Protein is an essential nutrient, especially in terms of weight loss.  Eating lean protein at each meal has been shown to aid in weight loss and can help you lose more weight in the long-term.  Eat an appropriate portion size of protein at each meal.  Aim to include about 3-4 oz of lean protein at each meal.  This is approximately about the size of a deck of cards or a checkbook. Include a variety of lean protein at each meal and throughout the day.  Lean protein options include:  poultry, eggs, lean red meat, pork, seafood, and low-fat dairy. Vegetarian protein sources are also considered lean.  These include:  beans, lentils, nuts, tofu, and tempeh. Fruits and vegetables should make up a fairly large portion of your diet.  These foods are low calorie and full of fiber, vitamins, minerals and antioxidants.  For a well-balanced diet, try to include a fruit or vegetable at each meal and snack. One serving of vegetables is about 1 cup or 2 cups of leafy green vegetables.  One serving of fruit is 1 small whole fruit, 1 cup of sliced fruit, or 1/2 cup dried fruit. Whole grain foods provide your diet with an essential source of fiber and some vitamin and minerals.  They are minimally processed and contain the bran, germ and endosperm of the grain.  1 serving of whole grains is 1 oz or 1/2 cup of grains like rice or pasta.  Using a food scale is another accurate way of measuring pasta or other grains. Examples of whole grain foods include:  quinoa, brown rice, 100% whole wheat bread, millet, barely, oats, or 100% whole wheat pasta. An occasional snack can help make weight loss easier.  This is especially true if a snack will help prevent you from overeating at a meal.  Take caution when deciding to snack.  A snack can be a great tool to get you through an extended period of time between meals (more than four or five hours) or as pre/post workout fuel.    Keep snacks to about 100-200 calories.  Also, try to include lean protein, fruits or vegetables, or whole grains.  The combination of protein and fiber may help...

TL;DR in Vietnamese:
Ăn các loại thịt nạc mỗi bữa ăn. Sắp xếp một nửa bữa ăn của bạn là hoa quả hoặc rau xanh. Chỉ ăn 100% ngũ cốc thô. Ăn nhẹ. Uống nước. Tránh các loại thức ăn giúp cải thiện tâm trạng. Tránh đồ uống có cồn.