free sugars Definition NMES are all extrinsic sugars that are not from milk. This is a term used only in the UK. Alternative Name NMES are also called 'free sugars'. Common NMES NMES consist largely of sucrose, but also include honey, glucose, fructose and glucose syrups. Recommended Sugar Intake Glycaemic Index (GI) 1 1. GI Rating 2 2. Blood Glucose The GI is a system of ranking how The GI relates to the rise in the blood glucose carbohydrate foods affect the blood sugar level two hours after consumption. levels. 3 3. Slow Absorption 4 4. Quick Absorption Foods that are absorbed slowly have a low GI Foods that are absorbed quickly have a high rating. GI rating. Glycaemic Index (GI) Ratings High GI Low GI The higher the GI, the faster the food is digested and the quicker blood sugar levels rise. Foods that are absorbed slowly have a low GI rating. The glycaemic index (GI) is a measure of how quickly different carbohydrate-containing foods raise blood sugar levels. It can be used to help you make informed choices about which foods to eat, especially if you are managing blood sugar levels. GI Examples of Foods 0 Meat, fish, chicken, foods with no carbohydrates 55 and below (classed as low) Dairy, green beans, cucumber, lentils 56–69 (medium) Sweet potato, sourdough, couscous