Written by justis berg
25 May 2010
No Juice Bodybuilding

By Layne Norton

The Great Macronutrient Debate Part II

"It is better to debate a question without settling it than to settle a question without debating it."

—Joseph Joubert

In last month's column, we talked about the many theories present in regard to optimal protein, carbohydrate, and fat intake. The take-away message was that what is optimal for one person may not be optimal for another, and anyone who only suggests one specific range of any nutrient for every person is bound to have problems, due to the differences in individual metabolisms from person to person.

So how do you figure out what is best? That's what we are all after in the end— optimization. We want to know that our efforts in the gym day in and day out are not being sabotaged by what we are doing in the kitchen, and vice versa.

In the case of 'the great macronutrient debate,' I can confidently say that there really is no substitute for experimentation and documentation. Over time, you need to be willing to change things around to see how your body responds to various manipulations in protein, carbohydrate, and fat. You want to change often enough so that you can try out various protocols, but you also want to give your body long enough to adapt to a protocol, to see if it actually works.

For example: you are used to a very low-carb diet, and then decide one day to switch to a much higher-carbohydrate intake (say 400 grams per day, as opposed to 100 grams per day). I can most definitely assure you that you will feel like garbage and look like garbage for the first few weeks, until your body adjusts to the shift. So if you changed that drastically and then saw that you looked like garbage the first week, you might think that you were very carb-sensitive, when in reality, you just did not give yourself enough time to see any benefits from the new protocol.

While experimentation is very important, my job is to make things a bit easier for you, not to say, "Just see what works for you, bro." While things are very different from individual to individual, there are a few factors than can provide insight into what range of macronutrient intake may be best for you as an individual. Those factors include lean body mass, age, training status, and body type. So let's take a look at each of these factors and see how they affect our recommendations.

Lean Body Mass. This one is pretty simple. All things being equal, people who have more muscle tissue will tend to burn more calories, since muscle is a very metabolically-active tissue. In addition to requiring more total caloric intake during a bulking phase, they will also be able to tolerate more calories during a cutting phase.

I'm sure we've all read about a few IFBB pros who eat 4,000 calories per day, while getting shredded for a show. I'm sure if they weighed 180 pounds versus 280 pounds, their body would not tolerate that level of calorie intake nearly as well. Additionally, because skeletal muscle contains the densest concentrations of mitochondria (organelle of the cell, where much of oxidation and energy production take place), they will also be able to tolerate a greater carbohydrate intake generally.

Furthermore, because they have more muscle, a larger person will also be able to store more glycogen than a smaller person, and this will allow them greater disposal of dietary carbohydrates. People with greater lean body mass will also need more protein intake in order to optimize protein synthesis. Larger body volume will mean they need a greater amount of dietary amino acids to initiate anabolic signaling in the muscle.

Age. This is a factor that affects all of us. As we age, our metabolic rate tends to decrease and thus decreases our caloric requirements. But it also affects the optimum intake of specific macronutrients. When we are younger (puberty to late teens), our bodies are much more sensitive to insulin, and growth is very much hormone-driven. Young individuals can tolerate much greater carbohydrate intake and require less protein to optimize muscle protein synthesis, as young people are much more sensitive to the anabolic effects of amino acids. Very rarely would I ever recommend a teenager consume more than 1 gram of protein per pound of bodyweight, but there are exceptions (extreme endomorphs and people who are dieting).

As we move into adulthood, we become less tolerant of carbohydrates and less sensitive to the anabolic properties of insulin. Our muscle growth becomes less growth hormone (Insulin, GH, systemic IGF-1) driven and more driven by nutrition inputs like amino acids (and of course proper training). Adults are also slightly less sensitive to the anabolic effects of amino acids, and optimal protein requirements will increase as well. There is also a shift as we get into our 50s and 60s; we are much less insulin-sensitive and far less sensitive to the anabolic effects of amino acids. Thus, our carb intake will need to decrease and our protein intake will need to increase to compensate for these differences. So younger individuals should be able to consume more carbohydrates and less protein, but the older we get, the less carbohydrates and the more protein/fat we should consume, to make up our caloric balance.

Training Status. This is a pretty general term, but to be brief, it is the difference between the average Joe Blow going into the gym to work up a light sweat, and a hardcore bodybuilder going into the gym and slamming around heavy weights for an hour and a half. Obviously, all things being equal, the more intensely you train, the more calories will need to consume to optimize recovery and growth and make up for the amount of calories expended during training.

Someone undergoing a vigorous routine that causes more muscle damage will need more total calories and probably more carbohydrates to fuel training, possibly more protein for recovery, and maybe even more fat. So although total calories will need to increase or decrease, depending upon training frequency, intensity, and duration, the ratios of protein, carbohydrates, and fat may not change that much.

Another difference in training status is whether or not an individual is calorically-restricted or not. Reducing calories will actually increase protein requirements, while increasing calories will actually decrease protein requirements. Typically, I recommend increasing protein intake 10-15 percent during caloric restriction.

Body Type. This also has a major impact on your protein, carbohydrate, and fat recommendations. Endomorphs are individuals who tend to have more difficulty losing body fat while dieting and more difficulty keeping body fat off while bulking. For these individuals, they usually should consume fewer carbohydrates, because they tend to have lower insulin sensitivity, and they should consume more protein and fiber, because protein and fiber have beneficial effects on thermogenesis.

Compare this with typical ectomorphs who have difficulty gaining weight, but have no trouble losing body fat. These individuals should consume more carbohydrates and less protein, because they are more sensitive to insulin and they do not want to create excess thermogenesis from greater protein intake, which will make it even more difficult for them to gain weight and muscle. Obviously, mesomorphs will fall in-between endomorphs and ectomorphs, in terms of recommendations.

The first step to figuring out protein, carb, and fat intakes is to figure out your total calorie goals. Experimentation is the best way to do this, but multiplying your lean body mass by 16-17 and then adding or subtracting 500 calories, depending upon whether you want to bulk or cut, will get you in the ballpark. Now I could write an entire book on the many factors that dictate protein/carb/fat intakes for individual body types, but these are my general recommendations:

Endomorphs

Bulking

Protein: 1.15-1.25 grams protein per pound bodyweight

Fats: 0.4-0.6 grams per pound bodyweight

Carbohydrates: Fill in remaining calories with carbohydrates

Cutting

Protein: 1.25-1.5 grams protein per pound bodyweight

Fats: 0.25-0.4 grams per pound bodyweight

Carbohydrates: Fill in remaining calories with carbohydrates

Mesomorphs

Bulking

Protein: 1.05-1.15 grams protein per pound bodyweight

Fats: 0.25-0.4 grams per pound bodyweight

Carbohydrates: Fill in remaining calories with carbohydrates

Cutting

Protein: 1.15-1.35 grams protein per pound bodyweight

Fats: 0.2-0.35 grams per pound bodyweight

Carbohydrates: Fill in remaining calories with carbohydrates

Ectomorphs

Bulking

Protein: 1.0-1.15 grams protein per pound bodyweight

Fats: 0.3-0.45 grams per pound bodyweight

Carbohydrates: Fill in remaining calories with carbohydrates

Cutting

Protein: 1.15-1.35 grams protein per pound bodyweight

Fats: 0.2-0.4 grams per pound bodyweight

Carbohydrates: Fill in remaining calories with carbohydrates

Obviously, you will want to adjust these numbers, based on how your individual metabolism responds and based on some of the other factors we talked about including age and training status. Just remember that there is no one right intake. Everyone is different, so use BOTH science and experimentation to determine what is optimal for you.

Layne Norton is a natural pro bodybuilder and pro powerlifter. He is a Ph.D. candidate in Nutritional Science at the University of Illinois. He offers contest prep, nutritional, and training consultation through his company BioLayne LLC. To learn more about Layne and the services he offers, visit http://www.biolayne.com.

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