The Digestive System

The Human Digestive system is a very complex system. It involves many organs to turn what we consume into nutrients. Digestion is the simple brake down of foods.

            The digestive track consists of:

•   Liver – main role to produce bile to digest and absorbs fats. 
• Pancreas – mixture of digestive enzymes to digest  carbohydrates, protein and fats
• Gallbladder- stores bile to brake down fats
• Mouth—chewing starts the brake down of foods
• Esophagus—tube connecting mouth to stomach.
•  Stomach—where the action really takes place. Digestion of protein  starts.
• Small intestine— where the absorption of nutrients take place
•  Large intestine – water is absorbed, feces are formed
• Rectum and anus – storage and disposal of waste 

The liver, pancreas and gallbladder I refer to them as accessory organs because they lie outside the digestive track.  Each of these organs plays an important role in the absorption of nutrients and removal of waste in our bodies.

            The actual process of digestion is divided into two different phases; The Mechanical and The Chemical process. The Mechanical and Chemical digestions work interchangeably  to process food, absorb nutrients and minerals and discard the waste. The Mechanical aspect of digestion is the actual movement of food through the different organs by peristalsis. The Chemical aspect of digestion occurs when the food mixes with the different enzymes and stomach acids to continue to transform the food into molecules of nutrients for the body to absorb. It is during the chemical aspect of nutrition where the body gets energy and nourishment. Let's discuss briefly how our sources of energy, macro nutrients, are digested!

  Carbohydrates (Glucose)     

The process of carbohydrates starts at the mouth—salivary glands moisten the food and the enzyme Amylase is release to brake down sugar. Once the food is chewed into smaller pieces it moves down the esophagus to the stomach. Once in the stomach it becomes chyme (partially digested food). From the stomach it enters the small intestine where digestive enzymes secreted from the pancreas continue to brake down the sugar.   These small sugar units can now be absorbed through the intestinal walls into the liver and turned into glucose. The glucose is passed from the liver through the bloodstream to the body. Once the pancreas detects the glucose in the bloodstream they will release insulin.  The excess glucose along with fiber and waste will move on to your large intestine, where it will eventually be eliminated.  The majority of the digestion of carbohydrates takes place in the small intestine.

 Protein (Amino Acids)

Protein digestion also starts in the mouth by chewing, where the food is broken down into smaller pieces. The food will travel to the stomach, where most of the brake down of protein takes place. The stomach releases hydrochloric acid and protease enzymes needed to digest protein.  The pancreas release enzymes (trypsin) into the smaller intestine. The food will stay in the stomach for about 2 – 6 hours. Once the protein molecules are disintegrated into amino acids they are ready to pass to the bloodstream through the intestinal walls. 

                    Fats (Fatty Acids)  

Fats will follow the same process as carbohydrates and protein but they really go undigested in the digestive tract until the reach the small intestine. The liver produces bile, which is stored in the gallbladder until it is triggered to be release. Bile is released into the small intestine where the fat emulsifier into smaller droplets. The bile and pancreatic lipase continue to brake down the fat into smaller pieces that are ready to absorbed into the bloodstream.

References:
National Digestive Diseases Information Clearinghouse/National Institute of Diabetes and Digestive and Kidney Diseases. The Digestive System and How It Works retrieved on Oct 2014 from http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/ .
  Merck Manual Home Health Handbook. Overview of the Digestive System retrieved on Oct 2014 from http://www.merckmanuals.com/home/digestive_disorders/biology_of_the_digestive_system/overview_of_the_digestive_system.html?qt=digestive&alt=sh
  Sizer, F., & Whitney, E. (2013). Nutrition Concepts and Controversies (13th ed.). Wadsworth Cengage Learning

Life-cycle Nutrition

Carbohydrates, fats, proteins, minerals and vitamins are needed through every life stage. The “content” per say of our diet does not change. Through out life we are encouraged to eat whole grains, vegetables, fruits, lean protein and healthy fats. The amount of each essential nutrient will change from one stage to another. 

 

Pregnancy:

Through pregnancy the amount of macro nutrients is slightly higher.  During the first trimester no additional energy is needed, but in the second trimester it is recommended women add 340 calories and 450 through out the last one. Doctors recommend prenatal vitamins for pregnant women to ensure essential nutrients such as folic acid, iron and calcium are part of their diet.

 

 

Infancy:

A baby’s digestive track is not ready to process the foods in the form we eat them, therefore 8-12 feedings a day of breast milk or iron fortified milk is recommended. Breast milk is highly recommended for at least the first 6 months. Cow milk is not recommended for infants younger than a year old. The protein content in cow milk is too high for babies and it can cause kidney problems. As babies grow, cereal, fruits, vegetables, whole grains are added to their diet. A daily requirement of macro nutrients is higher during infancy and early childhood than any other stage. This higher demand is justified by the rapid cell division and growth.


 

Childhood:

Children between the ages of 2-3 require between 1,000 -1,400 calorie intakes depending on their activity level while for children between ages 4-8 1,200 - 1,400 calories is the daily recommendation. Children ages 9-13 their calorie intake varies between 1,400 -2,000 depending on gender and activity level. There are physical, emotional, and psychological changes that take place through out this stage. Their brain and limbs are not fully developed and a healthy diet is critical to their development. In addition, they are like little sponges, absorbing and learning from their environment, this is the perfect opportunity to establish/reinforce good eating habits.

 

Adolescence:

Adolescence is the stage when kids experience their grow spurts, and they can certainly put away some food! A 15 year old boy may need 3,500 calories just to maintain their weight. Generally boys between the ages of 9 -18 will need 1,600 – 3,200 calorie intake based on their activity level. Girls the same age will need 1,400 – 2,400 calorie intake. 
Trying to get our children and adolescents to choose a fruit instead of a cookie can be a challenge. It is important than besides their macro nutrients they still take vitamins and minerals as these prove vital for their growth and development. Adding a daily vitamin might be a way to supplement any deficiencies.

Adulthood:

The calorie intake for adults follow the same guidelines as children, it is based on gender, activity level, and age. We can probably notice that we are no longer able to eat everything we want and not gain weight. Our daily routine, may sway us to choose "convenience" over "healthy". We need to eat a balance diet and stay active! Adults calorie intake may vary from 1,600 – 2,600 with activity level being the determining factor. 

Elderly:

It doesn't end, at this stage we must continue to eat a balance diet. The activity level declines and thus the calorie intake. It is extremely important to stay away from fatty food, avoid trans fat, and add calcium and perhaps a daily vitamin.

 


        Healthy eating starts when we are born and it ends when we pass. Our eating habits and nutritional choices start from infancy. We must introduce new foods, healthy foods to our children from an early age. Life is a cycle; if we teach our children from an early age to limit sweets and sugar and eat more vegetables and fruits they will more likely follow the same pattern as adults. Nutrition.gov along with Myplate offers many tools to help understand our nutritional needs as we experience the different stages in life.

References:


Center for Disease Control and Prevention. Health effect of childhood obesity. Retrieved on October 2014 from http://www.cdc.gov/HealthyYouth/obesity/facts.htm

Nutrition MD.org Nutritional Requirements through out the Life cycle. Retrieved on Oct 2014, from http://www.nutritionmd.org/health_care_providers/general_nutrition/lifetime_nutrition_requirements.html

Sizer, F., & Whitney, E. (2013). Nutrition Concepts and Controversies (13th ed.). Wadsworth Cengage Learning

Strive for Healthy Weight

To determine a healthy weight, we can use two quick techniques at the comfort of our home! A measure of our Body Mass Index (BMI), and a waist circumference measurement. BMI is basically your weight in relation to your height. You can use one of the many Adult BMI Calculators available in the internet to calculate your weight. Tools as this calculator provide you with an estimate of your BMI and it provides a baseline on where we are and where we need to be in regards to weight. The idea is to aim for a healthy weight, keep in mind that there are other factors, besides weight, height, and gender such as muscle tone, frame size and tone that helps determining a healthy weight.
Aiming for a healthy weight will prevent you from falling into any other unhealthy category, such as underweight, overweight and obesity. Underweight refers to body weight below healthy weight or a BMI of 18.5. Overweight is the opposite, body weight higher than healthy weight or BMI between 25-29.9 and Obese is the term use when your BMI is higher than 30.

                           Where do we start?

 

A Healthy diet is the key to a healthy weight! Dietary Guidelines point the consumer to balance calorie intake, increase intakes of nutrient dense foods, reduce the intake of some foods and build a healthy eating pattern. We are constantly on the go, and unfortunately we resort to prepackaged processed foods, exactly the food we should limit. Changing the way we eat is a must; we do not need to make big changes all at once. Small steps will get us there. Eating healthy is not temporary; it is a lifetime commitment.

               Tips to establish Healthy Eating Habits

When ordering/eating out, there are ways in which we can control the amount of food we eat. I personally ask the server to refrain from bringing complimentary “chips” or “bread” to the table while we wait for our food. I only order water for drinks. Portion control is a must! We can start by implementing small changes such as, sharing our meal with a friend, ordering a kids size meal, taking ½ of it to go, etc. All of these are great techniques in controlling our food portions and easier on our pocket. Double win!


At home, the use of measuring tools is great tool. The use of smaller plate, the 9” versus the 12”. Establish a time after dinner and make the kitchen off limits! Don't buy junk food, replace your snacks for fruits, vegetables and healthy granola bars. Read food labels! Food labels provide a simple breakdown of nutrients and ingredients. I have a rule of thumb in my house, if I do not understand the first four ingredients, or if sugar is within the first four, I do not buy it! Food labels provide awareness, education is the key! Last but not least, move, move, move! Stay active! Take the stairs, park farther away, dance, walk, stay moving! These are all small inexpensive changes with cumulative health benefits.

 

References:

Sizer, F., & Whitney, E. (2013). Nutrition Concepts and Controversies (13th ed.). Wadsworth Cengage Learning.

Variyam, J.N., 2008. Do nutrition labels improve dietary outcomes? Health Econ. 17(6), 695–708.

Time for a change

Is my Diet Good?
Once you acquire a general knowledge on what healthy eating encompasses, the next step is to take a close and personal look to your diet.

My Diet:
 For the most, I eat healthy food. I eat a variety of vegetables. I limit red meat, and eat mostly poultry and seafood. I love fruits, and though I could get carried away, I try not to eat more than 2 fruits a day. I drink plenty of water! Love water! Very rare, I have fast food, sweets, chocolate, fried foods or prepackaged foods. I cook every day, and  I strive for using fresh ingredients. I work out 5 times a week. I have  a cardiovascular routine with strength exercises.I also use Super Tracker from Myplate to keep a daily personal journal of my food intake.
My biggest problem is portion control. I eat a lot of food,  I am known for that! I have never watched my portions.  I also enjoy a lot of white rice, bread, and I love pasta! I don't time my meals. Breakfast is a foreign concept for me.  A normal day,  I get up at 4:00 a.m. I have a cup of coffee in the morning, and my first meal is about 2:00 p.m. My next meal is about 7:00 and those two meals are extremely big. Some days I eat very little, and some days I can't stop eating! Though I don't really eat desserts, I eat plenty of hard sour candies. From analyzing my personal diet there are some changes that need to take place.




My Changes: 
  I have realized that though I don't eat too bad, my eating habits need some tweaking. I have replaced bread for whole grain bread. I am not eating white rice at all. It's been three weeks! I am not saying white rice is horrible for you, and everyone should refrain from eating white rice. I just simply chose not to eat it anymore. I have added quinoa to  my diet. I am also very happy to report, I have not eaten any candy in the last three weeks either. When I feel the need to go for sugar, I go for a fruit instead.  I started timing my meals,  and now I am aiming for six small meals through out the day. This is hard! It has been my biggest challenge, but I will continue to try until I master the concept of portion control and timing. It is all about behavior modification, and retraining your mind. Small changes yield big results, It is a lifestyle change! I want to live longer and stay healthy--

Driving force behind our food choices.

Why do we choose to eat the way we do? Why do we go for seconds knowing that is not healthy? 

         There is a physiological need to eat, and of course we eat when we are hungry but there are other factors that may influence the choices we make, how much we eat, how often, etc. Sometimes we don't even know why we are eating, we just eat!  Understanding the driving force behind the impulse to eat can help us be in control and choose our meals wisely.

          Our culture influences may prompt us to eat certain foods and/or the restriction of other food groups. I grew up in a very traditional Hispanic family and we must have rice with every meal. I eat my beef stew over white rice; if I make spaghetti I will have a side of white rice. To some this is unacceptable but to me it’s perfectly fine. Breaking the cycle, and perhaps replacing the side of white rice for a side of vegetables may take some effort, but it is very much doable and a side or vegetables made this a balanced meal.

          There are psychological factors that may affect our healthy eating. Stress, happiness, sadness, and mood can affect our appetite. Some people eat when depressed others eat when all is going well.  We tend to look for emotional comfort in food; leading to unwanted weight and health issues.  Other times we eat because it is there; it is accessible!  Lack of knowledge, education, convenience, and money can also be barriers when trying to choose healthy foods. It is probably easier to go to a drive-thru window than come home a prepare a meal; but if we plan ahead we can stay away from drive-thru, unhealthy food and fuel our body with the right nutrients on a budget.

    Food should only have one meaning in our lives, healthy food nourishes our body. Food is not intended to provide us with a coping mechanism, or emotional comfort, or happiness, healthy food provides our body with essential nutrients.

 

 There are ways in which we can retrain our mind to avoid overeating or making unhealthy choices. Make gradual/small changes and stick to them.

• Don't buy junk food, if is not there you can't eat it
• Pack a lunch and only eat what you packed
• Get moving, go for a walk
• Drink water; lots of water

Internet Resources   

• Eating Healthy
• Quick healthy lunch and snacks
• Healthy Meals on a budget

References:

Bellisle, France (2005). The Determinants of Food Choice. Retrieved from http://www.eufic.org/article/en/expid/review-food-choice/

Sizer, F., & Whitney, E. (2013). Nutrition Concepts and Controversies (13th ed.). Wadsworth Cengage Learning

Macro nutrients and Micro nutrients Functions

 There are 2 types of nutrients

                      Macro nutrients –refers to the bulk of our food—carbohydrates, proteins and fats 

                     Micro nutrients – are vitamins and minerals essential to our body.  They consist of 13 minerals including fluoride, selenium, sodium, iodine, copper and zinc among others. They also include 12 vitamins such as vitamin C, A, D, E and K, as well as the B-complex vitamins.

                              Overview of Micro  nutrients.

             Micro nutrients are needed in tiny amounts yet they are vital to our health. As a matter of fact most of the diseases that people face today are because of micro nutrient deficiencies. Micro nutrients play an important role in all of our body’s systems.

                                            Minerals

Manganese- aids bone formation and metabolism
Magnesium – aid heart rhythm and helps convert sugar into glucose so the body can utilize it as energy

Iron—production of red cell, and lymphocytes

Iodine- aids thyroid gland developments and function, metabolism

Chloride – regulates water and electrolytes.

   
                                                    Vitamins

Vitamin C and B complex aid formation and repair of tissue, metabolism

Vitamin A - eye health

Vitamin E -protects body tissues

Vitamin D- absorb calcium into the body.

Vitamin K—aids blood

Some common micro nutrient deficiencies include iodine deficiency, vitamin A deficiency and iron deficiency.

                                         Overview of  Macro nutrients

         Macro nutrients are Carbohydrates, proteins and fats; they work together and have an essential role in our body. These nutrients are needed to support and maintain optimal health and performance.

Carbohydrates are your primary source of energy. They provide 4 calories per gram. Carbohydrates also assist in fueling our muscles and brain. Carbohydrates are in charge of two main purposes; energy and digestion. Most types of carbohydrates brake down into glucose which provides energy. There are two types of carbohydrates, complex and simple. Simple carbohydrates are mainly sugar; naturally added like the sugar we find in fruits, and manually added like the one in pastries.
     
Simple carbohydrates are digested quickly and turned into energy, thus sometimes we may feel a rush of energy after eating a bagel and then we crash.Complex carbohydrates are mainly starch; they digest at slower rate providing more of a sustained energy level. 

Carbohydrates provide the fuel our body needs to perform everyday tasks such as different body processes, physical activity, daily chores, etc. Fiber is another carbohydrate that plays a critical role in digestion. Fiber does not break down into glucose; therefore we do not receive energy from fiber. Our digestion is dependent of our fiber intake. Fiber, a complex carbohydrate, comes from fruits and vegetables.

     Fats are energy-yielding nutrients as well. They provide 9 calories per gram. Not all fat is created equal and not all fats are bad fat.  

• Trans fat and Saturated fat are the fats that we want to limit, trans-fatty acids not only negatively influence cholesterol levels but also increase triglyceride levels and increase inflammation, according to Mayo Clinic.com.

        Saturated fat is the fat that comes from animals, such as red meat, poultry, and dairy products. In simpler terms saturated fats are just fat molecules.  There are two plant sources for saturated fats, Palm Oil and Coconut Oil. 

 Trans fat is unsaturated fat which has been altered through hydrogenation to become saturated fat. Trans fat is also found in animals or is made out of oil. Trans fat mostly comes from processed foods, such as bake goods, fried food, crackers, etc.  It is believed that saturated fat and Trans fat raises cholesterol (LDL- carries cholesterol to the tissues) which is associated with in heart disease. 

• Unsaturated (healthy fat)  which is fat derived from plants, except palm and coconut, have great health benefits. Unsaturated fats, which includes, polyunsaturated and monounsaturated are believed to increase blood cholesterol levels (HDL- sends cholesterol away from cells) which can potentially decrease the risk of heart disease.

        
  Proteins also provide energy, 4 calories per gram have a significant role in building and repairing muscle tissue. Protein is what helps the body grow and develop!  The body uses proteins to build new cells, maintain tissue, and build muscles. Our nails, hair, skin cells, bones, muscle tissue, blood, they are all made of proteins! Proteins are made of amino acids, and amino acids are needed to break down food. Without amino acids the body cannot make proteins.Proteins play an important role in our body, besides strengthening cells and tissues, proteins help the immune system and regulate our metabolism. 

             This is just a small overview on macro nutrients and micro nutrients in an attempt to explain the importance of these essential nutrients and their functions. Macro are needed in larger quantities and micro in smaller, but they  both are as  important and even a small deficiency in either one may have a negative impact on our health.
         The video below explains Macro nutrients function in simple terms. Hope you enjoy! Remember, Knowledge is Power!

References:

Macronutients. 2014. Nutrients in Motion Retrieved on Oct 2014 from http://www.macronutrients.net/nutrients-in-motion/

Healthy Living. Org. Avoid Empty Carbohydrates (2014) retrieved on Oct 2014 from http://healthy-living.org/html/avoid_carbohydrates.html

eHealthmd. (2012) Fiber: It’s important in your diet. Retrieved Oct 2014 from http://ehealthmd.com/content/what-are-health-benefits-fiber  

Healthy Eating

     What is healthy eating?  Healthy Eating  has rules and boundaries; we do not have to give up the foods we love!

     We can apply a few rules to our eating habits and we can still enjoy those yummy treats that bring us such joy and emotional comfort. A healthy diet provides: Adequacy, Balance, Calorie control, Moderation and Variety.



Five Characteristics of Healthy Eating 
 
Adequacy: provides essential nutrients and energy 
Balance: provides all three macro nutrients, carbohydrates, protein and healthy fats, in the right quantity     
Calorie Control: provides the appropriate portion to sustain our bodies
Moderation: provides enough – no more no less 
Variety: provides a wide selection of healthy foods. 

          A healthy diet must have these 5 characteristics. When choosing meals let’s be mindful and aim to obtain enough of each vital nutrient while keeping balance among the three main elements and in the appropriate quantities. Our meals must be calorie controlled, it will be chaotic to have our meals packed with thousands of calories and having a sedentary lifestyle. Our calorie intake must match our calorie expenditure. We can eat the foods we love in moderation; control is the key not abstinence! And last but not least, our meals must come from a variety foods. We should eat from different types of food daily; not only it will help us consume the nutrients we need; it will prevent boredom and decrease the possibility to overindulge. We should always eat at the right time, planned our meals and eat at least three meals a day.
Choosing the right foods and combining them  to maintain balance can be a bit of a challenge.  Some may feel unsure on how to do it.  We are constantly being bombarded by the media with the “new” finding the “last” breakthrough, and unfortunately it creates more questions than answers.  Others may think that eating healthy is expensive or a lot of work.  I say, let's go back to the basics! Our body is designed to produce, absorb the essential nutrients to maintain a healthy body.  A healthy diet must be balanced – fruits, vegetables, whole grain, low-fat dairy products. Healthy eating provides a wide variety of choices; let’s concentrate on the foods that we can eat!
            Carbohydrates – are YOUR friend – any diet that restricts you from carbohydrates is not a healthy diet. Keep at about 55-60% of your meal.   Carbohydrates are the body’s main source of energy.  Choose your carbohydrates wisely – brown rice, vegetables, whole grain.  If you must have pasta or white rice, have it, but have half of what you would normally eat and replace the other half with vegetables.  
          Proteins – help growth and development! Keep about 15 -25% of your meal.  Protein helps you build muscle, build new cells and maintain tissue.  Protein mainly comes from animals – choose lean cuts, poultry, tuna, eggs.  Nuts also provide protein.
         Fats –not all fat is created equal --choose healthy fats, unsaturated fats, such as omega 3 fats found in fish. Olive oil, nuts are also sources of healthy fat.  Keep your fat intake at less than 30% of your daily intake. There are many resources available via the internet to help us achieve a healthy diet. Sites such as My Plate have lots of resources to facilitate healthy eating. 

References: 

Bellisle, France (2005).The Determinants of Food Choice. Retrieved from http://www.eufic.org/article/en/expid/review-food-choice/ 
Sizer, F., & Whitney, E. (2013). Nutrition Concepts and Controversies (13th ed.). Wadsworth Cengage Learning