Nutrition is not as complex as some like to make it seem. All humans are designed to live off of three primary nutrients: protein, fat and carbohydrate. Contrary to whatever exclusionary diets you have heard about on the news, our body needs all of these nutrients on a daily basis to function optimally. Carbohydrate provides the brain, red blood cells and Central Nervous System the energy supply they need, protein is used to produce over 250,000 cellular structures in the body, and every cell uses fat within its membrane to manage intercellular exchanges. That is by no means a complete list of why these nutrients are important, but it should indicate that diets that try to exclude any of these key nutrients are quite misguided.
Without getting into Sports Nutrition topics like nutrient timing or calorie-cycling, here is some basic information that anyone can use to make smarter decisions about what to eat.
Our bodies break down food we eat to obtain energy from the various nutrients within. That energy absorbed (heat energy) is measured in calories. The amount of calories a person uses varies day by day, but we have to replenish the calories we expend by consuming more through food. The amount of calories we consume compared to the amount of calories we burn is directly correlated with our bodyweight. While other factors apply, if your body requires more calories than you consume, it will use your stored energy (e.g. stored fat) to make up the difference, causing you to steadily lose weight. If you consume exactly as many calories as you burn, your weight will not change, as energy expended and energy replenished equalizes. If you consume more calories than expended, those extra calories are often stored in your fat cells for later use, resulting in a slow but steady increase in weight. Trying to find out precisely how many calories one has consumed, absorbed and burned is no small task, but the simple and scientific formula to controlling our bodyweight is calories in vs. calories out.
Protein is used to repair and build muscle tissue, bones, skin and other structures throughout the body. Protein can contribute to bodyweight fluctuations in a few different ways. Consume more than your body can use and protein will be converted into fat for energy storage, which increases body weight. Consume an adequate amount and it will be used for building and repairing cellular structures (possible weight increase or decrease). Consume too little and our bodies will have to tap into existing protein structures so it can break them down and recycle them for more immediate needs.
Proteins are made up of 21 various amino acids. For your body to be able to use protein it has consumed, it needs all of these amino acids present. Our bodies can synthesize 13 of these aminos, which means there are 8 we have to consume on a daily basis. These are called essential amino acids. Certain foods may contain protein, but not necessarily all 8 essential amino acids. Meats, fish, eggs and dairy products are the best at providing all the essential aminos when we consume them. Other sources of protein, like vegetables and grains, tend to lack at least one or more of these essential aminos and therefore need to be eaten along with other foods that contain the remaining amino acids we need. Keep all of this in mind when working towards specific fitness goals that may require specific amounts of protein be consumed every day.
Fats are not a bad thing. The reason fat gets a bad reputation is because it has more than twice the amount of calories per gram than protein or carbohydrates. For that reason, foods that are high in fat are likely to cause us to consume more calories than we actually burn, which results in weight gain. This is crucial to understand because many Americans eat foods high in fat every day and are completely oblivious as to how 2/3rds of Americans are overweight.
The other important thing to know about fats is that some are healthier than others. Fats that are liquid at room temperature (olive oil, vegetable oil, etc.) are considered healthier fats, i.e. unsaturated fats. Fats that are solid at room temperature (butter, coconut oil, animal fat, etc.) are more likely to contribute to higher blood pressure, heart disease, bad cholesterol levels and more. These are called saturated fats. If you’re unsure if you’re consuming dangerous levels of saturated fats, talk to your doctor or registered nutritionist.
Carbohydrates are our body’s preferred energy source. Without carbs, your body is forced to rely on protein and fats for energy, which is what it has to do when it goes into starvation. The processes to derive energy from these nutrients are far less efficient, so our bodies will not perform optimally if carbs are not part of our diet. But just like our intake of other nutrients can abuse the body, so can our intake of carbohydrates.
You’ve probably heard of the infamous ‘carb crash’. This is what happens when you consume too many carbohydrates at once, especially simple carbs like sugars. We need sugars, but sugar causes our insulin levels to spike quickly which decreases our energy levels. More complex carbs, like starchy vegetables or fibrous grains are harder to break down and therefore result in more gradual insulin responses. This gives our body consistent energy we can use for hours rather than all that energy at once that shuts us down.
As you may have figured out, there are ideal times for both sugars and starches. Since sugars absorb rapidly into our bloodstream, consuming them in appropriate quantities before, during and after exercise can provide useful energy to optimize our activity and recovery. For all other times, foods with complex carbohydrates are what we should be consuming. These will contain valuable fiber and other nutrients our bodies need in addition to providing sustained energy without the sugar crash.
How you organize these nutrients into each meal and your daily calorie structure depends on your particular fitness goals. Muscle building will require more protein, while endurance athletes will require more carbohydrates. For advice on how you should structure your nutrient intake each day, talk to your doctor, registered dietician or personal trainer. Everybody responds differently to different nutrient proportions, so even with professional nutrition guidance, you will still need to keep track of your own performance as you experiment with higher and lower nutrient intakes. Most people with general health goals won’t need to do this, they’ll feel better just by choosing healthier foods, so these tips are geared towards those with more advanced fitness goals.
No matter who you are or what your goal is, you can use these tips to become a better you, and do things you never thought you could. You can do what you can’t.