Carbohydrates in Human Diet

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Questions and Answers

What health risks are associated with the consumption of sugar-sweetened soft drinks?

Lower blood pressure

Improved digestion

Obesity and type 2 diabetes (correct)

Increased vitamin intake

Lactose intolerance is primarily caused by a deficiency in which enzyme?

Protease

Amylase

Lactase (correct)

Cellulase

What symptoms are commonly associated with lactose intolerance?

Fatigue and joint pain

Intestinal cramps and diarrhea (correct)

Nausea and vomiting

Hives and rashes

Which method can help manage lactose intolerance?

Using pretreated dairy products or lactase supplements Signup and view all the answers

What is the role of fiber in the digestive tract?

Helps regulate bowel movements Signup and view all the answers

What health risks can a high-fiber diet potentially reduce?

Obesity and type 2 diabetes Signup and view all the answers

What do scientific studies indicate about the effects of sugar on children's behavior?

Sugar consumption has no negative behavioral effects Signup and view all the answers

Which groups are more likely to experience lactose intolerance?

People of African and Asian descent Signup and view all the answers

What is the primary function of insulin in the body?

Enhances fat and protein storage Signup and view all the answers

What hormone is released by the pancreas when blood glucose levels decrease?

Glucagon Signup and view all the answers

What condition does ketoacidosis refer to?

High levels of ketone bodies and acidic blood pH Signup and view all the answers

How are ketone bodies formed in the body?

As a result of incomplete fat breakdown Signup and view all the answers

During the process of cellular respiration, what are the byproducts of glucose breakdown?

Carbon dioxide and water Signup and view all the answers

What percentage of total calories from added sugars is recommended to be less than, according to Dietary Guidelines?

10% Signup and view all the answers

What is a major effect of glucagon on body tissue?

Promotes fat breakdown for energy Signup and view all the answers

What proportion of total calories were reported to come from complex carbohydrates in the average American diet for 2017-2018?

26% Signup and view all the answers

What are the two major kinds of carbohydrates in human diets?

Sugars and Starches Signup and view all the answers

What is the primary role of carbohydrates in the body?

Providing quick energy Signup and view all the answers

Which of the following best describes a nutritive sweetener?

Contains calories and nutrients Signup and view all the answers

Which snack would typically be categorized under the cereals food group in the Caribbean?

Rice Signup and view all the answers

What distinguishes a simple sugar from a polysaccharide?

Simple sugars are absorbed more quickly Signup and view all the answers

Which type of vegetable is included in the dark green leafy and yellow vegetables group?

Cabbage Bush Signup and view all the answers

Which of the following fruits is not a starchy fruit?

Mango Signup and view all the answers

Which item is considered a non-nutritive sweetener?

Aspartame Signup and view all the answers

What is the primary storage form of glucose in plants?

Starch Signup and view all the answers

Where is glycogen primarily stored in humans?

Liver and muscles Signup and view all the answers

Which type of fiber is characterized by being non-digestible in humans?

Insoluble fiber Signup and view all the answers

Which enzyme begins the digestion of starch in the mouth?

Salivary amylase Signup and view all the answers

During carbohydrate digestion, where is the main site for absorption?

Small intestine Signup and view all the answers

What are the components necessary for a food to be labeled as 'whole grain'?

Fiber-rich bran, starchy endosperm, and oily germ Signup and view all the answers

What happens to blood glucose levels after meals?

Increases, prompting insulin release Signup and view all the answers

What type of fiber is fermented in the large intestine?

Soluble fiber Signup and view all the answers

What is a primary benefit of consuming high-fiber diets?

They may protect against colorectal cancer. Signup and view all the answers

How is the glycemic load (GL) of a food calculated?

By multiplying the grams of carbohydrate in a serving by the food's glycemic index and then dividing by 100. Signup and view all the answers

What does dietary fiber generally help to reduce?

Blood cholesterol levels. Signup and view all the answers

Which factors can affect glycemic index (GI) and glycemic load (GL) values of food?

Degree of ripeness and processing of the food. Signup and view all the answers

What is the main difference between nutritive and non-nutritive sweeteners?

Nutritive sweeteners contribute energy, while non-nutritive do not. Signup and view all the answers

What type of carbohydrates are polysaccharides classified as?

Complex carbohydrates containing multiple monosaccharides. Signup and view all the answers

Which of the following statements about diets high in glycemic index (GI) and glycemic load (GL) is accurate?

They may increase the risk of serious chronic diseases. Signup and view all the answers

What health issue might increase with the consumption of low-fiber diets?

Elevated blood cholesterol levels. Signup and view all the answers

Study Notes

Carbohydrates in the Human Diet

Two major types of carbohydrates in the human diet:
- Starch: Storage form of glucose in plants, mainly in seeds, roots, and tubers
- Glycogen: Storage form of glucose in humans and animals, primarily stored in the liver and muscles

Dietary Fiber

Complex carbohydrate that cannot be digested by humans
Two main types:
- Insoluble fiber: Includes cellulose, hemicellulose, and lignin
- Soluble fiber: Includes pectins, gums, mucilages, and some hemicelluloses

Whole Grains

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

Carbohydrate Digestion and Absorption

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

Blood Glucose Regulation

After meals, blood glucose increases, the pancreas releases insulin:
- Helps glucose enter most cells
- Enhances production and storage of fat, glycogen, and protein
- Decreases hunger
When blood glucose decreases, the pancreas releases glucagon:
- Stimulates glycogenolysis (glycogen breakdown) releasing glucose into the blood
- Stimulates lipolysis (breakdown of triglycerides) for energy

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.

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)
Ketone bodies can be used by certain cells for energy.
Ketoacidosis is a condition that occurs with very high blood ketone bodies, making the blood pH acidic:
- Poorly controlled type-1 diabetes
- Unconsciousness and death may occur

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.

Sugar-Sweetened Beverages

Added sugar consumption associated with body weight.
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.

Lactose Intolerance

Inability to digest lactose because of inadequate lactase, common 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.
Treatment involves:
- Avoiding lactose
- 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.
Lactose intolerance is not the same as milk allergy.

Fiber and Health

Some forms of fiber swell in the large intestine, leading to softer stools and more regular bowel movements.
May help prevent or relieve constipation.
High-fiber diets may reduce the risk of:
- Obesity
- Type 2 diabetes
- Certain intestinal tract disorders
- Heart disease and stroke
- Diverticulitis
- Swollen and inflamed hemorrhoids

Glycemic Index (GI) and Glycemic Load (GL)

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 carbohydrates in a food.
- Grams of carbohydrate in a serving of food × the food’s glycemic index; this figure is then divided by 100.

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 the risk of serious chronic diseases.
Low GI/GL diets can improve blood fat and cholesterol levels, reduce the risk of cardiovascular disease, and improve HbA1 levels.

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.

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Description

This quiz covers essential aspects of carbohydrates in the human diet, including types such as starch and glycogen, and the role of dietary fiber. Additionally, it highlights the importance of whole grains and the digestive process for carbohydrates. Test your knowledge on these vital nutritional components!