Bulking, as most guys typically think about it, is B.S.
Telling yourself you can eat anything you want because you’re skinny and trying to put on muscle is just an excuse to eat like a pig, and you’ll pay for it. Sure, you’ll gain some muscle, but you’ll also gain fat—and that fat will obscure your muscles until you decide you desperately need to lose it, and then you’ll have a hell of a time dieting it off.
In reality, eating anything you want to gain weight is called "dirty bulking," so named because your new muscle growth will come with some extra body fat that your body can't really use. On the other hand, the ideal way to gain muscle is called (appropriately) "clean bulking"—clean fuel, easily transferred into muscle, without too much caloric waste. The difference between the two isn't that complicated—one allows for Taco Bell, and the other does not—but it is challenging. And knowing is half the battle.
Here's the real science of gaining weight—without getting fat in the process.
The hard truth
Your body can only gain so much muscle in a given period of time; it’s dependent on your genetics, age, and training age (how long you’ve been lifting). According to Nate Miyaki, C.S.S.N., a San Francisco-based nutrition coach to physique competitors, a beginner in his teens up through his 30s can expect to put on two to four pounds of lean muscle per month for the first two or three months of his training. An intermediate (several months’ to a few years’ experience) might see 1–1.5 pounds per month. An experienced lifter, on the other hand, should be happy with just a few pounds per year.
This means that when you hear about somebody who “gained 20 pounds in a month,” he really put on closer to two pounds of muscle and 18 pounds of water and fat. Trainers, equipment manufacturers, and some muscle “gurus” like to exaggerate results, but if you measured the body fat of their subjects, you’d see only a modest increase in lean mass. And that’s fine.
“Go pick up a 2-lb top round steak and envision what that would look like on your body,” says Miyaki. “Very few guys on this planet have the potential to gain 20 pounds of rock-hard muscle in a month.”
How to bulk right
Because of the body’s limited muscle-building potential, it makes no sense to bombard it with a great excess of calories. A small surplus is enough. “Eating 200–300 calories above maintenance level will do the trick,” says John Alvino, a nutrition expert and strength coach in Morristown, NJ.
Start by eating 14–18 calories per pound of your body weight, and adjust from there. Consume one gram of protein per pound of your body weight daily, two grams of carbs, and 0.4 grams of fat. In other words, a 180-pound man looking to gain weight would eat between 2,500 and 3,200 calories daily, consisting of approximately 180 grams of protein, 360 grams of carbs, and 70 grams of fat. To make adjustments, tweak your carbs and fat, but keep your protein intake constant.
The fatal mistake bulkers make is eating too much too soon. They may start out following an intelligent diet, but when the scale doesn’t jump five pounds in a week, they assume the program isn’t working and start swallowing everything in sight to see gains—and then they get fat. Of course, it’s true that more calories provide more raw material for muscle, but the body is still capable of building muscle without them. In fact, it’s been shown that muscle growth can occur even while in a caloric deficit.
An American Journal of Clinical Nutrition study found that subjects who dieted and weight trained for 90 days lost an average of 35 pounds while gaining significant muscle mass. Don’t get too excited, as the subjects were obese women, but it proves that muscle gain isn’t dependent on big eating alone.
“Hypertrophy [muscle growth] is about the training stimulus,” says Miyaki, “and then adequate amounts of protein. Calories and carbs are for providing proper fuel for training and preventing the body from breaking down protein, your muscle tissue, as a reserve fuel. If I had to rank them in order of importance, I’d say hard training comes first, then protein, calories, carbs, and fats.”
Alvino seconds the notion of training over feasting. “The key element to focus on is increasing strength,” he says. Stronger muscles inevitably become bigger muscles, so while you can’t quickly eat your way to 10 extra muscle pounds without storing a lot of fat, you can—eventually—train your way there.
Stick with your eating plan for at least two weeks before making adjustments, and take photos every couple of days to assess your progress. “One of the simplest ways to tell if you’re gaining muscle instead of fat is to measure your waist circumference,” says Miyaki. If your belly is getting bigger, it’s the wrong kind of weight.
Timing is nothing
For the past decade, bodybuilding hype has stressed the importance of the so-called “pre- and post-workout windows.” The idea here is that ingesting protein and carbs up to an hour before weight training and within an hour after training will result in better absorption of these nutrients for superior muscle growth. Some product marketers and so-called nutrition experts have even threatened that your workout will be a complete waste if you don’t ingest protein and carbs at these times.
But the science to back this notion doesn’t exist. A 2013 meta-analysis published in the Journal of the International Society of Sports Nutrition found no significant benefit to rushing protein intake within one hour before or after training. In other words, as long as you eat the food you need over the course of a day, you’ll have no trouble growing muscle.
That said, it’s still a good idea to have a protein-rich shake after training. It may not offer any extra muscle-building benefit beyond that of eating later, but it will provide a convenient and easily digestible meal to tide you over until you do eat again.