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Why rapid weight loss is superior to slow weight loss

Warum ein schneller Gewichtsabbau einem langsamen Gewichtsabbau überlegen ist

When it comes to weight loss, we've all heard that "slow and steady" is the way to go. This rule of thumb has merit, as losing weight too quickly will result in agony, muscle loss and other ailments, but the following also applies: Losing fat too slowly is also not optimal and is also often unsuccessful.

I would even go so far as to say that more people are making the mistake of losing fat too slowly than too quickly, as crash diets are becoming less and less popular these days. In this article, I want to explain in more detail why I think losing fat too slowly is a mistake and what you should do instead.

Why fast fat loss is better than slow fat loss

I have a simple goal when I want to lose fat: I want to get it over with as quickly as possible, which means doing everything in my power to accelerate fat loss while maintaining my muscle mass.

While this may seem like an obvious choice, there is a school of thought in the fitness world that advocates a slow approach to weight loss. In other words, this means that a mild calorie deficit with low to moderate amounts of exercise is used to reduce body fat over a period of several months.

The "selling point" for these slow weight loss approaches revolves around maximizing maintenance of existing lean body mass and doing less exercise (and especially less cardio). This approach is often combined with exaggerated claims that you will burn all your muscle if you are too aggressive in your weight loss approach.

I strongly disagree with this approach to slow weight loss, as it has minimal benefits but major drawbacks due to the physiological changes that occur when you reduce your calorie intake in order to lose weight.

The longer you stay in a state of calorie deficit...

1... the more your metabolism will slow down, which means you will have to reduce your energy intake or increase your energy expenditure

This is the way metabolic adaptation works: Your metabolism adjusts to the amount of energy you're putting into your body, with the goal of maintaining a balance between energy intake and expenditure.

If you restrict your calorie intake and give your body less energy than it burns, you lose body fat, but your metabolism naturally starts to slow down, which means you use less energy (1). The longer you stay in a calorie deficit, the more your metabolism will slow down.

What do you think you need to do to maintain a calorie deficit and keep losing weight when your metabolism slows down? Right - you need to further reduce your calorie intake or increase your calorie expenditure (exercise). And then, a month or two later, you have to do it again. And then again.

This cycle repeats until you've either reached your goal or your metabolism has slowed down too much and you have to give up your fat loss efforts to work on getting your metabolism back on track.

It's not the end of the world, but it's unnecessary. By being more aggressive with your calorie restriction - which we'll talk about in a moment - you can shed significantly more fat without losing muscle or experiencing too much of a metabolic rate slowdown.

2. ...the longer you don't build muscle.

This insidious mistake can really hinder your long-term results.

If you're even semi-literate in the area of muscle building, then you know that you can't lose fat and build muscle at the same time. While this is not always the case (it is possible for beginners), in general, a calorie deficit impairs your body's ability to repair and build muscle proteins enough to effectively stall muscle growth (2).

Thus, the problem of slow fat loss quickly becomes apparent: the longer you diet, the longer you won't build significant amounts of muscle.

If you have reached your genetic potential for muscle gain, you may not care. However, if you are continuing to work on your body development and need to build more muscle to reach your goals, then this is crucial.

Time and time again I see exercisers who completely mess this up and only build half or even a third of the amount of muscle they could have built within 6 to 12 months because they simply maintain a mild calorie deficit for too long.

The bottom line is that when it comes to building muscle mass and strength over the long term, you should spend as little time as possible in a calorie deficit - and losing weight slowly won't get you there.

3 ... the greater the risk of physical and mental exhaustion.

Let's be honest: if you diet correctly, maintaining a calorie deficit will become dull and boring after a while. Workouts become more strenuous, energy levels can drop and hunger and cravings can occur more frequently, all of which means you'll need more and more willpower and discipline to stay on track.

I've seen this happen many times - the longer a person struggles with their body's cravings for food, the more likely they are to binge and eventually give up on the diet altogether.

Another interesting point is that you can be quite aggressive in your calorie restriction without it feeling much different than a mild calorie deficit. Generally, this means a week or two of mild starvation, after which it becomes much easier.

But wait...won't rapid weight loss lead to significant muscle loss?

This is one of the biggest fears in the fitness community, and like most "wisdom" in this area, it's only partially true.

The fact is that too large a calorie deficit will accelerate muscle loss and this is one of the reasons that crash diets are unhealthy (3).

But how big is too big a calorie deficit? And how do things change for athletic people who follow a high-protein diet compared to obese individuals who eat too little protein? We can thank the scientists at the University of Jyväskylä for an answer to this question!

In a study conducted by these scientists, they divided their subjects, aged between 20 and 35, who were top athletes at national and international level and had a low body fat percentage (below 10%), into two groups:

  • One group with a daily calorie deficit of 300 kcal (which was about 12% below the athletes' daily energy requirements).
  • One group with a daily calorie deficit of 750 kcal.

Both groups followed a high-protein diet.

The results after four weeks of dieting were surprising: the athletes who had maintained a 300 kcal deficit had lost very little fat and muscle, while the athletes who had maintained a 750 kcal deficit had lost an average of 4 pounds of fat and very little muscle mass.

However, it should be kept in mind that the group with the 750 kcal deficit did not starve themselves to death in any way and continued to consume 2000 kcal per day. Nevertheless, they used a fairly aggressive calorie deficit of around 24% and the results speak for themselves.

These results are in line with what I have experienced myself and what I have observed in thousands of people I have worked with: a slight calorie deficit can work if you are very overweight, but the leaner you get, the more a larger calorie deficit becomes necessary and you will not automatically lose muscle either.

This is why my standard recommendation for weight loss is a calorie deficit of between 20 and 25%.

As you can see, there is too much against slow weight loss to recommend it.

  • If you need to lose significant amounts of fat, then at best you will lose that fat slowly, but at too high a cost.
  • If you are already relatively lean, then you will probably never reach a single digit body fat percentage with a small deficit and will give up out of sheer frustration.

Now that we've seen that a more aggressive approach has nothing but benefits, I want to describe how I maximize my fat loss and get it done as quickly as possible without losing muscle or my mind.

How I lose fat while maintaining my muscle mass and strength

Over the years, I've tried many different things with my diet and training while dieting and have gradually developed and refined an extremely effective fat loss program.

With this fat loss program, even when I start with a body fat percentage of 9 to 10%, I lose about a pound of fat per week (I recently reduced my body fat percentage from 10% to 6% in 7 weeks) - without hunger or cravings. My energy levels stay high and my workouts are hardly affected.

Here is this program:

I use an aggressive (but not overly extreme) calorie deficit of 20 to 25%

Like the athletes in the study mentioned above, I reduce my calorie intake to 75 to 80% of my daily calorie expenditure and, like those athletes, I can see an immediate reduction in my body fat without noticeable muscle loss.

If you don't know how to determine your calorie consumption, we recommend using one of the many calorie calculators available on the internet, although it should be noted that due to individual differences, these can only provide a rough guide.

I follow a high protein and high carbohydrate diet

While the scientific search for the "ideal diet" continues, there is one thing we know for sure: this diet will include plenty of protein every day.

The bottom line is that study after study after study confirms that a high-protein diet is superior to a low-protein diet in every way (5, 6, 7). This is especially true if you are reducing calorie intake for the purpose of weight loss, as adequate protein intake plays a crucial role in maintaining existing muscle mass.

Most people know that a high-protein diet is superior to a low-protein diet, but many people do not realize that a high-carbohydrate diet is superior to a low-carbohydrate diet when it comes to weight loss and calorie restriction.

Why? Well, if you restrict your calorie intake, then ...

  • A high-carb diet results in less stress and fatigue than a low-carb diet (8).
  • Does a low-carb diet not result in greater fat loss than a high-carb diet?
  • Is a high-carbohydrate diet much better than a low-carbohydrate diet for maintaining muscle mass and performance?
  • Is it easier to overeat on a low-carbohydrate diet than on a high-carbohydrate diet?

This recommendation may be surprising to many, but trust me: if you usually use a low-carb diet when you want to lose fat, next time try a higher-carb approach (about 4% of your daily calories in the form of carbohydrates) and you'll be amazed at how easier and more enjoyable such an approach is.

I use supplements to accelerate fat loss

If you are skeptical about fat loss supplements, then I can well understand you. Many fat burners are advertised with absolutely exaggerated promises, but there are also a whole range of natural substances that can help you build muscle and lose fat.

Creatine is a good example when it comes to building muscle and there are also numerous supplements that have been proven to help with fat loss, including caffeine and green tea extract. I have dieted both with and without supplements and I have to say that fat loss is noticeably faster with the right supplements.

I train with heavy weights

Training with heavy weights will not only help you maintain your muscle mass during the diet - it can also help you burn more fat.

A study published by Greek sports scientists found that men who trained with heavy weights (80 to 85% of their maximum weight for one repetition - 1RM weight for short) increased their metabolic rate over the following three days and burned hundreds of calories more than men who trained with lighter weights (45 to 60% of 1RM weight) (9).

So train with weights and move heavy weights if you want to increase your metabolic rate and in turn accelerate your fat loss.

And if you want to score extra points, focus on heavy multi-joint exercises such as squats, as this type of exercise burns the most calories after training (10).

I perform HIIT cardio training

If you know my training strategies a little better, then you know that when it comes to cardio training, I'm a big fan of High Intensity Interval Training - HIIT for short.

Studies conducted at Laval University, East Tennessee State University, Baylor College of Medicine and the University of New South Wales have conclusively proven that shorter workouts consisting of high-intensity interval training result in greater fat loss over a longer period of time than longer, lower-intensity workouts (11, 12, 13, 14).

A study conducted at the University of Western Ontario showed that just 4 to 6 30-second sprints burn more fat than 60 minutes on a treadmill at an incline (one of the basic cardio workouts in bodybuilding) (15).

Keeping your cardio sessions shorter also means better maintenance of muscle mass and strength (16).




By Michael Matthews

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