Bulking up usually requires monk-like levels of dedication: lots of planning, lots of willpower, and, usually, lots and lots of calories. But, it doesn’t have to be this way.

According to research collated by supplement watchdog Examine, you can still build muscle on fewer calories.

Of course, the extra intake supports a hormonal environment conducive to bulking, but by pinpointing specific types of calories, you can eat less and still inch up a chest size.

The secret is protein. A four-month study of overweight men found that a group consuming 1.3 grams of protein per kilogram of bodyweight per day gained more lean mass and lost more fat than those eating smaller amounts. So if you’re on a diet to decrease fat but worry about gains, add extra sides of protein to keep your muscles in check.

It’s always worth totting up your carb and fat intake, too. You can still gain muscle by lowering both, but it makes sense to gradually decrease portions and supplement with protein. Otherwise, your weight loss may also result in muscle loss.

Calculate your bodyweight, adjust protein intake accordingly and quite possibly, you may drop the calories and still get stacked.