What are macronutrients?
Protein, fat, and carbohydrates are the three macronutrients that combine to make up virtually all of the typical human diet. We call them macronutrients because we consume them in large quantities compared to the essential micronutrients such as vitamins or minerals.
What follows is a general overview of each of the three macronutrients.
Protein
Protein is an essential part of your diet. These large, complex molecules are the building blocks of the body. Structural complexes like hair and fingernails, and connective tissue like ligaments and tendons are made of protein. Proteins in the form of enzymes serve as chemical catalysts which control every aspect of your cellular metabolism. Virtually everything that happens in the body happens with the direct participation of proteins. All of your genes represent proteins; when a gene is expressed, a protein is formed.
10% to 35% of your daily energy intake should come in the form of protein. Most of us get this amount of protein from our diets. The high-protein diets often touted by bodybuilders are almost certainly unnecessary.
Proteins are made up of molecules called amino acids. There are around 20 amino acids that make up the proteins you eat. Of these, 8 are essential amino acids in adults, so named because your body can’t synthesize them from other amino acids – you must get them from your diet.
Some sources of dietary protein supply all the essential amino acids. These foods are called complete sources of protein. You can satisfy all your body’s protein demands by eating these foods. Incomplete sources of protein lack one or more of the essential amino acids.
To avoid malnourishment, you should combine incomplete sources with other protein sources to ensure that you get all the essential amino acids in your diet. Since it takes hours to digest foods containing protein, it is probably unnecessary to combine incomplete protein sources in a single meal. Most modern, varied diets supply all the essential amino acids over the course of the day’s meals.
All unadulterated animal sources of protein – meat, fish, milk, eggs – are complete sources of protein. Most plant sources are incomplete, with the exception of rice, soy, and other less familiar alternatives.
Food sources of protein are classified as fast, slow, or anything in between. This classification system refers to the speed with which the food causes your serum amino acid concentration to rise during and after digestion. Whey protein, often sold as a bodybuilding supplement, is considered a fast protein. Casein is a slow protein.
Fat
It is important to include fat in your diet. Essential fatty acids are essential nutrients that must be supplied by the diet; your body can’t manufacture these molecules and you will die without them. Dietary fat also allows you to absorb certain vitamins; without these fat-soluble vitamins, you will die of malnourishment.
At a minimum, 20% of your daily energy should come in the form of fat. Low-fat diets are unhealthy and unnecessary.
Fats are divided into several major classifications: monounsaturated, polyunsaturated, and saturated.
Because of links to heart disease and atherosclerosis, nutritionists caution that less than 10% of our daily energy needs should come in the form of saturated fats. In a similar vein, because of some tenuous links to cancer, and because there is a better alternative, we’re also advised to get less than 10% of our energy from polyunsaturated fat. We should get as many of our fat calories as possible from monounsaturated fats like olive oil since they’re proven to decrease our levels of “bad” cholesterol, which is linked to heart disease and the formation of blood clots.
Cholesterol itself is a fat that is synthesized by your body. It is an essential part of your cells. Many foods contain cholesterol and, for a time, it was fashionable to reduce your cholesterol intake in hopes of reducing your blood serum cholesterol. These days, it’s generally recognized that reducing your total saturated fat intake is more important than reducing your cholesterol intake.
Carbohydrates
Surprisingly, though they usually account for most of our energy intake, carbohydrates are arguably not an essential macronutrient. Many scientists claim that, if necessary, you can survive entirely on fat, protein, and other essential nutrients. This is not yet considered a scientific certainty, but there is no evidence that disproves it. Nevertheless, the argument is academic; in practice, most of us get sufficient carbohydrates from our diets (with, perhaps, the exception of certain Arctic peoples like the Inuit, and even then, only at certain parts of the year).
A big problem with some modern diets is the reliance on empty calories. Refined sugars like those found in soft drinks can quickly add up to a significant portion of our daily energy intake without supplying any essential nutrients. Many people who subsist on a diet of carb-laden junk food are both overfed and malnourished at the same time.
In the past, carbs were classified as simple carbs or complex carbs. By way of example, sugars are considered simple carbs and starches, complex carbs. Now, food sources of carbohydrates are ranked on the Gylcemic Index (GI), which classifies food according to how quickly it raises the concentration of blood sugar during digestion. High-GI foods like pure sugar quickly spike the blood sugar concentration, while low-GI foods like whole-grains provide energy over a longer period of time.
How does this relate to bulking up?
Muscles are built in the kitchen, not in the gym.
When you design your bulking diet, determine the optimal ratio of macronutrients. Start by calculating how much protein you need then determine your dietary fat. After you have those numbers squared away, you can make up the rest of your needed calories with good-quality carbohydrates.
During your bulking phase, keep track of your progress weekly and/or monthly, and adjust your carb intake until you gain a pound of body weight every week.
If you get the right ratio of macronutrients in your diet, and enough calories to fuel your growth, you will enjoy great success from a bulking workout.