In one sentence, describe what the following article is about:

Green tea contains caffeine, which is why it can help to boost your energy. But unlike coffee, green tea may also reduce your risk of stroke, high blood pressure, depression, heart attack, and diabetes. Try having a cup of green tea to help boost your energy. Limit yourself to 400 milligrams of caffeine per day. Just keep in mind that different types of caffeinated drinks have different levels of caffeine. For example, coffee may have between 60 and 150 milligrams of caffeine per cup, while tea may have between 40 and 80 milligrams. Most people don't drink enough water throughout the day, which can lead to low energy. Aim for eight 8-ounce glasses of water each day, but drink more during a workout. For example, you should have a glass of water before and after workouts. If you exercise for more than 30 minutes, then take small sips of water during your workout. Some natural dietary sugar is important for normal brain function, but too much processed and concentrated sugar (such as a candy bar, cookie, or soda) spikes blood sugar levels. Sugary foods can give you a short energy boost, but then it will be followed by a slump. Some good snack choices include:  Whole wheat toast with nut butter A piece of fruit A handful of carrot sticks and a tablespoon of hummus Eating a nutritious breakfast keeps you alert, kick starts your metabolism, and prevents you from having sugar cravings in the afternoon. Skip sugary donuts and breakfast cereals. Some better choices include:  Whole-grain bread Oatmeal Eggs Fruit Yogurt Peanut butter Eating foods and snacks high in protein can give you a sustained energy boost. Protein-rich foods also provide your body with amino acids to repair and build tissues. Excellent protein sources include:  Poultry Fish Lean red meat Eggs Nuts Dairy products (milk, yogurt, cheese) Tofu

Summary:
Drink a cup of green tea. Stay well hydrated. Choose low-sugar complex carbohydrates instead of sugary snacks. Eat breakfast every day. Select foods that are high in protein.