A balanced diet must focus on all the categories, but also on the types of foods eaten within those groups. For example, instead of saying that 70% of your diet should be carbohydrate, the advice is more like :
a : 70% carbohydrate.
35% staples: whole-grains, brown rice, potato, pasta, cereals.
35% fresh fruits and vegetables.
b : 20% protein and fat.
10% dairy milk, cheese,yogurt.
10% eggs, poultry, red meat, fish, white fish and pulses.
c : 10% treats cakes, cookies, soda, chocolate, high fat cheese, cooking oils.