What Are Macronutrients? Why Balance Matters in Your Diet

How carbs, proteins and fats fuel your body and support your health

A bowl of whole grains, leafy greens, sweet potatoes, avocado and lean protein.

How carbs, proteins and fats fuel your body and support your health

Not all calories are created equal. If you’re focused on healthy eating, losing weight or boosting energy, understanding your macronutrients or “macros,” is a great place to start. 

  

Macros are the key nutrients your body needs in large amounts. These include carbohydrates, proteins and fats. Each one plays an important role and helps your body function daily. They fuel your brain, repair muscles and support your nervous system and hormone production. 


“Each group serves a different purpose, so it’s important to strike a good balance,” says Robert Elliott, DO, an internal medicine physician at Scripps Coastal Medical Center Hillcrest.  

 

“If you eat too much of one and not enough of another, it can throw off your energy levels, digestion and even how well your body recovers after exercise,” Dr. Elliott says. “A well-balanced intake of macros helps regulate blood sugar, supports a healthy metabolism and keeps you feeling full and focused throughout the day.” 

The three types of macronutrients 

Carbohydrates: Your body’s main energy source  

Carbohydrates are your body’s go-to fuel, especially for your brain and muscles. Each gram provides four calories. Once digested, carbs break down into glucose, which your body uses for energy. 


But not all carbs are created equally and the type you choose matters.  


Complex carbs — found in foods like whole grains, vegetables, legumes and fruits — are rich in fiber, vitamins and minerals. They digest more slowly, helping you feel full longer and providing steady, lasting energy. 


Simple carbohydrates — like those in cookies, soda and white bread — are often refined, meaning they’ve been stripped of fiber and nutrients. These break down quickly, leading to energy spikes followed by crashes. They’re often high in added sugars. 


You can find added sugars on food labels. Look for ingredients that end in “-ose” (like glucose or fructose) or “-itol” (like sorbitol). These often mean there are added or artificial sweeteners.   


Fruit has natural sugars and is often called a simple carb. However, its fiber slows down digestion. This makes fruit act more like a complex carb. It provides longer-lasting energy and helps control blood sugar better.   


For good health, try to get 45 to 65 percent of your daily calories from carbohydrates. Choose whole, unprocessed sources when you can.

Protein: Building and repairing tissues  

Protein provides four calories per gram and plays a vital role in almost every function of the body. It helps build and repair tissues, supports immune health and is essential for muscle growth and recovery.   


Choosing high quality sources of protein is key: 


Plant-based proteins — like tofu, beans and lentils — are rich in nutrients and naturally free of cholesterol. While some plant proteins may not contain all the essential amino acids on their own, eating a variety throughout the day provides everything your body needs. 


Lean animal proteins — like chicken, turkey and fish — are healthy choices. Make sure to pick options that are not heavily processed and have less saturated fat. 


Be careful with packaged or processed meats — like deli slices and some plant-based options. High sodium levels or long ingredient lists full of additives can be signs that a product is highly processed. 


Whenever possible, choose whole protein foods. They naturally provide vitamins, minerals and other important nutrients. They’re typically lower in additives and preservatives than processed options.

Fats: Energy and hormone support  

Fat is the most calorie-dense macronutrient, providing nine calories per gram. But that doesn’t make it unhealthy. In fact, healthy fats are essential for your body to function properly. They support brain health, hormone production and help your body absorb fat-soluble vitamins like A, D, E and K. 


Fats also play a role in nerve and cell function, making them a vital part of a balanced diet. 

Good fats vs bad fats  

You’ve probably heard the terms “good fats” and “bad fats.” Knowing the difference is important for your heart and health.    


Trans fats are the most harmful. These artificial fats are strongly linked to heart disease and inflammation. While they’ve been banned in the U.S., they may still appear in processed foods under labels like “partially hydrogenated oils.”  


Saturated fats are found in animal products (like red meat, butter and full-fat dairy) and in some tropical oils (like coconut oil and palm oil). These fats can raise LDL (bad) cholesterol levels and should be eaten in moderation.  

 

Unsaturated fats are the healthiest type. Found in foods like olive oil, avocados, nuts and seeds and fatty fish, these fats support heart and brain health, improve cholesterol levels and help reduce inflammation. 

 

“Instead of cutting fat altogether, focus on eating the right kinds,” Dr. Elliott says. “Emphasize unsaturated fats, limit saturated fats and avoid trans fats. This balanced approach supports your heart, brain and long-term health.” 

What is the right macro balance?  

Focusing on the balance of macronutrients, not just counting calories, can help you find nutritional gaps. This approach supports your health goals, like improving energy, building muscle or managing your weight.   

 

According to Dr. Elliott, a typical healthy adult should aim to get about: 

 

  • 45 to 65 percent of their calories from carbs 
  • 20 to 30 percent from protein 
  • 20 to 35 percent from fats  

 

“It’s important to have a good balance of these within the diet, not just overall, but with each meal,” Dr. Elliott says. “A good ratio of these different groups helps us process foods better and helps us feel more satisfied when we’re eating.”  

 

Keep in mind, these ranges are general guidelines. Your ideal macro split may vary based on your health status, activity level or goals. For example, someone trying to lose weight, manage diabetes or build muscle, may benefit from a more personalized macro plan.  

 

Always consult your doctor or a registered dietitian before making major changes to your diet. They can help tailor a plan that works best for your body. 

Tips for tracking your macros  

Understanding your macro breakdown can help you:  


  • Make smarter food choices  
  • Support fitness goals  
  • Identify nutritional gaps  

 

Use a nutrition tracking apps like MyFitnessPal or Cronometer make it easy to scan food labels, log recipes and check whether your meals are hitting your ideal macro range. If you use an iPhone, Apple Health can sync with these tools and others to give you a complete picture of your nutrition alongside your activity, sleep and overall health data.

Macros matter 

Balancing your macronutrients can help you feel better, stay energized and support your long-term health. Focus on quality, eat a wide variety of foods and aim for balance at every meal. If you need help adjusting your diet or tracking your progress, talk to your doctor or a registered dietitian.