1) Because we need to be healthy. 2) Because an unbalanced diet can cause (or exacerbate) any of the following: high cholesterol, anemia, beri beri, pellagra, scurvy, rickets, Diabetes, obesity, hypertension, osteoporosis, weakness, heart and artery disease, goiter, night blindness, high blood pressure, immune deficiency, liver disease, atherosclerosis, constipation, cognitive impairment, and hyperactivity. Among other problems.
Which of the body-parts are affected?
An unbalanced diet puts an added strain on your heart.
It puts your kidneys at risk because of the much higher likelihood of getting Diabetes. Diabetes can also bring blindness.
It interferes with breathing and may bring on sleep-apnea.
It puts extra strain on the skeleton, muscles and joints.
It increases the chance of acid reflux.
It causes problems in the legs' veins, sometimes bringing skin ulcers.
It puts a strain on the liver due to localized fat buildup and can cause cirrhosis or liver-failure.See also:
For a heathly lifestyle 
Its very good to have a well balance diet because it makes you feel more alive and its 5x more times healthier than normal diets. But to answer you question no you do not need to take a well balance diet ( unless you want to be skinny or super fit)
we need a balance diet because it help keep as healthy and well, fight infections and give as plenty of energy.
Balanced diet
a balance diet is one with three or more food groups in your meal or diet. c;
To be a footballer, you need to train hard, eat a right diet,and balance out your food, you need to have either or both stamina and speed, strengths...
Except for very overweight and obese teens, average teens don't need to go on diet. They just have to eat healthy and balance meals.
To balance your diet you need to hold up to a few specific rules. Only a few products that do not have calories are allowed during the diet. The products that contain calories but are eligible for diet-held food can be bought in special shops, markets, etc. that specifically sell food only for diet applying. Nuts are also allowed, otherwise, no icecream, chocolate or fats and calories.
Yes. If you go on the web, there will be a site known as every diet. This site will tell you all you need to know about any kind of diet, you are looking to find.
The three day diet is kind of iffy, WebMD has an interesting article that discusses this diet plan. What you need to realize is that the best way to lose weight is to cut out fats, sugars, soda and other things and then eat a balanced diet.
List the essential food a balance diet
it is important that you have a diet. chilren should he a diet too.