A lot of people do get sleepy in mid-afternoon. There's nothing wrong with a short power nap, but most of us have to work and don't have that luxury.
You've been given good advice so far, but let me throw in my two cents on your lunch: If you eat too much carbohydrate with not enough fat or protein in a meal you crash after a few hours. I've found that fruits and vegetables for lunch along with some lean protein make me feel great. That often means a big salad with diced chicken and light salad dressing, and a piece of fruit, maybe some whole grain bread. I drink a cup of green tea afterwards. This is, for me, a "power lunch" and I love the energy it gives me.
"I owe everything you see here to spaghetti."
| current weight: 173.3