What Kind Of Research Was This
This was a randomised controlled trial aiming to compare the effect of two dieting interventions alternate-day fasting and daily calorie restriction on body weight and reduction in risk of cardiovascular disease. Both were compared with a control group of no intervention.
Intermittent fasting diet plans, such as alternate day fasting, or the 5:2 diet, have increased in popularity in recent years.
Alternate day fasting is where individuals consume around 500kcal with normal days of full calories in between. However, whether this actually results in weight loss has not been assessed before.
This type of study is good for looking at the effects of different interventions as the randomisation process should control for other factors, such as exercise levels, that could otherwise vary between individuals. This trial carefully controlled the types and quantity of food given to each group to assess the specific effect of an alternate-day diet and a calorie restriction diet.
Fasting And Weight Loss
The scientists recruited 36 lean, healthy adults in the U.K. between 2015 and 2018 for the study and monitored their baseline diet and physical activity for 4 weeks. They then randomly allocated the participants to one of three groups of 12.
The participants in the first group, the energy restriction group, consumed 75% of their normal energy intake each day.
The second group used two methods of weight loss: fasting and energy restriction. They fasted on alternate days and consumed 150% of their regular calorie intake on their eating days.
The third group did not face any energy restriction. They fasted on alternate days and consumed 200% of their regular calorie intake on their eating days.
The fasting groups consumed no energy-providing nutrients during their fasting periods. This ensured that their dietary interventions were standardized and allowed enough time for fasting-related bodily functions to activate.
The participants underwent various lab tests before and after the 3-week intervention. The researchers also monitored the participants diet and physical activity levels throughout and extracted fat tissue samples from some individuals.
Those on energy restriction diets lost an average of 1.91 kilograms at the end of the study period. Meanwhile, those fasting with energy restriction lost an average of 1.60 kg, and those fasting without energy restriction lost an average of 0.52 kg.
Science Investigates: Fasting Vs Calorie Restriction
People are always on the lookout for quick and easy ways to lose weight, which is why there are approximately 5 billion new diet books written every year thats our unscientific, but probably not inaccurate, estimate. Speaking of unscientific, the problem with the plans in these books is their so-called new approaches to weight loss havent been tested, well, scientifically. And when they get scientists to pay attention, the plans often fail to produce the stellar results they claim.
One weight-loss method thats gotten a lot of attention lately is fasting, where people go without eating for several hours or even a full day. Search the internet and Reddit boards, and youll find passionate devotees talking about the advantages of fasting for weight loss, muscle gain and other benefits, like improved mental clarity. And while there is research to back up some of these claims, much of it is preliminary or was conducted on animals.
Lately, researchers have been looking into fasting more deeply and are starting to fill this knowledge void. A study published this May in the Journal of the American Medical Association: Internal Medicinesought to find out whether fasting was any better or worse at helping people lose weight than a more traditional diet. Heres what they discovered:
WHAT DID THE STUDY EXAMINE?
The study looked at the effectiveness of two diets:
WHO TOOK PART IN THE STUDY?
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HOW LONG DID THE STUDY LAST?
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Fasting For Weight Loss
So far, the research studies evaluating intermittent fasting have been relatively short and have enrolled only a limited number of participants. In one, published July 1, 2017, in JAMA Internal Medicine, 100 overweight people were assigned to one of three eating plans: restricting daily calorie intake by the same amount every day , fasting on alternate days, and continuing with normal eating habits. At the end of the 12-month study, both diet groups had lost weight compared with the normal eaters. However, the fasters didn’t fare any better than the conventional calorie cutters.
What Are The Different Forms Of Calorie Restriction And Fasting
Calorie restriction is a consistent pattern of reducing average daily caloric intake, while fasting regimens primarily focus on the frequency of eating. The fasting diet may or may not involve a restriction in the intake of calories during non-fasting times.
There are a variety of fasting diets, sometimes called “intermittent fasting.” You may have read about:
- Time-restricted feedingMeals are consumed within a limited number of hours each day, with nothing consumed during the other hours.
- Alternate-day fastingEating is unrestricted every other day, and no or minimal calories can be consumed on the days in between.
- 5:2 eating patternEating is unrestricted for 5 straight days each week, followed by 2 days of restricted caloric intake.
- Periodic fastingCaloric intake is restricted for multiple consecutive days, such as 5 days in a row once a month, and unrestricted on all other days.
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Benefits Of Calorie Restriction
Calorie restriction offers several benefits
Weight loss. If your body needs 2500 calories every day, taking 2000 calories every day, will lead to you losing weight since you are taking less than you body needs hence forcing your body to use the stored energy in the form of fats.
Prolonged life expectancy. Studies on individuals who practice calorie restriction found that these individuals have low levels of risk factors to cardiovascular diseases and diabetes 30151-2/fulltext” rel=”nofollow”> 1).
If Youre Stressed Or A Competitive Athlete
You can only take so much stress. If youre overly-stressed from a job, relationship, or health issue fasting may act as a bad stress rather than a good stress, causing more harm than good.
A similar principle applies to sleep. If you arent sleeping enough, youre less resilient to other stressors. And so if you have a bad night of sleep, you probably shouldnt skip your morning meal.
Finally, competitive athletes have much higher nutrient requirements than the rest of the population. Fasting may help with training-related adaptations, but its unlikely to help with gameday performance.
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Intermittent Fasting Vs Calorie Restriction
We are living at a time where almost everyone is consciously watching their weight. People all over the world are looking for different approaches to shed pounds quickly using both traditional and modern methods. This has then brought up comparisons between the different approaches in an attempt to find the better one. Intermittent fasting vs calorie restriction is one of the great debates when it comes to weight loss. It is time we try and settle this debate once and for all.
Both approaches have experts supporting them. There are reasons as to why each is better than the other. For us to get an almost definitive answer, we need to check things like the benefits of intermittent fasting vs calorie restriction, the effects of intermittent fasting vs calorie restriction weight loss and so on.
How To Get Started
When first trying IF, the transition can be challenging, Mattson admits.
Many fasters report uncomfortable, even painful hunger pangs as they abstain from food. Mattson suggests people take it slow, trying different kinds of IF to see what works with their goals and routine. He advises first narrowing the âfeeding windowâ from an initial unrestricted period down to 12 hours, then 10 hours, then eight hours, before finding a feeding window that is sustainable.
During the first week or two of IF, fasters may notice their stomachs grumbling or feel a sense of hollowness. Some people are exhausted, lightheaded, or shaky from diminished blood sugar on fasting days. Others experience poor concentration, irritability, mood swings, and even dizziness. In particular, people who work in long shifts or with heavy machinery should take more care when fasting to stay hydrated, rested, and alert.
After about a month, people typically feel better and less hungry, says Mattson.
Tello agrees: âThe longer you can go between meals, the less hungry you are. I think a lot of peopleâs hunger levels actually decrease as opposed to the very low calorie diet where youâre constantly feeding yourself small, tiny bits of food. Thatâs like a tease all day long.â
Mattson encourages fasters to be patient and wait for those side effects to pass.
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Intermittent Fasting Is Incredibly Popular But Is It Any Better Than Other Diets
Its possible weve simply yet to discover the best way to fast, especially considering that these diets are rarely tested against one another
Diets are funny things. They arent just a way to lose or gain weight a diet is part of your life.
Eating is one of the fundamental human recreational activities, which means that food is family, food is friends, food is sharing, culture and life no matter where you go.
What this means is that we are often really passionate about what we eat. This goes doubly for diets. Nothing starts an online argument more quickly than saying a diet any diet isnt the best of them all.
Which brings us to intermittent fasting. And why it probably isnt any better than most other diets, even if it is a bit more popular.
Hopefully we all escape the comments section alive.
Intermittent fasting describes a range of diets that all follow the same basic idea you eat as much as you want in a certain time period, but spend some portion of your life fasting by either eating very few calories or nothing at all. Some examples are the popular 5:2 diet, where you eat normally 5 days a week and restrict yourself to very little food on the other 2, or the various time-restricted fasts like the 10:14 or 16:8, where you only eat during a set number of hours a day.
Sadly, the reality seems to be a bit less positive than the optimistic headlines.
Risk Of Complications Of Fasts > 24 Hours
As you progressively go longer in fasting, the benefits accrue faster, but there is also more risk of complications. Since I often deal with type 2 diabetics and hard to treat obesity cases, I tend to gravitate towards longer fasting periods, but you must understand that I always monitor very closely their blood pressures, and blood work and progress. I cannot stress enough, that if you do not feel well at any point, you must stop. You can be hungry, but you should not feel sick.
Another major consideration is that medication must be carefully monitored by a physician. The major problem are diabetic medications because if you take the same dose of medication and do not eat, you will become hypoglycemic and that is very dangerous.
Blood sugars going low is not a complication per se, because that is generally the point of fasting. We want the sugars to go low. However, it does mean that you are overmedicated for that day. You must work very carefully with a physician to adjust medications and monitor sugars. Also, there are certain medications that may cause stomach upset on an empty stomach. NSAIDS, ASA, iron supplements and metformin are the major drugs here.
In general, diabetic medicates and insulin MUST be reduced on the fasting day to avoid hypoglycemia. Exactly how much to reduce it should be overseen by your physician.
I do not recommend anybody who is taking medication to try longer fasts without clearing it with their doctor.
42-hour fasts and beyond
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What Is Intermittent Fasting: How Long Do I Go Without Eating
How long you go without eating totally depends on the approach you take. There are many ways to approach a intermittent fasting diet, but here are the three most popular:
– 16:8 .
– 5:2 diet .
– Eat stop eat .
Fasting simply is another way to eat fewer calories than you burn. In other words, staying in a calorie deficit.
There is simply no way to “hack” the body’s system of weight loss and gain eating whatever you want within an 8-10 hour window doesn’t mean you’ll negate any effects of body fat. It simply means there’spotentiallyless chance you’ll snack the day away between meals and finish up in a calorie surplus.
One study compared the differences in weight loss and changes in body composition between 1, 3, or 6 meals per day, and found no significant differences .The most important thing is to eat what suits you and your lifestyle the most.
Only recently was the most comprehensive analysis into intermittent fasting done, whereby 40 studies were reviewed, with 12 directly comparing intermittent fasting with a standard weight loss diet of eating regularly . They found “apparently equivalent outcomes in regards to body fat loss and body composition change. They also found no differences relating to thyroid, cortisol, or sex hormones, though they concede more research is needed when it comes to those factors.
And so we return to our initial point, which is the most important thing anyone anywhere needs to know about weight loss:
What Is Fasting What Is Intermittent Fasting
Fasting, by definition, means going without food or drink for an extended period of time typically hours or days. Its practiced in various religions, including during the month of Ramadan for Muslims.
However, its gaining more of a following outside religious circles for its health benefits. Known as intermittent fasting, it cycles around an eating window, or a period of time when people can eat, anywhere between two and 12 hours a day. One popular fasting diet the 5:2 involves eating normally for five days a week, then fasting for the other two. Some people who follow that plan eat a limit of 500 calories on their fasting days the most hardcore go without food completely.
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Can Fasting Make You Smarter
A recent study conducted by Mattson and his team found that mice fed only every other day had improved cognitive function.
Ketones act directly on the nerve cells to stimulate production of BDNF, he says. BDNF is a protein that helps neuron growth and may help optimize cognition, learning and memory building.
The mice were also more alert during their fasting diets and Mattson thinks it might be a survival mechanism.
One would assume that in evolution, individuals whose brains did not function well in fasting state were likely not to survive, said Mattson. So, we evolved to eat intermittently, and its important that the brain function well perhaps even optimally when we havent been able to eat for an extended time period.
Mattson admits that most humans probably wouldnt follow this extreme type of diet, but that the 5:2 is similar. Hes currently studying how 5:2 plan might be beneficial to obese people.
Benefits Of Eating First Thing In The Morning
Intermittent fasting often means skipping breakfast and eating your first meal around lunchtime. There are, however, potential issues with this strategy.
The main issue involves your circadian rhythm, or your 24-hour wake / sleep cycle. The circadian rhythm, by the way, regulates a huge chunk of your genome genes that govern metabolism, cognition, DNA repair, and more.
So what controls the circadian rhythm? The obvious trigger is light. The less obvious trigger is food.
Its true. When you eat food, you stimulate secondary clocks scattered throughout your muscle and organ tissues.
In the morning, food is your get up and go signal. Because of this, you could argue that breakfast is the most important meal of the day.
Eating breakfast doesnt only affect wakefulness, but also affects sleep. For instance, one study showed that a high protein breakfast lead to elevated levels of melatonin the sleep hormone later at night. In other words, eating breakfast may help you conk out later on.
When it comes to a healthy breakfast, protein is the key. Protein contains the amino acid tryptophan, a precursor to both serotonin and melatonin .
Simply put: morning protein stimulates serotonin in the AM, which sets up melatonin in the PM.
Below are other potential benefits of eating breakfast. .
Eating breakfast is especially important for certain groups of people. Keep reading.
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What This Means To You
In a typical calorie-deprivation diet, your metabolism likely adjusts to the decreased calorie intake and your weight loss slows or halts completely.
Typical intermittent-fasting diets are often flawed, too. They require you to fast for a while and then eat “normally” for a truncated period. The trouble is, most people tend to have a “hyperphagic” response to this time-out in their dieting.
All that denial of food during the dieting phase causes them to oink out during the non-dieting phase and it ends up being a two forkfuls forward, one forkful back approach that often leads to disappointing results.
The approach outlined in the current study, however, was different in that it employed intermittent calorie reduction . Dieting phases were equal to non-dieting phases, time-wise, and the non-dieting phases required that dieters eat a maintenance diet, instead of a “normal” diet where one’s appetites can get the best of them.
It was undeniably successful, but why the intermittent calorie reduction approach worked better than the conventional calorie deprivation diet in keeping participants from yo-yoing back to their pre-diet weight is somewhat of a mystery, though.
Regardless, the take-home doggy bag message is that if you want to follow a calorie restriction diet, it seems the intermittent approach is the way to go.