5 - Discuss how fats, proteins, and carbs are digested and absorbed in the body, and describe the benefits from a dietary perspective. What are the good fats, bad fats, etc.? Why is fiber so beneficial?

How fats, proteins, and carbs are digested and absorbed in the body

These things are digested in the body during the digestive process. There are many things that go into this - like chewing, saliva, mucous and bile. Some of these things are excreted from the body if there is no use for it, and the rest ends up absorbed into the body, and possibly used for energy.

Sizer and Whitney explain that "Once the intestine's contents are emulsified, fat-spletting enzymes act on triglycerides to split fatty acids from their glycerol backbone." (Sizer and Whitney, p. 157).

Proteins are chewed and swallowed, and do not have much more action until they are in the stomach. At this point, they are surrounded by acid that breaks up the proteins so that they are pretty small. From here they enter the small intestine and are broken down into amino acids.

Benefits from a dietary perspective:

Protein ~ It is very important to maintain a diet high in protein so the body and muscles can heal themselves. We need proteins because this helps our body by strengthening our bones and teeth. This also allows the body to make the enzymes and chemicals it needs to function. The functions that proteins and amino acids serve in our bodies is to keep our immune system strong. This also helps give us energy, strength, and healthy muscles. The recommended protein intake for adults is 10-35%, and the reccomendation for a healthy adult is 0.8 grams for each kilogram of body weight.

Carbohydrates ~ Carbohydrates are very important for our body. Glucose is one thing that helps provide our body with energy, and we get this from Carbohydrates. This glucose helps our nerves, and our brain function.  Carbs are how our body gets fiber, minerals, vitamins and other things that keep the body running efficiantly. According to WebMD, in order "To meet the body's daily nutritional needs while minimizing risk for chronic disease, adults should get 45% to 65% of their calories from carbohydrates" (Good Carbs, Bad Carbs: Why Carbohydrates Matter to You)

Fats ~ Fats, or triglycerides have benefits for our body. One is that these fats are stored in case there is a time of hunger. If you encounter a time where you cannot eat for days, your body will use the stored fat for energy which will keep the body alive for longer. Fat is also good as a barrier around the bodies important organs so that nothing can get to them. It also helps us feel satisfied when eating, and can help us not to overeat. Fat also helps us absorb nutrients and photochemicals that we need.

What are the good fats, bad fats, etc.?

Saturated Fat consists of things like milk, butter, cheese and other foods we get from animals. These fats will give us high cholesterol if not limited. Monounsaturated fats are good for us and can be derived from olive oil, canola oil, nuts and other fruits and vegetables.
polyunsaturated fats is another good fat that can be received from vegetables and fish oil. It is good for us to replace trans fat with this to benefit our bodies because this can reduce our cholesterol and make our heart stronger.
According to Sizer and Whitney, "Animal Fats and the tropical oils of coconut and palm contain mostly saturated fatty acids, Some vegetable oils, such as olive and canola, are rich in mono-saturated acids, and
Many vegetable oils are rich in omega-6 polyunsaturated fatty acids" (Sizer and Whitney, 2011)

Trans-fats are the fats that are pretty bad for us. These are the fats that cause high cholesterol, and increase our chances for diseases like cancer, diabetes, obesity, etc.  These are found in a lot of processed foods and fast foods.

 The healthier of the fats are the polyunsaturated and mono-saturated. These two are beneficial to our bodies because they they can help increase our good cholesterol. If we eat more of the ‘good’ fat, then our good cholesterol will rise, and the bad cholesterol will be lower. This makes for a much healthier body that is less prone to obesity or disease.

Why is fiber so beneficial? 　

Fiber is something that is so important to our bodies. It can help prevent heart disease.

According to WebMD, "There is only one way to get fiber -- eat plant foods. Plants such as fruits and vegetables are quality carbohydrates that are loaded with fiber. Studies show an increased risk for heart disease with low-fiber diets. There is also some evidence to suggest that fiber in the diet may also help to prevent colon cancer and promote weight control."

References:

Carbohydrates. 2011. http://www.webmd.com/food-    recipes/features/carbohydrates retrieved form on September 16, 2012

Sizer and Whitney, (2011).  Nutrition: Concept and Controversies, 12th edition