Carbohydrates: Monosaccharides, Disaccharides, and More

Monosaccharides

• Glucose is the most important monosaccharide in the human body
• Monosaccharides are single sugar units absorbed directly into the blood
• Chemical names of sugars end in "ose"

Disaccharides

• Disaccharides are simple carbohydrates
• They consist of pairs of single sugars linked together
• Enzymes digest and break down disaccharides

Types of Disaccharides

• Sucrose is composed of fructose and glucose
• Maltose is composed of two glucose molecules
• Lactose is composed of glucose and galactose

Polysaccharides

• Polysaccharides include starch, glycogen, and fiber

Glycogen

• Glycogen is a key storage form of glucose in animals
• It is stored in muscles and the liver
• Glycogen is nearly undetectable in meats

Fiber

• Fiber is only found in plants, forming leaves, stems, and seeds

Ketosis

• Ketosis involves a high concentration of ketone bodies, which are products of incomplete fat breakdown

Insulin and Glucagon

• Insulin lowers blood glucose levels
• Glucagon facilitates the breakdown of liver glycogen

Blood Glucose Regulation Issues

• Diabetes involves high blood glucose levels
• Hypoglycemia involves low blood glucose levels

Lactose Intolerance

• Lactose intolerance is an impaired ability to digest lactose due to reduced lactase
• Symptoms include nausea, pain, diarrhea, and excessive gas

Carbohydrate Absorption

• Carbohydrates are absorbed into the bloodstream and used for energy

Recommended Fiber Intake

• Men: 38 g/day through age 50; 30 g/day for 51 and up
• Women: 25 g/day through age 50; 21 g/day for 51 and up
• Daily Value: 28 g/day based on a 2000 calorie diet

Recommended Carbohydrate Intake

• RDA: 130 g/day (minimum)
• AMDR: 45% to 65% of total calories

Consequences of Excess Fiber

• Excess fiber can limit the absorption of iron and zinc

Sources of Dietary Fiber

• Grains, fruits, and vegetables are the best sources

Nutrients Added During Enrichment

• Iron, thiamin, riboflavin, and niacin were added in 1942, and folate in 1996

Type 1 Diabetes

• Type 1 diabetes typically diagnosed in childhood, involves blood glucose staying too high due to lack of insulin

Type 2 Diabetes

• Type 2 diabetes, is blood glucose stays too high because cells do not respond to insulin

Grain Kernel Parts

• Germ: rich in oils, vitamins, and minerals
• Endosperm: mostly starch and proteins
• Bran: rich in nutrients and fiber
• Husk: inedible

Lipid Classes

• Triglycerides are the most common lipid in the body
• Phospholipids contains glycerol, two fatty acids, and phosphorus molecule
• Sterols consists of rings of carbon

Cholesterol

• Cholesterol is a sterol and is a component of bile and cell membranes
• The liver manufactures cholesterol

Trans Fat

• Trans fat is made via hydrogenation

Lipoproteins

• HDL (High-Density Lipoproteins) are smaller and denser, packaged with more protein
• LDL (Low-Density Lipoproteins) are larger and lighter, richer in cholesterol, and deliver it to tissues

Lipid Digestion

• Fatty acids split from glycerol in the mouth, stomach, and small intestine
• Bile shuttles lipids across mucus layer in the small intestine
• Gallbladder slows the digestion process

Essential Fatty Acids

• Omega-3 Fatty Acids (α-Linolenic Acid): Found in chia seeds, flaxseed, walnuts, and soybeans
• EPA/DHA: Found in eggs, fish, and seafood, and critical in regulating heart disease, cancer prevention, brain function, and vision
• Omega-6 Fatty Acids (Linoleic Acid): Found in vegetable oils like corn and sunflower and in cashews, walnuts, and poultry fat

Functions of Essential Fatty Acids

• Act as cell signals that modulate cell and tissue function
• Promote normal growth and vision

Purposes of Lipids

• Adipose tissue secretes hormones to regulate appetite
• Lipids act as shock absorbers and insulators
• Help form cell membranes
• Help transport substances
• Provide energy

Blood Lipid Levels

• Total cholesterol: < 200
• LDL cholesterol: < 100
• HDL cholesterol: ≥ 60
• Triglycerides: < 150

Fatty Acids

• Saturated fatty acids have no double bonds
• Monounsaturated fatty acids have one double bond
• Polyunsaturated fatty acids have two or more double bonds

Amino Acids

• Amino acids are molecules that combine to form proteins
• Essential amino acids can only be replenished from foods
• Peptide bonds link amino acids

Hormones

• Hormones are proteins that regulate body processes

Enzymes

• Enzymes are proteins that facilitate chemical reactions

Urea

• Urea is a waste product of protein digestion

Complete vs Incomplete Proteins

• Complete proteins provide enough of all 9 essential amino acids
• Incomplete proteins do not

Celiac Disease

• In celiac disease, gluten triggers abnormal immune responses

Antibodies

• Antibodies are molecules from the immune system that fight diseases

Amino Acid Supplements

• Branched-chain amino acids (BCAA) supplements are available

Wasting Amino Acids

• Lacking energy from other sources causes amino acids to be wasted
• Receiving more proteins than needed/low quality causes amino acids to be wasted
• Too much of any single amino acid causes amino acids to be wasted

Protein Supplements

• Bone broth, collagen, and gelatin are protein supplements

Amino Acid Parts

• Amino acids contain nitrogen, carbon, hydrogen, and oxygen atoms

Denaturation of Proteins

• When a protein molecule loses its shape, it can no longer function

Denaturing Agents

• Heat, alcohol, acids, bases, radiation, and salts of heavy metals can denature proteins

Recommended Daily Protein Intake

• 0.8 grams per kg of body weight
• AMDR is 10-35% of total kcalories

Nitrogen Balance

• Nitrogen balance is the amount of nitrogen excreted compared to nitrogen eaten
• Positive nitrogen balance: Nitrogen-in exceeds nitrogen-out
• Negative nitrogen balance: Nitrogen-out exceeds nitrogen-in

Vegetarian Diets

• Fruitarian: Includes only raw or dried fruits, seeds, and nuts
• Lacto-ovo-vegetarian: Includes dairy products, eggs, vegetables, grains, legumes, fruits, and nuts, but no flesh or seafood
• Lacto-vegetarian: Includes dairy products, vegetables, grains, legumes, fruits, and nuts, but no flesh, seafood, or eggs
• Macrobiotic diet: Primarily whole grains, beans, and certain vegetables; extreme, affecting nutrient status
• Ovo-vegetarian: Includes eggs, vegetables, grains, legumes, fruits, and nuts, but no flesh, seafood, or milk products
• Partial vegetarian (Flexitarian): Includes seafood, poultry, eggs, dairy, vegetables, grains, legumes, fruits, and nuts, but excludes or limits certain meats (e.g., red meats)

Benefits of Vegetarian Diets

• Defense against obesity, heart disease, hypertension, and cancer
• Beneficial impacts during pregnancy and infancy, adolescence, aging, and illness

Vitamins

• Water-soluble: dissolve in water; B vitamins (thiamin, riboflavin, niacin, folate, B12, B6, biotin), and vitamin C
• Fat-soluble: dissolve in fat; vitamins A, D, E, and K

Provitamins

• Provitamins can be converted into a vitamin in the body

Vitamin D Deficiencies

• Rickets: Vitamin D deficiency early in life
• Osteomalacia: Vitamin D deficiency in adults

Niacin Deficiency

• Pellagra: Niacin deficiency, particularly among alcoholics

Folate Deficiency

• Neural Tube Defect: Birth defects when the neural tube does not close completely (e.g., cleft lip)

Thiamin Deficiency

• Beriberi: Thiamin deficiency

Antioxidants

• Antioxidants protect cells from damage caused by free radicals

Prooxidants

• Prooxidants can damage cells by producing reactive oxygen species

Vitamin B12 Absorption

• Requires stomach acid and intrinsic factor for absorption

Functions of Vitamin A

• Eyesight: Healthy cornea
• Night blindness: Deficiency of vitamin A
• Immune function
• Reproduction and growth: Bones, teeth

Functions of Vitamin E

• Antioxidant, guarding against oxidative damage
• Reduced inflammation

Vitamin E Deficiencies

• Occur in people with diseases that cause fat malabsorption
• Premature babies

Functions of Vitamin K

• Blood clotting
• Bone protein synthesis

Vitamin K Deficiencies

• Dangerous in newborns
• Jaundice
• Drug interference

Functions of Vitamin B12

• Coenzymes in cell replication
• Maintains sheaths around nerve fibers

Vitamin B12 Deficiencies

• Anemia
• Presence of large, immature red blood cells
• General malfunctioning of nerves and muscles

Sources of Vitamin C and Beta-Carotene

• Fresh fruits and vegetables, white potatoes, and sweet potatoes

Beta-Carotene

• Dietary antioxidant
• Plant-based foods

Vitamin C Deficiency Symptoms

• Scurvy, more common in alcoholics

This covers the basics of Carbohydrates. It discusses monosaccharides, disaccharides, and polysaccharides, including examples like glucose, sucrose, and starch. It also touches upon glycogen, fiber, ketosis, insulin and glucagon.