AAT Bioquest

What are the differences between lipids and carbohydrates?

Posted October 12, 2023


Lipids and carbohydrates are two types of essential organic compounds that have similar chemical compositions but differ in terms of structure, behavior, function, and food sources.

Basis of differentiation 




Are water-insoluble biomolecules composed of glycerol and fatty acids

Are water-soluble biomolecules composed of carbon, hydrogen, and oxygen


Major elements - C, H, O Minor elements - N, S 

C, H, and O


Are hydrophobic and not soluble in water 

Are hydrophilic and soluble in water, except polysaccharides


  • Fats
  • Phospholipids
  • Fat-soluble vitamins 
  • Waxes
  • Sterols
  • Monosaccharides 
  • Disaccharides
  • Oligosaccharides
  • Polysaccharides 

Energy generated per gram

Generates 9 kcal of energy per gram – more than double that of carbohydrates

Generates 4 kcal of energy per gram 

Types of energy provided

Store energy for later use

Immediate energy source

Major Digestive Enzyme




  • Cellular energy storage 
  • Provide structural stability for cells
  • Insulation & cushioning for vital internal organs 
  • Facilitate signaling processes 
  • Reproductive hormone synthesis
  • Facilitating absorption & distribution of fat-soluble vitamins
  • Energy supply for body organs & tissues
  • Creation of structural components 
  • Synthesis of coenzymes
  • Play a role in the immune system
  • Prevent blood clotting
  • Backbone of RNA


Food sources 

  • Nuts, Seeds 
  • Legumes 
  • Fish & Seafood
  • Fruit such as Avocado
  • Starchy Plant-Based Foods (polysaccharides) 
  • Fruits (fructose)
  • Milk (lactose)
Additional resources

Evaluating analytical methods for the characterization of lipids, proteins and carbohydrates in organic substrates for anaerobic co-digestion