There is more to Carb

1️⃣ Types of Carbohydrates

Carbohydrates are organic molecules made of carbon, hydrogen, and oxygen (C₆H₁₂O₆) — the body’s primary energy source for brain and muscle function.

Simple Carbohydrates (Fast Energy)

• Monosaccharides → 1 sugar unit

  • Glucose: main blood sugar, used by all body cells for energy

  • Fructose: fruit sugar, digested slower; converted to glucose in the liver

  • Galactose: found in dairy, combines with glucose to form lactose

• Disaccharides → 2 sugar units

  • Sucrose (glucose + fructose): table sugar

  • Lactose (glucose + galactose): milk sugar

  • Maltose (glucose + glucose): from starch digestion

Complex Carbohydrates (Sustained Energy)

• Oligosaccharides: 3–10 sugar subunits (e.g., raffinose, stachyose)

• Polysaccharides: 10+ sugar subunits (e.g., starch, glycogen, cellulose)

  • Starch: plant energy source (amylose & amylopectin)

  • Glycogen: animal storage form of glucose (in muscle & liver)

  • Fiber: indigestible complex carbohydrate

2️⃣ Importance of Fiber

Fiber is a non-digestible carbohydrate vital for gut health and metabolic regulation.

Types:

• Soluble Fiber (oats, fruits, legumes)

  • Dissolves in water → forms gel

  • Slows digestion → stabilizes blood sugar

  • Lowers LDL cholesterol

  • Provides ~2 kcal/g

• Insoluble Fiber (whole grains, vegetables)

  • Does not dissolve in water

  • Adds bulk to stool → promotes regularity

  • Speeds waste movement through GI tract

Benefits:

• Improves satiety → aids weight control

• Supports gut microbiome health

• Reduces risk of heart disease, diabetes, colon cancer

• Optimal intake: 21–38 g/day (≈14g fiber per 1,000 kcal)

3️⃣ Glucose Storage & Energy Use

• Glucose fuels muscles, brain, and the nervous system.

• The body stores glucose as glycogen in:

  • Liver → regulates blood sugar

  • Muscle → powers contraction

• Storage limit: ~1,800–2,600 kcal worth of glycogen.

• For every 1g glycogen stored → ~3g water retained (why rapid weight loss from low-carb diets is mostly water).

Energy Conversion:

• 1 glucose molecule → ~30 ATP (cellular energy units)

• When glycogen stores run low → the body uses fats and proteins (gluconeogenesis) for energy.

• Balanced carbohydrate intake ensures consistent mental focus and physical endurance.

Regulation:

• Insulin (from pancreas): lowers blood glucose → stores glycogen

• Glucagon (from pancreas): raises blood glucose → releases glycogen

• Exercise boosts glucose uptake via GLUT4 transporters, improving insulin sensitivity

4️⃣ Carbohydrate Digestion

Step-by-Step Process:

1. Mouth:

   • Chewing (mastication) + salivary amylase start starch breakdown → maltose & dextrins

   • Only ~5% digested here

2. Stomach:

   • Mechanical mixing → forms chyme (no carb digestion by stomach acid)

3. Small Intestine:

   • Pancreatic amylase continues starch breakdown

   • Enzymes from intestinal villi:

     • Lactase: lactose → glucose + galactose

     • Maltase: maltose → 2 glucose

     • Sucrase: sucrose → glucose + fructose

   • Monosaccharides absorbed into intestinal cells (enterocytes) → bloodstream

4. Liver:

   • Converts galactose & fructose → glucose

   • Stores excess glucose as glycogen

5. Bloodstream:

   • Glucose used immediately for energy or stored for later

⚖️ Key Takeaways

• Carbs are essential for physical performance, cognition, and recovery.

• Choose complex carbs + fiber for steady energy and improved gut health.

• Manage glycemic index/load to stabilize blood sugar and appetite.