Although it's often best to get your essential nutrients from eating whole foods, protein shakes can offer a quick, low-calorie option, which is better than skipping a meal. Although most protein shakes contain between 200 and 400 calories, they aren't a magic bullet for weight loss. Losing weight requires that you burn more calories than you consume, and an additional 400 calories a day from a shake won't necessarily help. Thus, it's best to use the protein shake as a meal replacement.
Replace breakfast with your protein shake. Many people skip breakfast perhaps in an attempt to cut calories or because mornings can be hectic and they may not feel hungry. Eating breakfast gives you energy, wakes up your metabolism and decreases hunger later in the day. A study from the "Journal of Adolescent Health" found that skipping breakfast can actually lead to weight gain in people ages 11 to 27 years old. Consume your protein shake for breakfast, and you'll be on track to make healthier choices the rest of your day.
Choose a protein shake that doesn't contain added sugars. Because your shake is replacing a meal, you want to make sure that it has the same nutrients that you would otherwise get from a well-balanced meal. Protein shakes that are dairy-based, from milk or whey, will contain natural sugars, which your body responds to differently than added sugars. Read nutrition labels carefully. Shakes should not contain trans fats, and they should have very little cholesterol. Check the sodium content, especially if you are on a low-sodium diet for high blood pressure.
Make healthy food choices the rest of the day. Both lunch and dinner should consist of lean protein, high-fiber complex carbohydrates and healthy fats. According to the American College of Sports Medicine, a woman needs to eat at least 1,200 calories and a man needs at least 1,800 calories to keep the metabolism functioning. Eating too few calories will make your body think that there's a food shortage, which will cause your metabolism -- and your weight loss -- to slow down.