Food and Nutrition

in Science

ImageWhat is your favorite food? Some people love pizza. Some people love ice cream. Not many would say broccoli is their favorite food.

But you can’t eat only pizza and ice cream all the time. You also need fruits, vegetables, and other kinds of foods. Water is also very important for your body.

WHY DO WE NEED FOOD?

You need food for many reasons. You need food in order to live. You need food to satisfy hunger. Your stomach feels hungry when you need to eat more food.

Your body needs food to make energy. Every part of your body uses energy from food. Your brain uses energy to think. Your heart uses energy to beat. Your muscles use energy to move.

Growing requires food. Your body also needs energy from food to stay warm.

Eating the right kinds of foods can help keep you healthy. Eating certain foods can help prevent some diseases.

WHY DO WE NEED WATER?

The human body is 65 percent water. Water makes up most of your blood and helps carry oxygen and food to the cells in your body. Water helps your body get rid of wastes through urine and sweat. Water does many other things inside your body.

You could live only eight to ten days without water. You could live for weeks without food. You need eight to ten cups of water each day to replace the water that your body uses up. But don’t worry—drinks such as milk or juice contain mostly water. Many foods, especially juicy fruits, contain water as well.

WHAT ARE THE BEST FOODS TO EAT?

You need all kinds of foods to keep your body strong and healthy. Nutritionists (scientists who study food and nutrition) say you should eat grains, such as bread, pasta, and cereal. You should eat eggs, milk, cheese, and other dairy products. You should eat meat, fish, beans, or tofu (bean curd). They also say you need to eat plenty of fruits and vegetables every day. But you should not eat too many foods with lots of fats or sugars.

You need to eat some of each of these different kinds of foods to get chemicals called nutrients. Carbohydrates, proteins, fats, vitamins, minerals, and water are nutrients.

WHAT ARE CARBOHYDRATES?

Carbohydrates are your body’s main source of energy. Carbohydrates come from starches and sugars. Starchy foods are breads, cereals, pasta, corn, beans, peas, and potatoes. Sugars are in fruits, honey, maple sugar, and the sugar in your sugar bowl. Many vegetables and milk products also have some sugars.

Your body breaks down the carbohydrates in sugars and starches to make a very simple kind of sugar called glucose. Glucose goes into your bloodstream. Your blood carries glucose to your brain and your muscles for energy. Extra glucose gets changed so it can be stored in your liver and fat cells. You can use this stored energy later.

WHAT ARE PROTEINS?

Proteins build and repair body tissues, from hair and fingernails to muscles. Proteins also fight infection and carry oxygen from your lungs to the rest of your body.

 You get proteins from food that comes from animals, such as eggs, milk, meat, fish, and poultry. You can also get proteins from plants, such as vegetables, grains, beans, and rice. Some people called vegetarians do not eat foods from animals. Vegetarians can get all their proteins by eating grains, dried peas and beans, rice, nuts, and tofu.

WHAT ARE FATS?

Fats pack more energy than any other kind of food. Fats play an important role in protecting your cells. Fats help blood to clot if you cut yourself. Fats also help your body take up certain vitamins.

There are different kinds of fats. Animal fats come from eggs, dairy products, and meats. These foods are high in saturated fats and cholesterol. Nutritionists believe that eating too much saturated fat and cholesterol is bad for your health. Vegetable fats come from such foods as avocados, olives, nuts, and vegetable oils. These foods contain different kinds of fat that are healthier.

WHAT ARE VITAMINS AND MINERALS?

Your body needs small amounts of vitamins and minerals for good health. Vitamins are chemicals that help your body use carbohydrates, proteins, and fats. You need certain vitamins to build blood cells and body chemicals such as hormones.

Not getting enough vitamins can cause serious diseases. Long ago sailors on long sea voyages did not have fresh food. They suffered from a disease called scurvy. Their gums bled and their teeth fell out. They bruised easily. Many sailors died from scurvy. Scurvy is caused by a lack of vitamin C. A doctor in the 1700s discovered that giving sailors lime juice prevented scurvy. Citrus fruits like limes are full of vitamin C.

You need small amounts of certain minerals for healthy teeth and bones. The mineral calcium is very important for building strong bones. You need other minerals to help your muscles and nerves work. Iron is an important mineral for your blood.

You can get all the vitamins and minerals you need by eating a wide variety of foods. That is why you need to eat fruits, broccoli, and other vegetables along with your pizza and ice cream.

.Source: Microsoft ® Encarta