Many people believe that rapid weight loss is unhealthy, but if done correctly, it’s far superior to “slow cutting”…


When it comes to weight loss, we’ve all heard that “slow and steady” is the way to go.

There’s value in this rule of thumb as losing weight too quickly means misery, muscle loss, and other maladies, but there’s a kicker:

Losing fat too slowly is also non-optimum and is often unsuccessful as well.

In fact, I would say that more people make the mistake of losing fat too slowly than too quickly as “crash dieting” is becoming less and less popular these days.

Well, in this article I want to break down for you why I think losing fat too slowly is a mistake and what you should be going for instead. Let’s get to it.

Why Losing Fat Fast is Far Better Than Slow

I have a simple goal when I’m looking to lose fat: I want to get it over with as quickly as possible, which means I do everything I can to accelerate fat loss while preserving muscle.

While this may sound like an obvious choice, there’s a school of thought in the world of fitness that advocates a “slow cutting” approach to weight loss. That is, the use of a mild calorie deficit with low-to-moderate amounts of exercise to slowly reduce body fat mass over the course of several months.

The “selling points” of the slow cut mainly revolve around maintaining maximum lean mass, eating more on a day-to-day basis, and doing less exercise (and less cardio, in particular). These positives are often coupled with exaggerated claims about how you’ll burn away all your muscle if you try to be too aggressive with your weight loss.

Well, I strongly disagree with the “slow cutting” approach because it provides only minor benefits but comes with major drawbacks that stem from the physiological changes that occur when you restrict your calories to lose weight.

You see, the longer you remain in a calorie deficit…

1. The more your metabolism slows down, which means the more you have to reduce energy intake or increase output.

This is how “metabolic adaptation,” as it’s called, works: your metabolism adapts to the amount of energy you feed your body with the goal of balancing energy intake with output–a state of homeostasis.

When you restrict your calories and feed your body less energy than it burns, you lose body fat but your metabolism naturally begins slowing down (burning less energy). The longer you remain in a deficit, the more your metabolism slows.

As your metabolism slows down, what do you think you have to do to maintain a deficit and keep losing weight? That’s right–you have to further reduce calorie intake or increase output (exercise). And then, a month or two later, you have to do it again. And again.

This cycle continues until either you reach your goal or your metabolism has slowed down too much and you then have to abandon your pursuit of fat loss and work on speeding it back up.

This isn’t the end of the world…but it’s unnecessary. By being more aggressive with your calorie restriction, which we’ll talk more about soon, you can lose quite a bit more fat without losing muscle or experiencing any additional metabolic slowdown.

2. The more time you’re not building muscle.

This insidious mistake that can really hurt your long-term results.

If you’re even halfway well-read in this space, you’ve heard that you can’t build muscle and lose fat simultaneously. This isn’t always the case (newbies can), but it’s generally true: a calorie deficit impairs your body’s ability to repair and build muscle proteins enough to effectively halt muscle growth.

Thus, the problem with slow cutting becomes obvious: the longer you cut, the longer you fail to build any real muscle to speak of.

If you’ve basically reached your genetic potential in terms of muscle growth, you might not care about that. But if you’re still working on your physique and need to add more muscle to reach your ultimate goal, then this becomes vitally important.

I’ve seen guys really mess this up and gain anywhere from 1/2 to even 1/3 the amount of muscle they could have over the course of anywhere from 6 to 12 months by simply remaining in a mild calorie deficit for far too long.

The bottom line is when it comes to building muscle and strength over the long term, you want to spend as little time in a calorie deficit as possible, and “slow cutting” fails in this regard.

3. The more likely you are to fall off the wagon and quit early as you become physically and mentally fatigued.

Let’s face it: even when you’re dieting properly, staying in a calorie deficit gets old after a while.

Workouts get harder, energy levels can flag, and hunger and cravings can become more frequent, and we have to rely more and more on willpower and discipline to stay the course.

I’ve seen this many times: the longer someone has to fight his or her body’s desire for more food, the more likely he or she is to go astray with bingeing and, ultimately, abandon the mission altogether.

An interesting point about this, as well, is that you can be quite aggressive with your calorie restriction without feeling much different than if you use a mild deficit. Generally speaking it entails a week or two of mild hunger and then smooth sailing.

But Wait…Won’t Rapid Weight Loss Cause You to Lose a Lot of Muscle?

This is one of the biggest weight loss fears out there among us fitness folk, and like much of the “wisdom” in this world, it’s only partly true.

The fact is yes, too large of a calorie deficit will accelerate muscle loss and this is one of the reasons why “crash dieting” is so unhealthy.

But how large of a deficit is too large? And how do things change for athletic types following a high-protein diet, as opposed to untrained, obese individuals eating too little protein?

Well, we can thank researchers at the University of Jyväskylä for an answer!

In a study they conducted, they split their subjects–20 to 35 year-old national and international level track and field jumpers and sprinters with low levels of body fat (at or under 10%)–into two groups: a daily calorie deficit of 300 calories (about 12% below their total daily energy expenditure) and a daily calorie deficit of 750, with both groups following a high-protein diet.

After 4 weeks, the results were surprising: the athletes utilizing a 300-calorie deficit lost very little fat and muscle while the group utilizing a 750-calorie deficit lost, on average, about 4 pounds of fat and very little muscle.

Remember, however, that the 750-calorie deficit group was not starving themselves by any means–they were eating over 2,000 calories per day. Nevertheless, they were utilizing a pretty aggressive deficit of about 24% and the results speak for themselves.

These findings completely jive with my experience both with my body and the thousands of people I’ve worked with: mild deficits can work if you’re very overweight, but as you get leaner, larger deficits become necessary and don’t automatically cause muscle loss.

This is why my standard calorie deficit recommendations for weight loss are between 20 and 25%.

So, as you can see, the scales are tipped far too heavily against slow cutting for it to be advisable.

  • If you have a significant amount of fat to drop, the best-case scenario is you lose it slowly but at too high of a cost.
  • If you’re relatively lean, you’ll probably never see single-digit body fat percentages and quit out of frustration.

Before I sign off, I want to share with you how I maximize fat loss when I cut and make it as quick as possible without sacrificing muscle or my sanity.

How I Lose Fat Fast While Preserving Muscle and Strength

Over the years, I’ve tried many different things with both my diet and training when cutting and have dialed in an extremely effective and efficient weight loss regimen.

With this regimen I’m able to lose about a pound of fat per week, even when I’m starting around 9 to 10% body fat (I recently cut from 9 to 10% to 6% in about 7 weeks), without any hunger or cravings to speak of. My energy levels stay high and my training is barely impacted.

Here’s the regimen:

I use an aggressive (but not reckless) calorie deficit of 20 to 25%.

Like the athletes in the study cited above, I also reduce my calorie intake to about 75 to 80% of my TDEE and, like them, immediately start seeing reductions in fat without any noticeable muscle loss.

If you don’t know how to calculate your TDEE or work out a calorie deficit, this article on proper meal planning breaks it all down.

I eat a high-protein, high-carbohydrate diet.

While the scientific search for the “ideal diet” continues, there’s one thing we know for certain: it’s going to involve eating plenty of protein every day.

The bottom line is study after study after study confirm that high-protein dieting is superior, in every way, to low-protein dieting. This is especially true when you’re restricting calories for weight loss, as adequate protein intake plays a major role in the preservation of lean mass.

If you’re not sure how much protein to eat, check out my article on how much protein is needed to build muscle.

Now, most people know that a high-protein diet is superior to low-protein, but many people don’t know that a high-carbohydrate diet is far superior to low-carb when it comes to weight loss and calorie restrictions.

Why? Well, when you’re restricting your calories…

This recommendation comes as a surprise to many people, but trust me: if you usually use low-carb dieting when you want to lose fat, try a higher carb approach next time (about 40% of your daily calories from carbohydrate) and you’ll be amazed at how much easier and enjoyable it is.

I use supplements proven to accelerate fat loss.

If you’re skeptical of supplements…I understand. The industry is rife with fraudsters and worse and most of the stuff sold in your local GNC is more or less worthless.

That said, there are natural substances that can help you build muscle and lose fat.

Creatine is a good example of the former, and there are several supplements proven to aid with fat loss like caffeine, green tea extract, yohimbine, and more. I’ve cut both with and without using these supplements and find that it’s noticeably faster with them.

I lift heavy weights.

Heavy lifting will not only help you maintain your lean mass while cutting, it can actually help you burn more fat.

study published by Greek sports scientists found that men that trained with heavy weights (80-85% of their one-rep max, or “1RM”) increased their metabolic rates over the following three days, burning hundreds more calories than the men that trained with lighter weights (45-65% of their 1RM).

So hit the weights and hit them hard if you want to jack up your metabolic rate and in turn, speed up your fat loss.

And if you want to score extra points, focus on compound lifts like squats and deadlifts, because these are the types that burn the most post-workout calories.

I do HIIT cardio.

If you’re familiar with my work, you know that when it comes to cardio, I’m a big fan of high-intensity interval training.

Studies such as those conducted by Laval UniversityEast Tennessee State UniversityBaylor College of Medicine, and the University of New South Wales have conclusively proven that shorter sessions of high-intensity cardio result in greater fat loss over time than longer, low-intensity sessions.

In fact, a study conducted by The University of Western Ontario showed that doing just 4 – 6 30-second sprints burns more fat over time than 60 minutes of incline treadmill walking (one of the staples of “bodybuilding cardio”).

Furthermore, keeping your cardio sessions shorter means you better preserve your muscle and strength.


What do you think of rapid weight loss vs. “slow cutting”? Have anything else to share? Let me know in the comments below!