HOW DO HUMANS ACTUALLY GET THE NUTRIENTS FROM FOOD?

The process is called digestion and absorption, and it’s pretty amazing. Let’s walk through it step-by-step:

🍽️ 1. You eat the food

It all starts when you chew and swallow. Your teeth and saliva begin breaking the food down — especially carbs with an enzyme called amylase.

🧪 2. Stomach: chemical breakdown begins

• Your stomach acid (HCl) and enzymes break down proteins.
• The food turns into a thick soup called chyme.
• Not much gets absorbed here yet — mostly just alcohol and some meds.

🏭 3. Small intestine: the nutrient party

This is where the magic happens — almost all nutrients get absorbed here!

• Your pancreas and liver send in enzymes and bile to break down:
• Fats → into fatty acids and glycerol
• Proteins → into amino acids
• Carbs → into glucose (sugar)
• Tiny finger-like structures called villi and microvilli line the small intestine and soak up nutrients into your blood.

🩸 4. Absorbed nutrients go into your blood or lymph

• Water-soluble nutrients (like vitamins B and C, amino acids, glucose) go straight into your bloodstream.
• Fat-soluble nutrients (vitamins A, D, E, K, and fats) go into your lymphatic system first, then into your blood.

From there, your body sends them wherever they’re needed — to cells, organs, muscles, brain, etc.

🚽 5. Large intestine: water & leftovers

• Most of the nutrients are gone by now.
• What’s left? Fiber, water, and waste.
• Your gut bacteria also play a role here — they help break down fiber and make some nutrients like vitamin K.

🔄 Summary:

You eat food → break it down into tiny molecules → absorb those into your body → use them to fuel, build, repair, and stay alive.