NUT 1004 Carbohydrates Lecture Notes PDF

1 Caribbean Food groups & Carbohydrates Kemar Bundy MSc, MPH, PhD (C) NUT 1004 University of Technology, Jamaica  Learning Outcomes Identify the two major kinds of carbohydrates in human diets.. Identify the major role of carbohydrates in the body. Explain the dif...

1 Caribbean Food groups & Carbohydrates Kemar Bundy MSc, MPH, PhD (C) NUT 1004 University of Technology, Jamaica  Learning Outcomes Identify the two major kinds of carbohydrates in human diets.. Identify the major role of carbohydrates in the body. Explain the difference between a nutritive sweetener and a nonnutritive sweetener. Explain the difference between a simple sugar and a polysaccharide. Describe the major steps involved in digesting and absorbing starches and sugars. Assignment 1 (Due October 11, 2023) STEP1 You are required to record relevant nutritional information on your favorite snack in table one (All members of the group must provide 1 snack). STEP2 You are required to record relevant nutritional information on your favorite fruit in table one (All members of the group must provide 1 fruit). STEP 3 Complete form 2 as required with the additional row for average individual intake. STEP 4 Complete form 3 and replace the word daily with individual in row 1 STEP 5 Complete the questions on page 3 Six Food Groups for use in the Caribbean  Cereals: Bread (from whole grain or enriched flour), wheat flour, corn (maize), corn-meal, dried cereals, macaroni, spaghetti, rice, cereal porridges. Starchy fruits, roots, tubers/ground provisions: Banana, plantain, breadfruit, yam, potato, dasheen, coco/ eddoe, cassava. Kidney beans, gungo/pigeon peas, black-eye peas, cow peas, other dried peas and beans, peanuts, cashew nuts, sesame seeds, pumpkin seeds. Dark green leafy and yellow vegetables: Callaloo/spinach, dasheen leaves, cabbage bush, pak choy, string beans, pumpkin, carrot. Other vegetables: Squash, cho-cho, (christophene, chayote), cucumber, tomato, garden egg/aubergine Mango, guava, citrus (orange, grapefruit, limes, tangerine), pineapple, West Indian cherry, pawpaw/papaya, golden apple/Jew/June plum, sugar apple/sweet sop.. Meat, poultry, fish (fresh, canned, pickled, dried), milk, cheese, yoghurt, egg, liver, heart, kidney, tripe (offal), trotters, feet, tail, head Cooking and salad oils, butter, margarine, shortening, ghee, coconut cream/milk, meat fat, nuts, avocado pear, Jamaican ackee. Introducing Carbohydrates Major source of energy for the body Include both starches and sugars Grouped into simple or complex forms How Plants Make Carbohydrates Plants use the sun’s energy to combine carbon, oxygen, and hydrogen atoms to make carbohydrate (e.g., glucose). ©McGraw-Hill Education Review of Carbohydrate Classe Sareen S. Gropper, Jack L. Smith, Timothy P. Carr. 2017. Advanced Nutrition and Metabolism, 7th Edition. Wadsworth, Inc., Belmont ©McGraw-Hill Education  Sugars The simplest form of carbohydrate is a sugar. Monosaccharide The simplest sugar Basic chemical unit of carbohydrates Disaccharide Sugar comprised of two monosaccharides ©McGraw-Hill Education  Monosaccharides Glucose Primary energy source for cells Also known as “dextrose” or “blood sugar” Fructose “Fruit sugar” or “levulose” Galactose Part of “milk sugar” (lactose) ©McGraw-Hill Education  Disaccharides Maltose glucose + glucose Sucrose glucose + fructose Lactose galactose + glucose ©McGraw-Hill Education  Sucrose Table sugar (sucrose) Made from refining sugar cane or sugar beets Refinement strips away small amounts of vitamins and minerals naturally present in cane & beets. A tablespoon of table sugar is almost 100% sucrose. Occurs naturally in honey, maple syrup, carrots, and sweet fruits such as pineapples. ©McGraw-Hill Education  Polysaccharides - Complex Carbohydrates Polysaccharides are complex carbohydrates. Contain >10 monosaccharides bonded together Storage form of energy in plants and animals Common dietary polysaccharides contain hundreds of glucose molecules - Some of these polysaccharides are not digestible by humans. ©McGraw-Hill Education  Starch and Glycogen Starch Storage form of carbohydrate (glucose) in plants Mainly in seeds, roots, and tubers Glycogen Storage form of carbohydrate (glucose) in humans and other animals Stored primarily in liver and muscles ©McGraw-Hill Education  Dietary Fiber (“Fiber”) Most forms of dietary fiber are complex carbohydrates that humans cannot digest. Two types: Insoluble and soluble Cellulose, Insoluble hemicelluloses, forms include:and lignin Pectins, Soluble gums, forms mucilages, and include: some hemicelluloses ©McGraw-Hill Education Classifying Fiber ©McGraw-Hill Education ©McGraw-Hill Education  Starch Digestion and Fiber Fermentat ©McGraw-Hill Education 22 What’s a Whole Grain? The intact, ground, cracked, or flaked seeds of cereal grains To be labeled “whole grain,” the food must contain: Fiber-rich bran Starchy endosperm Oily germ Figure 5.6 ©McGraw-Hill Education  Carbohydrate Digestion, Absorption, and Elimination Mouth — salivary amylase digests some starch Stomach — acid inactivates salivary amylase Small intestine — main site for carbohydrate digestion and absorption Pancreatic amylase Maltase Sucrase Lactase Liver — receives absorbed glucose, fructose, and galactose from the small intestine Large Intestine — some soluble fiber and undigested carbohydrates are fermented Rectum — very little dietary carbohydrate eliminated in feces ©McGraw-Hill Education  Summary of Carbohydrate Digestion & Absorptio ©McGraw-Hill Education  What Happens When You Eat? After meals, blood glucose increases, the pancreas releases insulin, a hormone that is made by beta cells. Insulin is a hormone made by and released from the pancreas (beta cells): Helps glucose enter most cells Enhances production and storage of: Fat Glycogen Protein Decreases hunger ©McGraw-Hill Education What Happens When You Don’t Eat When blood glucose decreases, the pancreas releases glucagon, a hormone that is made by alpha cells. Glucagon stimulates: Glycogenolysis Glycogen breakdown-- releasing glucose into the blood Lypolysis Breakdown of triglycerides (fat) for energy ©McGraw-Hill Education  Maintaining Blood Glucose Levels ©McGraw-Hill Education 5 Glucose for Energy Cells use oxygen to release energy stored in glucose’s chemical bonds. Carbon dioxide and water are formed in the process. Energy is released. ©McGraw-Hill Education Ketone Bodies and Ketoacidosis Ketone bodies Form as a result of incomplete fat breakdown Fasting or starving Low-carbohydrate, high-protein diet (e.g., Atkins diet) Can be used by certain cells for energy Ketoacidosis Condition that occurs with very high blood ketone bodies and pH of blood becomes acidic. Poorly controlled type-1 diabetes Unconsciousness and death may occur Picture from Google ©McGraw-Hill Education  Carbohydrate Consumption Pattern In 2017-2018, the average American diet supplied: About 46% of total calories from carbohydrates - Almost 26% of total calories were from complex carbohydrates. - 20.5% of total calories were from sugars - Approximately 18% of total kcal were from added sugars (about 22 tsp). - According to the Dietary Guidelines, added sugars intake should be less than 10% of total kcal. Source: U.S. Department of Agriculture, Agricultura Research Service: Nutrient intakes from food and According to MyPlate, added sugars are beverages: Mean amounts consumed by individuals By gender and age. What We Eat in America, NHANE sources of empty calories. 2017 2018. 2020. www.ars.usda.gov/ARSUserFiles/80400530/pdf/1718 /Table_1_NIN_GEN_17.pdf. Accessed: August 7, 2020 ©McGraw-Hill Education 8  Nutrition Facts Panels The original Nutrition Facts panel has information about total carbohydrate, sugar, and dietary fiber contents in a serving of food. The new Nutrition Facts panel, which is shown here, includes information about added sugars content. ©McGraw-Hill Education ©Wendy Schi  Ingredients List The ingredients list provides information about sources of carbohydrates, including kinds of added sugars. ©McGraw-Hill Education 12  Are Carbohydrates Fattening? Possibly, likely to depend on the type and amount of carbohydrate Foods that contain high amounts of refined carbohydrates (added sugars, including high-fructose corn syrup, and refined starches) Do not satisfy hunger as much as fatty foods or protein-rich foods Popular snack foods often combine refined carbohydrates with fats, making them very tasty. Metabolic factors Excess carbohydrates are more likely to be burned for energy than fat, so the “carbs” spare stored body fat. Dietary factors Americans consume more food energy than they need. ©McGraw-Hill Education Sugar-Sweetened Beverages Added sugar consumption associated with body weight: Sugar-sweetened foods Sugar-sweetened soft drinks are one of the major sources of added sugars in American diets. Risks of obesity, type 2 diabetes, heart disease, and stroke are associated with sugar-sweetened soft drink consumption. Coca-Cola. Nutrition Label. https://us.coca- cola.com/products/coca-cola/original/ Accessed February 27, 2021. ©McGraw-Hill Education  Lactose Intolerance Inability to digest lactose because of inadequate lactase Common condition, particularly in people of African, Asian, or Eastern European descent Bacteria in the large intestine break down undigested lactose, resulting in: Intestinal cramps, bloating, gas, and diarrhea Avoiding lactose Treatment generally involves: Using dairy foods that have little or no lactose or have been pretreated with lactase Some people can consume small amounts of foods that contain lactose. Note: Lactose intolerance is not the same as milk allergy. ©McGraw-Hill Education Does Sugar Cause Hyperactivity? Cause is unknown, but genetic and environmental factors may play a role. Despite popular belief : Results of scientific studies do not indicate that eating sugar or sugary foods increases children’s physical activity level, causes ADHD, or has other negative behavioral effects. ©McGraw-Hill Education  Fiber and Health 1 Fiber and the Digestive Tract Some forms of fiber swell in large intestine Softer stools and more regular bowel movements May help prevent or relieve constipation High-fiber diet may reduce risks of Obesity Type 2 diabetes Certain intestinal tract disorders Heart disease and stroke Diverticulitis. https://www.mayoclinic.org/diseases- conditions/diverticulitis/symptoms-causes/syc- 20371758. Accessed March 1, 2021. May also reduce risk of diverticula and swollen & inflamed hemorrhoids (see Figures 5.15 and 5.16.) ©McGraw-Hill Education  Fiber and Health 2 According to Dietary Guidelines, fiber is a “ nutrient of public health concern.” Fiber and Colorectal Cancer: High-fiber diets may protect against colorectal cancer. Fiber Dietsand rich in fiber,Health: Heart particularly soluble fiber, can promote cardiovascular (heart & blood vessels) health. - Soluble fiber can reduce blood cholesterol level. High-fiber Fiber andfoods generally Weight have low energy contents. Control: ©McGraw-Hill Education Glycemic Response to Carbohydrate Glycemic index (GI) - Method of classifying carbohydrate-rich food by comparing the rise in blood glucose after eating a portion of food that contains 50g digestible carbohydrate to the rise that occurs after eating 50g of a standard source of glucose Glycemic load (GL) - Considers quantity and quality of CHO in a food Grams of carbohydrate in a serving of food × the food’s glycemic index; this figure is then divided by 100. ©McGraw-Hill Education Why Consider GIs and GLs? GI and GL values for a particular food may vary depending on: When food is grown Degree of ripeness Extent of processing Other components in the meal Diets with high GIs/high GLs may increase risk of serious chronic diseases. Low GI/GL diets can improve blood fat and cholesterol levels, reduce risk of cardiovascular disease, and improve HbA1 levels. ©McGraw-Hill Education  Summary Carbohydrates are the major source of energy for the body which include monosaccharide, disaccharide, oligosaccharide, and polysaccharide. The main difference between a nutritive sweetener and a nonnutritive sweetener is whether it contributes energy after intaking. Polysaccharides are complex carbohydrates, which contain >10 monosaccharides bonded together and store energy in plants and animals. Carbohydrate digestion occurs in mouth, and it needs different specific enzymes generated by GI system. Intestinal cells absorb glucose, fructose, and galactose, and the hepatic portal vain transports them to the liver. Question ？ ©McGraw-Hill Education Thank you ! ©McGraw-Hill Education