Proteins–over 100,000 different types–comprise about 15% of the average human’s body weight and perform many vital functions. Antibodies that fight disease, enzymes that digest food, hormones that regulate growth and development, muscles that let us move; all of these are proteins. In terms of educational psychology, food takes a pivotal role for healthy brain function. If you want to stay alert, you’ve got to feed your body accordingly. A healthy diet must include adequate protein.
The food we eat is broken down during digestion into component nutrients which are then carried throughout the body by the bloodstream to fuel activity. It could be said that the human body is a living chemical laboratory! Some substances from food are used as-is, while others are manufactured by the body from the nutrients broken down by digestion.
Proteins are too large to be carried in the blood in their whole state; they are composed of many smaller units that are bonded together, sort of like beads on a string. The “beads,” or building blocks of proteins, are amino acids. The human body uses twenty different amino acids; eleven of them are manufactured by the adult body, but nine cannot be manufactured and must be supplied by diet. They are called essential amino acids. Three amino acids that are nonessential for adults are essential for growing children: tyrosine, cysteine, arginine. Proteins in food are broken down into amino acids to make them small enough to be transported. Then the various body tissues assemble the amino acids, along with fats and carbohydrates, into whatever is needed.
If the necessary precursors aren’t available, then a process is limited and often cannot occur at all. In the brain the precursors are assembled into the neurotransmitters that carry instructions to move or to stay alert or to take a nap. The two neurotransmitters necessary for alertness are norepinephrine and dopamine. Tyrosine is an essential precursor for their manufacture. Blood levels of tyrosine are elevated for several hours after eating protein rich food and this allows increased production of dopamine and norepinephrine, which keep you alert. All of this has been a long-winded way of saying that if you don’t eat enough protein, you don’t have enough tyrosine to make the alertness transmitters; as a result, you’re tired.
More protein leads to more alertness! Yes, you get a short-term energy boost or “sugar high” from sodas, cookies and chips, and you do need carbohydrates for energy. But that energy boost goes away just as fast as it came on and you are left depleted and drowsy again. Chips, soda and cookies are also mostly “empty calories” — food with very little nutrition value. A steady diet of empty calories leaves you tired, and possibly overweight as well. Pizza is a bit better because it at least contains some protein, but its high fat content negates much of its nutrient value. For long-lasting focus, protein is the way to go. So, what’s the best kind of snacking? Fruit, vegetables or whole-grain bread for nutrient-rich carbohydrates and cheese, nuts or peanut butter for protein. That gives you both energy and alertness.
How much protein is enough? That depends on a person’s age and weight. Healthy adults can find their approximate requirement in grams by multiplying their weight in pounds by 0.4. Children, pregnant women, and nursing mothers have greater protein requirements. Protein should make up about 25% of daily calorie intake. Most people in industrialized countries easily get more than their daily protein requirement.
Are certain types of protein better than others? Yes and no. Nutritionists classify proteins by how many amino acids they provide. A protein which provides all of the essential amino acids is called a complete protein; one that doesn’t is incomplete. Most animal proteins–meats, eggs, dairy products–are complete proteins; many plant-based proteins are incomplete. Two or more incomplete proteins can be combined to make a complete protein; vegetarians need to know this so they can be sure to get all of the essential amino acids.
The “packaging” of a protein makes a difference. Many high-protein foods, such as red meats, are also high in fat. So, a meal including them should also include low-fat foods such as vegetables. Pizza and junk food should be occasional treats accompanied by green salad, not daily snacks. Low-fat proteins include fish, nuts, beans, and some whole grains.
When protein is eaten is important as well. To be alert for school or work, breakfast and lunch should include servings of protein (never skip breakfast!). Just a sweet roll isn’t enough for breakfast – it’s empty-calorie carbohydrates. Save the heavy carbohydrates for supper when it’s OK to get sleepy afterward, if you ever have to eat them at all!
A healthy diet takes a bit of knowledge and planning. It doesn’t have to be boring or complicated, but it’s vital if you want to put your best foot–or brain–forward!
This is a guest post from Allison Gamble. Allison Gamble has been a curious student of psychology since high school. She brings her understanding of the mind to work in the weird world of internet marketing.