Building Lean Muscle, Part 3: Selecting the Right Macronutrients

This is the third installment in a 10-part series on how to build lean muscle. Looking for the best way to build muscles? It all starts with your diet.

In part 2 of this series, we went over how to figure out your body compostion (% body fat vs. % lean muscle mass), how to determine your target calorie intake, as well as how to assess your bioenergetics needs (e.g., carbohydrate, protein, and fat requirements based on the energy needs of your sport). Now that we’ve covered the basics, let’s dive a little deeper into how to construct the perfect diet for gaining lean muscle.


Carbohydrates Are Good

Don’t be misled by fad diets that make blanket statements on the dangers of carbohydrates. Carbs are the body’s primary source of energy and are essential for your body to function. They are rich in fiber and vitamins and minerals, including antioxidants, which play a critical role in protecting against diseasesespecially heart disease and cancer. That said, when it comes to fueling your body for athletic performance and gaining lean muscle safely, some types of carbohydrates are better than others.

The best sources of carbohydrateswhole grains, vegetables, fruits, and beanspromote good health by delivering vitamins, minerals, fiber, and a host of important phytonutrients.

Sugary, processed carbohydrateswhite bread, white rice, refined grains, pastries, sugar-loaded sodas/sport drinksare highly processed foods that contribute to an increase in fat storage, interfere with fat loss, and promote diabetes and heart disease. They are best left off the athlete's plate.


How can you tell the difference between a "good" carb, one that helps you meet your muscle-building goals, and a "bad" carb? There are several different ways to identify the good carbs from the bad. First is the amount of fiber in the food. Fiber is a low-calorie filler that serves two health purposes: 1) it fills up your stomach so you feel fuller longer, and 2) your body takes much longer to break it down, suppressing your appetite.

There are two types of fiber: soluble and insoluble. Soluble fiber is found in foods like oatmeal (not the instant kind), beans, barley, and citrus fruits (oranges, grapefruits, kiwi, etc.), and has been shown to lower cholesterol levels. Insoluble fiber is important for normal bowel function and is typically found in whole-wheat breads and vegetables. Bottom line: eat foods that have not been highly processed and do not contain highly processed ingredients.


The second tool in identifying the best carbs for your diet is the Glycemic Index (GI). The GI measures the speed at which you digest food and convert it to glucose (the body’s primary energy source). The faster a food breaks down, the higher its rating on the index. Essentially, the GI is a measure of which foods cause your body to experience a rapid rise in blood sugarwhich then triggers the production of insulin. Since insulin’s two primary roles are to store that glucose as fat and to act as a sentry to keep fat cells intact, it is crucial to maintain low insulin levels when you are trying to lose and/or maintain body fat, and that means limiting high-GI foods.


Low-Fat Protein

Animal protein and vegetable protein probably have the same effects on health. It is the protein package that likely makes a difference. Let me explain: a 6-ounce rib eye steak is a great source of protein—38 grams worth. But it also delivers 44 grams of fat, 16 of them saturated. That’s almost three-quarters of the recommended daily intake based on a 2000-calorie allotment. The same amount of salmon gives you 34 grams of protein and 18 grams of fat, with only 4 of them saturated. A cup of cooked beans has 18 grams of protein, but less than 1 gram of fat. So when choosing protein-rich foods, pay attention to what comes along with the protein. The best animal protein choices are fish and poultry (without skin). If you are partial to red meat, stick with the leanest cuts. Choose moderate portion sizes, and make them only an occasional part of your diet.

The Good Fats

The total amount of fat you eat, whether high or low, isn’t really linked with disease. What really matters is the type of fat you eat. The “bad” fats—saturated and trans fats—increase your risk for certain diseases. The “good” fats—monounsaturated and polyunsaturated fats—lower disease risk. The key to a healthy diet is to substitute good fats for bad fats—and to avoid trans fats altogether. Although it is still important to limit the amount of cholesterol you eat, especially if you have diabetes, dietary cholesterol isn’t nearly the villain it has been portrayed to be. Limiting cholesterol in the bloodstream is most important. The biggest influence on blood cholesterol level is the mix of fats in your diet—NOT the amount of cholesterol you eat from food.


  1. Use liquid plant oils for cooking and baking. Olive, canola, and other plant-based oils are rich in heart-healthy, unsaturated fats. Try dressing up a salad or vegetables with an oil-based vinaigrette.
  2. Ditch the trans fat and butter. In the supermarket, read the label to find foods that are trans-fat free and contain no partially hydrogenated oils. In restaurants, steer clear of fried foods.
  3. Eat at least one good source of omega-3 fats each day. Wild-caught fish, almonds, ground flax seed, and canola oil all provide omega-3 fatty acids and are an important contributor to heart health.
  4. Go lean on meat and milk. Beef, pork, lamb, and dairy products are high in saturated fat. Choose low-fat milk, unsweetened almond milk, and savor full-fat cheeses in small amounts.

Maintain Proper Fluid Intake

After your macronutrient intake is in place, the next step in constructing a muscle-building diet is to maintain a proper fluid intake. Many athletes who are trying to learn the fastest way to gain muscle completely overlook how much they’re drinking on a day-to-day basis.

If you’re dehydrated, protein synthesis cannot take place as fast--and this can significantly hinder your results.

Aim to consume at least 10-12, 8 oz. glasses of water per day, if not more when you are exercising.

Remember that herbal tea and milk will both count towards your fluid intake as wellhowever, caffeine-containing beverages will not. Your grande vanilla latte does NOT count as 16 oz. of hydrating fluids...sorry!

Sugar-laden beverages (soda, fruit juice, milkshakes, etc) should be avoided regardless, so they won’t even factor in here.

To further assist you, check out The Hydration Calculator. The Hydration Calculator can help generate more precise custom hydration settings based on calories expended during your daily lifestyle and for specific continuous uninterrupted exercise activities.

Manage Your Sleep

Finally, the last step to help with safe weight gain is to make sure that you are getting enough sleep. Sleep is imperative to building lean muscle because sleep is when your body goes into a state of deep repair and recovery.

You want to aim to sleep at least 8 hours per night, if not slightly more when training gets very intense. Make use of naps if you can, as many athletes who are looking to build muscle will find they recover faster with these in place.

Sleep is also when the body is going to be releasing growth hormone as well, which plays a very important role in lean muscle mass growth and development.

The best way I have found to monitor your quality and quantity of sleep is with the Sleep Cycle app for your iphone or Droid. It has functions that record the time you spend in deep or REM sleep, track the quality of your sleep over time, and identify potential factors that may be interfering with your sleep (too much caffeine, late workout, etc.). You can even set the alarm to wake you within a specific window, when the app senses you are at your lightest level of sleep. Pretty cool!

The Takeaway

So there you have some of the key points to keep in mind when selecting macronutrients for your muscle-building diet, and adopting helpful lifestyle changes in hydration and sleep to support that diet. Check back for my next installment in my 10-part series on building lean muscle, when we get specific about timing your nutrients for optimal results.


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Mike Bewley, MA, CSCS, C-SPN, USAW-I is a guest contributor to the Volt blog. He is a Strength and Conditioning Coach at Clemson University, a specalist in sports nutrition, and the founder of online nutrition platform NutraCarina.