Adding Muscle While Losing Fat – Q&A

Question: Is it possible to stay at the same weight and replace fat weight with LBM, by making decent strength gains over time? (i.e by not actually leaning out and then mass packing etc). Can the body use the extra calories that are needed for new muscle gain from existing fat stores on the body?  I’m assuming this is the case for beginners, but how about intermediates/advanced trainees?  If so, roughly what sort of time frame would be needed to say drop 10lbs fat and replace with the same amount in muscle? Thanks.

Answer: I’m willing to argue that if there is a single question (or related set of questions) that comes up perennially in the field of training and nutrition, it’s something akin to the above.  The idea of ‘gaining muscle while losing fat’ in general or, better yet ‘replacing every pound of fat lost with muscle’ is sort of the holy grail of training and nutrition and a great deal of approaches that are supposed to generate that very thing have been thrown out over the years.

In essence, this is the basis of bodyrecomposition, you train and eat in such a way as to end up with more muscle and less fat than you had before.  People on forums either want to know how to accomplish the above or make statements such as “I want to gain muscle without gaining weight.” implying that they are replacing every pound of lost fat with the exact same pound of muscle.   Others will hide it in the math of the situation, wanting to move from one weight/body fat percentage to another without recognizing what that implies for the numerical changes that they are seeking.

Now, when I was younger and only thought I knew what I was talking about, I would often say that the above was impossible to accomplish.  In hindsight, impossible was a bit too strong of a term; clearly it’s not impossible as it does happen.  But it can sure be difficult depending on the situation.

There are a handful of situations where the combination of muscle gain and fat loss occur relatively readily.  The first of those is in overfat beginners.  I want to really stress the term overfat in the above sentence.  This phenomenon doesn’t happen in lean beginners for reasons I’m going to explain in a second.

A second situation where this phenomenon occurs readily is folks returning from a layoff.  Folks who are previously lean and muscular but who get out of shape (whether deliberately or not) often find that they get back into shape much faster than they did initially: they seem to magically replace fat with muscle.  In fact, with the advent of before/after transformation pictures for supplements, this has become a growth industry: people who are already in great shape will deliberately get out of great shape so that they can quickly reattain their previous shape in a short period.  Apparently there is huge money in selling such before/after pictures to help move supplements.

But that’s not really what the question was asking which had more to do with this idea: can the body use calories stored in fat cells to support muscle growth, essentially shunting calories from fat to muscle and achieving the holy grail: fat loss with concomitant muscle gain.

And, as a generality, this tends to be difficult for reasons that I discussed in some detail in the Ultimate Diet 2.0 and Calorie Partitioning Part 1 and Calorie Partitioning Part 2.

And this brings me back to my comment about overfat beginners as I think this explains some of the physiology involved.   Please note that I’ve never really seen this topic studied directly and much of what I’m going to write is based on either observation or other known aspects of physiology that I feel tie into the issue.

So consider an individual who is carrying quite a bit of fat and not very much muscle.  Your typical overfat beginner trainee.  Let’s look a bit at what’s going on physiologically for this person.

One consequence of the excess body fat is a systemic insulin resistance and this is especially true for fat cells.  Basically, when fat cells start to get full, they become more resistant to further caloric storage.  That is to say: insulin resistance actually develops as an adaptation to obesity and this is one reason that obesity is often associated with things like hyperglycemia, hypertriglyercidemia and hypercholesterolemia; the fat cells get so full that they stop accepting more calories.  So instead of being stored, glucose, triglycerides and cholesterol sit in the bloodstream.  In that vein, and quite contrary to popular belief, insulin resistance actually predicts weight loss and insulin sensitivity weight gain but that’s another topic for another day.

So we have a situation in overfat folks where fat cells are sort of trying to ‘push calories away’ from the fat cells.  That’s point #1.

The second thing to consider is the untrained state and the fact that when people start training, they always make gains in both strength and muscle mass faster.  That is, beginners have the potential to gain muscle at a much faster rate (and more easily in terms of the stimulus needed) than someone trained.  As well, keep in mind that regular training (both resistance training and cardio) improve muscular insulin sensitivity and nutrient uptake in that one specific tissue (training is probably the most powerful tool in our arsenal to improve nutrient uptake in that specific a fashion).  That’s point #2.

So consider the combination: we have a situation with overfat beginners where fat cells are very insulin resistant and essentially trying to push calories away.  Now we throw training on that, not only sending a muscle building stimulus via training but increasing nutrient uptake into skeletal muscle through effects on skeletal muscle nutrient uptake/insulin sensitivity.

And what happens under those circumstances is exactly what you’d expect: the body appears to take calories out of fat cells and use them to build muscle.  And this is effectively what is happening due to the combination of the above two factors. But the combination of the two is required.   A lean beginner won’t see the above because they don’t have the fat to lose/fat energy to shunt to the muscle.  And as they get more advanced, the rate of muscle gain slows way down.  Again, it’s the combination of overfat and beginner status that comes together here to let some magic occur.

And even there you’re not going to see the body replacing one pound of fat with one pound of muscle for very long.  The rates of the different processes are simply too different.  What you might see is an initial shift where muscle ‘replaces’ fat due to the calorie shunting effect but invariably it slows down and either muscle gain or (more frequently) fat loss becomes dominant.

Now, having looked at the specific situation of an overfat beginner, let’s look at what happens as one of two things (or both happen): the person becomes leaner and/or achieves a higher training status.

A known adaptation to fat loss is an improvement in insulin sensitivity especially in fat cells.  This is part of why fat loss becomes more difficult as folks get leaner as well as why the risk of weight/fat gain is higher at the end of the diet (you’re MORE insulin sensitive).  This means that the fat cells not only have less stored fat to give up but it becomes more difficult to get it out of there.

I discussed some of the reasons for this in detail in The Stubborn Fat Solution along with protocols to get around it.  But the point is made: as folks get leaner, getting fat out of fat cells becomes more difficult.  Some of the hormonal mechanisms involved are also discussed in Calorie Partitioning Part 1 and Calorie Partitioning Part 2.

Furthermore, as folks become better trained, it becomes more difficult to gain muscle under any condition.  The training stimulus is higher and the impact of training is lessened.

So the situation that was in place for the overfat beginner has reversed itself in someone who is leaner and/or better trained.  Fat cells are no longer insulin resistant and ‘pushing fat calories’ away; quite in fact they are ready to take up excess calories at any time. And since training has a lesser impact on muscle growth, the odds of getting the calorie shunting effect becomes lower and lower approaching nil.  Again, that’s on top of all of the hormonal stuff discussed in the above articles (e.g. fat loss and muscle gain requires different hormonal situations).

Which is why a lot of the approaches advocated for ‘gaining muscle while losing fat’ aren’t very effective.  In fact, I’d tend to argue that most people’s attempts to achieve the above results in them simply spinning their wheels, making no progress towards either goal.  Because invariably they set up a situation where neither training nor diet is optimized for either fat loss or muscle gain.  Calories are too high for fat loss and too low to support muscle gains and outside of that one overfat beginner situation, the physiology simply isn’t going to readily allow what they want to happen to happen.

But more specific approaches can be effective in achieving this goal.  The Ultimate Diet 2.0 has often generated muscle gains while people dieted to single digit body fat levels (I’d note that the gain in muscle never reaches equality with the fat loss) but it also alternates specific dieting and gaining phases during the week.

Many of the intermittent fasting (IF’ing) approaches do this more acutely and I’d suggest anybody interested go to Martin Berkhan’s Lean Gains site for more information about IF.  There are others, things like every other day refeeds (EOD refeeds) which are discussed in some detail in my The Bodyrecomposition Support Forums.  But all of those approaches are alternating dieting phases (lowered calories, a net ‘catabolic’ state) with gaining phases (increased calories, a net ‘anabolic’ state).

But none of those approaches generate a muscle gain to equal the fat loss, at best they generate a small muscle gain in the face of a much larger fat loss (e.g. someone might lose a lot of fat while gaining a pound or two of muscle or what have you).  But for the non-beginner/non-returning from a layoff trainee that’s about the best you’re going to get.  Potential rates of muscle gain are never going to approach the potential rate of fat loss once folks are past the beginner stage.  Even in the beginner stage, it’s generally always easier to lose fat much faster than you can gain muscle.

So the idea of replacing every pound of lost fat with exactly one pound of muscle will be essentially impossible for the intermediate/advanced trainee.  There’s simply not enough fat/the fat cells dont want to ‘give up their calories’ and the ability to stimulate rapid muscle gains isn’t there any more.

A followup question might be what about fatter but more advanced trainees.  Certainly in that situation, fat cell insulin sensitivity/etc. can approach what is occurring with the overfat beginner but there is still the issue of rate of muscle gain being drastically slowed.  It’s probably possible briefly at the start of the diet to get some caloric shunting but it’s never going to approach a 1:1 gain in muscle with fat loss; the potential rate of fat loss (1-2 lbs/week) to rates of muscle gain (0.5 lbs/week if you’re lucky) simply doesn’t exist.

As a final comment, I can say without hesitation that someone will post in the comments that they managed to achieve the above results in some form or fashion.  And while there are always going to be exceptions to any generality, that doesn’t tend to disprove the generality.  And generally speaking, the above is what happens in the real world.



26 thoughts on “Adding Muscle While Losing Fat – Q&A

  1. Lyle,

    Are there ever situations with professional athlete entering into the off-season where the fat loss-muscle gain combo is achievable to some degree?

    Coaches often throw around elaborate stats. Now while in-season to one degree or another is becoming more of a mainstream thing, I would still imagine that you get a number of athletes who, through some combination of hard living, the demands of a lengthy season, crappy diet (possibly with a fair amount of alcohol while on the road), and possibly some degree of de-training (although I suppose that depends on where they started and what they managed to get in throughout the season).

    I’m just curious if the potential for rebound gains/losses once a more controlled and “optimal” regimen is re-established come the off-season *at least for sports where this is applicable to any significant degree)

    I would suspect it would still not be to the degree seen with an overfat beginner, but I am just curious if this is one situation where things may line up to make it more feasible than usual.

    And while I am at it, I want to pass along a hearty thank you for all of the great content in 2009. And I hope that 2010 brings you much success and ends up being your best year yet.

  2. Lyle,

    Is this one of the things in which you and Alan disagree about? I’m referring to the “culking” approach.

  3. Mike: I think that is more akin to the situation I described above: someone who was in great shape who gets out of shape and then gets back into shape. But they aren’t improving upon their previous season’s shape. They are just getting back to where they were before they got fat and out of shape in the ‘off-season’.

    Eric: I think if you look at culking at Alan has it set up, it’s simply a very very very mild version of some of the more extreme EOD/IF stuff. A bit of a surplus on weights days a bit of a deficit (or maintenance) on non-weights days with some cardio. As well, if you look at the time frames involved….it takes forever to achieve what I think can be done much faster with more direct/focused approaches. So fine in 2 years you end up 10 lbs muscle heavier and 10 lbs fat loss lighter. Which you could do in maybe 30 weeks if you dieted and gained in alternating fashion. And which certainly isn’t what people are hoping for when they ask about ‘gaining muscle while losing fat’ (usually they want to shift 10-20 lbs fat into 10-20 lbs muscle in a 10-20 week period or some absurdist nonsense).

  4. The level of aggressiveness of the method of surplus or deficit depends on the individual’s goals & current status. Some folks don’t necessarily care about not getting significanty fatter while bulking, but a good portion of my clientele wants to (or in some cases, like actors & models) need to look good all year round. Thus the alternation of looking somewhat chubby while bulking before leaning down really isn’t an option. On the other hand, I think that people in general think I’m opposed to putting on any fat at all while bulking, or they think I’m not into the idea of separate cutting or bulking cycles, which isn’t true. With some clients, I choose a very specific & aggressive focus. For example, I’m building a plan for a natural BBing champ that’s specifically geared toward off-season gains. After that phase is done, it’s cutting time. With others, it’s more of the culking/recomp scenario involving less agressive surpluses or deficits. Not everyone gets the same treatment, because everyone is at a different place in their development, and people’s goals/objectives differ. One thing I want to get clear is that I’m not opposed to traditional cutting & bulking alternation, it’s actually best for some, and I do go that route with certain client cases that it’s well suited for. And I don’t disagree that the culking effect happens to a more pronounced degree in beginners with more fat to lose & more muscle to gain.

  5. I love this topic, I’ve lived it!
    Thanks for your input Lyle—-and Alan!

    I’ve went from 160 pounds, untrained/out of shape, to 160 pounds lean/fit & muscled in under 5 months. Changing body composition—adding muscle, losing fat is very much do-able at a beginner’s level.

  6. Hi,
    Great read. Had a few doubts though:
    1 pound of muscle burns approximately 600 calorie while 1 pound of fat around 3500 calories, which would mean ‘replacing’ fat with muscle(gaining 1 pound of muscle while burning 1 pound of fat ) won’t be possible, right? (Or does it require higher calories to create 1 pound of muscle?)

    Also, by what mechanism does the ‘replacing’ muscle with fat (also beginner-like muscle gain; does fascia has anything to do with it?) occur in those returning from a lay-off (those who are reasonably lean ie. not overfat at all)

  7. Lyle,

    What is it about the detrained state that makes it possible to get back into shape so quickly? What happens physiologically that makes muscle gain faster? I’ve heard of “muscle memory” but no one seems to be able to explain what that means on the cellular level.


  8. Ah, the alchemy of “turning muscle into fat”. Not very applicable to me, being female, and not into bodybuilding. However, not having studied insulin much, something here you said makes sense to recent experience. I have gone from obese to the edge of normal weight (by BMI), and while I still have a good 20 pounds to go at least, my body is different. I find that when I eat a whole lotta carbs (cake, noodles), I often need a nap afterwards, and I’m not really a napper. I was concerned about my blood sugar, though it didn’t make sense that I wouldn’t have blood sugar issues when I was obese, but now 60 pounds lighter, I’m starting to have them, but maybe I am now insulin sensitive. Am I understanding this right? Am I going to have to take a nap any time I eat pizza from now on?

  9. Im assuming this article was based on a “natural” approach, but it got me thinking of less than natural approaches. What type of impact could supplemental testosterone have on this type of partitioning? It would seem that low doses are used to retain muscle while cutting and higher doses are used to build mass in a caloric surplus. Could one conceivebly lose fat and gain muscle while on an anabolic like test? Or do the same rules still basically apply? If so, is this some of the explanation behind a “genetically gifted” lifter/athlete? What if we expand on that thought and look at a bodybuilder stacking anabolics with fat burners like thyroid and clen etc? Is it still just better in the long run to seperate everything and forget about it?

  10. Jad: Right, beginners.

    1. That’s what I said.
    2. Mechanistically, nobody can say what’s really going on. There is something to muscle memory but nobody knows for sure why it occurs.

    Tim: Nobody knows for sure. Just accept it as ‘magic’.

    Julie: Read around on the site, this is addressed elsewhere and not relevant to this article or the comments section.

    Eric: Yes, natural; had I wanted to talk about drugs, I’d have mentioned drugs (they are talked about in the Calorie Partitioning articles I linked). Drugs changes all the rules and a lot of what people think they can acheive comes out of bodybuilders using powerful repartitioning drugs (clen, testosterone, etc). So you’ll hear about contest prep pro bodybuilders losing fat while they maintain weight. What you don’t hear about is their drug stacks. And it doesn’t work for naturals.

  11. I have seen some research suggesting that working out in a cold gym, and generally working out during the winter, tends to help with the fat reduction/muscle gain equation. (Sorry I don’t have the link right now.)

  12. Lyle,

    Last fall I i had a cycle where i was cutting and bulking every other week.

    For example:

    Week 1: bulking
    Week 2: cutting
    Week 3: bulking
    Week 4: cutting

    And so forth…

    This experiment i kept doing from august until late november. On the “bulking” weeks i had a small surplus (about 500kcal) every day. On the cutting weeks i had a small deficit (about 500kcal) every day. I used certains keylifts such as benchpress, deadlifts, chins to keep track of my progress. During this 3 month stint i improved my bench from 2 reps at 76 kg to 2 reps at 84 kg. My deadlift from 2 reps at 140 kg to 5 reps at 152,5 kg. My bodyweight was about the same during the whole stint (somewhere between 80-82kg).

    So i guess what i want to ask you is this: Is it safe to say that i gained muscle while loosing fat (or at least keeping it to a minimum)? Do you think that i could have achieved greater gains (muscle + weight on the bar) if i followed a more traditional bulking and cutting approach? Im not so sure… shouldn’t what matters be the total net effect? For example: “My approach” with on week cutting followed by one week bulking for a timeperiod of 3 months would mean 6 weeks of effective cutting and 6 weeks of effective bulking simultaneously. Would the net effect be the same if i focused on bulking for 6 weeks and then afterwards started cutting for 6 weeks?

    I’m very interested in hearing your thoughts on this.

    I have nothing that supports this, but in my mind, “My approach” seems much more logical if one prioritizes staying in decent shape all year round.

  13. Ned: I’d have to see a link to what you thought you saw. Call me skeptical.

    Goran: I can’t say if you gained muscle and lost fat, that’s what body composition measures are for. Strength is a proxy but you can gain strength with no change in muscle mass so it doesn’t mean anything by itself.

  14. I was a weak overfat individual and gained strength while losing weight. About 40% strength (some of it non-neuro, as I had a base of on/off lifting before getting serious last 6 months). Went from 230 to 160 weight. I think if you are extremely fat or extremely weak (I wasn’t extremely weak, but was “untrained” and was definitiely very fat) that it just makes common sense that you can do both at the same time. My focus was the weight loss and I just did the lifting for health (and got what I got). I don’t think it needs any insulin story to explain it but just a combination of processes.

    I think people get in trouble when they decide that they will stay fat and “lfit to displace fat” (i.e. avoid dieting). Or conversely, they just decide “it would be a waste to lift” and blow that off. The former is a much worse practice than the latter.

    What’s even more bizarre is some who will say that “lifting prevented weight loss” as if a calorie consuming activity could prevent weight loss! It’s more the opposite! Some of them will even insist on this belief in COMBINATION with thinking that it is impossible to build muscle while dieting. I’m life wtf on that…

  15. I’m interested in the fat balance equation, and how this would be affected by an IF approach. For example, fasting from bedtime til lunch, with low intensity cardio + yohimbine, followed by lunch/snack, pre-post workout nutrition & heavy weights (3x per week) , Low to Moderate volume. Essentially catabolic in the AM fast, anabolic in the PM with 500 cal above maintenance.

    Could one burn fat in the morning, and build muscle through the evening?

  16. In case other readers are interested in my question posed above; Lyle, bless his heart (lol), did reply when I posted the Q in a newer thread. Here’s the copy/paste.

    “lylemcd on October 12th, 2010 12:20 pm

    It’s a good question. Certainly what we know about calorie partitioning and such would suggest that it’s possible, I might suggest that that’s what’s going on with some of Martin’s Leangains results and my own UD2 relies on a similar ‘trick’ (integrated over a weekly vs. daily schedule). So…maybe.”

    Thanks again Lyle, you’re awesome!

  17. For mixed sports athlete (I’m a kickboxer) who wants to add lean muscle while losing fat, would you recommend UD2, LeanGains, EOD, Tom Venuto’s Holy Grail, or it’s better to eat a little more on heavy weight training day and a little less on other days?

    Thank you.

  18. @ned lemme know when you get a link to show that plz I live in canada and its always cold here ! I could be in top shape easy haha

    great article man !!


  19. Hmm, if my muscles with increase stomach size(i dont’ see much diff now that i gained muscles, but slight difference, but i’m still gaining weight cause i gain muscles and lose not much fat), was replaced over a long period of time with fat, then you go back to workout, being in a shape that would require you to build up your body from scratch, both active muscleactivity and silent, is it possible to gain 2-4 lbs a week of muscles, with a -500 caloriesintake? What exactly happens with the fat and the muscles, cause I don’t feel like i’m getting a better shaped body doing this(since the stomach was too big in the first place(about 15 inches too much). I am fairly sure if I didn’t gain any muscles i’d lose about 50 pounds instead i lost only 10 during last year. I know i gained muscles cause i gained 2 inches on my hips and shoulders, and i know i’m losing fat cause the stomach size is going down slightly and so is the breasts.

  20. Lyle,
    I have been reading many of your blogs for advice and I love them! I am trying to attain a 6 pack, but I have this layer of fat above my up and coming 6 pack. I am still confused as to whether it is ok at my size to diet or not. I am 5’6”, I weigh 116, body fat is 15%, muscle is 37%, maintenance is 1840 for me. I feel as if I get so out of shape if I even go a week without training, I cannot imagine going two weeks off for cycling. HELP!

  21. Very good explanation for why you often see muscle gain while the body weight goes down but you almost never see fat loss while body weight goes up.

    Thanks Lyle!

  22. Hello Lyle!
    I’ve a question to ask and I humbly request you to please reply to this comment;
    I have heard that workouts in a cold gym help burn more fat and build more muscles. Is that true?

  23. Hi Lyle.

    Even in 2016, individuals like myself are benefiting from the advice that you have published in your articles. Thank you!

    I was just curious as to your definition of “overfat”. Would I be correct in thinking that an overfat individual is one who has a higher body fat than say, 15%? (figure guessed from your recommended cap on body fat when bulking)

    I was also curious as to whether an individual’s weight plays a factor into the definition of overfat. For example, I am around 65 kg (143 lb) and am 177.5 cm (5’10), but likely have a high body fat % due to very low muscle mass (recovered anorexic with little training during recovery).

    Should weight be considered when discussing bodyfat % as can “overfat” simply not be also attributed to low levels of muscle? Moreover, would you still recommend prioritising reduction of body fat in this context (for a more productive bulk in terms of partitioning)


  24. Overfat is an issue of BF% and nothing more. There is no strict definition and I am looking primarily at athletic populations. For a male above 15%, problems start, that’s the equivalent of perhaps a female at 26-28%.

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