"You can't build muscle on a calorie deficit"

I've wasted many months of my life listening to people on these forums and getting no results because of it. I now trust MFP recommendations for the most part.
I've always wondered about this particular thing though. So when you get muscles while in a calorie deficit, are you revealing the ones you already had by burning the fat around them or building some muscle while burning fat?
In my experience I could see more muscle definition, but I had not lost any weight AT ALL while eating in a calorie deficit, so I wondered "Is it possible that I burned fat and built muscle simultaneously"?

I've heard it as well, but those same people normally mention that there are beginner's gains..which would explain why you've gained muscle despite the calorie deficit.

Also, I've seen several thread's that encourage lifting on a deficit as it is necessary to maintain muscle mass. I don't think everyone is telling you there is no point to lifting while on a calorie deficit, and if they do, don't listen to them! However, I think there is a point where you will no longer gain muscle mass without eating more. Does not mean you shouldn't keep lifting, because either way it's beneficial!

I don't like blanket statements, like 'you can't build muscle in a deficit'. Especially when they're that general.

Now, it can be easily granted that it's easier to build muscle without being in a deficit, but I don't think it's impossible.

I've was 278 two months ago and am 244 now. My reps for 225 on the bench press have gone from 3 to 7 during that time. My arms have gotten bigger, also. Now, I guess it's possible that I haven't built any muscle at all and have instead just somehow gotten stronger with the same (or less) muscle and that my arms have added fat or water instead of muscle, but that seems to stretch the limits of credulity a bit far, to me.

I think if one were to add muscle in a deficit, it would require moderate strength training and adequate protein. And I think that any added muscle that you might be lucky enough to produce would be less than would have been produced by the same amount of lifting if you weren't eating at a deficit.

I think it's difficult and that the progress is not tremendous, but I just can't bring myself to agree with the common belief that it's impossible.

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I think this is the most cleverly disguised 1200 calorie thread I've seen. But, since I'm already here...

You can gain muscle on a deficit, I think. I believe that is what "newbie gains" means, but this phenomenon does not last as you progress. Lifting while on a deficit is done primarily to preserve muscle mass, not build.

Also, the increased definition in your arm is likely from fat loss to reveal the muscle. Nice job, btw.

As for your intake I'm not going to even look. Do whatchawanna.

Its nice to see I wasn't the only one drawn in only to go "Wait. What?"

I don't know a lot but I know if a grown man has to eat like a baby elephant and work very hard to put on a few pounds of muscle, a women eating at 1200 shouldn't be able to do it so easily. But maybe I've missed something somewhere. Maybe if I eat 1200 I too can get ripped.

You actually and physically can't build appreciable muscle on a deficit, just like you can't build fat on a deficit. You have to have materials build IYSWIM.

But that doesn't mean you shouldn't lift weights while in a deficit. Why lift?

1. Weight lifting is exercise, and while people fight and argue about how much it burns (answer-no one knows), it will contribute to your calorie deficit in some manner.
2. While you can't build muscle on a deficit, you can build strength and coordination-two good things to have.
3. While you can't build muscle, you can preserve what you already have, what this means is you have to lose less weight to get to a lower body fat percentage-end result is many people are happier with their bodies.

Have you been measuring your arms? Just because the muscle is more defined doesn't mean it is actually bigger. More likely is that as you have lost weight, you have lost fat which makes it more visible. (ie#3) Either that or you took the picture directly after lifting so it is pumped.

My arms haven't changed much in size since I started. they are less flabby and more muscular. I took this picture today and I have not lifted today.

Can you take a flexed one as well so we can compare?

Remember that the appearance of muscle definition is not the same as muscle growth or hypertrophy. Increased muscle definition becomes more apparent as we lose bodyfat. Increased muscle size happens as we eat enough calories and experience enough exercise volume. That's why bodybuilders go through a bulk and cutting phase, because you can't do both at the same time.

The scientific LAW of thermodynamics indicates that you can't make something out of nothing.

Thermodynamics has nothing to do with this. Noone has suggested that you can add muscle without eating at all. Having a deficit is not equivalent to not eating at all.

My maintenance is probably around 3000 or more, so anything less is a deficit. Let's say I eat 300g of protein (which is used to build muscle), 200g of carbs, and 44g of fat, for a total of 2400 cal/day. Let's also assume that my bodyfat% is about 22%, so there's plenty of fuel available there.

I see no reason why muscle couldn't be produce with moderate lifting, even at much less protein levels, but certainly can't imagine why not at the hypothetical levels indicated above. You'd be building the muscle out of 300g of protein, which far exceeds anyones estimate of what is needed for my size, while using the carbs/fat + bodyfat for energy.

It should go without saying that noone who's primary goal is to add muscle mass should eat at a deficit. But if your goal is to lose bodyfat and weight while maintaining or even slightly increases muscle mass, there's no reason not to lift heavy in a deficit. To the contrary, I think it's a pretty good idea, as long as you take care to get enough protein (would obviously require a higher protein % than at maintenance levels to achieve this).