Is the Ketogenic Diet Safe?

Written by Dr. Steve Chaney on . Posted in Ketogenic Diet

Is The Ketogenic Diet Effective?

Author: Dr. Stephen Chaney

ketogenic dietThe ketogenic diet has been around for a while. It has been used to control epilepsy in children since the 1920s. Nobody is quite sure why it helps control epilepsy, but it does. Once a mainstay of therapy, it is now primarily used as an adjunct to anti-epileptic drugs.

However, recently the ketogenic diet has gone mainstream. It’s no longer just for epilepsy. It has become the latest diet fad. If you believe the claims:

  • Hunger and food cravings will disappear. The pounds will melt away effortlessly and rapidly.
  • You will feel great. You’ll have greater mental focus and increased energy.
  • Physical endurance will increase. You’ll become superhuman.
  • Type 2 diabetes will disappear.
  • Your blood sugar, cholesterol, and triglyceride levels will improve, reducing your risk of developing diabetes and heart disease.

What’s not to like? This sounds like the perfect diet. But, are these claims true? More importantly, is this diet safe?

What Is Ketosis?

what is ketosisKetosis is a natural metabolic adaptation to starvation. To better understand that statement let me start with a little of what I’ll call metabolism 101.

Metabolism 101:

The Fed State: Here’s what happens to the carbohydrate, protein & fat we eat in a meal.

  • Most carbohydrates are converted to blood sugar (glucose), which is utilized in three ways:
    • Most tissues use glucose as their primary energy source in the fed state.
    • Excess glucose is stored as glycogen in muscle and liver.
    • Glycogen stores are limited, so much of the excess glucose is stored as fat.
  • A few tissues such as heart muscle use fat as an energy source. Excess fat is stored.
  • Protein is also used in three ways:
    • Some of it is used to replace and repair the protein components in muscle and other tissues.
    • In conjunction with exercise, protein can be used to increase muscle mass.
    • Excess protein is converted to fat and stored.

The Fasting State: Between meals:

  • Most tissues switch to fats as their primary energy source. Fat stores are utilized to fuel the cells that can use fat.
  • Brain, red blood cells, and a few other tissues still rely solely on glucose as their energy source.
    • Liver glycogen stores are broken down to keep blood glucose levels constant and provide energy for these tissues. (Muscle glycogen stores are reserved for high intensity exercise).
    • As liver glycogen stores are depleted, the body starts breaking down protein and converting it to glucose.

ketogenic diet problems and solutionsStarvation – The Problem: If the fasting state were to continue for more than a few days, we enter what is called starvation. At this point we have a serious problem. Fat stores and carbohydrate stores (liver glycogen) exist for the sole purpose of providing fuel during the fasting state. Protein, however, is unique. There are no separate protein stores in the body. All protein in our body is serving essential functions.

To make matters worse, our brain is metabolically very active. It consumes glucose at an alarming rate. Thus, large amounts of glucose are needed even in the fasting state. If protein continued to be converted to glucose at the same rate as during an overnight fast, our essential protein reserves would rapidly be depleted. Irreversible damage to heart muscle and other essential organs would occur. We would be dead in a few weeks.

Starvation – The Solution: Fortunately, at this point a miraculous adaptation occurs. Our bodies start to convert some of the fat to ketones.

  • All tissues that use fat as an energy source during fasting can also use ketones as an energy source, sometimes with greater efficiency.
  • Over a period of several days, the brain adapts to ketones as its primary energy source. This greatly reduces the depletion of cellular protein to supply blood glucose.
  • However, red blood cells and a few other cells still require glucose as an energy source. Essential protein reserves are still being depleted, but at a far slower pace.
  • With these adaptations, humans can survive months without food if necessary.

There are a few other adaptations that make sense if we think about the dilemma of going long periods without food.

  • Appetite decreases.
  • Metabolic rate decreases, which helps preserve both protein & fat stores.

 

What Is The Ketogenic Diet?

 

ketogenic diet keytonesProponents of the ketogenic diet advocate achieving a permanent state of ketosis without starving yourself. That is achievable because the real trigger for ketosis is low blood sugar, not starvation.

The starting point for the ketogenic diet is low-carb, high-fat diets like Atkins. However, ketogenic diets go beyond traditional low-carb, high-fat diets. They restrict carbohydrates even further to <10% of calories so that a permanent state of ketosis can be achieved. Basically, the ketogenic diet:

  • Eliminates grains and sugars.
  • Eliminates most fruits.
  • Eliminates starchy vegetables (root vegetables, corn, peas, beans, squash & yams).
  • Reduces protein intake. That’s because dietary protein will be converted to glucose when blood glucose levels are low.

You are left with a highly restrictive diet that allows unlimited amounts of fats & some vegetables and moderate amounts of meats, eggs, and cheeses.

The Ketogenic Diet Is Not For Wimps

ketogenic diet tough#1: You have to be committed. As noted above, this is a highly restrictive diet. You will have great difficulty following it when you eat out or are invited to a friend’s house for dinner. You will also have to give up many of your favorite foods.

#2: The transition is rough. Physiological adaptation to the ketogenic diet will take anywhere from a couple of days to a week or two. During that time, you will have to endure some of the following:

  • Headaches, confusion & “brain fog”
  • Fatigue
  • Hunger
  • Lightheadedness and shakiness
  • Leg cramps
  • Constipation
  • Bad breath
  • Heart palpitations

#3: There are no “cheat days”. On most diets, you can have occasional “cheat days” or sneak in some of your favorite foods from time to time. The ketogenic diet is different. A single “cheat day” is enough to take you out of ketosis. If you want to resume the ketogenic diet, you will need to go through the transition period once again.

Is The Ketogenic Diet Effective?

ketogenic diet effectiveWith this background in mind, let’s evaluate the claims made by proponents of the ketogenic diet. I’ll rate them on the “Pinocchio Scale”. “Zero Pinocchios” means they are mostly true. “One Pinocchio” means they are half true. “Two Pinocchios” means they are mostly false.

Zero Pinocchios (Mostly True Claims):

  • Reduced hunger. This is part of the starvation response.
  • Improved mental focus and increased energy. In part, this is simply in contrast to the “brain fog” and fatigue of the transition phase. However, you have also eliminated all foods that can cause blood sugar swings from your diet. Blood sugar swings can affect both mental focus and energy levels.
  • Rapid weight loss. If we focus on short term weight loss, this is true because:
    • A lot of the initial weight loss is water. Glycogen stores retain water. As glycogen stores are depleted, the water is lost along with them.
    • Most people inadvertently reduce their caloric intake on a highly restrictive diet like this. For example, fats are often consumed along with carbohydrate-rich foods (butter with toast, sour cream with potatoes, cream cheese with bagels). While it is easy to say that unlimited consumption of healthy fats is allowed, most people reduce their consumption of fats in the absence of their carbohydrate-rich companions.
    • Note: Proponents of the ketogenic diet will tell you that the weight loss associated with the ketogenic diet is because you are burning fat stores. You will only burn fat stores when dietary fat intake is not sufficient to meet your energy needs. In other words, you burn your fat stores when “calories in” are less than “calories out” – just as with any other diet.
  • Reversal of type 2 diabetes. Because carbohydrates are restricted in this diet, blood sugar and insulin levels will be low. If you are on medications, those will need to be adjusted by your physician.

 

One Pinocchio (Half-True Claims):

  • Improved cholesterol and triglyceride levels. The jury is out on this one. Some studies show an improvement on the ketogenic diet. Other studies show them getting worse.
  • Increased physical endurance. This is only true for low-intensity endurance exercise. It is not true for any exercise or event that requires spurts of high intensity exercise. That’s because:
    • The muscle fibers used for low intensity endurance exercise utilize ketone bodies with high efficiency. That means you can run for miles as long as you don’t care how fast you get there.
    • The muscle fibers used for high-intensity, short-duration exercise cannot adapt to use of ketone bodies because they lack sufficient mitochondria. They require glycogen stores, which are depleted on a ketogenic diet. Even in endurance events like marathons most people want to sprint to the finish line. They won’t be able to do that if they are on a ketogenic diet.

 

Two Pinocchios (Mostly False Claims):

  • ketogenic diet mythsLong term weight loss. Some long-term success has been claimed in a highly controlled clinical setting. However, most studies show:
    • People regain some or most of the weight after 6 months to a year.
    • After 1 or 2 years, there is no difference in weight loss between high-fat/low-carb diets and low-fat/high-carb diets.
    • That’s because:
      • Most people cannot stick to restrictive diets long term, and this diet is very restrictive.
      • Once you go off this diet, even for a short time, your glycogen stores will be replenished and the water weight will return along with the glycogen.
      • The reduction in metabolic rate and the reduction in muscle mass associated with the ketogenic diet make it difficult to keep the weight off long term
  • It is a healthy diet.
    • This is a healthy diet only from the point of view that it eliminates most fast foods and processed foods.
    • However, any diet that eliminates 2 and a half food groups (grains, fruits, and starchy vegetables) is setting you up for long term nutritional deficiencies. It is possible to cover some of those deficiencies with supplementation, but supplements can never provide all the nutrients found in real food.

 

Is The Ketogenic Diet Safe?

ketogenic diet safeFor most people the ketogenic diet is likely to be safe for short periods, maybe even a few months. However, I have grave concerns if the diet is continued long term.

  • I have already mentioned the likelihood this diet will create nutritional deficiencies. Long term, those deficiencies could have severe health consequences.
  • Proponents of the diet recommend that protein intake be limited so that “optimal” ketosis can be achieved. If the dieter is successful at doing that, it will result in a gradual depletion of essential cellular protein reserves as discussed above. Long term, that has the potential to weaken heart muscle, compromise the immune system, and damage essential organs.
  • Ketones can damage the kidneys. In the short term, damage is likely to be minimal as long as plenty of water is consumed. However, long term ketosis could be a significant concern for your kidneys.

I have seen proponents of the ketogenic diet shrug this off as a concern only if protein intake is excessive. They are missing the point. The problem is the ketones, not the protein.

  • Long term ketosis has the potential to cause osteoporosis. That is because the so-called “ketones” are actually organic acids except for the small amount of acetone that gives your breath a fruity smell. Organic acids must be neutralized to keep our body pH in the normal range. There are multiple mechanisms for neutralizing organic acids. One of those mechanisms involves dissolving bone and releasing calcium carbonate into the bloodstream. This slow dissolution of bone will continue for as long as someone is in ketosis.

 

Proponents of the ketogenic diet shrug this off by saying that you never get into ketoacidosis on their diet. Again, they are missing the point. Ketoacidosis simply means that the production of organic acids has become so great that all the body’s mechanisms for neutralizing those acids have become overwhelmed. Ketoacidosis occurs in uncontrolled diabetes and can be deadly. The problem is the slow dissolution of bone during long term ketosis, not a short-term crisis like ketoacidosis.

If you are considering the ketogenic diet for weight loss, my recommendations would be to:

  • Consider other equally effective, but less demanding, weight loss programs. Look for programs that help you preserve muscle mass and teach you healthy eating habits that can be sustained for a lifetime.
  • If you do decide to follow the ketogenic diet, only use it for a short period of time to jump start your weight loss. Then switch to a diet program that has been clinically proven to improve your health long term. Examples would be the Mediterranean diet and the Dash diet.

If you are choosing the ketogenic diet for health reasons, I would recommend the Mediterranean diet or Dash diet instead.

 

The Bottom Line

 

  1. The ketogenic diet is the latest diet fad. I give it a C+ compared to other popular diets.
  2. This is not a diet for wimps.
    • It is a highly restrictive diet
    • The transition period as you adjust to the diet is rough.
    • There are no “cheat days”
  3. Some of the claims made for the ketogenic diet are mostly true, some are half-true, and some are mostly false. I help you sort them out in the article above.
  4. Short term, the diet is probably safe for most people. However, long term I have several concerns.
    • The diet is likely to create nutritional deficiencies. Long term, those deficiencies could have severe health consequences.
    • The diet is likely to gradually deplete essential cellular protein reserves. Long term, that could weaken heart muscle, compromise the immune system, and damage essential organs.
    • The diet has the potential to damage the kidneys.
    • The diet has the potential to cause osteoporosis.
    • The metabolic rationale for those concerns is discussed in the article above.
  5. If you are considering the ketogenic diet for weight loss, my recommendations would be to:
    • Consider other equally effective, but less demanding, weight loss programs. Look for programs that help you preserve muscle mass and teach you healthy eating habits that can be sustained for a lifetime.
    • If you do decide to follow the ketogenic diet, only use it for a short period of time to jump start your weight loss. Then switch to a diet program that has been clinically proven to improve your health long term. Examples would be the Mediterranean diet and the Dash diet.
  6. If you are choosing the ketogenic diet for health reasons, I would recommend the Mediterranean diet or Dash diet instead.

 

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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Comments (11)

  • Eroca Zeviar

    |

    Love your detailed specicifity and clarity. With so many group things online ie Betrayal system and group anti cancer infos, many different diets being promoted without the public really knowing enough to make an informed choice based on real proven knowledge.

    Thanks for your valued presentation.

    Reply

  • Merlena Cushing

    |

    Thank you so much for an incredibly compelling and thorough article. I will simply say I second the accolades given by Eroca…she put it very well. We are indebted to you for your continued articles here and on FB and your generosity in sharing them with all of us. Bless you!

    Reply

  • Judy LaBrune

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    Thank you for clarifying the Ketogenic diet! I’ve heard several people talking about how great it is. This article will be very helpful in sharing the myths and truths.

    judy

    Reply

  • Bonnie zeman

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    We use keto but it is with two life shakes a day. Also the life strip. I suppose it is not true keto. But they are losing a pound a day. We really pay attention to fats, butter, mayo, 100% cold pressed virgin olive oil and coconut oil. Purified water every hour. So far it has worked great. All top grade meats, fish, chicken and eggs. And huge amts of veggies. We also check on them every week.

    Reply

    • Dr. Steve Chaney

      |

      Dear Bonnie,
      It looks more like the Atkins diet to me. As I said in the article, it will succeed short term, but it will be hard to maintain that weight loss long term. I would also remind you that the only diets proven to be healthy long term are the Mediterranean and DASH.
      Dr. Chaney

      Reply

  • Justin Carlson

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    Dr. Chaney I appreciate your efforts of looking into the ketogenic diet, which indeed is becoming popular, but many of your conclusions seems to be based on speculation and lack scientific backing. It also seems unfair to call the diet a fad, when it is used as a treatment for many medical conditions today (chronic fatigue syndrome, neurodegenerstive diseases, etc.) due to the increased energy that ketones yield per unit compared to glucose. Instead of brushing this diet off as a fad, you should be treating it as a legitimate diet and give specific advice on how to eat properly and get the right nutrition when in ketosis. I think that would be most beneficial for your readers.

    Reply

    • Dr. Steve Chaney

      |

      Dear Justin,

      I did open my article by saying that the keto diet was well established for treatment of epilepsy in children. I am also aware of the research into its use for other neurodegenerative disorders. It is not as well established for those uses, but the research is promising. If my article was focused on those uses of the keto diet, it would have been completely appropriate to discuss how to follow it.

      I was focusing on the current usage of the diet to lose weight and to promote long term health. Those applications of the keto diet are unproven at present. The studies to date support short term weight loss and the improvement of blood parameters that may or may not equate with long term health outcomes. At this point we have no long term studies showing that the weight loss is maintained long term or that there is an improvement in health outcomes long term. Until we have that kind of evidence, I think it is appropriate to consider it a fad diet.

      Dr. Chaney

      Reply

  • Bill Moore

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    Interesting. I’ve been on a keto diet for 4 years now and pretty much all the ‘1 and 2’ Pinocchio’s you claim simply aren’t so. I know many (many) people that have stayed on this diet for years and are very happy with it. Is it difficult? Not at all. Does society do it’s absolute best to make it difficult? Very much so.

    You should try reading what people actually doing this diet say vs. a doctor who is, clearly, biased against something he doesn’t fully understand and, frankly, shouldn’t be writing about.

    If you’d like to see a community of people (over 270,000 of them) on keto, go here: https://www.reddit.com/r/keto/ You’ll find many people that can give you actual real world facts as well as the science behind why it works and why it works long term.

    If you’re a science geek, go talk to the 14,000 plus PhD’s and keto nerds who study this stuff for a living here: https://www.reddit.com/r/ketoscience/

    Reply

    • Dr. Steve Chaney

      |

      Dear Bill,

      Let me start by reminding you of my credentials. I taught human metabolism and nutrition to medical students for 40 years, and received numerous teaching awards during that time period. It is fair to say that I am an expert on human metabolism and how that metabolism is affected by our diet.

      I appreciate that your experiences with the keto diet have been positive, and that there is a small community of adherents who have also had positive experiences. In the scientific community, we call those case reports and consider them the least reliable level of proof. Scientists prefer to do clinical studies to see if the same observations are true for the majority of people who follow the diet. For example, it is clear from existing clinical studies that most people who follow the diet achieve short term weight loss, which is why I recommended it for that purpose. However, the important question is whether most people can stick with the diet long enough to maintain that weight loss for two years or more. I laud you for your discipline of being able to stick with the diet for 4 years, and I suspect you have managed to maintain your weight loss. However, until I see published clinical studies showing that most people who embark on the keto diet maintain their weight loss for two years or more, I cannot recommend it for that purpose, and it deserves 2 pinocchios.

      As for the 1 pinocchios, even the proponents of the keto diet say that it is good for endurance exercise, but not for things like sprinting. As for the cholesterol and triglyceride levels, most proponents of the keto diet conveniently ignore the fact that not all reports support improved levels. Personally, I think that is likely to be the case, but we need to remember that improvements in cholesterol and triglyceride levels may or may not translate into improved health outcomes. Until long term studies on health outcomes have been conducted, we cannot claim the keto diet is healthy.

      Dr. Chaney

      Reply

  • Paul

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    I would like to see the research that you talk about but don’t quote! It seems you are one of the many not up with numerous studies showing the many benefits of a ketogenic diet. It is not hard and if you call not eating grains restrictive, you obviously don’t know what a well-formulated keto diet is. You can even do keto as a vegan if you don’t want to eat animal products. When you break down triglycerides, the glycerol back bone is converted into glucose, so you always have enough glucose for the brain. I could go on, but seriously check to see what many Doctors that understand this diet are saying like Dr Mercola.

    Reply

    • Dr. Steve Chaney

      |

      Dear Paul,

      Let me start by reminding you of my credentials. I taught human metabolism and nutrition to medical students for 40 years, and received numerous teaching awards during that time period. It is fair to say that I am an expert on human metabolism and how that metabolism is affected by our diet.

      I am aware of studies on the benefits of the keto diet and referred to some of them in my article. Those are all short term studies, and do not provide evidence for long term health outcomes. For example, unless there are published studies showing that most people can stick to a diet and maintain weight loss for at least one or two years, it cannot be recommended as a successful weight loss approach. Similarly, there are studies showing that adhering to a Vegan, Mediterranean, or DASH diet over decades results in improved health outcomes (lower prevalence of heart disease, cancer & diabetes). In spite of the fact that high fat, low carb diets have been around since the 50s, I am unaware of a single study showing they result in improved long-term health outcomes. In the absence of that kind of evidence, they cannot be recommended as healthy diets.

      If the keto diet simply eliminated grains, it might would be more acceptable. However, most descriptions of the keto diet I have seen also restrict starchy vegetable, most fruits, and legumes. With that kind of restriction (especially the legumes), it is hard to see how a Vegan diet and the keto diet would be compatible.

      You can get some glucose from the glycerol backbone, but that is not enough to supply the body’s needs. That is why many of the description of the keto diet also recommend that you restrict protein.

      Dr. Chaney

      Reply

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Latest Article

Does Protein Supplement Timing Matter?

Posted May 15, 2018 by Dr. Steve Chaney

How Do You Gain Muscle Mass & Lose Fat Mass?

Author: Dr. Stephen Chaney

 

protein supplement timingMost of what you read about protein supplements on the internet is wrong. That is because most published studies on protein supplements:

  • Are very small
  • Are not double blinded.
    • Both the subjects and the investigators knew who got the protein supplement.
  • Are done by individual companies with their product.
    • You have no idea which ingredients are in their product are responsible for the effects they report.
    • You have no idea how their product compares with other protein products.
    • There is no standardization with respect to the amount or type of protein or the addition of non-protein ingredients.

Because of these limitations there is a lot of misleading information on the benefits of protein supplements timing and maximal benefit. Let’s start by looking at why people use protein supplements. Let’s also look at what is generally accepted as true with respect to the best supplement timing.

There are 4 major reasons people consume protein supplements:

  • Enhance the muscle gain associated with resistance training: In this case, protein supplements are customarily consumed concurrently with the workout.
  • Preserve muscle and accelerate fat loss while on a weight loss diet: In this case, protein supplements are customarily consumed with meals or as meal replacements.
  • Provide a healthier protein source. In this case, protein supplements are customarily consumed with meals in place of meat protein.
  • Prevent muscle loss associated with aging or illness. There is no customary pattern associated with this use of protein supplements.

How good are the data supporting the customary timing of protein supplementation? The answer is: Not very good. The timing is based on a collection of weak studies which do not always agree with each other.

The current study  (J.L. Hudson et al, Nutrition Reviews, 76: 461-468, 2018 ) was designed to fill this void in our knowledge. It is a meta-analysis that compares all reasonably good studies that have looked at the effect of protein supplement timing on weight gain or loss, lean muscle mass gain, fat loss, and the ratio of lean muscle mass to fat mass.

How Was The Study Done?

The authors started by doing a literature search of all studies that met the following criteria:

  • The study was a randomized control trial with parallel design. This means that study contained a control group. It does not mean that the investigators or subjects were blinded with respect to which subjects used a protein supplement and which did not.
  • The subjects were engaged in resistance training.
  • The study lasted 6 weeks or longer.
  • Reliable methods were used to measure body composition (lean muscle mass and fat mass).
  • The subjects were healthy and at least 19 years old.
  • There was no restriction on the food the subjects consumed.

The authors started with 2074 published studies and ended up with 34 that met all their criteria. They then separated the studies into two groups – those in which the protein supplements were used with meals and those in which the protein supplements were used between meals.

Both groups were diverse.

  • Group 1 included subjects who consumed their protein supplement with their meal and those who consumed their protein supplement as a meal replacement.
  • Group 2 included subjects who consumed their protein supplement concurrent with exercise (usually immediately after exercise) and those who consumed their protein supplement at a fixed time of day not associated with exercise.

Does Protein Supplement Timing Matter?

 

protein supplement timing workoutsBecause the individual studies were very diverse in the way they were designed, the authors could not calculate a reliable estimate of how much lean muscle mass was increased or fat mass was decreased. Instead, they calculated the percentage of studies showing an increase in lean muscle mass or a decrease in fat mass.

When the authors compared protein supplements consumed with meals versus protein supplements consumed between meals:

  • Weight gain was observed in 56% of the studies of protein supplementation with meals compared to 72% of the studies of protein supplementation between meals. In other words, protein supplements consumed with meals were less likely to lead to weight gain than protein supplements consumed between meals.
  • An increase in lean muscle mass was observed in 94% of the studies of protein supplementation with meals compared to 90% of the studies of protein supplementation between meals. In other words, timing of protein supplementation did not matter with respect to increase in muscle mass.
  • A loss of fat mass was observed in 87% of the studies of protein supplementation with meals compared to 59% of the studies of protein supplementation between meals. In other words, protein supplements consumed with meals were more likely to lead to loss of fat mass.
  • An increase in the ratio of lean muscle mass to fat mass was observed in 100% of the studies of protein supplementation with meals compared to 87% of the studies of protein supplementation between meals. In short, protein supplements consumed with meals were slightly more likely to lead to an increase in the ratio of lean muscle mass to fat mass.

The following seem to suggest protein supplement timing matters:

The authors pointed out that their findings were consistent with previous studies showing that when protein supplements are consumed with a meal they displace some of the calories that otherwise would have been consumed. Simply put, people naturally compensate by eating less of other foods.

In contrast, the authors stated that previous studies have shown that when foods, especially liquid foods, are consumed as snacks (between meals), people are less likely to compensate by reducing the calories consumed in the next meal.

The others concluded: “Concurrently with resistance training, consuming protein supplements with meals, rather than between meals, may more effectively promote weight control and reduce fat mass without influencing improvements in lean [muscle] mass.”

What Are The Limitations Of The Study?

Meta-analyses such as this one, are only as good as the studies included in the meta-analysis. Unfortunately, most sports nutrition studies are very weak studies. Thus, this meta-analysis is a perfect example of the “Garbage In: Garbage Out (GI:GO)” phenomenon.

For example, let’s start by looking at what the term “protein supplement” meant.

  • Because the studies were done by individual companies with their product, the protein supplements in this meta-analysis:
    • Included whey, casein, soy, bovine colostrum, rice or combinations of protein sources.
    • Were isolates, concentrates, or hydrolysates.
    • Contained various additions like creatine, amino acids, and carbohydrate.
  • As I discuss in my book, Slaying the Food Myths, previous studies have shown that optimal protein and leucine levels are needed to maximize the increase in muscle mass and decrease in fat mass associated with resistance exercise. However, neither protein nor leucine levels were standardized in the protein supplements included in this meta-analysis.
  • Previous studies have shown that protein supplements that have little effect on blood sugar levels (have a low glycemic index) are more likely to curb appetite. However, glycemic index was not standardized for the protein supplements included in this meta-analysis.

protein supplement timing workout peopleIn short, the conclusions of this study might be true for some protein supplements, but not for others. We have no way of knowing.

We also need to consider the composition of the two groups.

  • Protein supplements used as meal replacements are more likely to decrease weight and fat mass than protein supplements consumed with meals. Yet, both were included in group 1.
  • Some studies suggest that protein supplements consumed concurrent with resistance exercise are more likely to increase muscle mass than protein supplements consumed another time of day. Yet, both are included in group 2. We also have no idea whether the meals with protein supplements in group 1 were consumed shortly after exercise or at an entirely different time of day.

This was the most glaring weakness of the study because it was completely avoidable. The authors could have grouped the studies into categories that made more sense.

In other words, there are multiple weaknesses that limit the predictive power of this study.

What Can We Learn From This Study?

Despite its many limitations, this study does remind us that protein supplements do have calories. This is of relatively little importance for people whose primary goal is to increase lean muscle mass.

However, most of us are using protein supplements to lose weight or to increase our lean mass to fat mass ratio. Simply put, we are either trying to lean out (shape up) or lose weight. And, we want to lose that weight primarily by getting rid of excess fat. For us, calories do matter. With that in mind:

  • If we are consuming a protein supplement immediately after exercise or between meals we probably should make a conscious effort to reduce our daily caloric intake elsewhere in our diet.
  • Alternatively, we could consume the protein supplement with a meal, but time the meal so it occurs shortly after exercise.

 

The Bottom Line:

 

A recent study looked at the optimal timing of protein supplements consumed by subjects who were engaged in resistance exercise. Specifically, the study compared protein supplements consumed with meals versus protein supplements consumed between meals on weight, lean muscle mass, fat mass, and the ratio of lean muscle mass to fat mass. The study reported:

  • Protein supplements consumed with meals were less likely to lead to weight gain than protein supplements consumed between meals.
  • Timing of protein supplementation did not matter with respect to increase in muscle mass.
  • Protein supplements consumed with meals were more likely to lead to loss of fat mass.
  • Protein supplements consumed with meals were slightly more likely to lead to an increase in the ratio of lean mass to fat mass.

The authors pointed out that their findings were consistent with previous studies showing that when a protein supplement was consumed with a meal it displaces some of the calories that would have been otherwise consumed. Simply put, people naturally compensate by eating less of other foods.

In contrast, the authors said that previous studies have shown that when foods, especially liquid foods, are consumed as snacks (between meals), people are less likely to compensate by reducing the calories consumed in the next meal.

As discussed in the article above, the study has major weaknesses. However, despite its many weaknesses, this study does remind us that protein supplements do have calories. This is of relatively little importance for people whose primary goal is to increase lean muscle mass.

However, for those of us who are using protein supplements to lose weight or to increase our lean mass to fat mass ratio, calories do matter.  With that in mind:

  • If we are consuming a protein supplement immediately after exercise or between meals we probably should make a conscious effort to reduce our daily caloric intake elsewhere in our diet.
  • Alternatively, we could consume the protein supplement with a meal, but time the meal so it occurs shortly after exercise.

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.

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