Digestion, Absorption, & Metabolism

I'm continuing to learn so much about my body and how it processes nutrients. The human body truly is amazing! Metabolism is all physical and chemical changes within our living cells including how a body obtains and utilizes the energy from food (Sizer & Whitney, 2017).The body takes in food and metabolizes it without us thinking about it at all! 

Take the digestive system, for example. The main function and purpose of the digestive system is to break food into small molecules and then assist in the absorption of nutrients throughout the body. It is a complex system which is anatomically comprised of the mouth, esophagus, stomach, intestines, rectum, anus, liver, pancreas, and gallbladder. Even though there are many anatomical components, the entire digestive process takes place in just four phases: ingestion (eating), digestion, absorption, and egestion (excretion). During these phases, nutrients (proteins, fats, carbohydrates, vitamins, minerals, and water) from food are broken down to molecules small enough for the body to absorb and use for energy, growth, and cell repair. Proteins are fragmented into amino acids, fats are dissolved into fatty acids and glycerol, and carbohydrates break down into simple sugars (National Institute of Diabetes and Digestive and Kidney Diseases, 2017). 

The digestion process has two components - mechanical and chemical. 

• Mechanical digestion is the physical breakdown of food and begins in the mouth, where the teeth grind food into smaller bits to aid in swallowing. Saliva mixes with the food and also aids in swallowing by lubricating or moistening the food so it can easily pass through the esophagus. During the process of peristalsis, the muscles of the tongue and esophagus begin to make squeezing movements which push food downward toward the stomach. The sphincter muscle at the base of the esophagus tightens and prevents the food from returning up the throat. While the food is in the stomach, it continues to break down and is mixed with acids and creates a fluid called chyme (more about the chemical components later). The pyloric valve at the bottom of the stomach controls the movement of the chyme from the stomach to the small intestine where it gradually moves to the large intestine; muscles continue to squeeze and undulate as they push the food further through the digestive tract, through the intestines (Sizer & Whitney, 2017). The large intestine, also known as the colon, absorbs minerals and excess water from the chyme and leaves indigestible material such as fiber; this indigestible material leaves the body through the rectum as feces. The entire mechanical process of digesting a meal can take anywhere from one to three days (Sizer & Whitney, 2017).  
• Chemical digestion is the chemical breakdown of food and relies on digestive enzymes to turn large food molecules into smaller ones which can be absorbed by the body. Chemical digestion also begins in the mouth. Saliva contains enzymes which begin breaking down starches and fat in food before it has even been swallowed; the chemical digestion of protein takes place in the stomach when gastric juices, a combination of water, enzymes, and hydrochloric acid, begin to break down the protein structure of food. A mucus lining protects the digestive tract from being damaged or digested along with the food. Once the food has sufficiently been broken down, it migrates to the intestines where, the gallbladder begins to excrete bile to emulsify fat and oils. At the same time, the pancreas begins to excrete pancreatic juice, which contains both digestive enzymes and protective neutralizing sodium bicarbonate; the alkaline pH of bicarbonate, also the active ingredient in baking soda, helps to counteract the acidic pH of the other digestive juices (Sizer & Whitney, 2017).

Like I said, the human body is amazing! 

References:

National Institute of Diabetes and Digestive and Kidney Diseases. (2017). Your Digestive System & How it Works. Retrieved from https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works 

Sizer, F. & Whitney, E. (2017). Nutrition: Concepts and controversies (14th ed.). Mason, OH: Cengage Learning. 

TTS International Schools. (n.d.). Digestion [image]. Retrieved from https://www.tts-international.com/digestion-poster/1008602.html

Macro & Micronutrients

Nutrients are nutrients, right? Well, not exactly. Nutrients can be considered macronutrients (macro from the Greek word makros, meaning large) or micronutrients (micro also from Greek, meaning small). Macronutrients are the nutritional building blocks the body needs in larger quantities while micronutrients are still needed but in smaller doses. 

Macronutrients are proteins, fats, and carbohydrates. Fats, carbohydrates, and protein are energy-yielding nutrients which assist the body in building and maintaining muscle. 

• Dietary protein is crucial to help the body build muscle, hormones, bone, and skin and can be found in foods such as meat, nuts, beans, and dairy. Animal protein contains amino acids, which are an essential nutritional building block. Although plant based protein is nutritious, most lack the amino acids that animal protein supplies (Sizer & Whitney, 2017). In order to obtain amino acids, a vegetarian diet should be varied and even supplemented with a product such as liquid aminos. Consuming sufficient amounts of protein on a daily basis is important as the human body doesn’t store it as it does with fats (U.S. National Library of Medicine, 2018).
• "Good fats" are naturally occurring and can be found in fish (Omega 3 fatty acids), nuts, and vegetables. When expressed from the natural foods, these fats are liquid at room temperature. Some sources of monounsaturated fats are olive oil, peanut oil, canola oil, avocados, and most nuts. Polyunsaturated fats are considered essential, which means the body requires them for regular functioning but cannot make them. Polyunsaturated fats help to build cell membranes, and assist in blood clotting and muscle movement (Harvard Medical School, 2017).
• Carbohydrates are an energy source which the body uses to support daily functioning. When the body begins to break down carbohydrates for use, glucose is created. This glucose supports the brain, central nervous system, and red blood cells. Additionally, the sugar molecules from carbohydrates have been shown to facilitate communication between cells and help create mucus and shape proteins (Sizer & Whitney, 2017). Dietary fiber, which can be categorized as soluble or insoluble, has important and unique benefits to the body. Soluble fiber, which dissolves in water, can help maintain colon health, reduce inflammation, support immunity, and may help thwart allergies; insoluble fiber, the tough fibrous structure of plants, is indigestible and reduces the risk of constipation, hemorrhoids, and colon cancer while creating a feeling of fullness when eating (Sizer & Whitney, 2017).

Micronutrients are vitamins and minerals. Vitamins and minerals are unique in that they provide no energy to the body. Instead, they assist the body in all functions such as moving muscles, digesting food, and obtaining energy from the other classes of nutrients (Sizer & Whitney, 2017). Vitamins are classified as either fat soluble or water soluble, which basically means we need both fat and water to properly absorb and utilize them! Although you can add a multivitamin or supplement to assist in meeting your recommended daily values of micronutrients, the best way to obtain these is by eating a varied diet. 

References:

Harvard Medical School. (2017). The Truth About Fats. Retrieved from https://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good

Illinois Farm to School Network. (2013). 13 Vitamins [image]. Retrieved from http://illinoisfarmtoschool.org/toolkit/751-2/

Sizer, F. & Whitney, E. (2017). Nutrition: Concepts and controversies (14th ed.). Mason, OH: Cengage Learning.

U.S. National Library of Medicine. (2018). Dietary Proteins. Retrieved from https://medlineplus.gov/dietaryproteins.html 

U.S. National Library of Medicine. (2018). Dietary Proteins [photograph]. Retrieved from https://medlineplus.gov/dietaryproteins.html

Cultural, Sociological, Psychological, and Contemporary Factors in Food Choices

Ciao, bella! 

In case you didn't know from my other blogs, I'm Italian and love to cook and eat. Nothing shows how much I care like the labor of love of a pot of marinara simmering away on a Sunday, waiting to be ladled on a bowl of pasta. There is no doubt that my Italian heritage and cultural upbringing has influenced my attitude toward food and nutrition; in my family, being a member of the "clean plate club" meant you appreciated the person who cooked and were eating healthy. I'm learning that other people's culture also has a direct influence on their food choices. In fact, partaking in traditional cuisines is a part of one’s heritage which can be considered symbolic or celebratory (Sizer & Whitney, 2017). There is a strong link between food choices and culture. 

In addition to familial culture, social factors can influence our food choices. I know that I tend to eat more when I am out in a social setting. The same is true for drinking alcohol. If I am at home by myself, I am unlikely to have fried mozzarella sticks as an appetizer. However, if I am out at a restaurant and my best friend orders some, of COURSE I want to share with her! Maybe it's time that I start to drive the change and be the influential friend who encourages my circle of peeps to eat better. I found a recipe for a baked version of mozzarella sticks that I can make at home for our next get-together. Check it out HERE. Baby steps, right? A lot of small changes can add up! 


I'm also learning that there are other influences which drive our food choices. For example, psychological factors. I have noticed a trend in my own dietary patterns. When I am stressed out I tend to emotional eat, which is defined as which is defined as a behavior which occurs as a response to emotions and not true hunger. (Serin & Sanlier, 2018). Just like the happy hours I mentioned earlier, emotional eating can also be a result of celebrations. Cake anyone?

Another influence on our eating patterns is contemporary or popular ways of eating such as Atkins, South Beach, Keto, or Paleo diets. A few decades ago the dieting and nutrition trends were low-fat and sugar-free. These diets and nutritional plans gain momentum by being highlighted on television shows, in magazines, and by word of mouth. I can personally list off at least 10 friends who are on some type of popular diet. Although there may be some validity to these ways of eating, one should be cautious as diversity is important in nutrition. Eliminating whole food groups such as carbohydrates can be dangerous to your health! The body might go into a state of false famine; additionally there is little known about long term effects of fad diets and many dietitians subscribe to the school of thought that the healthiest diets are moderate and well balanced (Rouden, Rasuli, & Lu, 2007).

References:

Applebees. (2018). Mozzarella Sticks [photograph]. Retrieved from https://www.applebees.com/en/menu/appetizers/mozzarella-sticks

Rouden, D., Rasuli, P., & Lu, X. (2007). Potential long-term consequences of fad diets on
health, cancer, and longevity: Lessons learned from model organism studies. Technology in Cancer Research and Treatment, ISSN 1533-0346 Volume 6, Number 2. 

Serin, Y., & Şanlıer, N. (2018). Emotional eating, the factors that affect food intake, and basic approaches to nursing care of patients with eating disorders. Journal Of Psychiatric Nursing / Psikiyatri Hemsireleri Dernegi, 9(2), 135-146. doi:10.14744/phd.2018.23600

Sizer, F. & Whitney, E. (2017). Nutrition: Concepts and controversies (14th ed.). Mason, OH: Cengage Learning.

Nutrition & Disease

Today was an interesting day to say the least. I went to the doctor for a cough that wouldn't go away and was shocked to learn that my weight has skyrocketed and my blood pressure has too. I knew I hadn't been eating the best, but I didn't realize the impact on my health would be so fast and furious. My doctor gave me some great information to help me take ownership of my health. 

Nutrition and disease are directly linked. It's logical & I have always known this. But I didn't realize just HOW much they are connected. 

It's no surprise that the foods and nutrients that comprise a person's diet have a direct correlation with their overall health. Although chronic diseases such as heart disease, diabetes, and bone loss have genetic influences, there are also direct connections between chronic disease and poor diet (Sizer & Whitney, 2017). Food and nutrients are intended to fuel the body, however an excess of foods (especially those which are high in saturated fats or void of nutrition) can lead to problems such as obesity. In fact, my doctor said that people who have a higher fast-food consumption weigh about 13 pounds more than their lower-consuming counterparts; similarly, it can lead to a larger waist circumference, a greater increase in triglycerides, and over double the risk of metabolic syndrome (Harvard School of Public Health, 2018). I have been so busy with work, school, and my son's activities that we have been hitting up the drive-through a lot lately. 

I chose a salad, so that can't be too bad, right? Wrong! My go-to chicken salad has breaded and fried chicken (which is high in saturated fats - eek), and ranch dressing (which has corn syrup in it - gross!). I even did some investigating on the calorie and fat count. 660 calories and over half of my recommended daily value of fat! No wonder my pants are fitting tight lately. 

But wait... there's more! 

An improper diet can increase an individual's risk of cardiovascular disease, high blood pressure, type 2 diabetes, certain cancers, and poor bone health which can lead to osteoporosis later in life. I'm certainly going to take an inventory of what I eat and see if there are any direct links to potential health concerns. I'm young enough that I can reverse this runaway health train and reduce my risks of chronic diseases by making better choices! 

References:

Harvard School of Public Health. (2018). Beyond Willpower: Diet Quality and Quantity Matter. Retrieved from https://www.hsph.harvard.edu/obesity-prevention-source/obesity-causes/diet-and-weight/

McDonald's. (2018). Crispy Chicken Salad [photograph]. Retrieved from http://www.mcdonalds.ie/iehome/food/full_menu/chicken/crispy_chicken_salad.html

Sizer, F. & Whitney, E. (2017). Nutrition: Concepts and controversies (14th ed.). Mason, OH: Cengage Learning.