Macronutrients 101
There are three essential nutrients that the body requires in relatively large amounts to function properly. These are called macronutrients, and include carbohydrates, proteins, and fats. Each macronutrient plays a unique role in supporting various physiological functions, and they have distinct effects on the body.
Carbohydrates (or “carbs”) are the body's primary source of energy. They provide fuel for the brain, muscles, and other organs. When consumed, carbohydrates are broken down into simple sugars during digestion and released into the bloodstream as glucose. Cells then absorb glucose as a source of energy with the help of insulin. Carbohydrates that are not immediately used for energy are stored in the liver and or converted to fat for later use. Some carbohydrates also include fiber, which slows the absorption of sugar into the bloodstream and helps to keep blood sugar levels more stable.
There are two types of types of carbohydrates. Simple carbohydrates are broken down quickly by the body and thus provide quick energy, while complex carbohydrates are larger compounds that take more time for the body to break down.
Foods that provide simple carbohydrates include those with naturally occurring sugars as well as processed and refined sugars. For example, fruits, vegetables, dairy products, honey, and maple syrup contain natural sugars, while table sugar, candy, soft drinks fruit juices, baked goods, jams, jellies and processed and packaged foods (breakfast cereals, granola bars, flavored yogurts) all contain added or refined sugars or sweeteners. In general, the less processed your carbs are, the better. Diets high in added/processed sugars have been linked to various health issues, including metabolic disorders and obesity. Choosing whole, unprocessed, and nutrient-dense sources of carbohydrates is generally recommended for optimal nutrition and health.
Complex carbohydrates include starches and fiber and take longer for the body to break down and absorb, which helps slow digestion and prevent spikes in blood glucose levels. Sources of complex carbs include vegetables (including starchy vegetables such as potatoes, corn, peas, squash, and carrots) beans and legumes, and whole grains (including rice, oats, whole wheat, and barley).
Proteins are essential for the structure, function, and regulation of tissues and organs. They are made up of amino acids, which are the building blocks of the body. Our muscles, bones, skin, hair, and nails are made primarily of protein! When consumed, proteins are broken down into amino acids during digestion. These amino acids are then used to build and repair tissues, produce enzymes and hormones, and support immune function. Adequate protein intake is crucial for muscle maintenance and growth.
Protein sources include meat, poultry, fish and shellfish, eggs, and plant-based choices. For meat and poultry, consider organic sources that are grass-fed or free-range, and free of hormones and antibiotics. Wild-caught fish and shellfish are likely to contain more nutritional value and fewer potential toxins. Dairy products can also be an excellent source of protein, especially Greek yogurt or cottage cheese. High-quality vegetarian sources of protein, include legumes (beans, peas, lentils), nuts and seeds, quinoa, and organic soy products such as tofu, edamame, and tempeh.
Fats play a vital role in energy storage, cell structure, and the absorption of fat-soluble vitamins (A, D, E, and K). Healthy fats are essential for brain function, hormone production, and inflammation control. Dietary fats are broken down into fatty acids and glycerol. These components are utilized for energy, cell membrane construction, and the synthesis of hormones and other signaling molecules. Essential fatty acids, such as omega-3 and omega-6, must be obtained through the diet because the body cannot produce them.
Fat helps food to taste good, and because fat takes longer to digest it helps keep us feeling full long after a meal is finished. However, there are several types of fat – and some are healthier than others – so it’s important to consider fat quality.
Healthy fats are found in sources such as avocados, extra-virgin olive oil, nuts, and seeds. They contain monounsaturated fats (MUFAs), which are heart-healthy and help to support “good”: cholesterol (HDL) and to lower “bad” cholesterol (LDL). Salmon, mackerel, tuna, chia seeds, flaxseeds and walnuts contain Omega-3 fatty acids, which help reduce inflammation, boost immunity, support cardiovascular health, and reduce the risk of Alzheimer’s disease and some cancers.
Fats to steer away from include synthetic trans fatty acids (they are found naturally in some animal products, such as meat and dairy, but the synthetic versions should be avoided). An ingredient list which includes the words “partially hydrogenated” is a signal that trans fats are present. Trans fats are associated with inflammation, heart disease and hardening of the arteries (atherosclerosis). Sources of trans fats include margarine, processed baked goods, fried foods, and frozen foods.
Why is a balance of macronutrients important? It is crucial for maintaining overall health and supporting various physiological functions in the body. Here are several reasons why a well-rounded mix of carbohydrates, proteins, and fats is essential:
As an energy source, carbohydrates provide the primary source of energy for the body, especially for the brain and muscles, while fats serve as an energy reserve, particularly during times of fasting or low food intake.
When considering nutrient absorption, fats aid in the absorption of fat-soluble vitamins (A, D, E, K) and other nutrients. These vitamins play essential roles in various bodily functions.
For cellular structure and function, proteins are essential for building and repairing tissues, supporting immune function, and serving as enzymes and hormones, and fats contribute to the structure of cell membranes, ensuring proper cell function and communication.
In the regulation of hormones, proteins and fats play a role in the production of hormones that regulate various physiological processes, including metabolism, growth, and stress response.
For blood sugar regulation, carbohydrates influence blood sugar levels, and a balanced intake helps prevent drastic fluctuations in energy and mood.
For muscle maintenance and growth, proteins are crucial for preserving and building muscle mass, especially during periods of physical activity or exercise.
For cognitive function, carbohydrates provide the brain's preferred source of energy, influencing cognitive function and mental clarity.
To support immune function, proteins are essential for the production of antibodies and other immune system components, and fats play a role in immune system regulation and response.
And for satiety and weight management, proteins and fats contribute to a feeling of fullness, helping control appetite and support weight management.
A balanced intake of macronutrients helps prevent deficiencies in essential nutrients, ensuring the body has all the necessary building blocks for optimal function. Achieving this balance provides the body with the right proportions of each nutrient to meet its energy needs, support growth and maintenance, and ensure proper functioning of various systems. The specific balance can vary based on individual factors such as age, gender, activity level, and health goals. Finally, it is important to note that the quality of macronutrients (choosing whole, nutrient-dense foods) is just as crucial as the quantity for overall health and wellbeing.