With so much talk about how to lose weight, it's easy to forget that there are people who want to gain weight with lean muscle mass, or bulk. To do that, you need to consume a caloric surplus — but it's not as easy as eating anything you want.
In order to bulk up, you need to build new muscle by doing weight- or resistance-training, according to the American Council on Exercise. As your muscles recover from that strength workout, though, it's important to not only consume more calories than normal to gain muscle mass, but also to focus on getting the proper macronutrient breakdown in your diet.
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Calories Needed for Bulking
The recipe for gaining muscle is the opposite of what it takes to lose weight — according to ACE, you need to consume more calories via your diet than the number of calories you burn through physical activity, in order to create a positive calorie balance. While protein is usually the star macronutrient when it comes to gaining muscle, you need to increase calories from all three macronutrient groups, including carbohydrates and fat, says Gatorade Sports Science Institute.
However, like trying to lose weight, gaining muscle mass takes time. You should aim for a healthy weight gain of around 1 to 2 pounds per week, says Sanford Health. To gain 1 pound of lean muscle mass, you need to consume approximately 2,000 to 2,500 extra calories over your resting metabolic rate, or RMR, which is the number of calories you need to maintain your weight. In contrast, it takes about 3,500 extra calories a week to gain 1 pound of fat.
Bulking Calories Formula
To figure out how many extra calories to eat, you first need to determine your RMR. Although you can find a calorie calculator online to tell you what your RMR is, you can also figure it out yourself by using the Mifflin-St. Jeor formula, according to the National Academy of Sports Medicine. All it takes is a little bit of math. The equations to calculating this number are:
- Men: (10 × weight in kilograms) + (6.25 × height in centimeters) – (5 × age in years) + 5
- Women: (10 × weight in kilograms) + (6.25 × height in centimeters) – (5 × age in years) – 161
Using this formula, a man who is age 35, weighs 185 pounds and is 6 feet tall has an RMR of 2,087 calories a day. Remembering that it takes between 2,000 and 2,500 extra calories to gain 1 pound of lean muscle each week, he'll want to consume between 2,373 and 2,444 calories per day to bulk out without gaining any extra fat.
Meanwhile, a 30-year-old, 145-pound woman who is 5 feet 5 inches tall would need 1,378 calories a day to neither gain nor lose weight. If she wanted to bulk out, she would divide those extra 2,000 to 2,500 calories by seven days, which means she should eat between 1,663 and 1,735 calories per day to gain muscle mass.
However, NASM notes that it's important to consider that this caloric estimation is just that: an estimate. The amount of lean muscle you already have will influence your RMR, sometimes significantly. For a more precise RMR, visit a professional for indirect calorimetry, which measures oxygen utilization rates to calculate a more specific number of how many calories you burn each day.
Protein for Muscle Building
When you're aiming for a caloric surplus to bulk out, it's essential that you're focusing on nutrition in order to gain lean muscle instead of fat. Increasing the amount of protein you eat is typically the first strategy that comes to mind, but you shouldn't go overboard. Too much protein will simply get stored as extra fat, says Providence Health & Services.
When you're in active bulking mode, your diet should consist of 10 to 35 percent protein, according to the Academy of Nutrition and Dietetics (AND). Using the previous example of a 35-year-old man who should eat between 2,373 and 2,444 calories per day, this equates to between 237 and 855 calories of protein daily. Because protein has 4 calories per gram, this further breaks down to between 59 and 214 grams of protein per day, depending on how many calories and grams of protein he eats.
For the woman who needs between 1,663 and 1,735 calories a day, she should aim for between 166 and 607 of those calories to be from protein each day. This breaks down to between 42 and 152 grams of protein each day.
If that seems confusing, you can also calculate your protein needs based on bodyweight. Research published in February 2018 in the Journal of the International Society of Sports Medicine noted that to maximize muscle gain, a person should aim to consume 0.4 grams of protein per kilogram of bodyweight during each meal to reach a minimum of 1.6 grams per kilogram of bodyweight per day. If you want more, aim for 0.55 grams of protein per kilogram of bodyweight at each meal.
For a person who weighs 180 pounds, this equates to somewhere between 32 grams and 44.5 grams of protein per meal; for a person who's 145 pounds, it's between 58 and 89 grams. It's not as hard as you might think to get this much of the macronutrient when you consider the protein content of common foods, as per the AND:
- 3 ounces lean ground beef: 22 grams
- 3 ounces grilled salmon: 21 grams
- 3 ounces skinless baked chicken: 26 grams
- 1/2 cup low-fat cottage cheese: 14 grams
- 1/2 cup cooked lentils: 9 grams
- 2 tablespoons peanut butter: 8 grams
- 1 large egg: 6 grams
Carbohydrates for Energy
Even though protein is at the forefront of the macros for bulking, those calories don't have to come exclusively from protein, according to the Gatorade Sports Science Institute. Case in point: your body needs carbohydrates to fuel your muscles, particularly during exercise. Carbohydrates convert to glycogen, which in turn powers the muscles, notes the AND, which also states that about half your calories every day should come from this macronutrient.
If that's the case, then the 180-pound man who needs between 2,373 and 2,444 calories per day should eat between 1,186 and 1,222 calories from carbohydrates. Like protein, carbohydrates contains 4 grams per calorie, so this breaks down to between 296 and 305 grams of carbohydrates a day. For a 145-pound woman, this equals between 831 calories and 868 calories from carbohydrates, or 207 and 217 grams of carbs a day.
Additionally, this can be also be calculated by bodyweight. Research published in June 2019 in Sports, which varies slightly from AND's nutrient breakdown recommendations, says that a person who's focused on gaining muscle mass without adding body fat should consume between 3 and 5 grams of carbohydrates per kilogram of body weight per day, which should be a sufficient amount to fuel muscles for resistance exercise. This is between 243 grams and 405 grams of carbohydrates daily.
The type of carbohydrates you eat matters, too. Unhealthy sources of carbs, according to the Harvard T.H. Chan School of Public Health, include high processed or refined foods, such as white bread, sodas and pastries.
Skip those in favor of unprocessed or minimally processed carbs such as whole grains, fruits, vegetables and beans. Not only will they provide your muscles with a good source of energy, but they also contain other nutrients that boost your health — including vitamins, minerals, fiber and phytonutrients.
Fats for Bulking
In addition to carbohydrates, your body uses fat as fuel. The macronutrient also goes a long way in helping you feel satiated between meals. Because of this, the AND recommends that fat should make up between 20 and 35 percent of your total bulking calories.
Going back one final time to the hypothetical 180-pound man who needs between 2,373 and 2,444 calories a day for bulking, the number of calories needed per day from fat breaks down to between 475 calories and 855 calories. Unlike protein and carbs, fat contains 9 calories per gram, so this is equivalent to consuming 52 and 95 grams of fat per day. For the female example, it's equal to between 332 calories and 607 calories from fat, or between 37 and 67 grams each day.
If you want to calculate this via bodyweight, the research published in Sports recommends consuming between 0.5 and 1.5 grams per kilogram of bodyweight per day. This is equal to between 40.5 and 121.5 grams of fat per day, or 347 to 1093.5 calories daily for the theoretical man and between 33 and 99 grams per day for the woman.
For the best results, focus on healthy sources of fat, like extra-virgin olive oil, canola oil, nuts, avocados and fatty fish. These are known as unsaturated fats. On the other end of the spectrum, according to the Academy of Nutrition and Dietetics, saturated fat should make up less than 10 percent of your daily calories — that is, less than between 237 and 244 calories, or between 26 and 27 grams of saturated fat.
When trying to bulk, some people like to turn to supplements, especially in the form of extra protein. This may not be the best strategy, however.
Providence Health & Services explains that while some trainers and the media may tout supplements as a way to increase muscle mass quickly, there's no scientific evidence that they help more than eating whole, unprocessed foods. In nearly all cases, the claims you'll bulk up quickly have not been evaluated by the U.S. Food and Drug Administration, and there will be a statement on the label confirming that.
However, the research published in Sports states that some non-protein supplements may have ergogenic — or performance-enhancing — benefits for bodybuilders looking to gain muscle mass. In other words, they won't help with bulking, but they may improve your workouts. These include consuming 3 to 5 grams a day of creatine monohydrate, 5 to 6 milligrams per kilogram of bodyweight of caffeine and 8 daily grams of citrulline malate.
- Academy of Nutrition and Dietetics: "4 Keys to Strength Building and Muscle Mass"
- Gatorade Sports Science Institute: "Nutrition for Muscle Mass"
- Sanford Health: "Weight Gain: Does It Impact Performance?"
- National Academy of Sports Medicine: "Resting Metabolic Rate: How to Calculate and Improve Yours"
- Providence Health & Services: "Ask an Expert: Can Supplements Help Increase Muscle Mass?"
- American Council on Exercise: "Diet Tips for Gaining Weight"
- Journal of the International Society of Sports Nutrition: "How Much Protein Can the Body Use in a Single Meal for Muscle-Building? Implications for Daily Protein Distribution"
- Harvard T.H. Chan School of Public Health: "Carbohydrates"
- Academy of Nutrition and Dietetics: "Choose Healthy Fats"
- Sports: "Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review"