Macronutrient recommendations vary depending on your overall health and what you're trying to accomplish. Some recommendations are specific, while others leave a large window for experimentation. Ultimately, you have to figure out what works best for your body.
There are three macronutrients: protein, carbohydrates and fats. Your body needs large quantities of them for energy. Vitamins, minerals, fiber and antioxidants are considered micronutrients because much smaller amounts are required by your body.
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Protein Is Irreplaceable
Your body relies on macronutrients to function in daily life. Each macronutrient plays a specific role, and it's nearly impossible to replace one with the other. Perhaps the most important one is protein.
There are popular low-fat and low-carbohydrate diets, but low-protein diets are quite uncommon. That's because every cell and tissue needs protein to work properly. This nutrient is found in every cell of your body and makes up the bulk of muscle tissue. Your body can't store protein for later use — as it does with carbs and fat.
You can get protein from plant and animal sources. Red meat like beef and pork, poultry like chicken and turkey and seafood like fish or shellfish are typical animal sources. Dairy products, such as milk and cheese, tend to be high in protein as well.
Vegetarian options for protein include nuts, legumes, soy and seeds. Most veggies contain small amounts of this nutrient too.
If you opt for animal sources, try to avoid excess fat. Choose lean meats, such as chicken breast and fish, as opposed to pork or fatty beef cuts. The latter tend to be higher in saturated fat, which should be limited in your diet to prevent heart disease.
When you eat protein-rich foods, your body breaks them down into amino acids, which are the building blocks of protein. Amino acids are then distributed through your bloodstream to the muscles, organs and other tissues. Your body reassembles these amino acids into structures like cells and muscle.
Carbohydrates for Fuel
It's no secret that humans have incredibly large brains for their size. These large brains demand a considerable amount of energy to keep going, and they prefer to use glucose for energy. In fact, a September 2015 research paper published in the Quarterly Review of Biology suggests that humans were able to evolve partly due to their access to high-carbohydrate foods.
When you eat foods high in carbs, such as bread, your body breaks them down into a simple sugar called glucose. This compound is then shuttled through your bloodstream until it's either used or stored for later.
Your muscles convert glucose into glycogen, which allows the sugar to be stored in the muscle and liver for later use. Carbohydrates are mainly used for energy to power your brain, muscles and various cellular functions that require glucose.
Carbs come in various forms in your diet. Fruit and vegetables are good sources. Bread, pasta, oatmeal, rice and cereal are examples of high-carbohydrate foods. Dietary fiber is a type of carbohydrate too.
There are two kinds of fiber: soluble and insoluble. This refers to whether or not the fiber dissolves water. Both types are critical in your diet. They keep your digestive system healthy and working properly.
Eating enough fiber may also help prevent heart disease. Since it's difficult to digest, this nutrient keeps you full longer, which may aid in weight loss and improve appetite control.
The Importance of Fat
Fat is an incredibly efficient form of energy storage. Per gram, protein and carbohydrates have 4 calories each. Dietary fat, on the other hand, has 9 calories per gram. That makes it the best energy storage unit your body has.
Besides providing energy, this nutrient supports the absorption of fat-soluble vitamins, such as vitamin A, D and E. These micronutrients dissolve in fat, so one of the best ways to ensure their absorption into your body is to eat fatty foods.
Animal sources of fat include meat, eggs and dairy. Plant-based sources include avocado, vegetable oils, nuts and seeds. There are different types of fat: saturated, unsaturated and trans fats.
Trans fats are mostly found in processed and fried foods. They're particularly dangerous for your heart. Try to avoid them as much as possible.
Saturated and unsaturated fats occur naturally in both animal- and plant-based foods. Unsaturated fat is perhaps the healthiest.
There are two kinds of unsaturated fat: polyunsaturated and monounsaturated. The latter fats may help lower your LDL cholesterol levels, which is the bad kind of cholesterol. Monounsaturated fats are typically found in nuts and unrefined oils, such as olive oil and sesame oil.
Polyunsaturated fats, such as omega-3 and omega-6 fatty acids, may help protect against cardiovascular disease and even cancer. Some types of fish, such as salmon and tuna, are rich in these nutrients. Unrefined vegetable oils are a good source too.
When you eat fat, it's broken down into fatty acids and monoglycerides. These compounds help build and maintain your cells and provide energy. Both fats and carbohydrates can be used as fuel for your muscles and organs.
Determine Your Ideal Macronutrient Ratio
Some diets, like the ketogenic diet or the Atkins diet, are low in carbs, moderate in protein and high in fat. Others, such as the DASH (Dietary Approach to Stop Hypertension) diet, require low fat and high carbohydrate intakes.
Each macronutrient plays a specific role in your body, so it's best to have some of each. However, there's plenty of room for flexibility. The Acceptable Macronutrient Distribution Range, or AMDR, is a widely accepted window for macronutrient recommendations.
It provides a recommended percentage of total calorie intake for carbohydrates, protein and fat. However, rather than suggesting a specific number, it gives you a range. For adult males and females age 19 and up, the ranges are:
- 10 to 35 percent of your daily calories from protein
- 45 to 65 percent of your daily calories from carbohydrates
- 20 to 35 percent of your total calories from fat
If your total calorie intake is 2,000 a day, for example, you can calculate your range of macronutrients based on that number. Simply multiply 2,000 by the bottom percent, then divide that number by the amount of calories per gram for the macronutrient you're measuring.
For protein, you'd multiply 2,000 by 0.1 to 0.35. Then you'd take those numbers and divide them by 4, because protein has 4 calories per gram. Your range for each macronutrient, based on a 2,000 calorie diet, would be:
- 50 to 175 grams of protein
- 225 to 325 grams of carbohydrates
- 44 to 78 grams of fat
Another option is to use the Recommended Dietary Allowance (RDA). While the AMDR gives you a range, the RDA is a specific number. These recommendations have been relatively unchanged for over 70 years, and they are meant to give you an idea of the minimum amount of each macronutrient you should have per day.
The RDA of protein for adults is 0.8 grams per kilogram of bodyweight. The RDA for carbohydrates is around130 grams for males and females, but this number depends largely on your activity level and health goals. For fat, the recommended daily intake is approximately 65 grams, based on a 2,000 calorie diet.
Macronutrients for Performance
Using a range of macronutrients is helpful because your diet depends on your lifestyle. If you're an athlete, chances are you need more protein and carbohydrates. Protein is important because it helps your muscles recover from exercise.
The RDA for protein is most likely too low if you're an athlete or fitness enthusiast, according to a June 2017 study published in the Journal of the International Society of Sports Nutrition. The AMDR is better, although the more intense your workouts are, the higher your protein requirements.
When you go up in protein, carbohydrates or fat, your macronutrient ratio changes. Therefore, you have to lower your intake of one nutrient or another to keep your calories in balance.
If you decide to eat more protein because you're active, it's probably best to slightly lower your fat intake. Carbs are helpful if you work out regularly because they supply fuel for your muscles.
A small, 18-person study published in October 2016 in the International Journal of Exercise Science looked at Crossfit athletes who lowered their carbohydrate intake. Subjects experimented with both low-moderate and high-moderate intakes, so their carbohydrate intake was still higher than on a diet like Atkins.
The study lasted nine days, and by the ninth day, researchers saw that the higher carbohydrate group could perform more repetitions. They concluded that a high or moderate carb intake was better for exercise performance.
Macronutrient Recommendations for Health
If you're looking to lose weight or simply live a healthy lifestyle, your goal should be to cut down on calories instead of switching up your macronutrients. While low-carbohydrate diets have been promoted for both weight loss and health benefits, the research is conflicting.
Macros for weight loss don't need to be different from the standard AMDR. Your fat and carbohydrate intake can stay the same. A February 2018 study published in the Journal of the American Medical Association showed that there was no significant difference between eating a healthy low-carb diet and a healthy low-fat diet in terms of weight loss.
If your goal is to stay as healthy as possible, the AMDR is a good place to start. Low-carbohydrate diets have been investigated for health benefits, but the negatives seem to cancel out the positives.
A September 2015 study published in Nutrients suggests that low-carbohydrate diets decrease inflammation and help cells function normally. However, researchers caution that higher fat intakes may increase the amount of saturated fat consumed, which can be dangerous for cardiovascular health.
Another study, published in September 2018 in the Lancet: Public Health, examined the carbohydrate intake of over 15,000 people. Researchers have found that a moderate intake between 50 and 55 percent of total daily calories was associated with lower mortality risk.
The type of food you eat is important for health. When you consume carbohydrates, try to include fiber from whole grains, vegetables and fruit. If you prioritize fat or protein, try to avoid foods high in saturated and trans fats.
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