There are some foods that make us sleepy, while others give us energy to burn.
It’s only in recent years, however, that scientists have begun to understand why.
The answer, as it often does, begins in the brain.

To a large extent our feeling, moods, and energy levels are controlled by neurons –
nerve cells in the brain that communicate with the help of chemical messengers
called neurotransmitters. Studies have shown that changes in the levels of
neurotransmitters such as dopamine and norepinephrine can dramatically affect
energy levels, which is why they are sometimes called wake-up chemicals.

Studies show that people tend to think more quickly and feel more motivated
and energetic when their brains are producing large amounts of theses chemicals.

Our diet provide  the raw materials needed for the production of these neurotransmitters.
What we eat – or don’t – can play a large role in how we feel.
“We’re talking about a whole symphony of brain chemicals that ebb and flow
throughout the day,” says Elizabeth Somer, RD, author of Food and Mood and
Nutrition for Women.

The building block for dopamine and norepinephrine, for example, is the amino acid
tyrosine. Tyrosine levels are elevated when you eat high protein foods, such as fish,
chicken, or low-fat yogurt.

“Make sure to eat some protein along with carbohydrates at each meal or snack,”
says Molly Kimball, RD, a sports and lifestyle nutritionist at the Ochner Health
System’s Elmwood Fitness Center in New Orleans.
For instance, instead of having whole-wheat toast with jelly or fruit with juice
for breakfast, have whole-wheat toast with peanut butter or fruit with cottage cheese.
The carbohydrates alone cause a rapid release of blood sugar and a rapid drop in
energy, but the protein helps even that out.”

You don’t have to eat huge amounts of protein to get the energizing effects.
Eating just 3 to 4 ounces of protein-rich food, like a broiled chicken breast  or
a hard-boiled egg “feeds” your brain enough tyrosine to get the dopanine and
norepinephrine flowing.

Even though protein-rich foods can help boost energy, the fats that often come
with them can drag you down. Digesting fats diverts blood from the brain,
which can make you feel sluggish. So don’t overload a turkey sandwich with
high-fat cheese and mayonnaise; dress it with mustard, lettuce, and tomatoes
instead, recommends Somer.