Food and Nutrition: How do nutrition and exercise affect our health?

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Food is anything we eat that gives us energy and helps us stay alive. It is made from six groups of chemicals called nutrients: protein, carbohydrate, fat, vitamins, minerals, and water. Nutrients provide energy for us to live.

In the first investigation, we test the content of one group of nutrients: fat.

Fats

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Fat is a good source of energy because 1 gram of fat provides 9 calories, while 1 gram of both carbohydrates and protein provide 4 grams each.

About 20% of what we eat should be fat. Most Americans, though, eat about 40%. That’s twice as much. Too much fat can be bad for our health. That’s why studying fat content in food is important to help us make good choices.

There are good fats, and bad fats. The good kind is unsaturated fat the bad kinds are saturated fat and trans fat. The two bad kinds clog arteries and cause heart disease.

Good fats are unsaturated fats. They are mostly found in fish and vegetables (avocados, olives, peanuts, canola oils, vegetable oils, and fish like tuna and salmon).

Unsaturated Fats

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Good fats are important in keeping us alive and healthy, because they:

  • Provide stored energy

  • Transport some vitamins (vitamins A, D, E, and K are fat soluble, meaning they can only be absorbed if there's fat in a person's diet)

  • Keep our skin healthy

  • Protect our body from injury

  • Helps our bodies make hormones

  • Helps our brain and nervous system develop

One bad kind of fat is saturated fat. You can find them in animal products (meat, butter, shortening, lard, cheese, and milk (except skim). Saturated fats are also in palm and coconut oils, which are often used in commercial baked goods. Eating too much saturated fat can raise blood cholesterol levels and increase the risk of heart disease.

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Trans fats (hydrogenated) are also bad for us. They are created after a chemical process, and they are found in margarine, snack foods and baked goods, and many fried foods. Like saturated fats, trans fats can raise cholesterol and increase the risk of heart disease.

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Carbohydrates

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Acids

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Acids and bases are in what we consume, and in products we use. Acids corrode or dissolve things. For example, the gastric acid inside the stomach breaks down food for digestion. When you mix a base, like baking soda, with an acid, like vinegar, a chemical reaction occurs, one that produces carbon dioxide. Thus, baking soda is an indicator of acids, as we learn in the acid test on vinegar.

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Many vitamins our bodies need are also acids. For example, Vitamin C is ascorbic acid. Vitamin C is found in many fresh vegetables and fruits, such as broccoli, green and red peppers, collard greens, brussel sprouts, cauliflower, lemon, cabbage, pineapples, strawberries, citrus fruits.

Why is vitamin C important?Vitamin C is an antioxidant vitamin needed for the formation of collagen to hold the cells together and for healthy teeth, gums and blood vessels; improves iron absorption and resistance to infection.

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Resources

1. Food and Nutrition Unit Summary

2. BBC Video: What is Fat?

3. Good Fats Versus Bad Fats

4. Kids Health: Fats

5. Web MD: Good Fats Versus Bad Fats

6. Video on acids

7. Food facts

8. Carbohydrates

9. PBS Video on Food Miles