Nutritional science grows increasingly intricate when the context concerns bodybuilders and athletes looking to maximize muscle growth and enhance fat loss. The physiology behind macronutrients enable these processes is complex, to say the least. Nevertheless, it serves to benefit any level of trainee to understand the basics of proteins, fats and carbohydrates, so put your thinking cap on and dive in!
Proteins are an essential macronutrient made up of tiny molecules called amino acids; proteins serve a crucial role in muscular development, repair, and maintenance, among a multitude of other physiological processes; such processes include brain metabolism, cardiovascular function, energy production, immune system function, and a variety of others.
Just like carbohydrates, proteins contain roughly 4 calories per gram. When assessing the value of protein sources from food, it’s pertinent to categorize them as either complete or incomplete proteins. Complete proteins consists of all eight of the essential amino acids (EAAs); incomplete proteins lack at least one (or all) of the EAAs necessary for protein synthesis.
Skeletal muscle tissue is the body’s largest reservoir of amino acids. In this sense, protein is sustenance for helping the body build lean tissue. Naturally, gym-goers assume that more protein is better and will result in extra muscle growth, but that isn’t necessarily true.
Adequate protein intake is undoubtedly essential for building and maintaining skeletal muscle tissue, but the body has a “cap” on how much it can synthesize at any given moment. Thus, it is imprudent to consume exorbitant amounts of protein as most of it will just be oxidized and possibly converted to glucose.
The calorie content of fats is more than double that of carbohydrates and proteins, coming out to about 9 calories per gram. Therefore, fats are typically more satiating per gram than fats and carbohydrates. This is why people on high-fat diets, like ketogenic diets, rarely complain of being hungry all the time.
Fatty acids are imperative for healthy cellular function and have myriad roles in metabolism. Hence, fats must not be overlooked on any diet plan, especially for gym goers and active people alike.
Fatty acids come are categorized as either saturated or unsaturated fatty acids, with both being comprised of hydrocarbon chains. Unsaturated fatty acids contain one or multiple double bonds in their hydrocarbon chain, whereas saturated fatty acids contain no double bonds. Butter and coconut oil are high in saturated fatty acids, particularly medium chain fatty acids, which are rapidly oxidized for energy rather than being stored.
Monounsaturated fatty acids are typically abundant in plant oils and nuts. Omega-3 fatty acids are polyunsaturated and found mainly in freshwater fish and appear to have many benefits on heart health and longevity.[i]
Just like proteins, carbohydrates have about 4 calories per gram (fiber typically contains around 2 to 3 calories per gram). Despite not being an essential macronutrient, carbohydrates support muscle anabolism and reduce muscle catabolism by sparing proteins and increasing insulin secretion (except fructose/fruit sugar). Theoretically, humans only need proteins and fats to survive, but survival doesn’t necessarily correlate with being lean, muscular, and fit (all the time).
Furthermore, it’s important to note that insulin is a highly anabolic hormone and enhances the muscle protein synthesis process.[ii] Insulin also protects against muscle protein breakdown, so it is not an inherently “bad” hormone like many gym goers seem to think.
Carbohydrates are generally divided into two categories: Simple carbohydrates (i.e. monosaccharides and disaccharides) and complex carbohydrates (i.e. polysaccharides). Examples of mono-/di-saccharides include ingredients like table sugar (sucrose), molasses, corn syrup, etc. Complex carbohydrates/polysaccharides come from foods like brown rice, oats, quinoa, wheat flour, barley, and yams.
Fiber provides bulk to waste in the intestines and promotes healthy gastrointestinal functioning. There are two classes of fibers—soluble and insoluble. Soluble fibers mesh with water to form a gel and slow the digestive process, which as aforementioned can help attenuate blood sugar levels.
Insoluble fibers, on the other hand, travel through the GI tract without dissolving and speed the passage of waste through the gut (i.e. they have a laxative effect).
Ideally one should aim to take in at least 30-40g of fiber per day. Fiber does not have a significant impact on insulin secretion, but they still count as part of your carbohydrate intake.
Without question, the single most important thing you can do for your dietary success is to plan meals ahead of time. The second most important thing you can do is actually prepare the meals you plan to eat. By planning/prepping meals in advance, you set yourself up to stay on track and actually hit your macro goals at the end of the day (which, as iterated over and over again in the book, is the absolute key to success).
The key to every diet is consistency, and when you plan/prep meals you are much more likely to avoid binges or temptations to overeat because you’ve already portioned out all your food.
Meal planning is rather intuitive, just use a spreadsheet, notebook or an app to record the foods you want to eat in the next meal(s). MyFitnessPal is my favorite website/app for tracking daily food intake.
While you certainly can just "wing it" and eat as your day goes on while logging meals, this is probably not the ideal way to start if you're a beginner. Reason being is that far too often people miscalculate how much food they actually ate if they don't plan/prep the food in advance. Remember, it's impossible to "uneat" those 50g of carbs that just put you way over your daily allotment. If you consistently overeat, you will stall and become frustrated with your lack of progress.
The idea of counting macros and planning/prepping meals in advance is very likely to overwhelm people at first. However, you'll find that the process is actually quite simple once you've integrated it into your daily routine and found your own groove. You'll likely find that you eat the same 10-15 healthy foods every day and the rest is smooth sailing. Remember, consistency and planning ahead are the keys to success!
[i] Kris-Etherton, P. M., Harris, W. S., & Appel, L. J. (2002). Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. circulation, 106(21), 2747-2757.
[ii] Kimball, S. R., Jurasinski, C. V., Lawrence, J. C., & Jefferson, L. S. (1997). Insulin stimulates protein synthesis in skeletal muscle by enhancing the association of eIF-4E and eIF-4G. American Journal of Physiology-Cell Physiology, 272(2), C754-C759.