Does eating every other day prevent the metabolic slowdown that accompanies weight loss, or improve compliance with consistent day-to-day calorie restriction?
Instead of cutting calories day after day, what if ate As much as you would like every other day or just a few hours a day? Or what would happen if you fasted two days a week or five days a month? These are all examples of intermittent fasting regimens, as you can see below and at 0:10 of my video. Alternate-day intermittent fasting put to the testand maybe that’s even how we were built. Three meals a day may be a relatively new behavior for our species. For millennia, “our ancestors could not eat three meals a day. “They ate meals much less frequently, often eating one large meal a day or going several days without eating.”
Intermittent fasting is often presented as a way to stress your body, in a good way. There is a concept in biology. called hormesis, which can be considered the principle of “what doesn’t kill you, makes you stronger.” Exercise is the classic example: You put pressure on your heart and muscles, and as long as there is enough recovery time, you will be much healthier. Is that the case with intermittent fasting? Mark Twain thought Therefore: “A little hunger can really do more for the average sick person than the best medicines and the best doctors. “I’m not talking about a restricted diet, I’m talking about complete abstinence from food for a day or two.”
But Twain too saying, “Many small things have become big thanks to the right kind of advertising.” Is the intermittent fasting craze just hype? Many fad diets have They are rooted “in legitimate science,” but over time the facts can be distorted, the benefits exaggerated, and the risks minimized. In other words, “science takes a backseat to marketing.” At the same time, you don’t want to miss out on any potential benefits by simply dismissing something based on absurd claims from overzealous promoters. You don’t want to throw the baby away with the baby fat.
Religious fasting is the most studied form of intermittent fasting, specifically Ramadan, a month-long period in which “Muslims refrain from food and drink from dawn to dusk.” The effects are complicated due to a change in sleeping patterns and also due to thirst. Same dehydration problem. arises with Yom Kippur, when observant Jews stop eating and drinking for about 25 hours. The most studied form of intermittent fasting that deals solely with food restriction is alternate-day fasting, which it implies eat every other day, alternating with days consuming few or no calories.
At rest, we burn about a 50:50 mix of carbs and fats, but usually run without glycogen (our carbohydrate reserves) between 12 and 36 hours after stopping eating. At that point, our body has to rely more on our fat reserves. This metabolic change can help explain That’s why the highest rate of fat breakdown and burning during a three-day fast occurs between hours 18 and 24 of the 72 hours. hope is collect some of the benefits of taking a break from food without the risks of prolonged fasting.
One of the potential benefits of alternate-day fasting over chronic calorie restriction is that you get regular breaks so you don’t feel constantly hungry. But could Are people so hungry on their fast day that they turn the next day into a holiday? After your fasting day, if you were to eat more than twice as much as you normally would, that would presumably defeat the purpose of alternate-day fasting. Mice fed every two days do not lose weight. They simply eat about twice as much food in one day as non-fasting mice would normally eat in two days. However, that is not what happens in people.
The study participants were random fast for a day and a half, from 8:00 pm to 8:00 am on the second day after starting. Fasting for 36 hours alone led people to eat an average of 20 percent more the day after breaking the fast, compared to a control group that didn’t fast at all. That would leave those fasting with a large caloric deficit, equivalent to a daily calorie restriction of almost a thousand calories a day. This particular study involved thin men and women, but similar results were found among overweight or obese subjects. Researchers usually found only about 10 to 25 percent compensatory increase in calorie intake from baseline on non-fasting days, and this seems This would be the case whether the fasting day was a true no-calorie fast or a modified fasting day of a few hundred calories, which may lead to better compliance.
Some studies have found that the participants seemed eat Do not eat more, or even eat less, in the days after a day-long mini-fast. Even within studies, great variability is observed. reported. In a 24-hour fasting study in which individuals ate an early dinner and then a late dinner the next day after skipping breakfast and lunch, the degree of compensation at the second dinner ranged from 7 to 110 percent, as can be seen in the graph below and at 4:40 in my video. This half that some of the participants were so hungry when dinner arrived that they ate more than 24 hours’ worth of calories in a single meal. The researchers suggested that perhaps people first try “test fasts” to see how much their hunger and subsequent intake increase before considering an intermittent fasting regimen. Hunger levels can change However, over time, it will dissipate as your body gets used to the new normal.
In an eight-week study involving obese subjects restricted At around 500 calories every other day, after about two weeks, they reportedly began to feel very little hunger on their calorie-reduced days. This certainly helped them lose about a dozen pounds on average over the duration of the study, but there was no control group to compare to. A similar study that did have a control group. found a similar amount of weight loss (about ten pounds) over 12 weeks in a group of “normal weight” individuals, meaning overweight on average. For these modified regimens in which people are prescribed 500 calories on their “fasting” days, the researchers found That, from a weight loss perspective, it didn’t seem to matter whether those calories were spread throughout the day or consumed in a single meal.
Instead of prescribing a set number of calories on “fasting” days, which many people find difficult to calculate outside of a study setting, a pair of Iranian researchers came about a brilliant idea of unlimited aerial vegetables. Starchy tubers are relatively high in calories compared to other vegetables. Vegetables that grow above ground include stem vegetables (like celery and rhubarb), flowering vegetables (like cauliflower), leafy vegetables (like, well, leafy vegetables), and all the fruits we tend to think of as vegetables. (such as tomatoes, peppers, okra, eggplant, green beans, squash, and zucchini). So instead of prescribing a certain number of calories for “fasting” days, the researchers had subjects alternate between their regular diet and an all-you-can-eat vegetable feast (along with naturally non-caloric beverages). , such as green tea or black coffee) every other day. After eight weeks, the subjects lost an average of 13 pounds and two inches off their waist, as you can see below and at 6:59 in my video.
The same variability discovered for caloric compensation has also been found to lose weight, as seen in the graph below and at minute 7:10 in my video. In a 12-month trial in which subjects were educated to eat only a quarter of their caloric needs every other day, weight changes ranged from a loss of about 37 pounds to a gain of about 8 pounds. The most important factor differentiating the low weight loss group from the high weight loss group seemed to be not how much they ate on their usual diet days, but how much they could meet the calorie restriction on their fasting days.
Overall, ten out of ten studies on alternate-day fasting presented Significant reductions in body fat. Small short-term studies. show approximately a 4 to 8 percent drop in body weight after 3 to 12 weeks. How does that compare to continuous calorie restriction? Researchers compared Fasting without calories every other day directly to a daily restriction of 400 calories for eight weeks. Both groups lost the same amount of weight, about 17 pounds, and, at the follow-up check six months after the trial ended, both groups had maintained a similar degree of weight loss; They both still weighed about a dozen pounds, as you can see below and at 8:10 in my video.
Hoping that intermittent fasting will somehow avoid metabolic adaptations that slow weight loss or improve compliance do not appear to have materialized. The same compensatory reactions in terms of increased appetite and slower metabolism affect both continuous and intermittent calorie restriction. The Longest Test of Alternate Day Fasting found that “alternate-day fasting may be less sustainable” than more traditional approaches. By the end of the year, the dropout rate in the alternate-day fasting group was 38 percent, compared to 29 percent in the continuous calorie restriction group.
Although alternate-day fasting regimens have not been shown to produce the greatest weight loss to date, for people who can prefer Does this pattern of calorie restriction have any disadvantages? Find out in my video Is alternate day intermittent fasting safe?.
I packed a lot into this one. Bottom line: Fasting doesn’t seem to offer an advantage over traditional calorie reduction, but if you prefer, why not try fasting? Before doing so, first take a look Is alternate day intermittent fasting safe?.
What about total fasting? For that and even more, watch the related videos below.
I have a whole chapter on intermittent fasting in my book. How not to diet-order now! (All proceeds I receive from my books are donated to charity.)