Protein Needs For Older Adults

Written by Dr. Steve Chaney on . Posted in Exercise, Fitness and Health, Muscle Therapy and Health

How Much Protein Do We Need?

Author: Dr. Stephen Chaney

 

man lifts weightsWhat are the protein needs for older adults?  In previous “Health Tips From the Professor” I have covered the optimal amount of protein for weight loss diets in high protein diets and weight loss and following workouts . In this issue of “Health Tips From the Professor” I will review the latest information about protein needs as we age.

To put this in perspective, many Americans suffer from sarcopenia (loss of muscle mass) as they age.

Some of you may be saying “So what? I wasn’t planning on being a champion weight lifter in my golden years.” The “So what” is that loss of muscle mass leads to loss of mobility, a tendency to fall (which often leads to debilitating bone fractures) and a lower metabolic rate – which leads to obesity and all of the illnesses that go along with obesity.

How Can We Prevent Loss of Muscle Mass As We Age?

Fortunately, sarcopenia is not an inevitable consequence of aging. There are things that we can do to prevent it. The most important thing that we can do to prevent muscle loss as we age is to exercise – and I’m talking about resistance (weight) training, not just aerobic exercise.

But we also need to look at our protein intake and our leucine intake. Protein is important because our muscle fibers are made of protein.

Leucine is an essential amino acid. It is important because it stimulates the muscle’s ability to make new protein. Leucine and insulin act synergistically to stimulate muscle protein synthesis after exercise. I have covered the evidence behind leucine’s importance in maintaining and building muscle mass in a previous “Health Tips From the Professor”, Leucine Triggers Muscle Mass.

Do Our Protein Needs Increase As We Age?

protein shakeInterestingly, our protein needs actually increase as we age. Campbell et al (Journal of Gerontolgy: Medical Sciences 56A: M373-M380, 2001) showed several years ago that RDA levels of protein were not sufficient to maintain muscle mass in both men & women aged 55 to 77 years old.

Many experts recommend that those of us in our golden years should consume the amount of protein in grams that is equivalent to half our body weight in pounds every day.

When Should We Eat Our Protein?

When we consume the protein is also important. Forget that continental breakfast, salad for lunch and protein-rich dinner. As we age we increasingly need high quality protein at every meal.

In one study, young adults (average age = 31), experienced increased muscle protein synthesis when they consumed as little as 15 grams of protein at a meal, but older adults (average age = 68) experienced no increase in muscle protein synthesis in response to the same low protein meal (Katsanos et al, Am J Clin Nutr 82: 1065-1073).

However, when the amount of protein in a meal was increased to 30 grams (equivalent to a 4 oz piece of chicken or beef) both younger and older adults were able to use that protein to build muscle (Symons et al,Am J Clin Nutr 86: 451-456, 2007).

But, 30 grams seems to be about optimal. Protein intakes above 30 grams in a single meal resulted in no further increase in muscle protein synthesis (Symons et al, J Am Diet Assoc 109: 1582-1586, 2009), which means you can’t hope to get all of the muscle building benefits of protein in a single meal.

As a consequence of these studies most experts recommend that we “golden agers” aim for 20 to 30 grams of high quality protein with every meal.

How Much Leucine Do We Need?

leucine triggers muscle growthThe story with leucine is similar. 1.7 grams of leucine was not sufficient to increase muscle protein synthesis following exercise in older adults, while 2.7 grams was sufficient (Katsanos et al, Am J Physiol Endocrinol Metab 291: E381-E387, 2006). So the experts recommend that older adults get 3 grams of leucine in our diet following workouts to maximize the effect of the workout.

And, of course, if we want to maximize the effects of resistance training, both the protein and leucine need to be consumed after we exercise, not before (Fujita et al, J Appl Physiol 106: 1730-1736, 2009).

Where Do We Get the Protein and Leucine We Need?

So, where do we get the amount of protein and leucine that we are looking for?

If you want to get them from food alone, 4 oz servings of meat are a good starting place – with chicken being the best (35 grams of protein and 2.7 grams of leucine). Dairy, eggs and vegetable foods are much lower in leucine, protein or both.

Unfortunately, I keep running into seniors who are fully convinced that broccoli and tofu will meet their protein needs. I fully understand the rationale for choosing vegetarian protein sources, but you need a bit more than broccoli and tofu if you are going to meet your protein needs in your golden years.

For example, a 4 ounce serving of tofu provides only 10 grams of protein and 0.8 grams of leucine, and a 1.5 cup serving of broccoli provides only 4.2 grams of protein and a miserly 0.36 grams of leucine. That makes it very difficult to meet your target of 20-30 grams of protein and around 2.7 grams of leucine with each meal.

I’m not saying that you can’t get enough protein and leucine to maintain muscle mass on a vegetarian diet. However, you will need to plan that diet very carefully.

So, if you want to know what the old professor does, here it is:

I work out almost every day. On the days when I work out in the morning I rely on a protein shake immediately after the workout to meet my protein and leucine goals. On the days when I train at the gym in the late afternoon, I rely on 4 oz of chicken or fish with dinner to meet those goals.

Those of you who know me know that I will never be featured in muscle magazine, but at least I’m gaining muscle mass – not losing it.

 

The Bottom Line

  • As we age many Americans suffer from sarcopenia (loss of muscle mass). The loss of muscle mass leads to loss of mobility, a tendency to fall (and break things) and a lower metabolic rate – which leads to obesity and all of the illnesses that go along with obesity.
  • The most important thing that we can do to prevent muscle loss as we age is to exercise – especially resistance (weight) training exercise – at least 30 minutes every day. It is also important to make sure that we are getting adequate intake of protein and the essential amino acid leucine.
  • Our protein needs increase as we age. Recent studies suggest that the RDA levels of protein are not sufficient to maintain muscle mass in people over the age of 55. Many experts recommend that those of us in our golden years consume the amount of protein in grams that is equivalent to half our body weight in pounds every day.
  • Recent studies show that it is important to spread that protein out through the day rather than consume one protein rich meal at the end of the day. If we are over 50 we should be aiming at 20-30 grams of protein per meal. However, more than 30 grams of protein at a single serving appears to provide no additional benefit.
  • Seniors also appear to need more leucine in each meal than younger adults if they wish to preserve muscle mass. Young adults need only around 1.7 grams of leucine per serving to stimulate muscle protein synthesis, while mature adults may need as much as 2.7 grams per serving.
  • Well-designed protein shakes and 4 ounces of lean meats are the easiest way for seniors to meet their protein and leucine needs. Vegetarian diets can provide the protein and leucine needed to maintain muscle mass in seniors, but those diets need to be very well planned. Broccoli and tofu just don’t make the grade if you are serious about preserving muscle mass.

 

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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