Protein shakes can replace extra calories from regular meals.
It’s a simple weight-loss strategy: Replace one or more of your meals every day with a protein shake. Scientific research shows that if using protein shakes as meal replacements lowers the total number of calories you eat in a day, you will lose weight over time - and likely improve your body composition as well. For the best results, work with your doctor to build a meal-replacement plan that corresponds to your health and fitness goals.
Choose the type of protein shake you want to use as a meal replacement. Whey is a well-studied protein powder; it has been shown to improve body composition and lower several risk factors for metabolic disease. Soy and casein protein shakes have also produced weight loss in clinical trials. Other protein powder sources include pea, hemp, brown rice and eggs.
Start your weight-loss diet by replacing one meal daily with a protein shake. For the quickest weight-loss progress, the meal you replace should be the one with the most calories. So if you usually eat a small breakfast, a light lunch and a big dinner, replace your dinner with the shake to see the fastest progress. You're still likely to lose weight by replacing a smaller meal with a shake, although your progress will be more gradual. Registered dietitian Emily Rubin recommends using protein supplements that have fewer than 200 calories per serving as meal replacements.
Prepare your meal-replacement shakes by blending one serving of your chosen protein powder with 1 cup of milk, water or plain nonfat yogurt with crushed ice. For extra flavor, toss in low-calorie additions like half a frozen banana, a handful of frozen berries or a spoonful of unsweetened cocoa powder. To track your weight-loss progress, keep a food journal and use online calorie counters to find out how many calories you ate prior to starting the plan and while following the plan. To lose about a pound a week, you'll need to cut approximately 500 calories from your daily diet.
Adjust what you eat at your two regular meals to fit with your weight-loss and calorie goals. For example, if you want to cut 500 calories daily but your meal-replacement shake only cuts 300, you may need to reduce your serving sizes at other meals or serve a main dish with a side salad instead of a roll or baked potato. Focus on eating vegetables, fruits, whole grains and lean or low-fat protein foods at your two full meals. Also limit processed foods, sugar, salt and saturated fat.
Enhance your results by getting regular exercise. Protein shakes stimulate muscle protein synthesis, the process of muscle-mass growth and recovery after strength exercise, and the shakes are especially effective if you drink them right after your workout. The American College of Sports Medicine recommends at least two resistance-training sessions per week and at least 150 minutes of moderate-intensity cardio exercise per week.