Lose weight, gain time and potentially boost exercise outcomes by replacing one meal a day with a protein shake. The high protein content in these meal replacement protein shakes curbs your appetite with a meal that's low in calories.
Living long-term on a meal-replacement protein shake isn't practical, but it can work for weight loss in the short term. You may also choose to occasionally use a protein shake for the sake of convenience by mixing protein in water for a quick, on-the-go meal.
About Meal Replacement Protein Shakes
Protein is made up of amino acids. Choose a protein shake that offers a "complete" protein, meaning it has a combination of the nine amino acids your body can't produce on its own.
Protein powders that can be made into meal replacement protein shakes usually contain one or more of the following:
- Whey protein
- Casein protein
- Egg white protein
- Soy protein
- Pea protein
- Rice protein
Protein Shakes Encourage Weight Loss
Protein shakes can curb your appetite and reduce your overall calorie intake. The American Journal of Clinical Nutrition published research in June 2015 confirming that a diet that contains 1.2 to 1.6 grams of protein per day for each kilogram of your body weight reduces appetite and helps with body weight management. This is equal to 0.55 to 0.73 grams per pound.
A meta-analysis published in the June 2016 issue of the Journal of the Academy of Nutrition and Dietetics confirmed the satiating power of protein.
Calorie Benefits of Protein Shakes
The advantage of protein shakes is simply that they offer protein, often with fewer calories than whole foods that contain protein. A scoop of whey protein, for example, contains about 90 calories and offers about 17 grams of protein, whereas a 4-ounce serving of beef contains 144 calories and 25 grams of protein. Steak is usually cooked with calorie-laden sauces or marinades and served with complementary foods that boost its overall calorie count.
Research Stands Behind Meal Replacement
A meal replacement protein shake can effectively promote weight loss. A study in the Journal of Nutrition and Healthy Aging in January 2015 showed that a 12-week weight-loss program that incorporated both soy and non-soy meal replacement products was associated with notable weight loss, as well as improvements in risk factors for major disease. Soy protein, as well as other protein sources, was effective when included as part of a comprehensive low-calorie diet.
Benefits of One Shake
Replacing one meal a day with a protein shake helps you reduce your calorie intake while still promoting optimal nutrient intake. Whole foods tend to be a better option when it comes to getting your protein because they contain additional nutrients — such as vitamins and minerals — not present in protein shakes. An article published in the Journal of Dietary Supplements in May 2018 confirms that getting your protein from whole foods is superior.
When you replace just one meal per day with a shake and consume whole foods at other meals, you're more likely to get all the nutrients you need for a healthy, energized body. For example, have a protein shake for breakfast and then a large salad with grilled chicken at lunch and baked salmon, sweet potato and broccoli for dinner for a balanced, highly nutritious meal plan.
Watch Out for Certain Powders
When you do use a protein shake for one meal per day, be sure the powder you use to make your shake doesn't contain a lot of added sweeteners to improve flavor.
Some protein drinks and powders also have unsafe levels of contaminants such as mercury and arsenic. The Clean Label Project independently tested a large number of protein powders and drinks to determine the ones safest for consumption. Use options that receive five stars in their rating system to get the safest meal replacement protein powder.
Since protein powders aren’t regulated by the FDA, do your research to find one that’s safe, especially if you plan to use it for a meal every day.
Comprehensive Nutrition in a Shake
If you're looking to create a protein shake that has comprehensive nutrition, add ingredients such as nut butter, flaxseed, frozen fruits (mango, strawberries, blueberries and bananas, for example) and even avocado. These foods can ramp up your overall nutrient intake for the day but do increase the caloric load of the meal replacement.
Add extra nutrients to your shake without a lot of calories by mixing the protein powder with unsweetened almond milk instead of water and mixing it up in a blender with a few ice cubes, raspberries and baby spinach. If you're trying to lose weight, this keeps the calorie count low.
Options for Timing
When on a once-daily meal-replacement shake diet, you can choose when to have the protein shake instead of a whole-foods meal. A protein shake for breakfast is often a good option because it's simple to make and gets you out the door without much morning hassle.
A protein shake for breakfast isn't your only option. Plan to have one at lunch, especially if you have a lot of meetings or choose to eat at your desk. You can also consider having your shake as a dinner replacement. A protein shake for dinner, after a workout, can be particularly valuable.
Frontiers in Nutrition published an analysis in September 2018 asserting there's a lot of evidence that consuming protein pre- and post-workout can increase your body's ability to build muscle and recover from intense exercise. A protein shake in place of dinner after a workout may be a prudent way to boost your performance and recovery efforts.
- MedlinePlus: "Protein in Diet"
- The American Journal of Clinical Nutrition: "The Role of Protein in Weight Loss and Maintenance"
- USDA National Nutrient Database: "Beverages, Whey Protein Powder Isolate"
- USDA National Nutrient Database: "Beef"
- Journal of Dietary Supplements: "Protein Supplements: Pros and Cons"
- Clean Label Project: "2018 Protein Powder Study"
- Journal of Nutrition, Health and Aging: "Effect of Protein Source During Weight Loss on Body Composition, Cardiometabolic Risk, and Physical Performance in Abdominally Obese, Older Adults: A Pilot Feeding Study"
- Frontiers in Nutrition: "Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training"
- Journal of the Academy of Nutrition and Dietetics: "The Effects of Increased Protein Intake on Fullness: A Meta-Analysis and Its Limitations"