Leucine And Muscle Gain

Written by Dr. Steve Chaney on . Posted in current health articles, Exercise, Fitness and Health, Food and Health, Healthy Living, Muscle Therapy and Health, Supplements and Health

Should Your Post-Workout Protein Shake Contain Added Leucine?

Author: Dr. Stephen Chaney

 

If you are an athlete – or just someone who is exercising to create a lean and healthy body, you are probably interested in increasing your lean muscle mass following each workout. You may leucinealready use leucine.  Of course, if you read any of the “muscle magazines”, you’ve seen the ads. “Explode Your Muscles.” “Double Your Gains.” They all claim to have the perfect post-workout protein shake, backed by science. They all sound so tempting, but you know that some of them have to be scams.

I told you about some of the sports supplements to avoid in previous “Health Tips From the Professor”. In this issue, I’m going to ask “What does the perfect post-workout protein shake look like?

For years athletes have been using protein beverages containing branched chain amino acids after their workouts to maximize muscle gain and recovery. There was some science behind that practice, but the major questions were unanswered. Nobody really knew:

  • How much protein is optimal?
  • What kind of protein is optimal?
  • What amount of branched chain amino acids is optimal?
  • Are some branched chain amino acids more important than others?
  • Does the optimal amount of branched chain amino acids depend on the amount of protein?

As a consequence, after workout protein supplements were all over the map in terms of protein source, protein amount, branched amino acid amount and type of branched chain amino acids. Fortunately, recent research has clarified many of these questions.

How Much Protein Do You Need and What Kind?

  • Recent research has shown that the optimal protein intake for maximizing muscle gain post workout is 15-20 gm for young adults (Katsanos et al, Am J Clin Nutr 82: 1065-1073, 2005; Moore et al, Am J Clin Nutr, 89: 161-168, 2009) and 20-25 gm for older adults (Symons et al, Am J Clin Nutr 86: 451-456, 2007).
  • More protein isn’t necessarily better. The effect of protein intake on post workout muscle gain maxes out at around 25 gm for young adults and 30 gm for older adults (Symons et al, J Am Diet Assoc 109: 1582-1586, 2009).
  • Whey protein is the best choice for enhancing muscle gain immediately after a workout. Other protein sources (soy, pea, casein, chicken) are better choices for sustaining muscle gain over the next few hours.

Leucine: The Only Branched Chain Amino Acid To Stimulate Muscle Protein

  • branched chain amino acidIt turns out that leucine is the only branched chain amino acid that actually stimulates muscle protein synthesis (Am J Physiol Endocrinol Metab 291: E381-E387, 2006). And protein is what gives muscles their strength and their bulk.
  • Recent research has shown that 2-3 gm of leucine (2 gm for young adults; 3 gm for older adults) is sufficient to maximize post workout muscle gain if protein levels are adequate (Am J Physiol Endocrinol Metab 291: E381-E387, 2006).

Unanswered Questions About Optimizing Muscle Gain Post-Workout

  • Do the other branched chain amino acids play a supporting role, or is leucine alone sufficient to drive post-workout muscle gain?
  • Can leucine still help maximize post-workout muscle gain if protein intake is inadequate? If so, how much leucine is needed?

Does Leucine Enhancement Improve Low Protein Shakes?

A recent study (Churchward-Venne et al, Am J Clin Nutr, 99: 276-286, 2014) seems to answer those two questions. The authors compared the effect of 5 protein-amino acid combinations on best post workout shakemuscle protein synthesis in 40 young men (~21 years old) following unilateral knee-extensor resistance exercise. The protein shakes contained:

  • 25 gm of whey protein, which naturally contains 3 gm of leucine (high protein)
  • 6.25 gm of whey protein, which naturally contains 0.76 gm of leucine (low protein)
  • 6.25 gm of whey protein with 3 gm of leucine (low protein, low leucine)
  • 6.25 gm of whey protein with 5 gm of leucine (low protein, high leucine)
  • 6.25 gm of whey protein with 5 gm of leucine + added isoleucine and valine (the other branched chain amino acids). (low protein, branched chain amino acids).

The results were clear cut:

  • The high protein shake (25 gm of protein) was far superior to the low protein shake (6.25 gm of protein) at enhancing post workout protein synthesis. This is consistent with numerous other published clinical reports.
  • Adding 3 gm of leucine to the low protein shake had no effect on post-workout protein synthesis, but 5 gm of added leucine made the low protein shake just as effective as the high protein shake at supporting post-workout protein synthesis.

In short, leucine can improve the effectiveness of a low protein shake, but you need more leucine than if you chose the high protein shake to begin with.

  • Adding extra branched chain amino acids actually suppressed the effectiveness of leucine at enhancing post-workout protein synthesis. These data suggest:
    • Leucine probably is the major amino acid responsible for the muscle gain reported in many of the previous studies with branched chain amino acids.
    • If the other branched chain amino acids play a supporting role in the muscle gain, the quantities that occur naturally in the protein are probably enough. Adding more may actually reduce the effectiveness of leucine at stimulating muscle gain.

While this is a single study, it is consistent with numerous other recent clinical studies. It simply helps clarify whether leucine can increase the effectiveness of a low protein supplement. It also clarifies the role of branched chain amino acids.

Also, while this study focused on protein synthesis, numerous other studies have shown that optimizing post-workout protein and leucine intake results in greater muscle gain (for example, Westcott et al., Fitness Management, May 2008)

 

The Bottom Line

Research on post-workout nutrition to optimize muscle gain from the workouts has come a long way in recent years. It is now actually possible to make rational choices about the best protein supplements and foods to support your workouts.

  • If you are a young adult (17-30), you should aim for 15-20 gm of protein and about 2 gm of leucine after your workout.
  • If you are an older adult (50+), you should aim for 20-25 gm of protein and 3 gm of leucine after your workout.
  • If you are in between you are on your own. Studies haven’t yet been done in your age group, but it’s reasonable to assume that you should aim for somewhere between the extremes.
  • If you are getting the recommended amounts of whey protein, the leucine level may also be optimal. If you are using other protein sources you may want to choose ones with added leucine.
  • The research cited above shows that you can make a low protein supplement effective by adding lots of leucine, but that’s going to require artificial flavors and sweeteners to cover up the taste of that much leucine. I would recommend choosing one that provided adequate protein to begin with.
  • While the research in this area is still somewhat fluid, I would avoid protein supplements with added branched chain amino acids other than leucine. If the paper I cited above is correct, you probably get all of the other branched chain amino acids you need from your protein and adding more may actually interfere with the effect of leucine on muscle gain.
  • I’d pretty much forget all the other “magic ingredients” in post-workout supplements. If you’re a novice there is some evidence that arginine and HMB may be of benefit, but if you have been working out for more than 6 months, the evidence is mixed at best. As for the rest, the clinical studies are all over the map. There’s no convincing evidence that they work.
  • Whey protein is the best choice for enhancing muscle gain immediately after your workout. Soy, pea, and casein are better choices for sustaining muscle gain over the next few hours. If you’re looking at meat protein, chicken is a particularly good choice. Four ounces of chicken will provide the protein and leucine you need to sustain muscle gain for several hours.

Even if you are not working out, recent research on dietary protein and leucine has important implications for your health. In a recent “Health Tips From the Professor” High Protein Diets and Weight Loss, I shared research showing that optimizing protein and leucine intake helps to increase muscle retention and maximize fat loss when you are losing weight.

 

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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A Low Carb Diet and Weight Loss

Posted January 15, 2019 by Dr. Steve Chaney

Do Low-Carb Diets Help Maintain Weight Loss?

Author: Dr. Stephen Chaney

 

low carb dietTraditional diets have been based on counting calories, but are all calories equal? Low-carb enthusiasts have long claimed that diets high in sugar and refined carbs cause obesity. Their hypothesis is based on the fact that high blood sugar levels cause a spike in insulin levels, and insulin promotes fat storage.

The problem is that there has been scant evidence to support that hypothesis. In fact, a recent meta-analysis of 32 published clinical studies (KD Hall and J Guo, Gastroenterology, 152: 1718-1727, 2017 ) concluded that low-fat diets resulted in a higher metabolic rate and greater fat loss than isocaloric low-carbohydrate diets.

However, low-carb enthusiasts persisted. They argued that the studies included in the meta-analysis were too short to adequately measure the metabolic effects of a low-carb diet. Recently, a study has been published in the British Medical Journal (CB Ebbeling et al, BMJ 2018, 363:k4583 ) that appears to vindicate their position.

Are low carb diets best for long term weight loss?

Low-carb enthusiasts claim the study conclusively shows that low-carb diets are best for losing weight and for keeping it off once you have lost it. They are saying that it is time to shift away from counting calories and from promoting low-fat diets and focus on low-carb diets instead if we wish to solve the obesity epidemic. In this article I will focus on three issues:

  • How good was the study?
  • What were its limitations?
  • Are the claims justified?

 

How Was The Study Designed?

low carb diet studyThe investigators started with 234 overweight adults (30% male, 78% white, average age 40, BMI 32) recruited from the campus of Framingham State University in Massachusetts. All participants were put on a diet that restricted calories to 60% of estimated needs for 10 weeks. The diet consisted of 45% of calories from carbohydrate, 30% from fat, and 25% from protein. [So much for the claim that the study showed low-carb diets were more effective for weight loss. The diet used for the weight loss portion of the diet was not low-carb.]

During the initial phase of the study 161 of the participants achieved 10% weight loss. These participants were randomly divided into 3 groups for the weight maintenance phase of the study.

  • The diet composition of the high-carb group was 60% carbohydrate, 20% fat, and 20% protein.
  • The diet composition of the moderate-carb group was 40% carbohydrate, 40% fat, and 20% protein.
  • The diet composition of the low-carb group was 20% carbohydrate, 60% fat, and 20% protein.

Other important characteristics of the study were:

  • The weight maintenance portion of the study lasted 5 months – much longer than any previous study.
  • All meals were designed by dietitians and prepared by a commercial food service. The meals were either served in a cafeteria or packaged to be taken home by the participants.
  • The caloric content of the meals was individually adjusted on a weekly basis so that weight was kept within a ± 4-pound range during the 5-month maintenance phase.
  • Sugar, saturated fat, and sodium were limited and kept relatively constant among the 3 diets.

120 participants made it through the 5-month maintenance phase.

 

Do Low-Carb Diets Help Maintain Weight Loss?

low carb diet maintain weight lossThe results were striking:

  • The low-carb group burned an additional 278 calories/day compared to the high-carb group and 131 calories/day more than the moderate-carbohydrate group.
  • These differences were even higher for those individuals with higher insulin secretion at the beginning of the maintenance phase of the study.
  • These differences lead the authors to hypothesize that low-carb diets might be more effective for weight maintenance than other diets.

 

What Are The Pros And Cons Of This Study?

low carb diet pros and consThis was a very well-done study. In fact, it is the most ambitious and well-controlled study of its kind. However, like any other clinical study, it has its limitations. It also needs to be repeated.

The pros of the study are obvious. It was a long study and the dietary intake of the participants was tightly controlled.

As for cons, here are the three limitations of the study listed by the authors:

#1: Potential Measurement Error: This section of the paper was a highly technical consideration of the method used to measure energy expenditure. Suffice it to say that the method they used to measure calories burned per day may overestimate calories burned in the low-carb group. That, of course, would invalidate the major findings of the study. It is unlikely, but it is why the study needs to be repeated using a different measure of energy expenditure.

#2: Compliance: Although the participants were provided with all their meals, there was no way of being sure they ate them. There was also no way of knowing whether they may have eaten other foods in addition to the food they were provided. Again, this is unlikely, but cannot be eliminated from consideration.

#3: Generalizability: This is simply an acknowledgement that the greatest strength of this study is also its greatest weakness. The authors acknowledged that their study was conducted in such a tightly controlled manner it is difficult to translate their findings to the real world. For example:

  • Sugar and saturated fat were restricted and were at very similar levels in all 3 diets. In the real world, people consuming a high-carb diet are likely to consume more sugar than people in the other diet groups. Similarly, people consuming the low-carb diet are likely to consume more saturated fat than people in the other diet groups.
  • Weight was kept constant in the weight maintenance phase by constantly adjusting caloric intake. Unfortunately, this seldom happens in the real world. Most people gain weight once they go off their diet – and this is just as true with low-carb diets as with other diets.
  • The participants had access to dietitian-designed prepared meals 3 times a day for 5 months. This almost never happens in the real world. The authors said “…these results [their data] must be reconciled with the long-term weight loss trials relying on nutrition education and behavioral counseling that find only a small advantage for low carbohydrate compared with low fat diets according to several recent meta-analyses.” [I would add that in the real world, people do not even have access to nutritional education and behavioral modification.]

 

low carb diet and youWhat Does This Study Mean For You?

  • This study shows that under very tightly controlled conditions (dietitian-prepared meals, sugar and saturated fat limited to healthy levels, calories continually adjusted so that weight remains constant) a low-carb diet burns more calories per day than a moderate-carb or high-carb diet. These findings show that it is theoretically possible to increase your metabolic weight and successfully maintain a healthy weight on a low-carb diet. These are the headlines you probably saw. However, a careful reading of the study provides a much more nuanced viewpoint. For example, the fact that the study conditions were so tightly controlled makes it difficult to translate these findings to the real world.
  • In fact, the authors of the study acknowledged that multiple clinical studies show this almost never happens in the real world. These studies show that most people regain the weight they have lost on low-carb diets. More importantly, the rate of weight regain is virtually identical on low-carb and low-fat diets. Consequently, the authors of the current study concluded “…translation [of their results to the real world] requires exploration in future mechanistic oriented research.” Simply put, the authors are saying that more research is needed to provide a mechanistic explanation for this discrepancy before one can make recommendations that are relevant to weight loss and weight maintenance in the real world.
  • The authors also discussed the results of their study in light of a recent, well-designed 12-month study (CD Gardener et al, JAMA, 319: 667-669, 2018 ) that showed no difference in weight change between a healthy low-fat versus a healthy low-carbohydrate diet. That study also reported that the results were unaffected by insulin secretion at baseline. The authors of the current study noted that “…[in the previous study] participants were instructed to minimize or eliminate refined grains and added sugars and maximize intake of vegetables. Probably for this reason, the reported glycemic load [effect of the diet on blood sugar levels] of the low-fat diet was very low…and similar to [the low-carb diet].” In short, the authors of the current study were acknowledging that diets which focus on healthy, plant-based carbohydrates and eliminate sugar, refined grains, and processed foods may be as effective as low-carb diets for helping maintain a healthy weight.
  • This would also be consistent with previous studies showing that primarily plant-based, low-carb diets are more effective at maintaining a healthy weight and better health outcomes long-term than the typical American version of the low-fat diet, which is high in sugar and refined grains. In contrast, meat-based, low-carb diets are no more effective than the American version of the low-fat diet at preventing weight gain and poor health outcomes. I have covered these studies in detail in my book “Slaying The Food Myths.”

Consequently, the lead author of the most recent study has said: “The findings [of this study] do not impugn whole fruits, beans and other unprocessed carbohydrates. Rather, the study suggests that reducing foods with added sugar, flour, and other refined carbohydrates could help people maintain weight loss….” This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.

The Bottom Line

 

  • A recent study compared the calories burned per day on a low-carb, moderate-carb, and high-carb diet. The study concluded that the low-carb diet burned significantly more calories per day than the other two diets and might be suitable for long-term weight control. If confirmed by subsequent studies, this would be the first real evidence that low-carb diets are superior for maintaining a healthy weight.
  • However, the study has some major limitations. For example, it used a methodology that may overestimate the benefits of a low-carb diet, and it was performed under tightly controlled conditions that can never be duplicated in the real world. As acknowledged by the authors, this study is also contradicted by multiple previous studies. Further studies will be required to confirm the results of this study and show how it can be applied in the real world.
  • In addition, the kind of carbohydrate in the diet is every bit as important as the amount of carbohydrate. The authors acknowledge that the differences seen in their study apply mainly to carbohydrates from sugar, refined grains, and processed foods. They advocate diets with low glycemic load (small effects on blood sugar and insulin levels) and acknowledge this can also be achieved by incorporating low-glycemic load, plant-based carbohydrates into your diet. This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.
  • Finally, clinical studies report averages, but none of us are average. When you examine the data from the current study, it is evident that some participants burned more calories per hour on the high-carb diet than other participants did on the low carb diet. That reinforces the observation that some people lose weight more effectively on low-carb diets while others lose weight more effectively on low-fat diets. If you are someone who does better on a low-carb diet, the best available evidence suggests you will have better long-term health outcomes on a primarily plant-based, low-carb diet such as the low-carb version of the Mediterranean diet.

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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