Even if you're eating enough food every day, it's possible you're not eating the right kinds of food. Dietary deficiencies are one of the most common causes of low energy levels, and protein in particular plays a big part in your daily energy levels.  Protein is essential to  increase energy levels. But not all protein is good protein. Some meats, for example, are high in protein but also come with high sodium or saturated fat levels.  Medical professionals recommend that adults consume at least eight grams of protein for every 20 pounds of body weight (or 0.8 grams of protein for every kilogram of body weight) every day.  Optimal sources of heart-healthy protein include salmon, eggs, and legumes like beans, lentils, and tofu. Starches and carbohydrates are an essential part of a healthy diet. They provide us with energy to complete all manner of activities, from running to breathing. But there are good carbs and bad carbs, and if you're feeling fatigued it's important to choose healthy carbohydrates that will help fuel your body throughout the day.  Eat four to eleven servings of grains each day, and opt for whole grain foods instead of processed or refined grains. Whole grain or wholemeal sources of starch and carbohydrates release energy gradually throughout the day, helping you feel more energetic. Choose whole grain, complex carbohydrates rather than simple carbs, which can cause an energy crash shortly after eating.  Some sources of energy-boosting, complex carbohydrates include vegetables, legumes, and whole grains like bran and germ.  Choose breads and pastas made from whole grain whenever possible. Fats act as a source of energy as your body begins to run low on carbohydrates. Your body needs some dietary sources of fat, but it's important to choose the right kinds of fat.  The four basic forms of fats are monounsaturated fatty acids, polyunsaturated fatty acids, saturated fats, and trans fatty acids. Of these, saturated fats and trans fats are the worst fats. Choose a diet high in monounsaturated...

TL;DR in Vietnamese:
Nạp thêm protein cho cơ thể. Chọn tinh bột hấp thụ chậm. Chọn các nguồn chất béo tốt. Ăn thêm rau xanh và hoa quả tươi. Uống nhiều nước. Tránh tiêu thụ đường.