Science · Classes 9-10 · Chapter 1 · 1.3

What will be the daily diet.

You get home from school and finish a packet of chips and a bottle of soft drink. Your stomach is full, but did your body get everything it needs? A balanced diet is not the name of one food. It is the name of a sum. This note teaches the sum: how much, of what, and which food sits at the base and which at the tip.

1. How much a day, and how it divides

An adult who does physical work needs food worth 2000 to 2500 kilocalories a day. On top of that come vitamins, minerals and fibre, which you get from vegetables and fruit.

How that food divides is shown in Figure 1.04, the component distribution of an adult's balanced diet. Tap the four slices of the pie to see the percentages. Fibre is not shown separately here.

The pie is the target. Now build a day's food in grams and see how close its energy split comes to Figure 1.04.

2. What a balanced diet is

A balanced diet is not one particular food. A balanced diet is a diet that holds all seven components of food in the right amounts, and gives you the calories and fibre your normal activities need.

Nature does not hand you a ready-made balanced diet; you have to build it. When you make the list, you look at the person's age, sex and kind of work.

Age and condition change what the body needs. Tap the grid to see what matters for whom.

The chart for preparing balanced food gives these sources. Carbohydrate: rice, wheat, sugar or molasses. Protein: fish, meat, eggs. Fat: butter, oil, ghee. Vitamin: milk, eggs, fruit, fish or meat. Mineral: milk, eggs, vegetables.

3. The food pyramid

Draw that division as a picture and you get the food pyramid (Figure 1.05). Carbohydrate sits right at the bottom, then vitamin and mineral (vegetables and fruit), then protein, and fat at the very top. Build the four tiers yourself, from the bottom up.

Carbohydrate is at the bottom because, in the menu of a teenager or an adult, there is more of it than of any other component. Fat is at the top because it is needed in the smallest amount. Now put the names on the pyramid of Figure 1.05.

The oil or butter shown in the pyramid is not eaten by itself. It is used to make other foods.

4. What to eat, and when

Nutritionists divide the sources of nutrition into four classes: (1) meat or fish, eggs and pulses (peanuts, chick-peas, nuts); (2) fat or lipids; (3) all edible vegetables and fruits; (4) cereals and the foods made from them, such as bread and rice.

To choose which foods and how much, you look at geography and nature, winter and summer, and the body's growth and physiological activity.

A breakfast of only a cup of tea is very harmful. Bread with butter or an egg, plus a banana, gives you all the nutrients. In summer, flaked rice with molasses is a good choice. Lunch is the main meal of the day. Dinner should be easy to digest, so you eat less protein at night.

In tropical countries fish is an excellent source of protein. In winter, adding meat to the fish brings variety to the menu. Yogurt and fruit after every meal are good for your health.

5. Fast food

Fast food, or junk food, is food that is tasty rather than nutritious. It is very pleasant to eat, but it is not good for your health.

Fast food carries lots of animal fat and sugar, and often unhealthy chemicals added to boost the taste. Burgers, fried chicken, pizza, chips, cakes and biscuits are heavy in animal fat; soft drinks hold a great deal of sugar. These foods lack vitamins and minerals. Sort the made-up meals below.

These fatty foods turn into fat cells in the body. Too much sugar can damage teeth and skin. Fast food can never be a balanced diet, and it causes obesity in growing boys and girls. So fresh natural food is better than canned or packet food.

6. Check yourself

Three questions in the exam's style. Start with the first.

The second also comes straight from the note.

The last one, then the cards.

The whole note on seven cards.

Source: Science, Classes 9-10 (NCTB), Chapter 1 “Healthy Life, Better Living”, section 1.3.