Macronutrients: What Are They and Why Do We Need Them?

Monday, March 6, 2017

300300p27278EDNmainMedical Monday Foley 114As a registered dietitian specializing in the treatment of severe eating disorders, I have a lot of conversations with patients about “fear foods”. These foods range the entire spectrum from sweets and desserts, to fruits and juices, to “everything”. Ultimately what the fear comes down to, though, is calories. How many calories does a food have? Where are those calories coming from? How are those calories going to affect my body? These are all typical questions I see my patients asking themselves. Interestingly enough, all calories are going to provide nutrition and we can find some sort of nutritional value in everything we eat. Why is that, you ask? Because all foods contain macronutrients, the fuel that allows our bodies to survive, endure and thrive.

Macronutrients are the building blocks for the human diet. There are three macronutrients: carbohydrates, proteins, and fats, and they act as an umbrella for all nutrition. Macronutrients are the compounds that we consume in to fuel our bodies on a daily basis. These macronutrients are composed of many things including vitamins, minerals and amino acids. All three macronutrients are vital for our bodies to be healthy and strong and should be consumed daily.

Carbohydrates are one class of macronutrients that my patients tend to fear the most. The reasons can vary from myths about carbs making you gain weight to the fear that you enjoy them so much that you might eat them in large quantities and in turn, gain weight. Carbohydrates are so important in our diets, though, and can be found in most food items including bread, pasta, rice, fruit, juice and milk. Carbs are basically the fuel that our bodies need to thrive and have energy. They provide glucose which we store in the liver as glycogen and use when our bodies are out of fuel. If we don’t have any glycogen storage due to lack of carb intake, our bodies will start to break down our muscles and, in turn, make us feel weak. Our brains and central nervous systems also need a constant supply of glucose to operate at their maximum ability. There are some physical indicators that we may feel if we aren’t getting enough carbohydrates in our diet including fatigue, dizziness, nausea and foggy thinking. It isn’t uncommon for patients to admit into treatment and not be able to focus or remember conversations and then start receiving nutrition and carbs and feel dramatic improvements in their ability to concentrate and retain information. Carbs also provide a litany of other nutrients such as vitamins and minerals so if we aren’t taking in carbs, we can have micronutrient deficiencies, as well. Another important nutrient we get from carbohydrates is fiber. Carbohydrate rich foods that contain fiber include fruits and whole grains and consuming these things can help to prevent constipation and reduce cholesterol.

Another macronutrient that patients tend to fear is fat. One thing I hear often is “if it has fat it will make me fat”. Fat is typically related to foods that people deem “unhealthy”: fried foods, desserts, full fat cottage cheese, yogurt or milk. However, it is important to remember that fat is a vital nutrient in our diet for many reasons and can be found in a variety of foods including avocado, hummus, olive oil and cheese. First off, fat is the most energy-dense nutrient. Fat contains nine calories per gram vs the four calories per gram we receive from carbohydrates and protein. Patients suffering from eating disorders who are trying to gain weight can greatly benefit from having fat in their diet simply due to the fact that they can eat small amounts of food without feeling too full but still receive the necessary calories that their bodies are so desperately craving. Fats are also carriers for fat soluble vitamins so avoiding fats will prevent our bodies from absorbing all of the vitamins that we need. In addition, fat assists with regulating temperature, so if you feel cold all of the time not having enough fat in your diet could be the culprit. It also provides padding for our vital organs, in turn protecting them from damage, and provides essential fatty acids that are vital for cardiac health.

The last, but not least, macronutrient we need in our diets is protein. Protein tends to be the least “scary” macronutrient for my patients, but that doesn’t mean it is any more or less important than carbohydrates or fats. Protein is important to have in our diets for a number of reasons and can be found in foods such as beans, chicken, fish, tofu and milk. Protein is made up of 20 amino acids, eight of which are considered essential and 12 of which are considered non-essential. The eight essential amino acids are as such due to the fact that we can only get them from our diet. Our body naturally produces the other 12. If we don’t consume protein we can’t consume the essential amino acids and therefore can’t make a complete protein for our body. Our body also doesn’t store these amino acids so we need a daily influx of them from our diet. Protein is important because it helps make up our skin, muscles and organs. We also need protein to help our body grow and repair itself so assuring we take in adequate protein daily is vital for our body’s strength and health.

My patients have taught me that struggling with an eating disorder is a prescription for anxiety, fear and intimidation related to food intake. Try to remember, though, that those thoughts are your eating disorder talking. If you break down the mechanics of what is in the food you are consuming hopefully you can remember that it is all helpful. Carbohydrates, proteins and fats are the perfect combination for a strong, healthy body. So go ahead, enjoy your eggs, avocado and toast, have a chicken and cheese burrito, even enjoy some ice cream and fruit, and remember eating these macronutrients and remembering why they are so important will take you one step closer to recovery.

Meghan Foley, RD