Everyone eats and if you’re like me, you love food. Many of us eat for enjoyment, in fact most celebrations and gatherings are revolved around food. We often reach for food when we are stressed, bored or simply because it’s there and it looks too good to ignore. Humans eat for so many different reasons that it’s often overlooked that the food we choose is intended to fuel our body and not just simply for pleasure.
The food we eat is broken down and used as energy to power our body’s necessary functions, similar to the gas you pump into your car to allow it to run. Unlike a car, we know there are more processes involved in extracting energy from our food than simply filling up our tank. So, how does our body actually get energy out of the food we eat?
Let’s first take a look at the different foods our body needs to fuel it’s many functions. These are your macronutrients.
Macronutrients
Carbohydrates, proteins and fats, these are the basic components of the foods we eat, known as our macronutrients. Carbohydrates are your body’s main energy source whereas protein works to help build and repair our tissue and fats help us to protect our vital organs. All of these nutrients perform many different functions aside from these and work together to carry out complex processes that allow our body to function at it’s prime. This is why it is important to consume a balanced diet high in nutrients to ensure we are providing the best fuel for our body.
What happens when we eat a food?
When you eat, your body will begin breaking down nutrients immediately, starting with carbohydrates and fats. The goal is to break down nutrients to their smallest form so that they are able to be absorbed into the bloodstream. This process is sometimes referred to as chemical digestion.
Once food enters our mouth, our salivary glands produce the enzymes salivary amylase to start the breakdown of carbs and lingual lipase to start the breakdown of fats prior to sending to the stomach. Similar to the glands in our mouth, our stomach also has glands that assist in chemical digestion. These are your oxyntic and pyloric glands [1].
Your oxyntic glands are what produce hydrochloric acid, a.k.a. stomach acid. This acid not only helps to kill any potential pathogens taken in with your food but it also helps to denature proteins and activate pepsin by decreasing the pH of your stomach. Once the pH drops to the 2-3 range on the acid-base scale, pepsin is able to work on breaking down the bonds on those proteins we ingested to make them smaller [1].
Your pyloric glands help to secrete a bicarbonate rich mucus to protect the lining of the stomach from the hydrochloric acid as well as secreting the hormone gastrin. Gastrin works to stimulate the production of hydrochloric acid by the oxyntic glands. This process helps further prepare nutrients for absorption in our small intestines [1].
The majority of chemical digestion occurs within the small intestines which is made up of three parts, the duodenum, jejunum and ileum however, most absorption or nutrients occurs within the jejunum. Once the remains of the nutrients eaten, now known as chyme, reaches the duodenum, your pancreas and duodenum will secrete enzymes to help further breakdown and begin the absorption process.
Our pancreas will produce a myriad of gastric enzymes for chemical digestion including pancreatic amylase, to further breakdown carbohydrates, pancreatic lipase to help break the bonds in fat molecules to make them smaller and, trypsynogen, chymotrypsinogen, procarboxypeptidase and proelastase that will eventually work to breakdown proteins later in the digestive process. These are released in their inactive form as a way to prevent auto-digestion, the process in which pancreatic enzymes actually breakdown their own tissue. These enzymes are released from the pancreas by a duct that connects to the liver and gallbladder and eventually terminates in the duodenum, known as the common bile duct [1].
Bile made from the liver is stored in the gallbladder. Once food begins it’s digestive process, this stored bile is released from the gallbladder through the common bile duct. Bile is an essential component for the absorption of fat by helping to further break it down into it’s smallest form, individual fatty acids [1].
Next our duodenum will release the enzyme enterokinase to convert trypsynogen, chymotrypsinogen, procarboxypeptidase and proelastase into their active forms. It will also release disaccharidases and dipeptidases which further breaks down your carbohydrates into their smallest forms of starches, disaccharides and monosaccharides [1].
By this time, all of our macronutrients have been broken down into their smallest form and are ready for absorption into the bloodstream to be utilized where they are needed.
Final absorption occurs within the villa of our small intestines. These are small, finger like projections that line our intestinal wall and grab onto and absorb nutrients into their capillaries for travel to the blood stream. Anything left from the foods we consume that cannot be utilized is then excreted from our body through our waste.
A Dietitian’s Approach to Building Healthy Dietary Plans
We know how important it is to get adequate nutrients for our body to thrive, so how can we go about building a healthy diet plan that will also work for our lifestyle, preferences and current needs?
When it comes to food, we all have ingrained habits. Whether developed during childhood or due to a new schedule, there are foods we are used to reaching for. When it comes to building a healthy diet plan, this is where you want to start. The way you eat now will tell you a lot about how to move forward.
First, take a look at the quality of your diet. Are you someone who eats out a lot? Maybe you opt for convenience meals at home or maybe you identify as a picky eater and often forgo most fruits and vegetables. Choose one area that you know you need and want to improve and start there.
Still unsure how you are eating? Try self-monitoring. Keeping track of your meals through an app or simply writing them down on paper can help to identify potential problem areas.
Now that you have found some areas to work on, start with making one small change in one of those habits. Go slow and practice until your feel you have completely incorporated this new habit into your routine. Only then should you move forward with another change.
For example, If you are someone who often stops at McDonalds for a quick breakfast sandwich every morning before work, practice adding in a few days a week of cooking something at home instead. You can also try choosing an alternative such as greek yogurt with fruit or granola.
Most importantly, go at a pace that works for you. Try to avoid changing too much at one time to avoid feeling overwhelmed. Change takes time, focus more on adding in more good things and less on trying to cut out all the bad things.
Diet-Building Methodology
When working on building a healthier diet, you first want to know what foods to look for. It’s recommended to consume a diet rich in whole fruits and vegetables, lean cuts of meat, low fat dairy and whole grains while limiting highly processed convenience foods. But what does this look like put together?
Let’s take a look at the MyPlate guidelines for building a balanced meal. Published by the United States Department of Agriculture (USDA) in 2011, this graphic depicts a simple way to adjust your everyday meals to include high quality foods in the recommended proportions to achieve balance [2].
As you can see from the graphic above, it is recommended to fill ½ your plate with a variety of fruits and vegetables, making your plate as colorful as possible. Choose at least ½ your grains as whole grains, such as whole grain bread, pasta or brown rice and limit to ¼ your plate. Choose the last ¼ of your plate for a protein, preferably a lean source such as fish, chicken or turkey. Lastly, choose 1 serving of low-fat dairy for each meal, such as low-fat milk, yogurt or cheeses.
Of course not everyone eats this way. Sometimes we might have a casserole, want a pizza, or even soup. Can we still use this method with those foods? Absolutely! The biggest takeaway from this method aside from the types of food to fill your plate with is the portions.
For example, if you wanted to use this same method for pizza how might you make some adjustments to make it more balanced? First, decrease the carbohydrates to better fit that smaller serving size, opt for a thin crust instead of deep dish or pan. Layer on any and all veggies you enjoy on top of your pizza or add in a side salad. Finally, swap out that pepperoni for a leaner meat such as chicken and you’ve created a meal that is more balanced.
When it comes to diet building methodology, it is not one size fits all. Knowing the general recommendations as mentioned above is helpful for making changes but in the end what is most important is knowing what will work best for you to achieve sustainability with your new eating habits.
