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

The digestive process starts with chewing up the food so that it can be swallowed. Once your food is in your stomach, the acid breaks up the food, and from there they enter the small intestine and then are broken down into amino acids. Your body absorbs the nutrients it needs from the food, and whatever it doesn’t use passes through as stool and is disposed of in the bathroom! "Once the intestine's contents are emulsified, fat-spletting enzymes act on triglycerides to split fatty acids from their glycerol backbone." (Sizer & Whitney). Good fats are those that are unsaturated fats, which can be found in fish, nuts, and avocado, and eating the good fats lowers your bad cholesterol and  raises your good cholesterol. Bad fats are unsaturated fats, and guess what! It raises your bad cholesterol and decreases your good cholesterol. They can be found in processed foods, and meats that are high in fat, as well as dairy.

Fiber is beneficial because it not only helps with digestion, but can reduce heart disease. You can absorb fiber from plant foods as well as carbohydrates that are enriched with fiber such as whole grain or whole wheat breads. 

References

Sizer, F. & Whitney, E. (2011). Nutrition: Concepts and Controversies (12th ed.). Mason, OH: Cengage Learning.