Lipid Digestion, Absorption, and Storage – Nutrition & Health Notes

Summary:

This note covers Lipid Digestion, Absorption, and Storage. It discusses the metabolism and function of various nutrients in the body, including carbohydrates, proteins, and lipids. The liver plays a significant role in energy metabolism, including the conversion of glucose into glycogen and fatty acids, and the breakdown of fatty acids for energy. The liver also detoxifies alcohol and other drugs, and stores vitamins and minerals. Food intake is regulated by hunger, satiation, and satiety, and the thermic effect of food varies depending on the macronutrient composition of the meal. The passage also provides formulas to estimate basal metabolic rates for males and females.

Excerpt:

Lipid Digestion, Absorption, and Storage

Energy metabolism

Metabolic work of the liver

Carbs:

• Converts fructose and galactose to glucose metabolites.
• Makes and store glycogen.
• Breaks down glycogen and releases glucose.
• Breaks down glucose for energy when needed.
• Makes glucose from some amino acids and glycerol when needed.
• Converts excess glucose to fatty acids.

Protein:

• Manufactures non-essential amino acids that are in short supply.
• Removes from the blood amino acids that are present in excess of need and converts them to other amino acids or deaminates them and converts them to glucose or fatty acids.
• Removes ammonia from the blood and converts it to urea to be sent to kidneys for excretion.
• Makes other nitrogen-containing compounds the body needs (such as bases used in DNA and RNA).
• Makes plasma proteins such as clotting factors.

Lipids:

• Builds and breaks down triglycerides, phospholipids, and cholesterol as needed.
• Breaks down fatty acids for energy when needed.
• Packages extra lipids in lipoproteins for transport to other organs.
• Manufacture bile to send to the gall bladder for use in fat digestion.
• Makes ketone bodies when necessary.

Other:

• Detoxifies alcohol, other drugs, and poisons; prepares waste product for exertion.
• Helps dismantle old red blood cells and captures the iron from recycling.
• Stores most vitamins and many minerals.