Nutrition is the science of how food impacts our life. 

Everything that we eat offers us different benefits, which in turn influence how we look, feel, and even act. There are many different facets to nutrition since it encompasses both how our body processes the nutrients in our food and how that influences our eating habits overall.

When we eat a piece of food, the digestive process starts as soon as the food hits our stomach. There, it’s broken down into particles by our stomach’s acids and enzymes. Once those particles leave the stomach, they’re sent through the intestines. 

From there, some particles are absorbed into the bloodstream, while others (like proteins and fats) require further processing in the liver. Carbohydrates are some of the fastest to reach the circulatory system since they easily break down into glucose. However, after they are processed, all nutrients are delivered to cells, where they’re turned into the energy that sustains us.

The nutrients that we require can be broken down into a few different categories. Let’s have a refresher about the fundamentals of the nutrients our bodies need and how our DNA impacts these requirements.

Our body requires a large variety of nutrients to function at an optimal level. To make things easier to understand, nutrients are broken down into two categories—macronutrients and micronutrients.

Macronutrients are the nutrients that we need to eat in large amounts in order to survive. They provide all the energy that your body uses throughout the day and support the continued health of all our vital systems.

There are three different macronutrients—fat, carbohydrates, and protein.  

Fat

Fats provide the body with energy while also supporting cell growth. There are different types of fats: saturated fat, which, if consumed in excess amounts, may lead to high cholesterol and heart disease. It is generally solid at room temperatures, such as butter and lard. There are also unsaturated fats, which are liquid at room temperature, such as olive oil. Unsaturated fats are generally considered “healthy fats” and are part of a healthy diet. The fats that we eat protect our organs, keep our body warm, and help to produce important hormones like leptin, the hormone that regulates food intake and energy expenditure during physical activity.

Carbohydrates

Carbohydrates, which turn into glucose once our digestive system processes them, are what our body uses as its most accessible form of energy. 

There are two different types of carbohydrates found in our food today. Simple carbs (typically found in processed flour, candy, or soda) are digested quickly, providing a quick spike of energy that doesn’t last long. Complex carbs, which are an important part of a balanced diet, are found in whole foods like fruits, veggies, and whole grains. They are released more slowly into our bloodstream and provide a more sustained amount of energy.

Protein

Proteins are formed by amino acids, the building blocks of our body’s tissues, helping our muscles, skin, and hair to grow effectively. Like fat, they also support the proper functioning of hormones and enzymes that our body needs to survive.

Read this article to learn more about your macros: An Introduction to Macros.

Like macronutrients, micronutrients are essential to the healthy functioning of our bodies. However, we need micronutrients in much smaller quantities. They are divided into two categories: vitamins, such as Vitamin D and Vitamin C, and minerals, such as calcium, potassium, and phosphorus. Our bodies cannot produce most vitamins and minerals, so we must get the daily required amounts through our food.  

We won’t go into too much depth here, but to learn more about micronutrients, read our article: An Introduction to Micros.

Vitamins can be absorbed by our body in two different ways—either through fat or water.

Water-soluble vitamins can be dissolved in water and are generally absorbed and expelled quickly. They cannot be held in our bodies for long periods of time. As a result, it’s quite difficult to accumulate toxic levels of any water-soluble vitamin since they’re so quickly passed in our urine. Some of the most popular water-soluble vitamins are the B-vitamin group and vitamin C.

Fat-soluble vitamins are less prevalent than water-soluble vitamins, but they play an important role in our health. Fat-soluble vitamins are processed along with fat, which means that they have to go through the liver to be effectively absorbed. 

Fat-soluble vitamins can be stored for longer periods of time in fatty tissue, which means that it’s possible for them to build up to toxic levels. However, this is unlikely unless you’ve overdosed on fat-soluble vitamin supplements. Some of the most popular fat-soluble vitamins are vitamins A, D, E, and K.

Learn more about the science behind vitamins and supplements in our article Fat vs Water Soluble Vitamins.

Sometimes, our bodies respond negatively to certain food choices. This is typically referred to as a food allergy, sensitivity, or intolerance. A food allergy is a negative response triggered by the immune system, and it can be fatal if left untreated.

In contrast, food sensitivities and intolerances are caused by a reaction from our digestive system. They are not usually fatal and, instead, may bring unpleasant symptoms such as gas, stomach aches, diarrhea, and nausea.

In the past, it has been a challenge for healthcare professionals to diagnose and understand food allergies. Overall, the prevalence of food allergies has been increasing and currently affects roughly 8% of children and 5% of adults. New and emerging research offers insight into how our DNA impacts our food allergies and sensitivities. 

Genetic factors, combined with environmental factors, are currently the two largest risk factors for food allergies and sensitivities. Despite knowing this information, scientists are still unable to determine firm and consistent associations between certain genetic mutations and food allergies, since an individual’s environment plays such a large role and is so difficult to control.

Although the genetic basis of allergies has yet to be determined, scientists and geneticists have been able to isolate certain genetic variants that indicate our likelihood of being sensitive to two major nutrients—lactose and gluten.

To learn more about how genetics affect our everyday lives, read our dedicated article on the topic in our blog Genetics 101.

Lactose Intolerance

Lactose is a type of carbohydrate found in dairy products like milk and cheese. Being lactose intolerant means that your body doesn’t produce enough of the hormone that breaks down lactose and its variants. Without this hormone, which is known as lactase, lactose moves through the digestive system without being broken down, which can cause painful symptoms like bloating, gas, cramps, or diarrhea.

Geneticists have pinpointed genetic variants in the MCM6-LCT gene region and in the LCT gene, which may make a person more likely to be sensitive to lactose.

Gluten Intolerance

Gluten is a protein found in many grain and cereal products like wheat, barley, and rye. Individuals who have a gluten intolerance experience digestive problems when they eat products that contain gluten. It’s quite common in children, but most grow out of it by the time they reach the age of 12.

After years of research, geneticists found genetic variants in the HLA-DQA1 and HLA-DQ8 gene region that may make a person more likely to be sensitive to gluten.

Substance Sensitivities

Gluten and lactose are two of a variety of foods that can trigger sensitivities. Some people are even sensitive to popular substances like alcohol and caffeine. Like other types of sensitivities, there is likely both a genetic and environmental component at play that can trigger this type of digestive sensitivity.  

Alcohol

In general, most of us experience alcohol as a depressant—a substance that slows the activity of our central nervous system. However, some people metabolize alcohol differently because of their unique genetic variants, causing them to react with symptoms like a skin flush, hives, diarrhea, or low blood pressure. 

At GenoPalate, our genetic testing kits can analyze genetic variants on the genes ADH1B and ADH1C to see how quickly your body metabolizes alcohol. Personalized nutrition and a personal eating plan based on your DNA can help you make choices to feel your best. 

Caffeine

Caffeine is a stimulant found naturally in many food products ranging from coffee to chocolate. As a stimulant, caffeine speeds up the activity of our central nervous system, helping us be more alert and aware. By analyzing information on the gene CYP1A2, we can see how quickly your body metabolizes caffeine. 

Sensitivities and allergies are complex subjects; it may seem like there’s a fine line between the two. To learn more, read our article Food Sensitivities: What's the Connection to our DNA.