The Case Against Slow and Steady Weight Loss

Here are some pictures sent in by a Muscle Evo reader who managed to drop 86 pounds over a six-month period by applying the principles laid out in my Gutless nutrition manual.

Eighty six pounds in six months works out at around 14 pounds (6.4 kilograms) of weight loss a month, which many people will tell you is too fast.

The stock advice on weight loss is that slow and steady wins the race. Losing weight slowly just seems like the sensible thing to do. Plus, the results are more likely to stick.

Lose weight too quickly, and you’re far more likely to gain it back again once the diet is over. You’re just setting yourself up for failure.

Or are you?

In fact, there’s very little evidence to show that people who lose weight more quickly have a harder time keeping the weight off than those who lose it slowly.

Why Slow and Steady Doesn’t Always Win the Weight Loss Race

Back in 1997, Danish researchers Søren Toubro and Arne Astrup took a group of 43 obese adults, and put them on one of two different diets [1].

Group one followed a very low calorie diet lasting just eight weeks. Participants in the second group two used a more conventional diet that lasted 17 weeks. The amount of weight lost in both the slow and fast weight loss groups was identical.

Subjects in the very low calorie group lost around 3.5 pounds, or 1.6 kilograms, per week. This was twice as fast as subjects on the conventional diet, who lost 1.8 pounds (0.8 kilograms) per week.

The conventional group lost fat more slowly, which meant the diet lasted longer. While the very low calorie group lost weight more quickly, they finished the diet in half the time.

After adjusting for possible confounders, Toubro and Astrup found that the weight loss maintained in the very low calorie group was greater by 5.3 pounds (2.4 kilograms) after one year and 6.6 pounds (3 kilograms) after two years, although none of these differences reached statistical significance.

In other words, subjects who lost weight more quickly were no more likely to regain that lost weight than those taking the slow and steady approach.

Of course, these are the results from just one study. And drawing conclusions about anything from the findings of one study is rarely a good idea.

However, it’s not a single, lone piece of information that contradicts a sea of existing research on the subject.

In fact, many other studies show much the same thing.

People who lose weight more quickly in the early stages of a diet are no more likely to gain the weight back than those who lose it slowly.

Slow vs Fast Initial Weight Loss

Researchers from the University of Florida, for example, examined whether slow or fast initial weight loss was linked with greater long-term weight maintenance [2].

Subjects were categorized as fast, moderate or slow losers based on how much weight they lost during the first month of dieting.

The result?

No significant group differences were found in weight regain between 6 and 18 months. In fact, the fast and moderate groups were 5.1 and 2.7 times more likely than the slow group to have lost 10% of their weight after 18 months.

Here’s how the researchers sum up their findings:

“Collectively, findings indicate both short- and long-term advantages to fast initial weight loss. Fast weight losers obtained greater weight reduction and long-term maintenance, and were not more susceptible to weight regain than gradual weight losers.”

In one of the longest studies on the subject, researchers from Melbourne, Australia tracked a group of overweight and obese subjects for more than three years [3].

During the first phase of the study, subjects were assigned to either a 12-week rapid weight loss or a 36-week gradual weight loss program.  

In the rapid weight loss program, participants consumed a meal replacement supplement three times a day for 12 weeks. The diet contained between 450 and 800 calories per day, which led to an average rate of weight loss of 2.7 pounds (1.2 kilograms) per week.  

In the gradual weight loss program, participants consumed an energy-reduced diet (400–500 calorie deficit), with the aim of losing around one pound (0.5 kilograms) per week.

Both groups lost about the same amount of weight – 32 pounds, or 14.5 kilograms. But subjects in the rapid weight loss group did it in 12 weeks. The gradual weight loss group took three times as long.  

Those in the rapid group did lose more lean tissue. But it wasn’t a lot, amounting to 1.3 pounds (0.6 kilograms) more than the gradual group during the weight loss phase of the study.  

According to conventional wisdom, the rapid weight loss group should have regained the lost weight more quickly.  

But that isn’t what happened.  

Over the next 144 weeks, subjects in the rapid weight loss group regained 23 pounds (10.5 kilograms). Which is exactly the same amount regained by the gradual weight loss group.

What’s more, participants who lost weight faster were more likely to achieve their target weight loss: eight out of 10 participants in the rapid group lost 12.5% of their bodyweight or more, versus just five in 10 of the gradual losers.

The extreme diet was also more tolerable.

Only 3% of those in the rapid weight-loss group dropped out of the study, compared with 18% in the gradual program, most likely because it lasted three months rather than nine.

“Across the world, guidelines recommend gradual weight loss for the treatment of obesity, reflecting the widely held belief that fast weight loss is more quickly regained,” says lead author Katrina Purcell.

“However, our results show that achieving a weight loss target of 12.5% is more likely, and drop-out is lower, if losing weight is done quickly.”

Final Thoughts

To sum up, research going back more than 20 years finds very little evidence to show that people who lose weight more quickly have a harder time keeping the weight off than those who lose it more slowly. 

Fast weight loss doesn’t always equal “bad” and slow weight loss doesn’t always equal “good.”