In Part One we explored how animal foods are an important source of essential nutrition and addressed some of the concerns with consuming animal foods. In Part Two we explored why animal foods are the ideal protein source for human beings. In Part Three we will be exploring one of the most important reasons to optimize your protein intake: your muscle mass and your ability to repair, maintain, and build skeletal muscle.
If you are in your teens or 20’s, and are active, you will probably be able to get away with consuming less protein than what I will suggest. But, if you’re over the age of 30, you would be wise to optimize your protein intake, and be eating and living in a way to optimize muscle growth and maintenance, and stave off muscle wasting (sarcopenia).
It is inevitable as we age that we will eventually experience muscle wasting. The more muscle you can put on and maintain now (no matter what your age), the longer you can stave sarcopenia off, and the higher your likelihood of maintaining a high quality of life (in terms of mobility, activity, metabolic health, cognitive health, and general resilience) into your elderly years. The more muscle mass that is preserved with age, the longer the life expectancy. The older we get, the more challenging the process of muscle growth, repair, and maintenance becomes, and the higher our protein needs will be. This is known as anabolic resistance.
For a powerful perspective on the importance of optimizing protein intake and muscle mass as you age, listen to the final 7 minutes (or better yet all) of this interview with protein researcher, expert Dr. Gabrielle Lyon, discussing what she calls muscle-centric medicine, and her work with elderly patients in end of life care.
Muscle can be thought of as your body’s blood glucose reservoir, and once it’s filled, like from chronically over consuming foods (especially those rich in refined carbohydrates), excess glucose begins being stored as fat. As fat accumulates, you start to develop poor metabolic health, and are at high risk of developing a chronic disease. In this regard over-fat could also be considered under-muscled.
The ways we stimulate muscle protein synthesis (MPS), or the building, repair and maintenance of skeletal muscle are resistance training and exercise, and adequate protein (amino acid) consumption. It's crucial that you are regularly doing at least one or ideally both of these practices.
Animal protein intake is a reliable indicator of the quantity of your skeletal muscle. If you consume little or no animal foods, then supplementing with a protein powder, essential amino acids, or some BCAA's alongside your meals can be a good way help you reach optimal protein (or amino acid) requirements in order to stimulate muscle protein synthesis. However, as a strong proponent of whole food consumption, as whole foods are more complex, and provide far more than just single constituents like isolated proteins or nutrients, I don’t think reliance on supplemental powders is ideal for our health.
To optimize MPS (muscle growth, repair, and maintenance) through diet, you should consider the protein quality, quantity, and timing. Based on protein and amino acid requirements (especially the amino acid leucine) to stimulate muscle protein synthesis (MPS), and in order to optimize this process, it's crucial we consume adequate protein from high quality, complete sources.
It may be best to aim for a minimum 30 grams of complete protein per meal, distributed evenly each meal, and consumed in a bolus (within about 30 minutes)- so for example, if you snack on your meal over a long period of time, or make a protein smoothie and slowly drink over a few hours, you miss the mark for stimulating MPS.
The graph below on the left shows unbalanced protein synthesis (the common way protein is generally distributed in people's daily eating), where they miss the mark on the MPS threshold for the first two meals. I encourage you to experiment incorporating meals like on the right graph below; with that minimum of 30-50 gram bolus of complete protein each meal. You can also experiment with around 1 gram of protein per 1lbs of ideal body weight, divided evenly throughout your meals (So if your ideal body weight is 150 lbs, you would consume a 50 gram serving of complete protein with breakfast, lunch, and dinner). You should find that this strategy generally allows you to go several hours comfortably, without hunger and craving between meals, and with sustained energy (no significant lulls), especially with animal protein sources.
I have made the case that animal sources of protein are ideal for human health, however, you can of course still meet your protein needs with plant sources. Although you can get adequate protein intake from plants, it will require adequate nutrition knowledge, and awareness of strategies like food combining (combining plant foods to get a complete spectrum of the amino acids that plants are lacking in, such as combining legumes and grains). It will require reliance on supplements and highly processed supplemental powders that are not whole foods. It will also require a higher caloric intake to meet your protein needs if from whole food plant sources.
If you are trying to lose body fat, the caloric deficit required to do so may be more challenging to achieve while still meeting your nutritional needs and feeling satiated. My digestive tract shudders at the amount of grains and legumes you would have to consume each meal to meet your protein needs for MPS without supplemental powders. Let's compare some plant and animal protein sources for meeting the amino acid ranges (specifically leucine) to stimulate muscle protein synthesis, especially if you do not resistance train or weight lift.
To consume a 30 gram serving of protein with comparable amino acids quantities needed to stimulate muscle protein synthesis, you would have to eat a 4oz sirloin steak at 181 calories, or 12oz of kidney beans + 1 cup of rice, at 638 calories with 122g of carbohydrates (not to mention that 4 oz piece of steak also meets 95% of the daily recommended intake for B12 as well as more than half the RDI of zinc and selenium).
If you have excess body fat and insulin resistance and are trying to manage those states, then meat and animal foods will make it easier to feel satiated and create a caloric deficit for fat loss, while better maintaining muscle mass, providing significant amounts of essential nutrients, and managing blood glucose effectively. More comparisons can be found in the graphics below:
How Much Protein Should You Consume
To obtain the most benefit from your dietary protein, and to stimulate MPS, especially if you are in your thirties or older, experiment with:
Consuming complete protein sources that meet amino acid requirements. Animal sources are the best choice due to low caloric content alongside a high nutritional density, essential nutrients provided, and the bioavailability of those nutrients.
Consume three even, or similar servings of complete protein, that provide a minimum 30 grams of protein per meal, (likely more depending on your ideal weight, lifestyle, and personal needs), and in a bolus (within about 30 minutes).
This would look like 4-6+ ounces of animal protein, distributed evenly throughout the day with each meal (like breakfast, lunch, dinner). If your diet doesn't include animal foods, supplement with a protein powder, essential amino acids, or some bcaa’s alongside your whole food plant based meals.
Example Meals:
5 eggs, 1 cup vegetables
Smoothie with 2 scoops protein powder, 1 cup greens, 1/2 avocado, 1 cup water, 1 cup berries
5 oz chicken breast, ½ cup rice, ½ avocado, 1 cup broccoli
5 oz steak, ½ cup quinoa, 1 cup spinach
6 oz salmon, large side salad
As I have laid out in this three part series of articles, animal foods are clearly important for the overall function of your body. They are important for effectively meeting your protein and essential nutrient requirements, for building, repairing, and maintaining your muscle mass, and can help ensure a higher quality of life as you age.
If, like me, you wish to optimize your health, meet your nutritional needs consuming whole foods, and with little to no reliance on supplements, then consuming meat and animal foods are necessary and essential to include in your diet.
Experiment with these strategies, and see how they makes you feel. Experience is believing, and results are truth!