Atwater System and Vitamins


Atwater System

How to solve!



The Atwater system is used to calculate the total calories of foods using standard values:

9 kcal per gram of lipids
7 kcal per gram of alcohol
4 kcal per gram of carbohydrates and protein

1000 C = 1 kcal
1 kcal = 1 C

Sample calculation:
4 g lipids
3 g carbohydrates
50 C declared value

NOTE: Don’t forget to cancel units!

4 g × 9 kcal = 36 kcal = 36 C
3 g × 4 kcal = 12 kcal = 12 C

Total = 48 C
50 C − 48 C = 2 C difference



What are vitamins? Vitamins are organic compounds required in very small amounts. Too much fat-soluble vitamins (A, D, E, K) can be harmful.
Fat-soluble vitamins: Stored in fat and liver (A, D, E, K)

Water-soluble vitamins: Not stored in the body (except B12) and must be consumed regularly (B-complex and C)

Water-Soluble Vitamins Vitamin B
B1 – Energy from glucose
B2 – Energy production
B3 – Converts carbs, fats, alcohol to energy
B5 – RBC & steroid production
B6 – Protein & RBC formation
B7 – Hair, nails, metabolism
B9 – RBCs & fetal nervous system
B12 – Nerve protection & RBCs

Vitamin C
Supports immune system, wound healing, and collagen production.

Deficiency causes scurvy and delayed healing.

Fat-Soluble Vitamins Vitamin D
Strengthens bones and teeth by helping absorb calcium and phosphorus.

Deficiency causes rickets and bone weakness.
Note: Sunlight triggers production—it doesn’t contain vitamin D.

Vitamin E
Supports skin, eyes, and circulation.
Deficiency may cause weakness and vision problems.

Vitamin A
Important for eyesight, immunity, and white blood cell production.
Deficiency may cause blindness and skin disorders.

Vitamin K
Essential for blood clotting, bone metabolism, and heart health.