Diet

Carbohydrates

Source

Starch and sugar

Function

Respiration needs carbohydrates

Fats and oils

Source

Saturated(饱和) fat: animal fats - meat, butter, cheese
Unsaturated fat: plant oils

Function

energy store, making cell membranes, insulation, protect organs

Proteins

Source

meat, fish, egg, beans, nuts

Function

build new cells , growth, make antibodies, hemoglobin, enzymes, hormones

Water

Solvent

Fiber

Keep the digestive system work properly
Soft foods without fibers do not stimulate the muscles in the intestines(肠道) Peristalsis(蠕动)^[muscle contractions that move food through the digestive system]
prevents constipation

Source:

All plant foods contain fiber: cellulose cell walls. Humans cannot digest cellulose.
wholemeal bread, celery, oats, apple

Minerals

Calcium

Source

Milk and diary products

Function

For bones and teeth
for blood clotting

Deficiency

Brittle bones and teeth
poor blood clotting

Iron

Source

Liver, red meat, egg yolk, dark green vegetables

Function

making hemoglobin in red blood cells

Deficiency

Anemia: lack of red blood cells

Vitamin

Vitamin C

Source

Citrus fruits, raw vegetables

Function

Strengthens immune system
make connective tissues
repairs tissues

Deficiency

Scurvy: Pain in joints, bleeding from gums

Vitamin D

Source

Butter, egg yolk, vitamin D made by skin when sunlight falls

Function

Helps calcium to be absorbed

Deficiency

Rickets: Bones becomes soft and deformed (佝偻病)
Common in children in industrial areas, who rarely got sunshine

Balanced Diet

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A diet that contains all 7 nutrients in the right amounts