Does Intermittent Fasting Work?

Will Intermittent Fasting Help You Lose Weight?

Author: Dr. Stephen Chaney

intermittent fastingIf you are like millions of Americans, one of your New Year’s resolutions is to lose weight. Now your dilemma is how to accomplish that. You have tried various diets before – Atkins, paleo, keto, Whole 30, etc. You lost some weight, but it came right back. You are looking for something new, something different from anything you have tried before.

What about intermittent fasting? It’s hot right now. It’s probably different from what you have tried in the past. It doesn’t require radical changes to what you eat. Some of your friends are singing its praises. Could this be the one that solves your weight problem forever?

A Primer On Intermittent Fasting

professor owlLet’s start by defining intermittent fasting and reviewing what we already know about it. There are several variations of what the mass media refers to as intermittent fasting, but the two most popular versions are:

  • Time-restricted fasting which limits daily intake of food to a 4 to 12-hour period. The most popular version of this restricts food intake to 8 hours followed by 16 hours of fasting.
  • Intermittent fasting in which there is a day or more of fasting or decreased food intake between periods of unrestricted eating. The most popular version of this allows 5 days of unrestricted eating followed by 2 days of fasting.

A major review (Di Francesco et al, Science, 362: 770-775, 2018) of time-restricted and intermittent fasting was published a little over a year ago. At the time that review was published, there were lots of studies comparing time-restricted fasting with continuous caloric restriction. I summarized those findings in a previous issue of “Health Tips From the Professor” last January.

Here is a brief summary of the key findings from that review:

  • If you read the blogs about time-restricted fasting, you will come across all sorts of metabolic mumbo-jumbo about ketone bodies, adiponectin, leptin, IGF-1, and blood glucose levels. It sounds so convincing. Don’t get sucked in by these pseudo-scientific explanations. At this point they are mostly speculation.
  • Although there is no conscious effort to control calories, time-restricted fasting result in an inadvertent reduction in food intake by restricting the time allowed for eating and by eliminating late night snacking. This reduction in caloric intake is likely responsible for most of the weight loss associated with intermittent fasting. When you control for calories, there is no difference in weight loss between time-restricted fasting and continuous caloric restriction (your typical reduced calorie diet).

However, at the time the review was published, far less was known about the relative benefits of intermittent fasting and simple caloric restriction. Since that time, two studies have rigorously compared the effectiveness of intermittent fasting and continuous caloric restriction on weight loss. I review those studies below

Will Intermittent Fasting Help You Lose Weight?

The first study (YM Roman et al, International Journal of Obesity, 43: 2017-2027, 2019) was a systematic review and meta-analysis of 9 clinical studies comparing intermittent fasting with continuous caloric restriction. Total caloric reduction was controlled and was the same for both intermittent fasting and continuous caloric reduction.

The studies ranged from 12 weeks to 52 weeks with most of them in the 20 to 30-week range. This meta-analysis found:

·       There was no difference between intermittent fasting and continuous caloric restriction in terms of weight loss, waist circumference, or body fat loss.

·       Loss of lean body mass, on the other hand, was greater for intermittent fasting than for continuous caloric restriction.

The authors concluded: “Since it is ultimately fat mass loss that improves health indices, and not the loss of muscle, the significantly greater loss of lean mass in the intermittent dieting group versus the continuous dieting group is concerning and needs to be further assessed.”

I would add, it is also concerning because lean mass muscle burns calories faster than fat mass. Loss of lean muscle mass could lead to a lower metabolic rate. That would make maintenance of the weight loss more difficult.

The second study (ML Headland et al, International Journal of Obesity, 43: 2028-2036) compared intermittent fasting versus continuous calorie restriction for 12 months in a group of 332 healthy overweight or obese adults. Again, total caloric reduction was the same for the two groups. In this study:

·       There was no significant difference between intermittent fasting and continuous caloric restriction for weight loss, body fat loss, and lean body mass loss. [Note: The retention of lean body mass in this study differs from the loss of lean body mass reported in the previous study. Additional studies will be required before we become overly concerned about potential loss of lean body mass with intermittent fasting.]

·       There were also no significant differences between the groups for blood levels of glucose, total cholesterol, triglycerides, HDL, and LDL.

Does Intermittent Fasting Work?

does intermittent fasting workThese studies make it clear there is no “magic” associated with either time-restricted or intermittent fasting.

·       If either time-restricted or intermittent fasting allows you to reduce your daily caloric intake by restricting the time that you are eating, you will lose weight and keep it off. However, if you compensate for the fasting periods by consuming additional calories when you are eating, all bets are off.

·       In clinical studies that restrict calories to the same extent in the various diets, neither time-restricted nor intermittent fasting results in greater weight loss than continuous caloric restriction (your typical reduced calorie diet).

o   In addition, neither time-restricted nor intermittent fasting results in better improvement in blood parameters (glucose, total cholesterol, triglycerides, HDL, and LDL) than continuous caloric restriction.

·       Intermittent fasting may result in greater loss of lean muscle mass than continuous caloric reduction. If confirmed by subsequent studies, this would be concerning.

This also means:

·       If you happen to read the blogs about time-restricted or intermittent fasting, you can forget all the metabolic mumbo-jumbo about ketone bodies, adiponectin, leptin, IGF-1, and blood glucose levels.

o   At this point this metabolic information comes mostly from animal studies. Its application to humans is purely speculation.

o   Since time-restricted and intermittent fasting offer no advantage over continuous caloric restriction, there is no evidence that changes in any of those metabolic markers has any effect on weight loss in humans.

Finally, you need to ask whether time-restricted and intermittent fasting are something you can maintain in the real world.

·       Your friends are unlikely to be on the same schedule. It won’t be easy to fit your diet around socializing, travel, and holidays.

The Bottom Line

There are several variations of what the mass media refers to as intermittent fasting, but the two most popular versions are:

  • Time-restricted fasting which limits daily intake of food to a 4 to 12-hour period. The most popular version of this restricts food intake to 8 hours followed by 16 hours of fasting.
  • Intermittent fasting in which there is a day or more of fasting or decreased food intake between periods of unrestricted eating. The most popular version of this allows 5 days of unrestricted eating followed by 2 days of fasting.

The latest studies make it clear there is no “magic” associated with either time-restricted or intermittent fasting.

·       If either time-restricted or intermittent fasting allows you to reduce your daily caloric intake by restricting the time that you are eating, you will lose weight and keep it off. However, if you compensate for the fasting periods by consuming additional calories when you are eating, all bets are off.

·       In clinical studies that restrict calories to the same extent in the various diets, neither time-restricted nor intermittent fasting results in greater weight loss than continuous caloric restriction (your typical reduced calorie diet).

o   In addition, neither time-restricted nor intermittent fasting results in better improvement in blood parameters (glucose, total cholesterol, triglycerides, HDL, and LDL) than continuous caloric restriction.

·       Intermittent fasting may result in greater loss of lean muscle mass than continuous caloric reduction. If confirmed by subsequent studies, this would be concerning.

Finally, you need to ask whether time-restricted and intermittent fasting are something you can maintain in the real world.

·       Your friends are unlikely to be on the same schedule. It won’t easy to fit your diet around socializing, travel, and holidays.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Can Chocolate Help You Lose Weight?

A Candy a Day Keeps The Weight Away?

Author: Dr. Stephen Chaney

chocolateSometimes you come across news that just seems too good to be true. The recent headlines saying that you can lose weight just by eating chocolate are a perfect example. Your first reaction when you heard that was probably “Sure, when pigs fly!”

But, it’s such an enticing idea – one might even say a deliciously enticing idea. And, in today’s world enticing ideas like this quickly gain a life of their own. Two popular books have been written on the subject. Chocolate diet plans are springing up right and left. A quick scan of the internet even revealed a web site saying that by investing a mere $1,250 in a training course you could become a “Certified Chocolate Weight Loss Coach” earning $50,000/year.

If you like chocolate as much as most people you are probably wondering could it just possibly be true?

Can Eating Chocolate Help You Lose Weight?

The idea that chocolate could help you lose weight does have some support. There are actually three published clinical studies suggesting that chocolate consumption is associated with lower weight (European Journal of Clinical Nutrition, 62: 247-253, 2008; Nutrition Research, 31: 122-130, 2011; Archives of Internal Medicine, 172: 519-521, 2012).

While that sounds pretty impressive, they were all cross-sectional studies. That means they looked at a cross section of the population and compared chocolate intake with BMI (a measure of obesity). Cross sectional studies have a couple of very important limitations:

1)    Cross sectional studies merely measure associations. They don’t prove cause and effect. Was it the chocolate that caused the lower weight, or was it something else that those populations were doing? We don’t really know.

2)    Cross sectional studies don’t tell us why an association occurs. In many ways this is the old chicken and egg conundrum. Which comes first? In this case the question is whether the people in the studies became obese because they ate less chocolate – or did they eat less chocolate because they were obese and were trying to control their calories? Again, we have no way of knowing.

If Pigs Could Only Fly

If Pigs Could FlyChocolate is relatively rich in fat and high in calories. It’s not your typical diet food. On the surface it seems fairly implausible that eating chocolate could actually help you lose weight.

Scientists love to poke holes in implausible hypotheses, so it is no surprise that a recent study (PLOS ONE, 8(8) e70271) has poked some huge holes in the “chocolate causes weight loss” hypothesis.

This study analyzed data from over 12,000 participants in the Atherosclerosis Risk in Community (ARIC) Study. This was also a cross sectional study, but it was a prospective cross sectional study (That’s just a fancy scientific term which means that the study followed a cross section of the population over time, rather than just asking what that population group looked like at a single time point).

The authors of the study assessed frequency of chocolate intake and weight for each individual in the study at two separate time points 6 years apart. The results were very interesting:

  • When they looked at a cross section of the population at either time point, their results were the same as the previous three studies – namely those who consumed the most chocolate weighed less. So the data are pretty consistent. Overweight people consume less chocolate. But, that still doesn’t tell us why they consume less chocolate.
  • However, when they followed the individuals in the study over 6 years, those who consumed the most chocolate gained the most weight. The chocolate eaters were skinnier than the non-chocolate eaters at the beginning of the study, but they gained more weight as the study progressed. And, the more chocolate they consumed the more weight they gained over the next 6 years. [No surprise here. Calories still count.]
  • When they specifically looked at the population who had developed an obesity related illness between the first and second time point, they found that by the end of the study those participants had:

– Decreased chocolate intake by 37%

– Decreased fat intake by 4.5%

– Increased fruit intake by 20%

– Increased vegetable intake by 17%

  • In short, this study is more consistent with the “obesity causes reduced chocolate intake” model than the “reduced chocolate intake causes obesity” model. Simply put, if you are trying to lose weight, sweets like chocolate are probably among the first things to go.

Of course, even prospective cross sectional studies have their limitations. Double blind, placebo controlled studies are clearly needed to resolve this question. The only published study of this type has reported a slight weight gain associated 25 g/day of dark chocolate, but the study was too small and too short in duration to draw firm conclusions.

In summary, more studies are needed, but the current evidence does not support the “miracle diet food” claims for chocolate.

The Bottom Line:

1)    Pigs still haven’t learned how to fly. As enticing as it may sound, the weight of current evidence does not support the claims that chocolate is a miracle diet food or that eating chocolate every day is a sensible strategy for losing weight.

2)    On the other hand, dark chocolate is probably one of the healthier dessert foods. There is no reason not to enjoy an occasional bite of chocolate as part of a healthy, calorie-controlled diet.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

7 Easy Ways To Spot Fad Diets

The FTC Finally Targets Deceptive Advertising

Author: Dr. Stephen Chaney

Fad DietsI think it was P. T. Barnum who said “There’s a Sucker Born Every Minute”. That’s particularly true in the diet world where hucksters seem to be all around us – especially this time of year.

You’ve seen the weight loss ads touting:

  • Pills or powders that suppress your appetite or magically prevent you from absorbing calories.
  • Fat burners that melt the pounds away.
  • New discoveries (juices, beans, foods) that make weight loss effortless.
  • The one simple thing you can do that will finally banish those extra pounds forever.

You already know that most of those ads can’t be true. You don’t want to be a sucker. But, the ads are so compelling:

  • Many of them quote “scientific studies” to “prove” that their product or program works.
  • Their testimonials feature people just like you getting fantastic results from their program. [You can do wonders with “computer enhanced” photographs.]
  • Many of those products are endorsed by well known doctors on their TV shows or blogs. [It is amazing what money can buy.]

So it is easy to ask yourself: “Could it be true?” “Could this work for me?”

Fortunately, the Federal Trade Commission (FTC) has stepped up to the plate to give you some guidance. Just in time for weight loss season, they have issued a list of seven claims that are in fact too good to be true. If you hear any of these claims, you should immediately recognize it as a fad diet and avoid it.

7 Easy Ways To Spot Fad Diets

Here are the seven statements in ads that the FTC considers as “red flags” for fad diets that should be avoided:

  1. Causes weight loss of two pounds or more a week for a month or more without changing your diet and exercise routine.
  2. Causes substantial weight loss no matter what or how much you eat.
  3. Causes permanent weight loss without lifestyle change even after you stop using the product.
  4. Blocks absorption of fat or calories to enable you to lose substantial weight.
  5. Safely enables you to lose more than 3 pounds per week for more than 4 weeks.
  6. Causes substantial weight loss for all users
  7. Causes substantial weight loss by wearing a product on your body or rubbing it on your skin.

I’m sure you have heard some of these claims before. You may have actually been tempted to try the products or program. You should know that the FTC said that it considers these to be “Gut Check” claims that simply can’t be true.

Operation Failed Resolution

Unfortunately, the FTC guidelines didn’t exactly make it to the front page of newspapers and blogs. They weren’t featured in the network news shows. So the FTC went one step further. In a program called “Operation Failed Resolution”, the FTC:

  • Sent letters to 75 publisher and broadcasters asking them to review the FTC’s “Gut Check” claims when screening ads for publication.  The implication, of course, is that the publishers and broadcasters could be held liable for false advertising if they ignored the FTC guidelines in accepting advertisements.
  • On January 7, 2014 they initiated legal action against what they considered the four most outrageous weight loss claims. Those were:

Shake, Shake, Busted

Sensa, the company who’s ads claimed that you could just “shake, shake” their ‘fairy dust’ on your food and lose weight, was required to pay $26 million for unfounded weight loss claims and misleading endorsements (testimonials).

And, as for those clinical studies Sensa claimed to have had, the FTC alleged that one study was based on fabricated data, and the other two studies were equally flawed. The FTC also alleged that Sensa paid people for their testimonials.

Acai Nonsense

LeanSpa was fined $7 million for claiming that a mixture acai berry and a colon cleanse could help you lose weight. Among other things, the FTC prohibited LeanSpa from claiming that products were clinically proven to work when they are not.

Rub A Dub, Dub

L’Occitane was fined $450,000 for claiming that a skin cream called Almond Beautiful Shape would slim a person’s body “1.3 inches in just 4 weeks.”

HCG Deception

HCG Diet Direct was fined $3.2 million for claiming that human chorionic gonadotropin (HCG) plus a very low calorie diet could help you lose a pound a day. The FTC alleged that HCG had not been proven to provide any more weight loss than the low calorie diet alone. The FTC stated that HCG “has been falsely promoted for decades as a weight loss supplement.”

Don’t Wait For the FTC to Act

You probably recognize that there are a lot of other companies out there hawking similar products. There are lots of similar weight loss ads that seem just too good to be true. The FTC is watching them and will probably try to shut them down one by one. When the actions against these four companies were announced, the FTC said:

“We cannot comment on companies that either we haven’t brought an action against in the past or we aren’t announcing today, because our investigations are non-public. We do have other investigations going on in the health area, but we can’t identify the companies we’re investigating”.

The good news is that you don’t have to wait for the FTC to act. They have given you “7 Easy Ways To Spot Fad Diets”. All you need to do is to avoid diets that make those kinds of claims.

The Bottom Line

  • Don’t be a sucker. Don’t fall for those enticing weight loss ads that sound too good to be true. The FTC has given you 7 simple rules for identifying the weight loss products that you should avoid, based on the claims they make. I listed those at the beginning of the article.
  • The FTC has taken enforcement action against manufactures of appetite suppressants, acai berry weight loss products, HCG weight loss products and sliming creams for false advertising.
  • The Director of the FTC Bureau of Consumer Protection summed up the enforcement actions by saying “The chances of being successful just by sprinkling something on your food, rubbing cream on your thighs, or using a supplement are slim to none. The science just isn’t there.
  • There are no magical pills or potions that will make the pounds melt away. You need to change your diet, change your activity level and make significant lifestyle changes if you want to achieve long term weight control.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Are Diet Pills Safe?

Another Diet Pill Bites the Dust

Author: Dr. Stephen Chaney

New Year DietThe New Year is upon us, and everyone is looking for an easy way to lose weight.

Let’s face it. Losing weight is difficult. You have to give up your favorite foods. You’re often hungry and cranky. You have to change your lifestyle. And did I mention that you might need to put on your running shoes and go for a run or, heaven forbid, actually go to the gym.

It’s so much easier to take one of those diet pills. You know the ones I’m talking about. They promise to give you energyburn the fatsuppress your appetite. All you need to do is take one of those little pills every day and, voila, you’re ready to try on that bikini.

It all sounds great. But are those diet pills really safe? A few weeks ago I shared with you that the experts have warned against the use of fat burning sports supplements. They consider them unsafe. Now it’s time to turn our attention to the fat burning diet pills.

Are Diet Pills Safe?

Lots of diet pills have come and gone over the years. Some have just faded away because they didn’t work. They didn’t live up to their claims. Others have been withdrawn from the market by regulatory agencies because they were dangerous or actually killed people- Ma huang and Fen-Phen come to mind, but there have been many others.

And now it looks like yet another diet pill, one called Dexaprine, may have the same fate.

The ads make it sound like a wonder pill.

  • “With one little change…you could feel energy all day long”
  • “With one little change…you can suppress your insatiable appetite”
  • “You can try another unsuccessful diet without it, but when you’re ready…the ultimate fat burner will be waiting for you with open arms.”

The Dark Side

And yet, like most diet pills, it also has a dark side. Side effects include insomnia, sweating, heart palpitations and high blood pressure. As if that weren’t bad enough, the supplement manufacturer that makes Dexaprine conducts no clinical studies on their products, so they have no idea whether their product is safe or not.

And, it appears that it may not be safe. Dutch authorities banned Dexaprine in August after reports of 11 adverse reactions associated with Dexaprine use in Holland since March of this year, including hospitalizations and severe heart problems. British authorizes followed suit the next day and issued a warning against use of “fat burner” supplements in general. It’s probably just a matter of time before other governments step in and ban Dexaprine as well.

And, it’s not just Dexaprine. New diet pills hit the market almost every day. And, they all have those same “magical” claims.

The Only Safe Drug Is A New Drug

It reminds me of the wise advice that a physician colleague of mine gave to the medical students near the start of their first year. He told them “The only safe drug is a new drug”. He went on to say that he didn’t mean that new drugs were safer than the older drugs. It’s just that we don’t know all of their bad side effects until they’ve been on the market for a few years.

Diets pills are no different. They burst on the market full of promise. But, once they’ve been on the market for a year or two, reports of their bad side effects start to appear. We start to learn just how dangerous they are. And, one by one, they all bite the dust.

The Bottom Line

1)     There is no “Tooth Fairy”. There is no “Easter Bunny”. And, there is no magical pill that will SAFELY melt the pounds away. You simply don’t want to risk the diet pill solution – no matter how easy it sounds. No magical, “quick fix” diet solution is worth risking permanent heart damage – or worse.

2)     If you are fortunate to lose weight safely using one of those diet pills, you won’t have learned anything. You won’t have changed anything. The weight will come right back on.

3)     Permanent weight loss requires a permanent change to your lifestyle. Some of those changes will be difficult at first, but once those lifestyle changes become habits – once they become part of who you are, they will become easy.

You can achieve both the weight and the health you want!

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

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