A Guide to Navigating High-Protein Diets for Optimal Health
High-Protein Diet Controversy
It seems that everyone is talking about high-protein diets. But is this just another fad diet?
In doing research for this post, I came across every opinion - from "high protein diets are unnecessary" to "you must eat a high protein diet," and from "carnivore meat eating all the way!" to "plant-based proteins are best." Nutrition can be divisive because studies are often based on people reporting what they've eaten, which isn't always accurate. Diets can also be controversial because people have valid feelings and they can read and interpret nutrition research in the way that best suits their feelings and beliefs.
I always use caution when making blanket recommendations about nutrition. In this post, I’ve tried to take all the information, digest it, and distill it. But still, I’ve only succeeded in coming up with a nuanced interpretation that is meant to be further individualized. And I am completely open to changing my mind if new evidence is presented.
Okay with that out of the way, I generally support higher protein diets for certain circumstances, with a note to pay attention to the quality of the sources of protein we consume (ie processed vs unprocessed, saturated fat content, etc). If you are particularly environmentally conscious, as we all should be, you will also care about the source of your protein (ie plants vs animals).
Let’s get into the basics of protein.
Protein Basics
What is Protein?
Proteins are essential macronutrients necessary for structural and mechanical functions, cellular processes, and sometimes for energy. Proteins are made up of smaller building blocks called amino acids. When you eat protein, it is digested into amino acids and absorbed into the bloodstream. Amino acids are transported to muscle cells and taken up by them. Within the muscle cells, amino acids are assembled into new protein strands and incorporated into existing muscle fibers or used to build new muscle proteins. The size of the muscle cells can increase or undergo hypertrophy. The quality of the protein we eat, as well as how we use the muscles, can impact the size and strength of our muscles.
Protein Role for Muscle Health
We are born with a set number of muscle fibers that last us our whole life, but they are not static but rather ever-evolving and being reshaped. Existing muscle proteins are constantly being broken down, recycled, carried to other parts of the body, or oxidized to be used for energy.
The balance between muscle protein synthesis and breakdown determines whether there is a net gain (hypertrophy), maintenance, or loss (atrophy) of muscle mass. This continuous cycle of protein synthesis and breakdown is known as protein turnover, with a typical turnover rate of around 1-2% of muscle proteins per day in healthy adults. Factors like exercise (especially resistance training), nutrition (adequate protein and energy intake), hormones, and age can shift this balance.
Protein intake, especially after resistance exercise, stimulates muscle protein synthesis and leads to a positive net protein balance. A sustained positive protein balance over time results in skeletal muscle hypertrophy (increase in muscle size).
Dietary Protein
Sources of Protein
While it is commonly associated with meat, there are proteins in numerous plant sources as well, for example, legumes, nuts, and grains.
The nine amino acids that humans cannot produce on our own are called essential amino acids. Protein foods that contain all essential amino acids are called complete proteins. Complete proteins include fish, meat, dairy products, quinoa, hemp seeds, chia seeds, and soy. Many plant-based proteins are not complete proteins. These include beans, grains and legumes as well as vegetables, which contain only some of the essential amino acids. Incomplete proteins can be combined to create complete proteins. Creating complete plant-based protein combos includes eg. Beans and rice, peanut butter, and whole grain bread.
The bottom line is a high plant-based protein diet can be as effective in increasing muscle mass as an omnivorous diet.
Recommended Protein Intake
The recommended daily allowance of protein is 0.8 grams per kilogram of body weight per day. Americans typically get plenty of protein in their diets often exceeding the RDA recommendations. I do acknowledge that these recommendations were made based on studies conducted in young healthy adults as a minimum requirement to prevent a deficiency and do not take into account the many physiological changes that occur with aging, weight loss, or weight gain. Therefore these recommendations for the minimum intake meet the needs of some individuals, but they are not necessarily optimal for all people.
For example, during energy restriction (ie. calorie restriction) for weight loss, higher protein intake is recommended to preserve lean body mass and promote fat loss. Protein intake closer to 1.6 g/kg body weight per day is effective for preserving lean mass (ie. muscle) and promoting fat loss.
Determining optimal protein intake entails a nuanced understanding of individual needs. Let’s take a glimpse at different scenarios next.
High-Protein Diets
When You May Benefit from a High-Protein Diet
Following a higher protein regimen offers advantages, especially in the context of weight management, menopause, and aging - which are all times in which you may need to work harder to increase your muscle mass.
Fat Loss:
Higher protein intakes during energy restriction result in greater fat mass loss while preserving lean body mass. Especially when combined with resistance exercise, the resulting increase in muscle mass burns more calories. Protein can also have a greater satiating effect and burns more calories during digestion than other macronutrients like carbohydrates.
Muscle Preservation in Aging:
Sarcopenia, or weak muscles, is a huge driver of morbidity later in life, a time when falls are more deadly. Combining resistance exercise with increased protein intake fosters muscle preservation. Oder adults exhibit anabolic resistance, where their muscles have a reduced ability to utilize dietary protein for MPS. Therefore, they require a higher protein intake compared to younger individuals to maintain skeletal muscle mass and function.
Menopause:
A study in post-menopausal women showed that their baseline muscle turnover was elevated, and when they exercised or ate protein, they had a blunted muscle synthesis. This suggests that postmenopausal women may need more protein than the RDA and that weight training may be extra important to maintain muscle strength.
Muscle Gain:
Many people purely want to target increased muscles, whether it be for weight maintenance, sport, competition, or even vanity. The importance of higher protein diets is well-known among the weightlifting and bodybuilding community.
Illness Recovery:
Adequate protein intake, combined with resistance exercise, helps preserve skeletal muscle mass during periods of disuse or illness, preventing muscle wasting and functional decline
For older individuals seeking to increase muscle mass and strength, a protein intake of at least 1.2 grams per kilogram of body weight per day. For those seeking fat loss while preserving lean mass during weight loss, a protein intake closer to 1.6 grams per kilogram of body weight per day is recommended. Of course, this increased protein intake should come along with strength exercises two to three times a week. Individuals looking to gain extra muscle or engage in bodybuilding pursuits may target an even higher protein intake of 2 grams per kilogram of body weight or more.
The Role of Protein Supplements
While protein powders offer a convenient way to increase protein intake, they are not essential for all healthy adults who can meet their protein needs through a balanced diet rich in high-quality protein foods. Again the vast majority of people are getting plenty of protein, especially if the goal is to maintain current weight and avoid deficiency.
However special populations may have a harder time meeting a higher protein target like athletes, older adults, vegans/vegetarians, or those restricting calories, such as in weight loss. When your goals are to increase muscle and your target is >1.6g/kg body weight, it becomes hard to eat enough protein from food sources without overeating calories or being too full to do so.
While excessive reliance on protein supplements can potentially lead to adverse effects such as weight gain, dehydration, and renal issues, these concerns are often overstated, particularly for individuals who are generally healthy.
My go-to recommendations are for whey protein or pea protein for vegans. While there is evidence that flavors with natural artificial sweeteners are likely safe, I am not a big fan of anything overtly artificial. Therefore I particularly like unflavored unsweetened protein powders, which can easily be mixed into oats or smoothies. Look for something with at least 20g of protein and around 100 calories per serving.
The goal should be to prioritize whole food sources of protein, strategically spaced out throughout the day. This entails a mix of plant-based options and high-quality, unprocessed animal-based sources tailored to dietary preferences. To effectively support muscle building and recovery, it's recommended to consume 20-40 grams of protein-rich foods at various intervals throughout the day, including snacks and meals.
Conclusions
In conclusion, it's clear that protein intake is crucial for nurturing optimal muscle health and overall health, whether your goals are to lose weight or increase strength. However, it's important to understand individual needs and take a balanced approach, as consuming excessive amounts or unhealthy sources of protein, such as those found in highly processed foods, can lead to inflammation and heightened cardiovascular risks.
I don’t think nutrition needs to be so polarizing or divisive. After all, most people who are nerding out about protein are trying to do the right thing. Achieving desired outcomes and preserving long-term health hinges on striking the right balance in protein intake that suits one's unique needs and goals. It's crucial to grasp these individual requirements and embrace a comprehensive approach to nutrition, as this is fundamental to promoting not only optimal muscle health but also overall well-being.
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