A heavy or fatty meal — think Thanksgiving dinner — can make you tired. Some foods or eating strategies do just the opposite. Candy and other simple sugars give you a quick burst of energy — but that boost fades quickly and can leave you feeling depleted and wanting to eat more. On the other hand, whole grains and healthy unsaturated fats supply the reserves you can draw on throughout the day. So to keep your energy up and steady, limit refined sugar and starches.
How you eat can also either boost your energy or drag it down. Eating small meals and snacks every few hours throughout the day provides a steady supply of nutrients to body and brain. Some people begin feeling sluggish just a few hours after eating. But it doesn't take much to feed your brain. A piece of fruit or a few nuts should do it.
Smaller is better especially at lunch. Researchers have observed that people who have a big lunch typically show a more pronounced afternoon slump. One possible explanation is a sharp rise in blood sugar after eating, following by an energy dip a few hours later.
For more advice on ways to feel energized, purchase Boosting Your Energy from Harvard Medical School.