we need food to satisfy three tipes of need: energetic structural and function and regulatory
one gram of fats: 9 kcal
one gram of sugar: 3,75 kcal
one gram of proteins: 4 kcal
the minimal amount of energy is the basal metabolic rate. Is the energy we requiered to keep our vital functions going.
men: 66.5 +(13.7 x body mass) + (5 x heigh) - (4,7 x age)
women: 55+ (9.5 x body mass) + (4.8 x heigh ) -4.7 x age)
basal rate= basal metabolic rate +physical activity
food provides the body with esential substances to buil and repair biological structures. Most important nutrients are proteins. We need 0,8 grams daily per each kilogram of weigh.
our body need other kind of nutrients like vitamins and mineral salts