Whether you’re following a time tested method, fad diet, or simply just improvising, a foundational understanding of the core macronutrients, protein, fats and carbohydrates is relevant to any diet. Each of these categories of nutrients has a varying degree of necessity to our bodies and how much you require of any of them will be almost always be unique to the individual, may change over time and for different reasons.
If you follow a “calories in, calories out” or macronutrient ratio model, you’re likely giving the lion’s share of your dietary focus to the energy you’re receiving from food. This, at least in part, makes sense. We certainly need energy for each movement we make and just as much to perform the countless biochemical processes throughout the day. In the simplest forms, our bodies rely on the consumption or creation of glucose for energy. Glucose is a form of sugar we mostly obtain through dietary carbohydrates.
Through certain metabolic pathways, glucose works as a resource to form a chemical called Adenosine Tri-Phosphate (ATP) which is the ultimate source of energy used by our body’s cells to function. Since we store very little ATP, we need to synthesize this continuously throughout the day in order for all the cells of the body to maintain their normal function. Each gram of carbohydrate we consume provides us with four kilocalories of energy we can use to maintain blood sugar levels for short term energy production or to be stored in adipose cells (fat tissue) for later use.
The fats and protein we consume from the food we eat can also be converted into glucose through a process called gluconeogenesis (New Glucose Creation). Although these processes are less efficient methods of generating glucose than acquiring it from dietary carbohydrates, it does account for the reason carbohydrates are not “essential” nutrients in the same way certain proteins and fats are.
Since the early 1980’s, the U.S. governmental policies on diet have deemphasized the requirement for dietary fat, however, this trend has been changing in recent years. It is now common to see dietary fat recommendations in excess of 30% to 40% of one’s daily caloric intake which are ratios consistent with those of the pre-1980’s diets when we were a more weight-stable population. From the perspective of energy consumption, dietary fat provides us with a robust nine kilocalories per gram. Beyond this, dietary fat also plays other crucial roles in our bodies. When we consume fat, we obtain the essential fatty acids (Omega-3 and Omega-6) our bodies use to promote or temper inflammation, to maintain the integrity and efficiency of our brain and central nervous system, support a healthy cardiovascular system and help prevent a number of other diseases and symptoms.
If we were to look at protein through the lens of energy value, we would see that each gram of protein gives us an identical number of kilocalories per gram (4) as does carbohydrate. Protein, though, has a much more substantial purposes in our diet though than just any energy we might derive from it. When we consume dietary protein, our bodies break it down into smaller molecules called amino acids. These biological compounds help us build every build every tissue in our bodies including muscle, ligaments, and bones. Amino acids also supply the raw materials for our bodies to build hormones, neurotransmitters and essentially all other critical chemicals in the body (including glucose).
It’s crucial to recognize the significance of adequate protein levels in the diet as a there are at least nine essential amino acids we must get from the diet. Included with that are at least eight others labeled “conditional” amino acids which may be created by the body under certain circumstances including during times of disease and malnutrition. Altogether, it is best to obtain these through your whole food diet.
Macronutrients, in the proper balance and amounts, play a significant role in the optimal functioning of our bodies as well as in attaining the physical goals we set for ourselves. It is important to be aware that the macronutrient needs may differ for each of us based on our levels of activity, health circumstances, genetics, and other reasons. Following guidelines such as ratios may be helpful while you’re developing a nutrition plan, but it a wise idea to adjust or intelligently experiment with varying amounts of each macronutrient to help you determine the levels you need to achieve your goals and be well.