By Victor Prisk, M.D.
There are many aspects to developing the concept of eating to grow.
First, you have to determine just how many calories you actually need to maintain your weight with regards to total daily energy expenditure. Using equations like the Harris Benedict Equation x 1.2, you can determine your minimum energy requirements before exercise. Be aware that this equation can be off by as much as 30 percent. Thus, you may have to adjust your diet as you go to counter any misdirection.
Second, you need to consider how active you are in the gym or on your job. One way to get a sense of this is to use a wearable calorie-counting device or phone app. Again, these aren’t very accurate so you will have to adjust as you go. Add your extra calorie burn to your caloric needs and then add up to 500 calories. This will ensure you that you are never energy deficient. More calories will help with gaining weight, but you will run greater risk of storing fat.
NOT ALL PROTEIN IS CREATED EQUAL
The ISSN and ACSM recommend nearly 1 gram per pound of bodyweight for strength-training athletes.1,2 However, some believe that this may be insufficient for maximizing gains from heavy resistance training.3 In fact, I believe that counting the absolute number of all grams of protein may be a little misleading, because all proteins are not created equal.
Proteins are made of amino acids. Some of these amino acids are essential, meaning your body can’t make them and they must be obtained from your diet. Proteins that have appreciable amounts of all the essential amino acids are considered “complete” proteins. Some proteins, incomplete proteins, can be deficient in one or more of the essential amino acids like legumes (methionine). If we assume that we are only counting the “complete” protein content of our meals in calculating our protein intake, we may be consuming less than required by whole numbers. Once we have verified that we are getting the majority of our protein intake from complete proteins, we must also realize that all complete proteins are not created equal. Each protein has different ratios of the essential and non-essential amino acids. Some proteins such as the dairy proteins are particularly rich in the branched-chain amino acids (BCAAs; leucine, isoleucine, valine). It turns out that this difference in BCAA content is an important distinction.
A recently published study has shown that when we consume protein in a skewed fashion (like most Americans) with the majority of our protein intake at dinner and much less at lunch and breakfast, we do not maximize our muscle growth potential.4 This study looked at the difference between eating ~10 grams, 15 grams and 65 grams of protein for breakfast, lunch and dinner, respectively, versus eating 30 grams for each meal. By increasing the protein content of the first two meals, it is theorized that a threshold was met whereby muscle protein synthesis was turned on at each meal. It has been postulated that the switch to be turned on is mTOR.
mTOR is a molecular nutrient sensor that turns on muscle protein synthesis in response to the presence of insulin and amino acids. In other words, mTOR is the molecular switch that turns on muscle growth. mTOR can be directly activated by the BCAA L-leucine.5 Multiple studies have demonstrated leucine’s ability to turn on muscle protein synthesis. Norton and Wilson have suggested that the leucine content of a protein is the major determinant of its ability to turn on muscle protein synthesis.5 In my opinion, it would be safe to assume that the leucine content of the skewed meals was insufficient to turn on muscle protein synthesis in the breakfast and lunch meals.
Therefore, I propose that we don’t look at all proteins in the same light. They are not all created equal because they have varying degrees of leucine content. For instance, casein is approximately 9 percent leucine while whey isolate can be as high as 12 percent. Moreover, lean beef has higher leucine content per ounce compared to lean turkey. Norton and Wilson have extrapolated from various studies on leucine that 0.05 grams of leucine per kilogram bodyweight per meal will maximize mTOR activation and thus muscle protein synthesis.5 Thus, knowing the leucine content of foods will help determine how much of a particular protein you will need to maximize your muscle growth and/or maintenance, especially in an energy deficit. It is fair to say that augmenting some of your meals with a little leucine, especially in the form of whey protein, will help you to maximize muscle growth during the off-season or even during the competition season.
It is also pretty safe to say that if you are maximizing the leucine content of your food, you will likely be consuming more than the suggested 1 gram of protein per pound bodyweight. Although the science isn’t great, mostly anecdotal evidence has suggested that eating a meal every three to four hours will adequately turn on muscle protein synthesis.5 It is reasonable to maximize your leucine and protein needs with each of your meals. However, when it comes to the other macronutrients, fat and carbohydrate, the amount with each meal can vary as long as energy needs are eventually met.
HEALTHY AND UNHEALTHY FATS
There are essential fats that we can’t live without. Even though recent studies suggest that saturated fat may not be as evil as once thought, if you eat too much when trying to grow, you will probably not be at your healthiest. That being said, restricting your cholesterol and saturated fat intake excessively can cause reductions in testosterone production, potentially hindering muscle growth.6 So, extreme limitations of your fat intake can be detrimental to your goals. By maximizing the polyunsaturated fatty acids, especially the omega-3s from fish oils, you are more likely to see some health benefits from eating to grow. I would recommend keeping your fat content above 30 percent of your total daily calories and strictly avoid toxic and inflammatory trans fats. As for all of the macronutrients, getting the majority of your fat from whole (unprocessed) foods will help you to avoid unhealthy fats.
Science suggests that we do not necessarily need “fast carbs” after our training to get a muscle protein synthetic response.7 However, if you aren’t focused on being as lean as humanly possible, carbohydrates are beneficial to muscle growth. Carbohydrates fuel muscle contraction and fill muscle with glycogen stores, contributing to muscle size.
Carbohydrates stimulate the release of insulin, your body’s most anabolic hormone. Insulin pushes nutrients into your muscle cells and turns on the synthetic machinery via acting through mTOR. It helps your muscle build contractile proteins, store glycogen and prevents breakdown. By consuming more than adequate amounts of carbohydrates with each meal and around your training, you can maximize strength-training performance in the gym to attain the most adaptive responses for muscle growth. Carbohydrate-deficient diets can limit testosterone production8; whether this is significant enough to limit muscle accresion is not known. Regardless, low-carbohydrate diets can limit strength as glycogen fuels weight training.
The American College of Sports Medicine recommends consuming 2.7 to 4.5 grams of carbohydrate per pound of bodyweight per day. The amount required is very dependent on energy requirements after calculating your protein and fat needs. The more endurance or high-volume training you perform, the more you should consume. Additionally, .5 grams of carbohydrate per pound of bodyweight will be more than enough in a post-workout meal to restore muscle glycogen stores. Again, whole foods such as yams, potatoes, rice, quinoa and others would be recommended over sugars. Excessive sugar intake can lead to unhealthy “caramelization” of proteins leading to inflammation and the detrimental effects of insulin on fat storage.
The data about the “anabolic window” has become muddied in recent years. There is data to support consuming protein and carbohydrate within an hour before or after your training. However, other studies have shown that if you are consuming adequate amounts of protein throughout the day, the timing around the workout doesn’t matter.9 Essentially, if you are consuming your protein (and thus leucine) every three to four hours as we previously discussed, you will have some protein fairly close to the start of your
Another, often under recognized, aspect of “eating to grow” is the importance of vegetables. Vegetables are not only important for their antioxidant vitamin, mineral and fiber content. Veggies, especially green leafy veggies, are rich in nitrates. Nitrates act as nitric oxide donors. This is just like the arginine- and citrulline-rich supplements used to boost your pump in the gym.
Foods like spinach, celery and beets are rich in nitrates and boost nitric oxide. Researchers have found that beetroot juice supplementation results in better tolerance of the intense exercise and better metabolic handling of oxygen than beetroot juice that was depleted of nitrate.10 The subjects on the nitrate- rich beetroot juice took longer to fail at a high-intensity sprint than those on a placebo-nitrate depleted beetroot juice. With higher intensity training you can imagine this could provide greater potential for muscle growth stimulus. With the added antioxidants, you may even recover from that training faster.
In summary, there are a few things you need to be certain your diet contains:
- Whole food sources of quality proteins, fats, and carbohydrates
- 0.05 grams of leucine per kilogram bodyweight per meal
- Nitrate-rich veggies
Dr. Victor Prisk is a board certified orthopaedic surgeon and IFBB professional bodybuilder in Pittsburgh, PA. Dr. Prisk is an active member of the GNC Medical Advisory Board and creator of the “G.A.I.N. Plan.” He is an NCAA All-American gymnast, champion swing dancer and NPC Welterweight National Champion. For week-to-week updates on his app and books, check out his blog at www.YourGAINPlan.com and Twitter posts @victorprisk.
- Campbell B, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2007 Sep 26;4:8.
- Rodriguez NR, et al. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 2009 Mar;41(3):709-31
- Helms ER, et al. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. 2014 May 12;11:20
- Mamerow MM, et al. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults. J Nutr. 2014 Jun;144(6):876-80
- Norton LE, Wilson GJ. Optimal protein intake to maximize muscle protein synthesis. AgroFOOD industry hi- tech.March/April 2009; 20(2):54-57
- Hämäläinen EK, et al. Decrease of serum total and free testosterone during a low-fat high-fibre diet. J Steroid Biochem. 1983 Mar;18(3):369-70.
- Koopman R, et al. Coingestion of carbohydrate with protein does not further augment postexercise muscle protein synthesis. Am J Physiol Endocrinol Metab 2007, 293:E833– E842.
- Lane AR, et al. Influence of dietary carbohydrate intake on the free testosterone: cortisol ratio responses to short- term intensive exercise training. Eur J Appl Physiol. 2010 Apr;108(6):1125-31.
- Aragon AA, Schoenfeld BJ. Nutrient timing revisited: is there a post-exercise anabolic window? J Int Soc Sports Nutr. 2013 Jan 29;10(1):5.
- Breese BC, et al. Beetroot juice supplementation speeds O2 uptake kinetics and improves exercise tolerance during severe-intensity exercise initiated from an elevated metabolic rate. Am J Physiol Regul Integr Comp Physiol. Am J Physiol Regul Integr Comp Physiol. 2013 Dec 15;305(12):R1441-50