Balanced Diet: Components, Carbs, and Solubility

Balanced Diet

• A balanced diet involves consuming a variety of foods in appropriate amounts.
• Ensures the intake of essential nutrients, vitamins, and minerals.
• Supports proper growth, development, and body maintenance.

Components of a Balanced Diet

• Carbohydrates
• Proteins
• Fats
• Vitamins
• Minerals
• Fiber
• Water

Carbohydrates

• Primary energy source for the body
• Solubility is related to size
• Smaller carbohydrates (monosaccharides) are more water-soluble.
• Larger carbohydrates (polysaccharides) are less water-soluble.

Soluble vs. Insoluble Carbohydrates

• Glucose: a monosaccharide, very soluble in water.
• Glucose transports through the bloodstream, taken up by cells for respiration and energy.
• Starch and Glycogen: polysaccharides, composed of many glucose units.
• Insoluble or slightly soluble in water due to size and complexity.
• Functions as food storage.
• Starch is the main storage form of glucose in plants
• Glycogen is for animals.
• Cellulose: a polysaccharide providing structural support in plant cells, preventing bursting from osmosis.

Proteins

• Necessary for growth, repair, and new cell development.
• Used in enzyme production.
• Made of amino acids.
• Polypeptides are chains of amino acids.
• Functional proteins are folded polypeptides with specific structures.
• Proteins are not specifically stored in the body, as all cells consist of them.
• Excess amino acids are deaminated in the liver and are broken down into other substances.

Lipids (Fats and Oils)

• Act as an energy store.
• Provide heat insulation.
• Protect organs.

Energy Storage

• Lipids store energy efficiently, providing more energy per gram than carbohydrates or proteins.
• Lipids act as long-term energy reserves.
• They can be broken down to release energy when needed.

Protection and Insulation

• Lipids protect vital organs and act as insulation.
• They cushion organs and help maintain body temperature by preventing heat loss.

Saturated Fats

• Saturated fats are mainly from animal sources which include meat and dairy, also coconut oil.
• They provide a concentrated energy source
• Aid in hormone production.
• Support cell membrane structure.
• Excessive intake can raise cholesterol levels, increasing heart disease risk.

Unsaturated Fats

• Unsaturated fats come mainly from plant sources, including nuts, seeds, vegetable oils, and fatty fish.
• Unsaturated fats help lower cholesterol levels, reducing heart disease risk.
• They provide essential fatty acids for various bodily functions.

Vitamins

• Play a crucial role in maintaining good health and preventing deficiency diseases.
• The body cannot store vitamins, requiring daily intake in small amounts.
• Vitamins assist enzyme action and are essential for cell reactions.
• Vitamin B6 acts as coenzymes or cofactors, crucial for proper enzyme function.

Minerals

• Used to maintain healthy bones, teeth, and bodily functions.
• Calcium and iron are essential mineral salts.

Calcium

• Sources include dairy products, nuts, and seeds.
• Necessary for strong bones and teeth.
• Provides structural support, strength, and helps prevent osteoporosis and rickets.

Iron

• Sources include meat, chicken, fish, and legumes.
• Used for red blood cell production.
• Involved with haemoglobin, which carries oxygen throughout the body.
• Deficiency reduces haemoglobin production, leading to decreased oxygen transport, fatigue, weakness, and shortness of breath, a common cause of anaemia.

Fiber

• Indigestible but vital for digestive health.
• Adds bulk to the diet, which prevents constipation.
• Promotes fullness, aiding in weight management.
• Regulates blood sugar levels.
• Lowers the risk of heart disease and colon cancer.

Water

• Helps in chemical reactions, breaking down large molecules and building new ones.
• Important for digestion and protein synthesis.
• It dissolves substances to transport chemicals and nutrients.
• Carries water and nutrients in plants from roots to leaves.
• Carries nutrients and waste products in animals in the blood.
• Helps control body temperature via sweating.

Biochemistry of Carbohydrates, Lipids, and Proteins

• Carbohydrates, lipids, and proteins consist of simple elements:
  • Carbon
  • Hydrogen
  • Oxygen
• Proteins mainly contain carbon, hydrogen, oxygen, and nitrogen.
• Complex carbohydrates, lipids, and proteins are large molecules made from smaller molecules.

Carbohydrate Molecules

• Carbohydrates can be monosaccharides.
• Examples are Glucose and Fructose (one carbohydrate ring).
• Disaccharides consist of two carbohydrate rings.
• Examples are Sucrose(fructose and glucose) and Maltose (2 glucose molecules).
• Polysaccharides consist of many carbohydrate rings.
• Examples are Glycogen and Cellulose.

Lipids

• Lipids consist of fatty acids and glycerol.

Proteins

• Proteins are made of amino acids arranged into polypeptide chains forming a functional protein.

Food Tests for Carbohydrates

Benedict’s Test

• Used for reducing monosaccharides.
• Add Benedict’s solution to the food sample and place it in a boiling water bath.
• The solution changes color: green, yellow, or brick-red, depending on sugar concentration.
• A color change indicates the presence of reducing sugars.

Iodine Test

• Used for Starch.
• Add iodine solution to the food sample.
• Solution turns from brownish-yellow to blue-black if starch is present.

Food Tests for Lipids

Translucent Stain Test

• Rub food sample on filter paper.
• If a translucent stain forms, lipids are present.

Emulsion Test

• Add ethanol to the food sample.
• If fat droplets form on the surface, the solution becomes cloudy, indicating oil (lipid) presence.

Food Tests for Proteins

Biuret Test

• Add sodium hydroxide solution and copper (II) sulphate solution.
• A change from blue to purple indicates protein presence.

Conditions Linked to an Unbalanced Diet

Eating Disorders

• Anorexia: Restricting food intake and distorted body image.
• Bulimia: Binge eating followed by self-induced purging.

Obesity

• Excessive calories, unhealthy fats, sugar, and processed foods, combined with an inactive lifestyle.

Type 2 Diabetes

• High intake of refined carbohydrates, added sugars, unhealthy fats, and low fiber.
• Body's inability to regulate insulin.

Deficiency Diseases: Vitamin C and Scurvy

• Vitamin C deficiency causes scurvy.
• Citrus fruits prevent scurvy.
• Scurvy symptoms include fatigue, weakness, swollen gums, joint pain, and easy bruising.
• Scurvy was common in sailors, also known as sailor's disease, due to the lack of citrus fruits on long voyages.