What happens when you don't eat?
Refusing one meal won't stunt your growth. But lack of proper food over a period of time can lead to malnutrition. That means, the body is not getting enough nutrients to grow and stay healthy. Kids who are malnourished may not grow as tall as they would otherwise.
Why We Need Food
Did you ever hear the old saying, An apple a day keeps the doctor away? Do apples really prevent you from getting sick? Probably not, but eating apples and other fresh fruits can help keep you healthy. Do you eat your vegetables? Maybe you do, but you may have friends who won't touch a piece of broccoli or asparagus. Should you eat these foods and food like them? The girls pictured in the figure below are eating salads. Why do you need foods like these for good health? What role does food play in the body?
Your body needs food for three reasons:
- Food gives your body energy. You need energy for everything you do. Remember that cellular respiration converts the glucose in the food you eat into ATP, or cellular energy. Which has more glucose, a salad or a piece of meat? Do you remember what types of foods produce glucose? Recall that glucose is the product of photosynthesis.
- Food provides building materials for your body. Your body needs building materials so it can grow and repair itself. Specifically, it needs these materials to produce more cells and its components.
- Food contains substances that help control body processes. Your body processes must be kept in balance for good health.
For all these reasons, you must have a regular supply of nutrients. Nutrients are chemicals in food that your body needs. There are five types of nutrients.
Carbohydrates, proteins, and lipids are categories of organic compounds. They give your body energy, though carbohydrates are the main source of energy. Proteins provide building materials, such as amino acids to build your own proteins. Proteins, vitamins, and minerals also help control body processes. Carbohydrates include sugars such as the glucose made by photosynthesis. Often glucose is stored in large molecules such as starch. Proteins are found in foods like meats and nuts. Lipids includes fats and oils. Though you should stay away from many types of fats, others are needed by your body. Important vitamins include vitamins A, B (multiple types) C, D, and E. Important minerals include calcium and potassium. What should you drink to get calcium? Milk is a good source.
Use the resource below to answer the questions that follow.
- Nutrition at http://www.youtube.com/watch?v=2xbD6--X0IA (6:39)
- What is nutrition?
- What do organisms use "food" for?
- What is a heterotroph? Are humans autotrophic or heterotrophic?
- What are the three types of heterotrophic organisms?
- Why does your body need food? Give two reasons.
- What are nutrients?
- What are the five types of nutrients?
- Why are carbohydrates a necessary part of your diet?
- Why are proteins a necessary part of your diet?