How To Use a Low Carb Diet to Burn Fat Without Losing Muscle

These days, chances are that if you’re watching your waistline, you’re also watching your carbs. Carbohydrates are one of the “Big Three,” the macronutrients that your body gets from food (the other two are protein and fat.) Carbohydrates are your muscle’s preferred source of energy for resistance training, so your diet has to be sufficiently high in carbs to help you power through your workouts. On the other hand, if you consume too many carbs, you could end up singing the Spare Tire Blues. What to do? In this article we examine ways that you can use a reduced carb diet with your resistance training to help you get leaner and more muscular faster— without burning away your hard-earned muscle tissue.

Not everyone is interested in competing as a bodybuilder, but you can sure learn a thing or two about dieting from them. Having gotten my start in competitive bodybuilding in the late ‘70s, I experienced the infancy of the modern-day low-carb diet, first hand. The late Dr.Robert Atkin’s first book, Dr.Atkin’s Diet Revolution, was published in 1975 and quickly grew in popularity as the diet du jour. Bodybuilders were amongst those who jumped on the bandwagon, and low carb diets became part of the pre-contest training regimen of many of the top champions. Three-time Mr.Olympia Frank Zane and Mr.Universe Tom Platz were early proponents of low carb diets. So was yours truly, an up-and-coming young Lee Labrada. The common wisdom in those days was to limit carbohydrate intake to just 40 grams per day, usually consumed just before the workout.

I initially liked the low carbohydrate approach because it curbed my appetite, an advantage for any precontest dieter. But this came with a price. My low carb diet also had the nasty side effect of leaving me tired and listless for much of the day. The workouts aggravated this effect. Of the small amount of carbs that I did allot myself each day, I ingested all prior to my workout. This provided me with a temporary burst of energy which my muscles gobbled up during weight training. After the workout, it was back to being tired and listless again. To make matters worse, sometimes I ran out of energy during the workout—a “crash.” Crashing was no fun, because at that point the only way I could go on was by the sheer strength of my will. Muscles are fuel hogs during workouts, and once again, their preferred fuel for high intensity training is carbohydrates.

The low carb diet worked well for some competitive bodybuilders of that era, allowing them to get ripped to ridiculously low levels of body fat. But there was another big drawback to the low carb approach: it also cost bodybuilders valuable muscle size. That’s because strict , low carb diets can wreak havoc on muscle tissue. Sure, you burn lots of fat, but you also burn lots of muscle.


First off, stores of glycogen (stored glucose from carbohydrates) inside your muscle tissue and liver are compromised when your food intake is too low in dietary carbohydrates. And with low stores of glycogen, it is difficult for your muscles to exert the sustained, high intensity effort required to lift weights. That means your strength gets compromised. When that happens, your training poundages go down and there is less muscle stimulation, which sets you up for muscle loss. After all, your body never keeps what it doesn’t need. If you’re lifting lighter loads, your body doesn’t need the added muscle.

Secondly, when you diet, you’re almost always in a hypocaloric state (taking in less food calories than you burn on a daily basis.) When you’re hypocaloric, your body looks for the “missing energy” it needs to function in other places. After all, it’s not getting it from the food! Your body can get the “missing calories” from two places: stored body fat (you want to reduce this!) or muscle (“don’t you dare touch this,” you say!)

Unfortunately, muscle tissue is easy to break down. The amino acids in muscle can be broken down and converted to glucose for energy by your liver. During an intense weight training workout, the lack of carbohydrates forces your body to break down muscle tissue to supply the energy. Not a good thing! Carbohydrates are actually protein-sparing.

“ When blood sugar levels are low or are suboptimal during exercise, the body will initiate the creation of new sugar by breaking down glycogen (stored sugar) and protein for amino acids through Cori Cycling and other processes. Sugar is used exclusively for anaerobic energy production – contracting a muscle, lifting weights and even all-out sprints are examples of anaerobic exercises. If your blood sugar is uneven or low, the ability of the muscle to forcefully contract and to do so fully is slightly impaired. This results in suboptimal muscle performance,” says Douglas Kalman MS, RD, FACN.

By the early ‘80’s, low carb diets had fallen from favor with bodybuilders for these obvious reasons. Low carb diets waned as the USDA food pyramid embraced diets that were high in carbohydrates and low in fat.  The food industry followed suit, and began producing low fat, high carb foods for dieters.

This set the stage for the high-carb dieting paradigm that has ruled the pre-contest bodybuilding diet until the last few years. The Achilles’ heel of the high-carb diet is that too much of a good thing can also be counter-productive making it hard for you to lose as much body fat as you want. Excess carbs will stimulate an abnormally high insulin (a fat storage hormone) response, causing you to gain unwanted body fat.

The question then, is: How many carbs do I consume to get ultra-lean and ripped, while holding on to all of my hard-earned muscle?

The answer is, enough to fill your glycogen reserves (stored carbohydrates) in both your muscle tissue and liver, plus enough to power your workouts. That leaves very little dietary carbohydrates left over at the end of a day to turn into fat. Here’s one way to integrate a reduced carb diet into your precontest training regimen.

The Reduced Carb Diet

During the low carb phase of your training, I recommend consuming 150-200 grams of complex carbohydrates per day for an average male weighing 200 pounds. This works out to about .75-1.0 grams of complex carbs per pound of bodyweight. That’s higher than is typically considered a low-carb regimen, but keep in mind that as a bodybuilder, you are hardly the typical person. You have a higher than average amount of muscle, train hard with weights, and are in better shape. That being the case, your carbohydrate requirements will be higher. “Low” carbohydrate is relative, both to your size and metabolism.

You should stick to consuming only complex carbs from sources such as oatmeal, whole grain cereal, yams, sweet potatoes, whole grain rice, beans, lentils, and peas. That’s because these complex carbohydrates are broken down slowly by your body, keep your blood sugar stable, and keep your insulin levels down. Complex carbs such as these are considered to have a low “glycemic index,” a measure of how quickly a carbohydrate is broken down by your body into blood sugar. Remember, it’s necessary to keep your blood sugar level as stable as possible in order to manage your insulin levels.

Consume your carbohydrates along with proteins and fats, never alone. When combined with the aforementioned, the breakdown of carbs is slowed down even more. Take in 50 grams of your carbs in the meal prior to your workout (about 1-1.5 hours before), then 70 more grams in the meal immediately after your workout. This is for two reasons.

One, the carbs immediately prior to your workout will help to fuel your training.

Two, the carbs immediately after your workout will replenish glycogen stores in your muscle tissue. Replenishing glycogen stores within 30 minutes after a workout will enable you to take advantage of your body’s compensatory mechanism, enabling you to actually store more carbs as glycogen. Your post workout meal should always be your highest-carb meal of the day.

If you follow the guidelines that we’ve discussed, you will have about 50-100 grams of carbohydrates left to dispense over your remaining meals. Of this remaining amount, I recommend consuming up to 75% of it in the meals prior to your pre-workout meal, with the remaining 25% in the meal after your post-workout meal:

Meal one 20g of carbohydrates

Meal two 20g

Meal three 20g

Meal four (pre-workout) 50g


Meal five (post workout) 70g

Meal six 20g

On days when you don’t train, cut your carbohydrate intake back to 100 grams, spread out evenly over each meal. You won’t need the extra carbs on your day off. One important caveat: whether you are training that day or not, be sure to consume sufficient protein and healthy fats (most fats of plant or fish origin) to fuel your body and help recuperation. A product such as Labrada’s EFA Lean is an excellent choice for this. Being in a slight caloric deficit (eating fewer calories than you burn) is necessary for you to lose unwanted body fat, but cutting your overall calories back too far will cause you to lose muscle mass.

Says Douglas Kalman MS, RD, FACN], “When you do not eat sufficiently, weight loss and muscle loss can occur 24 hours per day. If your meal timing and overall nutrient ratio is sub par, this can greatly hurt your ability to gain muscle since the effects of progressive resistance overload make your muscles scream for the right nutrients at the right times. Under eat or eat at the wrong times and watch your muscles grow…smaller and not stronger. Understanding nutrient timing is paramount to avoiding inappropriate muscle loss.”

Training on the low carb diet…

It is important to structure your resistance training so that it is brief, heavy and intense. Brief workouts consume fewer calories than longer workouts, which will help you conserve energy so that you don’t feel beat for the rest of day. High intensity workouts are also more productive for stimulating muscle tissue — that means “GROWTH.” High intensity workouts burn glycogen and carbs primarily. Combined with the meal carbing regimen I’ve recommended, you’ll be a like an F-16; powerful, yet fueled up just enough to get the job done. Take a serving of Labrada’s SuperCharge! Xtreme Pre-Workout N.O. formula prior to your training to give you extra energy, focus and pump.

For workouts, check out my weekly workouts posted here: Weekly Muscle Building Workouts

Cardio on the low carb diet…

To help the fat burning process along on a low carb diet, there’s nothing like adding a little cardio to your workout.

Cardio should take the form of 30 minutes of stationary bicycling, stair-stepping, or jogging on the treadmill, immediately following the workout, 3-5 times per week. While on a low carb diet, keep your cardio intensity level to 70-80% of your maximum heart rate. You can roughly calculate your target heart rate by taking 180 and subtracting your age. So if you are 30 years old, your target heart rate is about 150 beats per minute. By doing your cardio following your workout, you’re in a state where you’ve used up the glycogen necessary to train your muscles with heavy weights, and your body will be ready to switch over to burning stored fat for energy.

If you can’t do your cardio after your training because of time constraints, or because you are too tired, try doing it in the morning, prior to breakfast. Because you are in a fasted state upon awakening, you are already burning fat for energy. This makes for a good state to be in when you start your cardio, enabling you to burn even more stored fat! Not to mention that it is an energizing way to start your morning.

Speaking of energizing, there’s no reason that you have to feel tired when you are on a low carb training regimen. The idea is balancing your carbs so that you have enough to fuel your activities, but not more. Try this reduced carb training regimen 4-6 weeks prior to your bodybuilding competition or to improve your physique for the summer. Your reward will be a leaner, more muscular body that turns heads everywhere you go!

Until next time, I am

Lee Labrada
Your Lean Body Coach™

3 Responses for How To Use a Low Carb Diet to Burn Fat Without Losing Muscle

  1. Alex


    January 29, 2013 7:14 pm

    Yet another great article!

  2. Mike


    January 29, 2013 7:19 pm

    I can’t say it enough. This man knows his stuff. I have tried and tested Lee’s low carb plan and it flat out works. I was once a victim of going too low on carbs because I felt I couldn’t lose the fat without severely cutting carbs. I’ve found my sweet spot of about 150-175 a day for carbs just like Lee recommends and I never feel sluggish but I’m still burning fat. Another great article Lee!

  3. TG


    January 29, 2013 8:16 pm

    Hi there. Great post!! However, I wake up at 515 in the morning, and workout at 530am (This is just what works for me being a busy stay at home mom that babysits). Just curious what the best lay out would be for my carb consumption with this type of workout timing?? Thanks in advance.