Low Calorie Diets. How Low Calorie Can You Go, Without Losing Muscle?

Low calorie diets are a great way to lose weight quickly. You can create a much larger calorie deficit through dieting than you can though exercise.

The challenge is that most of the time we want to lose body fat instead of muscle. If your calorie intake is too low, you can eventually lose muscle as well as body fat.
low calorie diet
[Mr T’s Son, James T., Displays a Great Slim and Toned Look]

Why Low Calorie Diets Are Effective

The most effective way to lose weight is to create a calorie deficit. You do this by burning more calories throughout the day than what you eat…simple enough. There are two ways to create this deficit, eat less or exercise more. I believe that it is much easier to create this deficit through dieting than it is through exercise.

Here is an article I wrote about this exact subject: Is Diet OR Exercise More Important for Fat Loss and Getting Lean?

Won’t Going Too Low Calorie, Slow The Metabolism?

Drastically reducing your calories does slow down your metabolism, but it doesn’t happen as quickly and easily as you have been led to believe. People who push the idea of eating every couple of hours would like you to believe that skipping a meal will immediately cause the body to hold onto fat for the next meal.

This idea of going into “starvation mode” has been greatly exaggerated. I have written another article that explains more about starvation mode: Skipping Meals Will NOT Slow Your Metabolism and Cause Weight Gain! This article talks mainly on the subject of meal frequency, but it also explains how the body goes into starvation mode over a period of time.

So How Many Calories Per Day is Enough?

Here is where things get REALLY complicated. There are tons of variables that dictate how many calories per day is the optimum amount to lose body fat, without sacrificing a bunch of muscle. Someone who has a lot of body fat to lose, can get away with eating less than someone who is closer to their target weight.

A person who is extremely active has to eat more than someone who is not that active. A person with a slow metabolism should eat fewer calories than someone with a higher metabolism.

I can’t give a perfect formula to tell you exactly how many calories is ideal for you, but I can give you a way to figure it out for yourself.

A Simple Method to Figure Out If you Are Getting Enough Calories

I believe in simple solutions to complex problems, and this is as easy as it gets in my opinion. This simple method does require that you are performing some type of resistance exercise.

If you lift weights in a gym, then this will be easy for you. Okay…when you begin a low calorie diet for fast fat loss, I want you to begin a strength training routine as well. Don’t worry, you won’t get bulky off of a strength training routine while experiencing a daily calorie deficit.

While you are dieting hard, if you either maintain or gain strength on a consistent basis…you are eating enough calories per day…end of story!

Shouldn’t We Lift High Reps For Muscle Tone?

If you are consuming a low calorie diet, you won’t have the energy for a high rep workout routine. This is one of the many reasons I’m against the traditional “high reps for tone” approach.

If you gain strength while dropping weight, your body is becoming more efficient and will quickly display greater muscle tone. Think along the lines of an Olympic gymnast.

They aren’t even trying to look toned…their muscle tone is the result of being light, yet amazingly strong for their size.

What Does This Strength Routine Look Like?

There is a ton of flexibility here. My favorite strength routine on a really low calorie diet is to choose 2 exercises per body part and perform 3-4 sets of 3-5 reps.

So for chest, I might start with “45 degree angle dumbbell incline presses”. I would warm up with 50 pound dumbbells for 5 reps…then maybe 60 for 5 reps…then grab 80’s and do three work sets of between 3-5 reps. My next chest exercise might be a “low incline bench press on a smith machine”…I would do one warm up set, since my chest was already warmed up from the previous lift…at that point I would hit 3 work sets with a weight I could get up 3-5 times.

I would do the same for every major muscle group.

How Would I Split up The Muscle Groups?

I recommend splitting the muscle groups into two workouts. My favorite is to work Back and Chest on day one and Shoulders, Biceps, and Triceps on day two. Ideally you would workout 4 times per week, so the body would get worked two total times each week.

Note: I like the way intense cardio shapes the legs and butt, so I don’t really recommend direct leg work unless your legs are very skinny (this is the most controversial piece of advice I give on my website on a regular basis). I simply think that excessive direct leg work ruins the physique.

How many male and female Supermodels do you think hit the squat racks? I rest my case.

So…How to Tell If You Aren’t Getting Enough Calories

As long as you are either getting stronger each workout, or maintaining your strength each workout…you are getting sufficient calories each day.

If you begin to lose strength or have a tough time finishing your workout, you need to bump up the calories a bit. It is important to have the same “test conditions” each workout…so if you begin your chest workout with “incline dumbbell presses”, you need to do that every chest workout.

I only monitor the strength progress of the first exercise per muscle group. Feel free to vary the exercise choice for the second lift to get variety in your workout.

What is a Good Low Calorie Baseline?

Take your target bodyweight in pounds and multiply it by 10. So if you weighed 200 pounds and wanted to get to 150 pounds, then you would eat 1,500 calories per day.

If you have 30 or more pounds to lose, begin with this daily calorie amount (your target weight multiplied by 10). If you have 10-30 pounds to lose, this may be too low. If you have less than 10 pounds to lose, you will need to be careful and really monitor the way you feel and your strength levels.

Note: You may need to eat more than this. Also, this is a low calorie diet and isn’t meant to be a year-round deal. Be sensible about this…I like you guys and don’t want to create any eating disorders!

The main thing is to find out “how low you can go” while still gaining strength.

60 thoughts on “Low Calorie Diets. How Low Calorie Can You Go, Without Losing Muscle?”

  1. Finally! I have been scouring the web trying to find support for my very low calorie diet, and it is hard to find. I got rid of the sugars and bad carbs, and stick to protein, leafy greens in the main, and have carefully tracked my eating for the last three years. At the normal recommended macros, for me around 1400 cals & 30 carbs perday, I could lose nothing of the extra 30# I carry, despite doing Hiit and walking several miles a week. All I saw was fearmongering about what will happen, but finally decided to see where I would begin to lose, so
    dropped a hundred calories at a time over several weeks, finally when I dropped to <900 I began to lose weight.
    I have plenty of energy, keeping pushing to greater gains in lifting, and feel great.
    The fact that there is a metabolics spectrum gets lost in what is "normal/average"; some people can't gain, I knew several on my paternal side; others, like me need very little to sustain our body mass.
    Thank you for pointing put the truth, that you can measure whether your needs require more or fewer calories. I'm just aggravated it took me so long to get past the conventional BS.
    So glad to finally see this put in plan language.

  2. It is even more complicated than mentioned to find the right calorie count as not all calories are nutritionally equal. You will be able to eat less nutrient dense foods and maintain/build strength (eg vs eating donuts 3x a day).

    I found that Juicing once a day helped me maintain/build with less hunger issues.

  3. Hi,

    Hoping you still respond to this post after so long…

    I have recently taken up pro wrestling which requires me to work on a wide range of fitness areas including strength, physical appearance (more muscle, less fat!!), agility, speed, stamina, jump height etc etc. The work out is going great, but I am concerned that I will be burning too many calories through excersise as my current daily calorie intake never really exceeds 1400.

    I want to lose the gut, but at the same time, I want to build muscle and fitness – I am worried that my calorie defisit is too high (I am now burning an additional 5000 calories per week through a mixture of cardio, yoga, claistenics and weights) so I will end up losing muscle as well as fat, and lose weight too fast (which from experience I know I will end up struggling too keep off and be healthy).

    Any advise?


  4. You give some wonderful advice on this blog, but I disagree with the advice about not doing direct leg work. I always did direct leg/glute work on my weightloss regime and gained some size +beautiful definition in the quads/butt. But of course, I do not find the ‘lean’ and muscular look on women attractive in the slightest. I like the lower body to have some muscle size covered with a nice layer of fat. I guess everyone needs to remember to train for their goal.

  5. Hello Rusty,

    I a 18 years old male, 5′ 8”, and around 138 lbs. I have a small upper body and naturally have bigger legs and carry more fat on my legs. My main goal is to tone down my legs and and gain some muscle in my upper body. Like four months ago, I used to weight around 136 lbs but I know I had more muscle and a lot less fat on my body. So, I’m afraid that I lost too much muscle mass in the past couple of months. To s tart burning this extra fat off but not lose even more muscle at the same time, I was plannning on going on a 1000-calorie diet for 2 weeks, and then 1500 calories for one week, and keep cycling like that. I was also going to lift in my upper body and do the elliptical for at least an hour a day. What do you think?

  6. @Doug. I asked the same ? on another article but didn’t get a response. That’s what I’m doing, Phase 3. They are short, intense workouts and I have found it really allows me to cut way back on calories, more than I would ever do otherwise, and still maintain my strength. I sometimes gain strength. I did this morning. The focus on this kind of workout is the cardio. I follow each lifting session with 1/2 hour cardio, 6 days a week. I’m never hungry, even with a huge deficit. Good luck.

  7. So is this the number of net calories we eat? Or is it that many in general? What I’m asking is should we eat the calories we burn from exercise?

  8. Hey I was 387 pounds, I started a low calorie high protein diet, I do cardio for 1 hour in the morning before I eat and 1 hour of cardio in the evening after I eat a high protein supper… I lost 35 pounds in 3 weeks, and that’s on a 800 to 1100 calorie diet… Should I be eating more on my calorie intake a day, because I’m so big. I’m thinking at this rate I should loose 150 in three months. Any advice would be greatly appreciated.

  9. I think you have just replaced Lebron James as my idol. Please tell me you have a website or some way of keeping up to date with your tips. After i found your post i literally read every single comment to soak up that much more of your advice.

    Just one quick question. What and when do you normally eat earlier on in the day?

  10. Hi Rusty!

    Love your posts! What do you think about upping protein when going low calorie? Do you agree with lyle mcdonal that it would spare lean muscle mass?

    What about during maintenance? Does Brad Pilon haver it right that for maintenance you could shift some calories from protein to fat or carbs? Because it seems that Martin Beckhan doesn’t agree with him on that…

    Also I’ve heard that body temperature could be a good indicator of when you’ve been going low cal for too long.. like need to go to maintenance for a week or so… Just asking cause I’m trying to cut down and tend to eat one big meal at night with mostly meat and veggies.
    What are you’re thoughts on that ? I’m referring to the research done by matt stone over at 180 degreehealth…

    Thanks for your great blogg. It helps to have someone how can explain stuff in such an easy manner!

  11. I am currently 130 pounds and 5 feet 2 inches. I have signed up with a doctor and am on an 800 calorie diet and only 20 carbs with no excersise. I lost weight quickly with this plan and it is suppose to be for 21 days but I can’t seem to stick to it for more than 7-10 days. I become almost obsessed with eating carbs and sugar. I have a cruise in April and really must loose this weight fast for my husband. He hates the weight I have gained and it has strained our marriage. I really want our cruise to be a turning point. So I guess I am asking you…..Should I be doing exercise during this 21 days? Should I add carbs such as more fruit and veggies and just calorie count? Also I work nights 7p-7a. Is it beneficial for me to work out after work in the morning before I go to bed or is that defeating the purpose??

  12. im 14 and currently weigh 113 , not overweight but i want to get a 6 pack so i want to weigh around 109, im on a 1200 calorie diet, is this healthy and will this stop or slow my growth since 14 is one of the ages you grow a lot?
    i am not very active do not have any sports at the moment, jus skool and back home. so will i stop growing because of lacking calories?

  13. Hello Rusty, I am on a low-calorie diet now where I eat about 800 calories or less a day. I’ve been o this diet for almost two weeks now and I have lost excess weight around the sides and stomach. I work out almost every day and sometimes twice. I’m not overweight but I think I do need to eat more calories. If eating that low of calories for a nineteen year old who is average weight and works out is bad, will I re-gain the weight I lost if I increase my calorie intake? Or does it depends on if you increase the calorie intake slowly or quickly?

  14. Hey Rusty,
    I love your site you have a huge amount of knowledge!I wanted your help on my diet and excercise plan, up until a year ago I was 119lbs at 5 feet 7 inches, but since then I quit smoking (a pack per day) and put on 26lbs which has been a nightmare to get rid of because I replace the ciggies with food,Im wanting to start a serious plan to get rid of the extra weight,and was wondering if 800cals per day for 6 weeks would be safe?and how long does it take to loose weight when your on a x10 per pound plan. I walk up hill 5x per week for 60min-90mins which keeps my heart rate up,is this a good level to keep up?
    I really would love your advice on how I can get rid of the weight quick and easy,thanks rusty

  15. Hi Rusty, im 17 years old and 6 foot tall, weighing in at 165 lbs. Here is my story. Last year i weight 180 lbs but i was in the weight room every day i gained serious mass in my arms and pecks but gained some dreaded flab on my sides and stomach, but i was okay with that. Well at the beginning of this summer i fell off a roof (working at my job) and injured my shoulder. The docs orders were not to lift for a few months and i followed the orders (even though it hurt inside that i couldn’t lift). Now the dreaded no lifting ban is well lifted, but there is a problem. While i wasn’t lifting i was getting smaller in my arms and pecks so now i have tiny arms again with a fat stomach. My question is is it possible to gain some serious mass in my arms and pecks while simultaneously getting that skinny muscular stomach i dream of with the low calorie diet? If so then how? Any help is GREATLY Appreciated.

  16. Beverley,

    At the top of my site under the banner, you will see a link to “The Rapid Fat Loss Handbook”. It is an instant downloadable e-book that costs $34.95. It sounds like a lot of money, but it is one of the best diet plans I have ever seen for someone who needs to drop a lot of weight quickly. It would work very well for you.

    If you can’t afford that, here is my advice…you can go very low calorie for two weeks straight, then take one week breaks where you eat a more normal amount of calories. This is a way for you to lose weight without having your metabolism slow down too much. So basically two weeks on and one week off. Sounds basic, but works pretty well.


  17. hi rusty
    i just found your site by accident i was looking for very low diet,could i ask you how many calories a day do i need to lose 3lb a week,i have a very inactive job were i st mainly through out the day.i weigh 13stone 5lb i want to get to 10 stone for ist of augest 2008 im getting married
    could i lose 3lb a week on a 800 caloroe a day diet, i want to do this but everyone keeps saying you go in starvation mode and not lose any weight,but i thought no matter how low you go in calories you lose weight,am i right
    please help im desparate
    ps ive baught my wedding dress few sizes to small to give me the goal,i can stick o 800 a day thats not the problem its knowing will i lose all the weight on a 800 cal day diet

  18. Lynn,

    Losing 2 pounds per week is exceptional. I mean…that is outstanding! You will probably be at a sticking point for a while. It does happen. The only thing I would suggest it to pick 2-3 days per week where you increase the intensity of your walking. You absolutely can’t reduce your calories…you don’t want to shut your metabolism down.

    The only direction you can go is to increase the intensity a bit on your daily exercise. It may take 1-2 years to lose those last 20 pounds, but it will happen…it could happen much sooner. Just keep doing the right things.

    You are doing great!


  19. I am 45 and have had 9 children. I used to be able to lose quite easily. but in the past two years it has been impossible. Well finally for the past 7 months I started this routine where I water fast 2 days a week and then eat mostly salads and protein the other days. Still I am stuck at losing a maximum of 2 lbs. per week. I have finally lost about 45 pounds. I took a test to see if my thyroid was a problem and it is normal. I walk 7 days a week 30 minutes a day. I still have 20 more pounds and feel it will never come off. Any advice? I would estimate that I eat 3500 to 4000 calories per week.

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