Types of Macronutrients
Carbohydrates
The USDA offers general guidelines on how Americans should distribute their calorie intake among macronutrients. These guidelines are reflected on the nutrition facts labels found on food packaging, which are based on a 2,000-calorie diet for the average American.
A calorie measures the energy in food. If a food item has 100 calories, your body uses 100 calories of energy to process it. Each person has a unique basal metabolic rate (BMR), which is the amount of energy or calories needed just to stay alive. A rough estimate for BMR is your body weight multiplied by 11 for men and by 10 for women. Any physical activity adds to this BMR. The macronutrients you consume, along with alcohol, require additional energy for your body to metabolize.
Many diets work by changing the ratio of macronutrients you consume to achieve specific results. For instance, consuming more protein (along with weight training) can help build muscle mass, while reducing carbohydrate intake can promote weight loss.
Calories per Macronutrient
Each macronutrient provides a different amount of calories per gram:
Fat: 9 calories per gram
Protein: 4 calories per gram
Carbohydrates: 4 calories per gram
Alcohol: 7 calories per gram
These values are averages, as the calorie content of proteins, carbohydrates, and fats can vary slightly.
What About Alcohol?
Alcohol (ethanol) contains seven calories per gram. While some nutritionists consider it a macronutrient, biologists do not because it is not required in large quantities for survival. It can be seen as a nutrient but does not provide any nutritional value. Although moderate alcohol consumption is sometimes said to have health benefits, there is substantial evidence suggesting that avoiding alcohol is the healthiest choice.
Alcohol is metabolized by the alcohol dehydrogenase enzyme in the liver. Until it is fully metabolized, alcohol remains in the breath and urine, which is why breathalyzer tests can detect it.
What Are Carbohydrates?
Carbohydrates include starches, sugars, and fiber, and they provide about four calories per gram. Your body uses carbohydrates as fuel. They come in two forms: complex and simple. Simple carbohydrates, like table sugar and high fructose corn syrup, have one or two sugar molecules. Honey and maple syrup also contain simple sugars and other nutrients.
Complex carbohydrates are long chains of simple sugars, known as polysaccharides, and include starches and fiber. Foods like whole wheat pasta and white potatoes are rich in complex carbohydrates.
How Many Carbohydrates Do You Need?
Adults should get 45-65% of their daily calories from carbohydrates, according to the USDA. Although humans cannot digest fiber, it is essential for health. Your gut microbiota ferments fiber, using it as an energy source. A balanced, well-nourished gut microbiota is crucial for various bodily functions, so include plenty of fiber-rich foods in your diet.
Sources of Carbohydrates
The best sources of carbohydrates are whole foods that are rich in micronutrients and contain sugars or starches along with fiber. This includes whole fruits, winter squash, beans, and ancient grains like quinoa. Despite some definitions categorizing whole fruit as a simple carbohydrate, it is an essential part of a healthy diet, and many Americans do not consume enough of it.
What Is Protein?
Protein is vital for the growth and maintenance of your eyes, skin, hair, nails, organs, and muscles. During digestion, protein breaks down into polypeptides and amino acids. Of the 22 amino acids that make up proteins, nine are essential, meaning the body cannot produce them and must obtain them from food. These include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Histidine is only essential during infancy.
Proteins perform various functions in the body, such as regulating cellular processes and transporting molecules. Enzymes, hormones, immune proteins, and antibodies are all made from amino acids.
How Much Protein Do You Need?
Adults should get 10-35% of their calories from protein, as recommended by the USDA. This range covers most of the population, but individual needs may vary based on age and health. Protein provides four calories per gram.
Sources of Protein
The best sources of protein are whole, nutrient-dense foods. High-quality protein sources have amino acid ratios similar to human tissue. Regular consumption of meat, even organic or free-range, can lead to health issues. Plant foods like nuts, seeds, grains, and vegetables are incomplete proteins because they do not contain all nine essential amino acids. However, a balanced plant-based diet can provide all necessary amino acids.
What Is Fat?
Fat is the densest source of energy, providing nine calories per gram. Fats are essential for cell membranes, steroids, cholesterol, and brain function. They help absorb fat-soluble vitamins, cushion organs, and store energy.
Dietary fats include saturated and unsaturated fats. Saturated fats are usually from animal sources, while most plant fats are unsaturated. Essential fatty acids, like omega-3 and omega-6, must be obtained from the diet. Trans fats, created through food manufacturing, are harmful and should be avoided.
How Much Fat Do You Need?
Fats should make up 25-35% of your daily calories, according to the USDA. Healthy fats are necessary for a balanced diet. Good sources include nuts, seeds, coconuts, avocados, and olives. These foods also provide fiber and beneficial micronutrients.
Sources of Fat
The best sources of fat are plant-based and nutrient-dense. Nuts, seeds, avocados, olives, coconut, and dark chocolate are excellent choices. For healthy oils, consider flaxseed, hemp seed, avocado, grapeseed, sunflower, walnut, sesame, and coconut oils. Use flaxseed oil for cold dishes and oils with higher smoke points, like grapeseed and avocado oil, for cooking. Always choose expeller-pressed and unrefined oils to avoid chemicals and extensive processing.
Don’t Focus on Macronutrients Too Much
While it’s important to consider macronutrient ratios, don’t forget to focus on the quality of your food. Eat a balanced diet of whole, plant-based foods. Your macronutrient needs may vary daily based on activity level, health, and other factors. If you’re making significant dietary changes, consult a certified dietitian or nutrition counselor for personalized advice.
Adjusting the proportion of one macronutrient affects the others. For example, a high-fat diet is usually low in carbohydrates or proteins. A balanced diet can include various macronutrient proportions, but extreme imbalances can negatively impact micronutrient intake and increase disease risk. Diets extremely low in protein can harm the immune system and development. The USDA recommends a minimum of 10% protein for a healthy body.
The USDA’s major dietary recommendations include:
1. Follow a healthy eating pattern throughout your life.
2. Focus on variety, nutrient density, and portion sizes within your calorie limits.
3. Limit calories from added sugars and saturated fats, and reduce sodium intake.
4. Choose healthier food and beverage options.
The goal of a good diet is to fuel your daily activities while keeping you nourished. Choose foods that are rich in micronutrients, which are needed in smaller amounts but have a significant impact on health. For more information on important nutrients, check out my article on micronutrients.