Bodybuilders and body composition experts often advise against bulking (maintaining a calorie surplus) unless you’re already lean. 

I’ve been one of them—in the first edition of my book Bigger Leaner Stronger (2012), I recommended men start a bulking phase around 10 percent body fat and women at around 20 percent.

So, if a guy was at 17 percent body fat, I was telling him to cut down to around 10 percent before bulking. And if a gal was in the mid- or high-twenties, I was telling her to get to around 20 percent before trying to maximize muscle and strength gain. 

Is that advice still sound? Is it still supported by the weight of the evidence? For the most part, yes, but not for the same reasons I originally thought.

Back then, I explained that beginning a bulking phase with low body fat levels had three main benefits:

  1. You can bulk for longer before needing to stop due to excessive fat gain.
  2. Post-bulk cuts are shorter since there’s less fat to lose to get back to an ideal “maintenance body.”
  3. Being lean led to greater muscle gains because our body’s “muscle-building machinery” worked better when we were leaner.

Today, my stance on the first two points remains the same, but the third no longer passes muster. It seems that having lower body fat (10-to-15% in men and 20-to-25% in women) doesn’t significantly impact muscle growth rates. To put it simply, if your main goal is building muscle and strength, you’re probably never “too fat” to bulk.

I’ll spare you the technical details of why the “lean people gain muscle faster” hypothesis didn’t pan out, but the summary looks like this:

A series of studies conducted in the 1970s and 1980s on weight gain found that when people with high body fat levels gained weight, it was mostly fat, whereas when people with low body fat levels gained weight, it was mostly muscle. Eventually, evidence-based fitness experts stumbled upon this research and speculated that the same principle might apply to bodybuilding—and that’s how the idea took root.

However, the rub is that these studies didn’t involve resistance training and often included people recovering from anorexia, who were severely under-muscled. This was uncovered in a later review of the data that showed that when the anorexia studies were excluded from the analysis, body fat levels didn’t seem to influence the ratio of muscle to fat gain.

There’s still an ongoing debate about whether body fat can meaningfully affect muscle growth, I’m not convinced it’s a significant factor. That said, I lean toward the position that our physiology is likely most “anabolic” at an athletic body composition (something in between “shredded” and “fat”).

So what are the significant factors?

  1. Maintaining a steady calorie surplus (about 10% above your total daily energy expenditure)
  2. Eating enough protein (0.8 to 1 gram per pound of body weight daily)
  3. Following a well-designed training program that progressively overloads your muscles
  4. Prioritizing rest and recovery (getting enough sleep, taking rest days, deloading regularly, limiting cardio, etc.)

While I still recommend getting lean before bulking for the reasons mentioned (longer, more productive bulks and shorter, easier cuts), my guidance now comes with a caveat:

If you’d rather bulk now and cut later—maybe because you feel “skinny fat” or are just excited to eat big and train hard—go for it. You won’t be held back by any so-called “anti-anabolic” barriers.