Like the ketogenic diet, fasting for a week or two can actually slow body fat loss rather than speed it up.
Fasting obviously Causes Consistent and dramatic weight loss, as shown in the graph below and at 0:09 of my video. Is fasting beneficial for weight loss?, but how do fasting people fare in the long term? Some research groups reported “extremely disappointing long-term effects”, as you can see in the chart below and at 0:19 of my video.
The average subjects started at around 270 pounds and, in the six months before fasting, continued to gain weight as obese people tend to do. After 24 days of “hospitalized starvation,” they experienced a dramatic 27-pound weight loss. So what do you think happened? 
They got it all back and more, although one could argue that if they hadn’t fasted, they could have weighed even more at that point, as seen in the graph below and at 0:45 in my video. 
In another study with follow-ups of up to 50 months, only 4 of 25 “super obese” patients accomplished even partial sustained success. Based on this type of data, some researchers “concluded that complete starvation is of no value in the long-term treatment of obese patients.”
Other research teams reported best results. One series with about 100 people found that 60 percent maintained at least some weight loss at follow-up or even continued to lose weight. However, follow-up periods ranged from 1 to 32 months without breaking down who fasted and for how long, making the data difficult to interpret. In another study, 62 patients were lost an average of 16 pounds after fasting for 10 days. After a year, 40 percent of the group had retained at least 7 pounds of that weight loss.
As you can see below and at minute 1:37 in my videoWhen six such studies are brought together, hundreds of obese subjects on an empty stomach for an average of 44 days and lost an average of 52 pounds. And, about a year or two later, 40 percent retained at least some of that weight loss. Most then regained all the weight they had lost, but 40 percent is extraordinary for a weight loss study. 
After a hundred obese people got treaty In a weight loss clinic on a standard low-calorie diet, researchers found that only one in a hundred lost more than 40 pounds and only one in ten lost even 20 pounds, with overall successful weight maintenance in just two patients over two years old. years, as seen below and at minute 2:08 in my video. That is why it is so important to have a control group. What may seem like a general failure may actually be a relative success compared to more traditional weight loss techniques.
Researchers new to the field can find It was “clearly disappointing” that the “overall results of follow-up for 12 months or more” found that “two-thirds of patients were ‘failures’ and more than a third actually regained all of their lost weight.” But 12 percent were labeled successes, maintaining 59 pounds of weight loss two years later. As you can see in the graph below and at 2:42 in my videothe subjects lost massive amounts of excess weight and I kept it off.
In a direct comparison of different weight loss approaches at the same clinic, five years later starting With a conventional low-calorie approach, only about one in five lost 20 pounds compared to nearly half of the group who had instead undergone a few weeks of fasting years earlier. For the seventh year, as you can see in the graph below and at minute 3:03 of my videomost of those educated With daily calorie restriction they returned to their original weight or even surpassed it, but that was only true for about one in ten in the fasting group. In an influential article in the New England Journal of Medicine Of seven myths about obesity, fallacy number three was identified as: “Large, rapid weight loss is associated with worse long-term weight loss outcomes, compared to slow, gradual weight loss.” In reality, the opposite occurs. The hare can end up thinner than the tortoise.
As shown in the graph below and at 3:39 in my videoResearchers conducted a study that compared the sustainability of weight loss at three different rates: six days of fasting, three weeks on a very low-calorie diet of 600 calories a day, or six weeks on a low-calorie diet of 1200 calories. one day.
The question is: What happened a year later? At one year, the fasting group was the only one that suffered significant weight loss, as you can see below and at 3:55 in my video.
What happened nine years later? “Therapeutic Fasting in Morbid Obesity” is the largest and longest follow-up study I could find. At least some of the rapidly induced weight losses were kept a year later by the vast majority. After one year, 90 percent were still lighter than they were at the beginning, but after two years, three years, four years, and seven years, fewer and fewer patients were maintaining their weight loss. Nine years later, that number has dropped to less than one in ten. By then, almost everyone had regained the weight they had initially lost while fasting, as you can see in the graph below and at minute 4:17 of my video. “Many patients thought that the temporary loss was worth the effort,” however. As a group, they had lost an average of about 60 pounds. They described improved health and quality of life and stated that “reemployment was facilitated and income increased” during that time period. But fasting did not appear to result in any permanent changes in the eating habits of the vast majority. 
The small minority for whom fasting led towards sustainable weight loss “everyone admits a radical change in previous eating habits”; In fact, fasting only works in the long term if it can act as a push toward a healthier diet. In a long-term retrospective comparison of weight loss after a hospital stay at a naturopathic center, those who fasted lost heavier at that time, but they returned to the same weight about seven years later, as you can see in the graph below and at 5:14 in my video. 
It is no surprise since most reported return to the same diet they had followed before. However, those who instead ate a healthier diet, based on whole foods and plants, were more likely to make persistent changes to their diet and, seven years later, were lighter than when they started, as can be seen in the graph below. and at 5:36 in me video.
But why can’t you have it both ways? Use fasting to kick-start a big crash and then start a healthier diet. The problem is that the big drop is largely illusory, as you can see in the chart below and at 5:48 in my video.
Fasting for a week or two can cause You lose more weight than calorie restriction, but, paradoxically, it may actually lead to less body fat loss. How can eating fewer calories lead to less fat loss? Because during fasting, your body begins to cannibalize itself and burn more of its own protein for fuel. Emperor penguins, elephant seals, and hibernating bears can survive simply burning fat without diving into your muscles, but our big voracious brains seem need at least a splash of blood sugar. If we don’t eat carbohydrates, our body is forced to start converting our proteins into sugar to burn. Even get Just a few grams of carbohydrates (for example, adding honey to water during fasting) can reduce protein loss by up to 50 percent.
How about adding exercise to prevent The loss of lean tissue during a fast? That can make things worse! At rest, most of the energy needs of your heart and muscles can be met. met with fat, but if you start exercising, some of the blood sugar destined for the brain begins to be absorbed and your body may have to break down even more protein.
As you can see in the graph below and at 7:00 in my videoLess than half of the weight lost during the first weeks of fasting ends up in next of your fat reserves. So, even if you double your daily weight loss with a fast, you may actually be losing less body fat. 
In an NIH-funded study, obese people were put He followed an 800-calorie-per-day diet for two weeks and consistently lost about a pound of body fat per day. Then they switched them to about two weeks of no calories and started losing more protein and water. However, on average, they only lost a few ounces of fat per day. When they subsequently returned to the initial diet of 800 calories a day for a week, they quickly replaced protein and water, so the scale registered their weight increasing, but their body fat loss accelerated to about a pound. one day. The scale made it seem like they did better when they fasted completely, but the reality is that they did worse. So, during the five-week experiment, they would have lost even more body fat if they had followed their calorie-restricted diet instead of stopping eating completely halfway through. They would have lost more body fat if they consumed more calories. Fasting for a week or two can interfere with body fat loss, rather than speed it up. You can see a series of graphs representing this starting at 7:13 on my videoincluding the following.
This is the tracking of Benefits of fasting for weight loss put to the test. It seems that fasting can only work in the long term if it can act as a push towards a healthier diet, and simply fasting for a week or two can be counterproductive, like the ketogenic diet. Is it even safe to fast longer? Find out in Is it safe to fast to lose weight?.
To learn more about the ketogenic story and more about fasting for weight loss, watch the related videos below.
I did my third live webinar on fasting, fasting and cancer. Those videos are also on NutritionFacts.org.
