Weight Loss Fast Or Slow: Which Is Best?
When it comes to losing body fat, the common belief is that slow and steady wins the race. Baby steps can allow you to make changes little by little, develop habits, and minimize the day-to-day suffering.
On the other hand, if you’re like a lot of people, you’re not all that patient. If you had your choice, you would want to lose weight in the shortest time possible. Taking the long view can feel like a death sentence, particularly when you aren’t seeing the scale change.
Then there is the fact that fat loss should not be an all the time goal. Plan it, do it, and move on. So wouldn’t losing weight faster be a better option?
This article will discuss the pros and cons of gradual versus rapid fat loss and give you recommendations for choosing an approach that will give you the best outcome.
Gradual Weight Loss Preserves Muscle Mass
The best argument for gradual fat loss is that it minimizes the loss of lean mass. Maintaining muscle mass is incredibly important because it serves as the engine for your metabolism, driving calorie use. Muscle is closely linked with longevity and is a strong predictor of survival if you experience a disease or serious injury.
The general rule when losing weight from a diet that does not include exercise is that 70 percent of the weight lost will be fat and 30 percent will be lean mass. This is typical of studies that use a gradual weight loss approach equaling 0.5 to 1 lb a week from an energy deficit of about 500 calories a day. More severe diets with larger calorie deficits skew the percentage so that greater than 30 percent of the weight lost is from lean mass.
For example, in a study of obese individuals who were assigned to either a Fast (weight loss of at least 5 percent of body weight in 5 weeks) or Slow (weight loss of at least 5 percent in 15 weeks), 81 percent of the weight lost was body fat and 19 percent was lean mass in the Slow group. In the Fast group, 43 percent of the weight was from lean tissue and 57 percent was from fat. The Slow weight loss group lost 1 kg of lean mass whereas the Fast group lost 2.2 kg. Body fat percentage decreased by 6.2 percent in the Slow group compared to a much smaller 2.7 percent reduction in the Fast group.
A second study of obese, older women found that both Fast and Slow weight loss was successful in reducing body fat, however, the Fast group also lost significant lean mass, whereas in the Slow group, muscle loss was not significant. Another study compared a Fast weight loss approach using a very-low calorie diet (only 500 calories a day for 5 weeks) with a Slow approach using a low-calorie diet (1,200 calories a day for 12 weeks) and found significantly greater lean mass loss in the Fast group (8.8 percent decrease) compared to the Slow group (1.3 percent decrease). This study looked at weight regain over a 9-month period after the diets ended and found that volunteers who lost more lean mass regained more body fat.
So, it’s safe to say that loss of lean mass is a major disadvantage to fast weight loss, however, there are some effective strategies that can minimize the loss of lean mass, while also reducing the degree of misery involved.
How To Maintain Lean Mass: Increase Protein & Do Weight Training
Factors that can tip the balance so that you preserve lean mass include eating a higher protein diet and exercising, especially with anaerobic modes like intervals and weight training.
Protein foods provide the amino acid building blocks necessary to stimulate protein synthesis, which is the process by which the body maintains lean mass. Therefore, eating a higher protein diet may preserve muscle during dieting.
For example, simply doubling the U.S. RDA of protein to 1.6 g/kg/body weight a day can minimize lean mass losses during weight loss to the point where they are not detectable by statistics. In one study that compared weight loss with a diet that supplied the RDA of protein of 0.8 g/kg (Low Protein) with a diet that supplied 1.6 g/kg (High Protein), lean mass was preserved in the High Protein group, whereas men in the Low Protein group lost 6.2 kg and women 2.6 kg of lean mass.
Adding exercise to the equation can sweeten the pot. Performing strength training in conjunction with a high protein intake may eliminate the loss of lean mass associated with weight loss. It also decreases the amount of calorie restriction necessary, which is important for reducing the suffering that comes with dieting.
One carefully controlled study from Canada found that doing an intense 6-day a week training program and eating a high-protein diet preserved muscle mass. Subjects who ate 1.2 g/kg of body weight of protein maintained muscle while losing 3.5 kg of body fat. A subset of volunteers who had an extra high protein intake (2.4 g/kg) actually gained 1.2 kg of muscle while losing 4.8 kg of fat.
Another study compared Slow and Fast weight loss in athletes. The Slow group achieved a 500-calorie a day deficit in order to lose 5 percent of body weight in 9 weeks and the Fast group had a daily 1,000 calorie deficit to lose the same amount in 5 weeks. Results showed that although it took the athletes four weeks longer to lose the weight with the 500-calorie deficit diet, the greater daily energy intake allowed them to gain 2.1 percent muscle mass at the same time. The group on the 1,000-calorie deficit diet dropped 0.2 kg of muscle. Both groups ate a higher protein diet and did a heavy weight-training program in conjunction with regular sport training, which is likely the reason the muscle loss in the 1000-calorie deficit group was minimal.
Hopefully you’re convinced that it’s worth the effort to preserve all your beautiful muscle when trying to reduce body fat. And this appears to be easier when weight loss is more gradual. But what about the other reasons experts often give for avoiding rapid weight loss?
Don’t Get Sidetracked By Misconceptions About Rapid Weight Loss
This is an area where cautions often fall short. For example, a common argument against rapid weight loss is that it will induce eating disorders, however, a review of the issue showed that as long as participants get clinical supervision from a nutritionist, severe diets appear safe and beneficial for the general population and may even be appropriate for individuals with a history of binge eating.
In regard to sustainability of weight loss, both the typical fast and slow weight loss approaches fall short, but it should be noted that fast weight loss does not appear to set dieters up for failure at a higher rate than slow weight loss. For example, an Australian study found that weight loss maintenance was similar regardless of the rapidity of weight loss. This study used two phases. Phase 1 was a weight loss phase during which volunteers were put into either a 12-week Fast weight loss group whose sole calorie intake was from weight loss shakes containing between 450 and 800 calories a day or a Slow group that took 36 weeks to lose weight using a diet that reduced calories by about 500 a day.
Phase 2 was a 9-month maintenance period in which participants were given nutrition counseling to maintain weight loss. Unfortunately, most were unsuccessful, with participants in both groups regaining about 70 percent or an average of 10.4 kg of the weight they had previously lost. There was no difference in the rate of weight regain between the Fast and Slow weight loss groups.
The researchers pointed to a few benefits of rapid weight loss. First, there is evidence that a greater initial loss of body fat is associated with greater long-term success. Second, in this study, physical activity and step counts were higher in the Fast weight loss group, which was attributed to the fact that losing weight quickly may have motivated the individuals in the Fast group to boost activity rates. Additionally, the diet in the Fast weight loss group was clear cut and simple to follow (the only thing they consumed for 12 weeks was meal replacement shakes), resulting in fewer choices to be made compared to a low-calorie diet of regular foods. Finally, there was evidence of ketosis in the Fast group, which has an appetite suppressing effect.
Of course, living off meal replacement shakes for 12 weeks is probably the last thing you want to do. Fortunately, there is another way to get some of same effects seen in this study while eating real food. Ketogenic diets provide a safe way to lose fat quickly and minimize the need to count calories that may make the typical low-calorie diets difficult to follow.
A Ketogenic Diet Encourages Rapid Fat Loss & Sets The Stage For Maintenance
High-fat, low-carb ketogenic diets are our go-to approach for rapid weight loss because they stimulate ketosis, which means that the body shifts from using glucose for energy to burning fat for fuel. Ketosis dulls appetite, rendering calorie counting unnecessary because people will automatically reduce food intake and create a calorie deficit.
Ketogenic diets allow you to eat regular food and can often be accommodated by restaurants, which is important for people who want to enjoy the social component of eating during weight loss. That said, it should be noted that studies consistently show that people who are successful at maintaining long-term weight loss cook at home more often and eat out less frequently than unsuccessful dieters who have re-gained lost weight.
Another benefit of the low-carb ketogenic diet is that it allows for a rapid drop in body weight due to a reduction in the amount of water stored by the body. As glycogen stores (the form of carbs that is stored in muscle for energy) go down, the body sheds water, which leads to a quick drop in body weight, which can be motivating for people who want to see the number on the scale go down.
Although a low-carb diet can be followed for the long-term, most people will benefit from using it to lose a lot of fat quickly and then transition to more sustainable diet that incorporates habits that enable weight loss maintenance.
Take Away Recommendations For Sustainable Fat Loss
At the end of the day, whether to choose a fast or slow approach to fat loss comes down to the individual. If you lack patience, or have not had success with gradual weight loss, a rapid approach can build confidence in your ability to make change. Fast approaches are more likely to be successful if you have a coach or nutritionist to guide you and if your life stress is minimal. Losing body fat quickly is very stressful and the body will fight back by upregulating release of the stress hormone cortisol, which stimulates hunger and blunts fat burning.
For the fast approach, try a ketogenic high-fat, low-carb diet because this will help to minimize hunger. The typical ketogenic diet results in people eating around 1,300 calories without restricting energy. Although this is not as severe as the very low-calorie diets used in some studies, it’s much more doable and can help reduce the loss of lean mass associated with rapid weight loss.
The ketogenic diet requires an initial 14-day period in which you eat a very low carb intake (less than 50 grams a day) with a higher fat (75-80 percent of calories) and protein (15-20 percent of calories) because this will help the body to develop the metabolic machinery necessary for fat burning. After the initial 14-day low-carb period, you can include a higher carbohydrate meal every week to provide mental relief and prevent metabolic adaptation whereby the body decreases energy expenditure in response to weight loss. This is important because studies show that having a higher carb day can improve thyroid function, which has been linked to maintenance of muscle.
On the other hand, if stress is an everyday part of your reality, a slow and steady approach may be just the ticket. Slower weight loss minimizes suffering and allows you to develop habits on a reasonable time frame. You change a little and get a little bit uncomfortable with this new lifestyle. Then, when what was a bit uncomfortable becomes comfortable, you change a little more, and you get a bit uncomfortable again. It is very rationale, sustainable overhaul.
Whichever approach you take, always remember these key factors for successful, long-term fat loss:
#1: Minimize the loss of lean mass. This can be done by eating a higher protein intake (minimum of 1.6 g/kg/bodyweight a day) and performing strength training.
#2: Develop habits that help you maintain fat loss: Exercise, being generally physically active, cooking at home, developing a method for managing calorie intake when eating out, and monitoring body composition either with skinfold or circumference measurements are all strategies that will help keep you from gaining fat.
#3: Have a detailed plan for what happens once the weight is lost: One of the biggest reasons people don’t maintain fat loss is that they have no road map for what happens once the diet ends. This is especially true with crash diets that don’t encourage development of skills that allow them to keep the weight off. Once the diet is over, they simply return to their previously poor habits.
Instead, you need an in-depth plan for how you’re going to eat, train, and be in the world once you’ve lost the weight. Regular meal times, cooking at home, exercising regularly with weights and intervals, getting sufficient sleep, and managing stress are all important considerations when developing a plan that will sustain weight loss.