Possible to lose fat and gain muscle?

I know losing fat and gaining muscle at the same time is generally thought of as impossible, as you need to be in a calorie deficit to lose fat and a calorie surplus to gain muscle and can’t be in both at the same time.

But what if I went from a poor diet of low protein and a bit of junk to a higher quality Huel diet that equalled about 120 to 150 grams of protein a day.

Say I was getting my maintenance amount of calories per day but my protein intake had gone up a fair amount and my processed sugars/carbs had gone down.

What would happen to my body? Would there be a recomposition of fat and muscle or no change at all?

Let’s assume I’d still be going to the gym 2-3 times a week, as I was before Huel.


With the law of thermodynamics, it’s impossible. However, you can get this net result by being in an energy surplus as certain times of the day or week and a deficit at others.

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So the day is divided into portions, and for some of the day (like just after eating) you are in a surplus and gaining muscle.

But at other time, when you haven’t eaten for X hours, you are in a deficit, and are losing fat?

Or is it much more complicated than that? :wink:

Also, what effect would switching from a low protein diet to a high protein diet, but keeping calories the same have, hypothetically?


No. But you can reduce the inevitable amount of muscle lost (when losing fat) by consuming plenty of protein (to stay in a positive nitrogen balance). Huel will do that for you.

It’s a little more complicated: it’s about structuring exercise with meals . I wrote this article about 10 years ago: http://www.muscletalk.co.uk/articles/losing-fat.aspx

Hypothetically, it depends on how low the protein was to begin with. If it was adequate, then no difference, if inadequate, then you should get better gains.


I appear to be losing fat and gaining muscle… or is it an illusion in that with the fat loss, my muscle appears more prominent?

Maybe a bit of both - bodybuilding is based on illusion!

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This is a topic close to my heart!

I was obese with virtually no muscle strength at all.

I did some fairly extreme fasting to shed 4 stone via ketosis. I knew that couldn’t be a long term solution so I then spent a month doing weights whilst on a slightly less extreme fast, but still more than most would like to endure. I packed on about a stone but the fat kept falling while the muscle built. I think this becomes harder to the point of impossible at a certain crosspoint i.e.- you can no longer convert calories from burning fat into lean muscle mass.

I knew I had to introduce more calories so I started Huel. I still fast a couple of days a week (to help kill remaining fat) but while I’m training, I make calories available to my body.

Best of luck!

According to some it is definitely possible: http://www.leangains.com/2010/04/leangains-guide.html?m=1

It takes a lot of specific fasting, feeding and nutrition. I tried for a while, but couldn’t keep up, because I don’t have full control over my eating schedule and sometimes I had to break fast (lunch time) with low protein food.

My own meals are about 70% Huel. I have been active, mostly cardio, but started focusing on lifting weights some months ago. I add vegan protein to my Huel. I also have fruit smoothies with creatine on workout days. I was not fat at all, but I am gaining muscle and not putting on any weight at all.

I am just figuring out what works for me. What you have to keep in mind is that you have to get enough protein. I find that’s more important than pure calory intake for muscle growth.


I’m sceptical of the idea that this is not possible - I seem to be managing it ok at the moment (though apparently starting from a relatively untrained state can make it easier). I’ve bulked up significantly over the last 6 months muscle-wise, as well as losing over a stone (mostly from the abdominal area). This is at the age of 42 so it’s not a case of me still growing and losing a little puppy fat.

Thermodynamically I see no reason to say that if the body has a reasonably small external energy deficit and is releasing a net amount of fat, that incoming protein can’t be used to build muscle. It’s not like all repair and growth processes stop during a net energy deficit, energy is taken from reserves and used elsewhere. The net increase in entropy is preserved; no laws of thermodynamics are broken any more than when your car uses fuel to charge the battery. Granted, there may be some biological reasons that make it difficult to do both at the same time (it’s not easy to find anything detailed on this, going from what I know, many of the body’s anabolic signalling systems are not tissue-specific, so perhaps that is one of the factors…).

I went on a weight loss course at the gym a little while back- at the end of the course I had only lost 100 grams on the scale, but had lost 4 inches from my belly, which suggests some muscle had been put on somewhere and some fat had been lost.

I would imagine when you are talking about the amount of muscle bulk gained and the fat loss requirements in the bodybuilding world, though, then things become quite different (James, I notice in your article it twice mentions cutting regime meal plans is “for a bodybuilder who wishes to lose body fat, whilst gaining muscle mass…” - has someone been doing naughty edits on your text?) :wink:


I was going to mention the same thing about thermodynamics. As long as there’s energy being released from fat couldn’t this be used to build muscle?

I was pretty ill until about 4 years ago with Cushing’s Disease which causes muscle wasting and truncal obesity. Since I’ve been in remission I’ve thankfully lost 35 kilos and gained back muscle.

This year, Huel’s made it easy to make sure I get the nutrients I need and I’ve definitely made improvements to my fitness without needing to cut calories.

I’ve read some studies recently, which show that yes you can lose fat and build muscle at the same time, as long as you are taking in sufficient protein.

The whole argument that you have to choose either bulking or cutting has been shown not to be correct.

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It’s incorrect yes, but your body will generally regenerate fibres without adding mass to them. No where near as many lean fibre gains as when in a surplus.

You’ll gain barely size and very little strength, but perhaps a nice bit of definition and tone. If you want to gain muscle, go hard and smash 3000cal per day. Worry about losing the fat later.

I think while this is the way serious competition lifters and bodybuilders approach things, from what I have read it is not really needed for beginners and intermediates who are not competing and not in a massive hurry to absolutely optimise gains (at the cost if significant dieting non-fun later). Also, significant cycles of weight gain and loss are not especially healthy.

My words are just a replication of the video by the way - so if you’ve watched that don’t read this.

Positive Nitrogen Balance, rest/protein/relaxation correct diet and the right exercises.

Muscle building isn’t dependent upon caloric surplus, but burning fat is dependent upon caloric deficit. You can still maintain muscle amounts and even increase it so long as you have adequate protein intake (nitrogen intake) and do not overtrain and do get enough sleep.

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